Yak-50: A Poor Man's Warbird

Using a GPS tracker for flight monitoring - Part 2

2011-12-17T18:22:00.022+11:00

December 2011 Today, the weather cleared sufficiently for me to fly my long-awaited test sortie with the GPS tracker. Although the cloud cover was scattered at 4,000 ft, I expected cruising at 3,500 ft would be high enough to get good GSM network coverage.

After take-off, I headed out west towards Mayfield before turning southwards for the next waypoint at The Oaks. Once overhead the township, I headed out to intercept the southern end of Lake Burragorang before turning north to follow its course towards Katoomba.

Nearing the Three Sisters, and having been satisfied the tourists were behaving themselves, I turned DZY back on a dog-leg track towards Warragamba Dam.

On the way back to Bankstown between Warragamba Dam and Prospect Reservoir, I did my usual practice forced landing over a paddock near St Mary's airstrip before heading onto Bankstown.

After an uneventful landing, I called my pilot friend to check if he had received SMS messages giving updates on my position. When he replied that he hadn't, I wondered if it was due to the lack of GSM coverage. If it was, then my experiment had failed.

Upon returning home, I checked the GpsGate tracking software and found that the experiment was actually successful in that my entire flight had been tracked properly via the GPRS data link.

However, I still needed to understand why the parallel SMS updates hadn't been sent. While reviewing the MT90 tracker's settings, I discovered that I simply missed out one digit while entering my friend's phone number in the tracker - duh! So the problem wasn't due to equipment failure but brain failure on my part.

Overall, the experiment to use a GPS tracker for flight monitoring was successful. At altitude, GSM network coverage is enhanced due to greatly reduced terrain masking effects. It is therefore best to trigger a MAYDAY alarm with such devices before descending into zones of poor coverage.

For my experiment today, I set the distance interval between reports to 500m and the time interval between reports to 20 seconds. What these settings mean is that a position report is relayed back to the tracking centre (in this case, my home computer) every 20 seconds or every 500m; whichever occurs first.

Doing so means that the tracker's last known position is broadcasted as close as possible to the time at which GSM coverage is lost in areas of poor close to ground coverage (as the aircraft descends). Of course, this is a non-issue if a forced landing occurs in areas of good ground coverage.

My next test sortie will be flying the same route but using the Optus network; as today's test used the Vodafone network.

Using a GPS tracker for flight monitoring - Part 1

2011-12-11T17:22:00.063+11:00

December 2011 How time has flown since my last post in May this year. In between, the big bird underwent its usual annual inspection and I spent three and a half months redecorating the home. Suffice to say, I didn't get too many flights done during the home duties.

During the home redecoration, I did have time to think about ways to improve the operational safety of my flights. At present, before a flight, I send an SMS message to a pilot friend, nominating a SARTIME. And upon landing, I send another message to cancel the SARWATCH.

If my friend doesn't receive my message to cancel the SARWATCH, he first calls my mobile to check if I just forgot to send the cancellation message. And if he doesn't receive a reply after repeated attempts, he is supposed to alert the relevant search and rescue agencies.

I set up this arrangement with my friend when I first began flying DZY because unlike renting an aircraft from an aviation organisation, private owners flying OCTA have to make their own flight monitoring arrangements. However, there was a weak point which was difficult to address.

When flying within the training area, I'm pretty much near or over populated areas at all times, so someone on the ground is very likely to see an aircraft making a forced landing. However, I often fly outside the Bankstown training area into the Blue Mountains National Park.

The terrain there is not especially favourable for successful forced landings. And with nobody living in a national park, awareness of a downed aircraft is pretty much zero. So even if my friend knows I may be down, nobody has a good idea of where to start searching.

It was with this weakness in mind that I first considered the SPOT and Spider Tracks satellite tracking products. Both are quite impressive products but were a little costly owing to the relatively higher cost of satellite-based messaging (used for transmitting position reports).

While there's no doubt satellite-based position reporting is the best option for operations in remote areas, I think my areas of operation don't warrant use of SPOT or Spider Tracks. So I wondered if GPS trackers using mobile phone networks to relay position reports would be feasible.

To cut a long story short, I bought Meitrack's latest MT90 tracker to test out my idea. It uses the GPS satellite network to obtain positional fixes and GPRS mobile networks (quad band 850/900/1800/1900 MHz) for relaying position reports.

My test unit came from Meitrack China just three working days after I ordered it. The tiny device came in a small box with a lid secured by magnets. Very neat.

Click on photo for a larger image

About the size of a car door remote control, you are even supplied with a mini-screwdriver to open the IP66 compliant (waterproof rating) case; to get at the battery, SIM card and micro-SD card.

Note the silicon gasket around the edge of the case for sealing the interior from fluid and dust intrusion.

The MT90 can be configured via SMS message commands or from a PC application via the USB cable link. I found it easier (and free) to use the PC application.

When connected to Meitrack's web-based tracking service via a GPRS network, you can remotely configure the device and also send commands for it to do a wide range of things.

The same can be achieved using SMS messages but of course, this could be expensive if you set the device to send frequent position updates.

After configuration, I ran a static ground test for a Mayday alert. A couple of things followed:

1. A call went out to my emergency contact number (you can pre-program up to three numbers). If answered, normal two-way voice communications (like a mobile phone) commences.

2. A MAYDAY text message was sent to my emergency contact number. The message included a link to Google Maps showing the location of the MT90 tracker.

3. A MAYDAY alert popped up on the Meitrack web tracking screen. And again, the location of the MT90 tracker was shown using Google Maps.

I also tried using the Meitrack tracking service on a small 11.6 inch netbook PC. But I found the small screen made it a little difficult to view the various windows and small text comfortably. It's really best to use a larger desktop PC screen for this sort of activity.

Aside from the regular position reports to the tracking service, the device independently logs your position on the micro-SD card. The data can be downloaded later for replay or track display etc.

Part 2 will involve an airborne tracking test based on a flight out to the Blue Mountains National Park.

Although I'm itching to run the airborne test, the weather is not looking conducive for the next week or so.

Tracking down the bird's first roost

2011-05-31T17:05:00.033+10:00

May 2011 How quickly time passes these days. It must be a sign of old age that time seems to accelerate as one gets older. I can still remember how slowly time passed when I was a boy; impatiently waiting for the weekend to roll around so that I could play!

When I began preparatory research on the metal bird DZY, I was never quite able to pin-point the exact location of its first home in the Ukraine. All I had was a place name, Odessa-Lyman, courtesy of a Dutch aviation enthusiast, Marcel De Jong's website. He had noted a Yak-50 with the serial number 853101 wearing the number 59 in blue.

At that time, my attempts to contact Marcel for the location of the airfield failed and so I was reduced to scanning Google Maps of the Odessa area. I did find a place named Lyman sort of near Odessa but it proved a dead end as I didn't even see the faintest remnants of an airfield around. At that point, I stopped because the exercise was simply one of curiosity rather than necessity.

Fast forward to today.

I was reading an article about the Aral Sea and looked it up using Google Earth. When zooming in to look at some areas, I discovered some people had posted some geo-tagged photos of places around the area. It didn't take me long to wonder if someone by chance, had done the same for DZY's first home. But my old problem was still unsolved - where was it in the first place?

My previous lack of success told me I had to try something better than futile map searches. Using keywords I knew were factual about the bird (DOSAAF Odessa Ukraine), returned about 158,000 results from Google. On the first results page, I found an intriguing reference to a DOSAAF 'outfit' that was located in Odessa-Lyman in the mid-1990s. A kmz data file was referenced to show the location using Google Earth.

When Google Earth displayed Odessa-Lyman, it turned out to be an airfield right next to a town named Naberezhne; about 15km NNE from the city of Odessa. Even more intriguing were the geo-tagged pictures (taken in 2008) for this airfield.

There appeared to be a mixed collection of Mi-2s, An-2s, a Yak-18T and two Yak-50s! One Mi-2, one An-2, one Yak-18T and one Yak-50 appeared to be airworthy. The other Yak-50 was missing its right wing but was supported by jacks. The cockpit, engine and prop were shrouded - all sure signs that it was in service perhaps waiting for some maintenance work on its missing wing.

So was this the same airfield which Marcel visited in September 1996?

Since the Mi-2s and An-2s appeared to have been around for a long time (they hadn't gone very far given they were missing rotor blades or wings) I decided to cross-check the aircraft in the photos against his list to verify the location.

The three best photos from a number documenting aircraft on the airfield were:

Mi-2 marked yellow 29 (USSR) and UR-BSQ (Ukrainian civil registration)
An-2 marked UR-BSK (Ukrainian civil registration)
Mi-2 marked yellow 09 (USSR)

When cross-checked against Marcel's 1996 survey, I was able to verify these derelict birds were indeed on his list!

Hence, I am now certain of the location of DZY's first roost; and it's found here.

While I was elated by finally being able to pin-point DZY's first home, the photos of forlorn An-2s and Mi-2s quietly falling to pieces was a little sad to me.

Even though these are in the end, just machines, somehow these birds assume an almost mystical life-likeness after coming to life with their first flight. Or perhaps it's just me who sees their slow demise as a metaphor for my own mortality!

Video walk around of the beast

2010-03-14T22:10:00.007+11:00

March 2010 Two successive weekends of unfavourable flying weather left me with little else to do except record a video walk around of the beast inside the hangar.

Interestingly, although the negligible weight of the iPod Nano made it easy to film, the absence of mass meant there was no damping of the inherent unsteadiness of the handheld camera.

In contrast to digital still and video cameras, the Nano doesn't have an optical image stabilisation feature. If it did, the Nano would have cost me a bit more than it did!

The Nano's native resolution is 640 x 480 pixels. At this size on a PC screen, the image is reasonably sharp. But of course, the quality suffered much degradation once it was uploaded and converted into Flash format to a resolution of 320 x 240 pixels.

Experimenting with a simple video cam

2010-02-28T20:16:00.020+11:00

February 2010 Work and life in general, kept me from updating this blog since my last post in April last year. Fortunately, things didn't keep me from flying the beast (and getting my relaxation therapy).

Even before I received DZY, I had thought of getting some sort of video camera to film my flights. There were a number of options including helmet-mounted bullet cameras feeding into very neat and compact mini digital video recorders. However, I haven't quite got around to buying such a system yet.

Recently, I began to experiment with using my little iPod Nano's built-in video camera as a cheap interim solution. The main challenge was working out how to mount such a small flat device on the top of the glare shield and isolating it from most of the engine vibration.

Eventually, I simply used a bit of velcro tape to strap the iPod to an old dishwashing sponge. Then I attached the jury rigged contraption to the top of the glare shield with a small velcro pad.

The contraption stayed mounted throughout the flight, but the following video shows the camera was still affected by vibration. So I'll have to work out better mounting arrangement.

First annual inspection

2009-04-03T00:07:00.020+11:00

April 2009 It's hard to believe that a whole year has passed since the beast first received its Australian certificate of airworthiness. Along with this anniversary, DZY's annual inspection also fell due.

Over the past year, I didn't get to fly the bird as much as I wanted. Owing to unsuitable flying weather on weekends (week days tended to have good weather), I ended up putting about 20 hours on the clock in 12 months.

Anyway, I decided to keep a photographic record of the annual inspection for posterity.

First the engine cowlings were removed and 18 spark plugs pulled for inspection and cleaning. Then each cylinder was compression tested. Happily, all cylinders returned between 74-78 psi for an input pressure of 80 psi.

Various aircraft systems are coded with different colours. eg oil tanks and pipes are painted brown. The fuel tanks and pipes are painted yellow, and the air bottles and pipes are painted black.

The underside wing root panels were removed for inspection of the wing attachment joints. Note the massive size of the front spar attachments. After this photo was taken, the oil spots were cleaned off to avoid staining the light blue paint.

Here, the underwing access panel has been removed to inspect the aileron control rods and bell cranks. Although not readily apparent in this photo, the aileron control rod is a hefty 2.5 cm in diameter.

With the access panel removed, a landing gear system air hose showed signs of wear. Close examination suggested the air hose was being pushed against the wing stringer (immediately left of the wear point) when the landing gear retracted. The solution is to replace the hose with one slightly longer and slightly rotating the hose coupling anti-clockwise to move the hose further away from the stringer.

This shows the elevator and elevator trim control system. The massive greenish-yellow arm and weight at the end of it, is the elevator mass balance. Concealed inside the horizontal/vertical fin attachment area, the mass balance is used to alter the structural resonance frequency of the elevator for flutter prevention purposes.

With the tailwheel access panel removed, the gas-oil shock absorber (attached to the tail skid arm) can just be seen along the right edge of the access hole.

A little excursion

2009-03-29T09:50:00.003+11:00

March 2009 Ever since I started flying the beast a year ago, I had not formally measured its cruise fuel flow; so preoccupied was I with getting comfortable with its general and aerobatic handling.

But with its annual inspection due on 28 March, I decided to conduct this long deferred exercise before the big bird was temporarily taken out of service. I also wanted to test my new Lowrance 2000c GPS unit out on the same flight.

The night before, I had programmed a short trip from Bankstown to the Three Sisters (near Katoomba) via The Oaks and Lake Burragorang. All up, the route was about an hour's flight interval.

As the bird cruised towards The Oaks at 4,500 ft, I spotted a few columns of smoke a few miles west of Lake Burragorang. It looked like these were burn offs to reduce the risk of bush fires.

For simplicity, I used a cruise setting of 60% rpm and about 55 cm manifold pressure. Although this lower of two recommended cruise power settings yielded an indicated airspeed of only 205 kph (111 kts), I chose it as it would be the power setting for maximum endurance.

After the flight, I refuelled the big bird to obtain an accurate measurement of the fuel consumed. I was happy to find the cruise fuel flow was an average of 45 lph.

This result would have been even lower after correcting for takeoff fuel flow and the higher power settings used for the brief run-in to the Three Sisters waypoint and the short climb following the practice force landing.

Compared to the Yak-50, the Yak-52's higher cruise consumption (between 50-60 lph) is mostly due to the extra drag from the exposed retracted landing gear, and the about 350 kg extra weight.

Finding clear weather

2009-02-28T22:13:00.007+11:00

February 2008 What a difference in weather a week makes. The last day of February was sunny in contrast to the previous weekend. And as I climbed out of the Bankstown control zone, I could see all the way to the Blue Mountains.

Arriving just east of Warragamba Dam at 4,000 ft, I identified two aircraft about 2-3 nautical miles to the south below me. They were heading west out to Lake Burragorang, so I was clear to begin exercising the big bird for a while.

After the workout, I headed to Lake Burragorang via The Oaks for a bit of sightseeing. Again, I was struck by the relatively clear sky in contrast to last week. Arriving overhead Lake Burragorang, it was time for another workout for DZY.

Away from the training area and under a 7,500 ft controlled airspace step, I was able to use higher power settings for better vertical performance without worrying about punching into controlled airspace. So running at 80% power, the bird climbed vertically with little effort and fuss.

Having had my fill of high G manoeuvres, it was time for a practice forced landing near St Mary's Airstrip before an uneventful recovery back to Bankstown.

Go or no go

2009-02-23T00:29:00.005+11:00

February 2008 I was looking forward to flying the beast down to Wollongong to attend the Historical Aircraft Restoration Society's (HARS) Open Day on Sunday 22nd February.

But as I left Bankstown Airport enroute to my first waypoint overhead Camden Airport, I had difficulty seeing clearly beyond about 3-4 nautical miles.

And as the beast continued chugging towards Camden, my GPS said the airport was supposed to be 3 then 2 nautical miles ahead. Except that I couldn't see it for the now thick haze from ground level up past my 2,500 ft cruise altitude!

At that point, I reviewed the situation. I could see the Southwestern Freeway on my left and I was overhead Narellan so I was on track. But my next way point, overhead Wedderburn Airstrip, was shrouded in ground fog or haze.

I was concerned that the visibility was worse over the escarpment surrounding Wollongong Airport. If the visibility around Wollongong was indeed poor, then it seemed to me that pressing on with the flight would develop into a classic weather trap.

Mindful of the fact that accidents are typically the culmination of a series of errors or problems, I decided to bug out while my escape window was still open. So I turned DZY to fly through my escape window back to Bankstown.

Discretion is indeed the better part of valour.

Checking out the RSAF museum

2009-01-27T23:05:00.012+11:00

January 2008 While in Singapore last year, I had intended to visit the Republic of Singapore Air Force (RSAF) museum but ran out of time. So when I returned to the country again this month, I made a point of visiting the facility soon after my arrival.

Compared to other air force museums elsewhere around the world, the RSAF's facility is a modest but modern building adjacent to Paya Lebar airbase. The front of the building is guarded by a Douglas A-4 Skyhawk, a Hawker Hunter, an Aermacchi S-211 and an SIAI-Marchetti SF-260. All four types served the RSAF faithfully for many years.

The above photo is of the SF-260, which I knew well. I flew Noel Kruse's machine for a few years before it was badly damaged in a crash landing following an engine failure after take off. That bird (VH-ARV) was rebuilt and bought by someone in Queensland.

Duh! I forgot to take a picture of the S-211, so I'll move on to another interesting beast - the Hawker Hunter. In the 50s and early 60s, this bird was to British fighter pilots, what the F-86 Sabre was to American fighter pilots.

When I first learned to fly, my training was conducted by a former RAF fighter pilot, Roy Garthwaite. He flew Hunters in Germany during the Cold War, and had many interesting stories of near shooting dogfights with Soviet Bloc fighters. Roy also used to go on about the Hunter being a fighter pilot's fighter.

Some years later, my aerobatics training was conducted by a former RAAF fighter pilot, Noel Kruse. He flew the Australian version of the F-86 Sabre, the CAC Sabre. Noel too, believed the Sabre was a fighter pilot's fighter. Interestingly, both the Hunter and the CAC Sabre rivals were powered by the Roll Royce Avon engine (with the Hunter having a higher thrust version).

The gate guardian above is the Douglas A-4SU Skyhawk. Unique to the RSAF, the SU model was an A-4 re-engined with a non-afterburning General Electric F-404 engine (similar core engine as the F/A-18 Hornet). A then new avionics package was also fitted to this version of the bird.

During my visit, I was surprised to learn that the RSAF also operated Lockheed T-33 Shooting Stars for four years. These ex-French Air Force birds were a stop gap measure until the Aermacchi S-211s arrived. And after about 23 years' service, the S-211s have themselves been replaced by the Pilatus PC-21s.

As I salivated over these beasts of the air, I found myself wishing that I owned an oil refinery and an aircraft maintenance company. Nothing would please me more than to have these birds as my personal toys to blast around the sky.

Formation flying

2009-01-20T20:51:00.003+11:00

January 2009 For several months, I had been wanting to undergo formation flight training. But a combination of being too busy, poor flying weather and baulking at the proposed 0700 starts from Camden, delayed the training.

But finally, on 18 January, the weather improved and the instructor conducting the training, Niall, agreed to a more reasonable start time in the late morning!

For my first sortie, Steve flew my beast, VH-DZY, while I flew Niall's and Doug's Yak-52 (VH-VHV) with Niall in the back seat.

Although I had done my Yak conversion training in a 52 with Steve, a year had since passed. The 52's cockpit layout is somewhat different to that of a 50. So I had to get re-acquainted with switches and instruments in unfamiliar places.

We adopted a streaming takeoff in which Steve, as the formation leader, took off first; followed by me four seconds later. Then the hard workout started.

With Niall coaching me, I manoeuvered the 52 into line astern, and right/left echelon positions. But not quickly nor closely enough apparently.

For the first half hour or so, the cockpit conversation between Niall and I consisted of him cajoling me with the words, "closer...not close enough...get right in..."

Over that same half an hour, I was muttering, "you want me to do WHAT and then WHAT??" as I marvelled at the tiny spatters of engine oil on the 50's aft fuselage and tail feathers.

Why, I could even see the grease smeared around the tailwheel strut and the smashed insects on the leading edge of the horizontal fins, for heaven's sake!

And while Niall kept pushing the stick towards the 50, to get in closer, I was pushing the stick in exactly the opposite direction in an attempt to avoid scratching the 50's paintwork with the 52's wing tip or propeller!

At some point past the halfway mark in the sortie, Niall had stopped his insane urgings for me to get closer. He may have realised that it was futile for him to try overcoming my instinct for self-preservation (and preservation of my beloved 50).

Or I had finally succumbed to his cajoling to hold a position sufficiently close to conduct an in-flight inspection of every rivet and screw on the 50!

After an hour of a busy workout, I called time and Steve took our formation back for a run and break recovery to Camden.

My T-shirt and flight suit were soaked when I climbed out of the 52.

I must hasten to add that the water was lost through sweating and not from a bladder reacting badly to flying so close to another aircraft!

Last workout for 2008

2008-12-30T23:00:00.004+11:00

December 2008 Since late November until today, I hadn't flown the beast as much as I wanted. Owing to either gusty crosswinds, low cloud base or rain, the big bird stayed put in its roost. Yesterday, 29 December, was a case in point.

During my drive from home to Bankstown Airport, the weather seemed good for flying. Then as I strapped in, fired up the engine and switched to the ATIS frequency, I was disappointed to hear that thunderstorms were present to the north and west of Bankstown.

Not wishing to have the metal bird's wings plucked by a cumulo-nimbus storm cell, I shut down the engine and hauled the beast back into its roost.

Today, 30 December, started out mostly cloudless. But wind gusts up to 20 knots were forecast later in the afternoon. So I launched the sortie just before 1300 hrs, expecting to return by about 1400 hours.

Upon arrival over Warragamba Dam, I conducted a short workout before heading off to Mayfield; enroute to The Oaks township. The township is roughly due west of Camden and has a grass airstrip popular with ultralight pilots.

I arrived over The Oaks at 4,500 ft and then proceeded to climb to 7,000 ft while flying a racetrack pattern over some flat ground to the south-west.

This was going to be my first run at conducting fully developed spins in the bird. After completing my pre-aerobatics checks for the second time, I brought the throttle back to idle while holding altitude.

Based on a stall speed of 100 kph, the spin entry speed is 1.1 x Vs = 110 kph. So when the airspeed slowed to 110 kph, I applied full aft stick and full left rudder. After a momentary pause, the big bird rolled and pitched gently into a left spin.

Counting four turns, I relaxed the stick to neutral and applied full right rudder. The autorotation stopped somewhere between a third and half a turn after applying the right rudder. Easing back the stick and opening the throttle, I climbed back to 7,000 ft for a spin to the right.

Spins to the right are in the same direction as the propeller torque. And indeed, entry into a right spin is slightly quicker and exhibited a slightly steeper pitch down angle while spinning. Nonetheless, the entry was again smooth and gentle.

I was pleasantly surprised at the smoothness and gentleness of the spin entries; compared to the Robin and Marchetti, Yakovlev's beast is a mild-mannered pussycat. This isn't to say the Robin and Marchetti had aggressive spin entries. But in relative terms, the 50 is mild-mannered.

After the spins, I headed further west to Nattai. Passing Nattai, I arrived overhead Lake Burragorang at 4,500 ft for another aerobatic workout. Then it was time to head for home via a leisurely cruise up Lake Burragorang and then Warragamba Dam.

Enroute from the dam, I conducted my customary practice forced landing before heading back to Bankstown for an uneventful landing.

The beast featured on Yakovlev's site

2008-12-08T21:33:00.021+11:00

December 2008 Back in June this year, I sent some pictures of the beast to Yakovlev Design Bureau (YDB) to let them know at least one of their birds is still flying on the other side of the world. In turn, they kindly posted my email and pictures of the beast on their website.

When I bought 853101 from Mark Jefferies of Yak UK, he asked YDB to provide written confirmation that this bird had never served with the Soviet National Aerobatics team and had never been written off. There was a reason for needing such confirmation.

Aircraft flown by the Soviet National team were typically scrapped after about 40 to 50 flight hours. Team pilots routinely flew their Yak-50s beyond the +8G/-5G limit load factors; such was the brutal reality of modern world competition aerobatics.

So these poor birds ended up with buckled skin panels or worse, overstressed wing spars or suffered damage to other major load bearing components.

In many cases, severely damaged machines were simply scrapped. And in the Soviet era, since the state owned everything, the poor economics of the practice didn't matter. In other cases where the aircraft weren't scrapped, they were overhauled and sent out to DOSAAF (military flying club) units for less hazardous duty.

By 1984, the Soviet National team had re-equipped with Yak-55 birds. Therefore any Yak-50s built in 1985 and 1986 (last production year), never served with the team.

My particular aircraft (853101) didn't serve with the Soviet National team but was a DOSAAF bird in the Ukraine. The "85" meant it was built in 1985 while the next two digits "31" meant it was part of the 31st batch of ten units. And the last two digits "01" meant that it was the first unit in batch 31.

In all, YDB built 312 units. So this meant 31 full batches ten units each plus two extra units were produced.

Before YDB's confirmation, I had already concluded it wasn't a team bird because of its construction (or serial) number. And indeed, 853101's original Russian log books show it flew 220 hours with the Ukrainian DOSAAF as Blue 59 until it was taken out of service some time after the collapse of the USSR in 1991.

While undertaking research into various Yak-50s offered for sale to me, I came across an unexpected source of information on the history of some of them. A Dutch aviation enthusiast, Marcel de Jong, had visited a number of ex-Soviet air bases in the mid to late 1990s.

I was happened to find his website and studied his comprehensive list of aircraft in which serial numbers, fuselage numbers and general condition were noted. After wading through a large number of aircraft types, I found an entry listing a Yak-50 with the serial number 853101.

Marcel noted that this Yak-50 was a DOSAAF bird with fuselage number 59 Blue. It was in storage (probably just parked) at a former Soviet airbase in Odessa-Lyman, Ukraine in 1996.

This was the independent confirmation I needed to corroborate YDB's information along with the log books. It also meant that the rest of 853101's history from the time of its rescue from Ukraine to overhaul by Shakhty Aviation in Rostov and then onto the UK, was very likely to be true as well.

I wasn't concerned about the aircraft's history after its arrival into the UK in 1998, as it was well documented. I was more interested about its life during the Soviet era.

An extended rest ends

2008-11-17T22:32:00.009+11:00

November 2008 Since the last post, the big bird had not been exercised very much. A persistent flu on my part and several weekends of poor flying weather conspired to keep the bird in its roost.

Eventually, I did get a chance to haul the aircraft out of its hangar for a flight last weekend. As I pulled the prop through two blades, I felt an unyielding resistance - signifying a hydraulic lock. It was the first hydraulic lock I experienced for this bird, and it probably wouldn't be the last.

Having stood still for about seven weeks before this flight, oil must have flowed into and collected in the lower cylinders. Oil drain valves reduce but don't eliminate the chance of such hydraulic locks. Rather than pull the spark plugs from the lower cylinders, I gently moved the prop backwards a little until oil flowed from the drain valves and exhaust pipes.

When the flow stopped, I moved the prop backwards again until the oil resumed flowing and eventually stopped. Then I began pulling the prop through again and confirmed the lock had cleared. To be extra cautious, I pulled 24 blades (12 full revolutions) just in case residual oil remained to cause another lock.

After my tiring pre-flight calisthenics (ie prop pulling), I climbed into the big bird's cockpit and strapped in. Just before pushing the starter button, I hoped the extended rest wouldn't cause a difficult start as I wasn't in the mood for refilling the air bottles manually.

As I pushed the starter button, the customary "pop" sounded. Promising. Counting two blades, I then flicked both magnetos on. With a big cough, cloud of white smoke followed by a throaty roar, the trusty M-14P radial came to life and settled into its trademark "chug, chug" sound. Satisfaction. Boy, the Russians build dependable flying tractors!

The rest of the flight was fun as the bird metal bird was put through its usual exercise routine. I did monitor the engine instruments far more frequently than normal - just in case. In the end, the aircraft behaved very well. And finally, a good workout was rounded out by one of my smoothest landings yet in the beast.

Weekend at the office

2008-08-30T21:12:00.012+10:00

August 2008 During the week, I spend much time in an office to earn money to feed a hungry big bird. Nonetheless, one of the best things about owning an aircraft is that one can roll out of bed in the morning and just decide to go flying. No need to book an aircraft days beforehand and no flow on delays from earlier bookings running behind schedule.

And this morning, despite having flown DZY quite a few hours now, I still savoured looking into the cockpit before climbing into it, ready to strap in for a hard day at the office.

Once seated in the flying office, the instrument panel is also another sight that continues to bring great pleasure and excitement to me. Now if only my other office was as fun and exciting as this one all day every day...

Trying to avoid bird strikes

2008-08-18T19:37:00.014+10:00

August 2008 Winter this year has been a little less conducive to flying than the same time last year. Over the last few months, I had only managed to exercise the big bird about once every two weeks rather than every week. In most cases when a flight was precluded, the skies were generally clear.

But westerly to south-westerly weather patterns (typical during winter) created strong crosswinds exceeding the Yak-50's capability - or my comfort level. Although I often flew the Alpha/Robin with crosswind components up to 25 knots, I had over 200 hours experience in the tricycle landing gear aircraft. On the other hand, my less than 10 hours familiarity with the tailwheeled beast demanded caution rather than recklessness.

Sunday, 17 August, was one day during which the wind cooperated long enough for me to launch a sortie. Arriving at the hangar early, I dragged the big metal bird out into the brilliant sunlight. Completing the pre-flight inspection, I then proceeded with my pre-flight workout.

For radial-engined aircraft, pulling the propeller through before flight is vital if one wants to avoid hydraulic locks. Hydraulic locks are commonly caused when engine oil that has collected in the bottom cylinders, is not cleared. Since liquids are incompressible, the oil trapped in the combustion chamber acts like a solid block to a moving piston; leading to a bent or snapped connecting rod or complete engine destruction.

When fitted with suitable excess oil drain valves, pulling through a propeller clears any residual oil from the lower cylinders. The workout comes from pulling the propeller through at least six complete revolutions. It is not easy overcoming the natural compression of the nine cylinders.

Eventually, I arrived in the training area and flew the bird through its exercise routine. This time, I decided to use higher power settings of 75% rpm and 80 cm manifold pressure. Vertical performance along with fuel consumption rose accordingly. Rather than use a starting altitude of 4500 ft, I started at 4000 ft to avoid punching through the Sydney CTA lower limit during vertical manoeuvres.

After executing the usual practice forced landing, I pointed the bird for home. Approaching the Prospect Reservoir VFR checkpoint, I spotted two flocks of Ibises closing fast on a reciprocal heading. Bracketing me on the high and low sides, I had little choice but to maintain my altitude and hope they would do the same. Instinctively, I hunched down a little lower and hoped for the best.

The lower flock whipped past below and to the right of my right wing. They probably saw my strobe light and veered away from my flight path. On the other hand, the higher flock whipped past no more than 30 ft above my mid left wing. Fortunately, they did not dive as most birds seem to do instinctively when confronted with danger.

My arrival and recovery to Bankstown was much less eventful. Reflecting on the near miss, it seemed to me that flying a steady course and altitude at relatively low speed (130 knots) gave both flocks time to avoid colliding with the metal bird. Or I could have just been lucky.

Christmas turkey nails its forced landing

2008-06-23T23:57:00.020+10:00

June 2008 The weekend of 21-22 June ended up being no-fly days despite the clear cloudless skies. Cross-winds gusting 15-16 knots were too strong for my liking and so I decided discretion was the better part of valour and scrubbed plans to go flying.

All in all, three weeks of unfavourable flying weather kept me from exercising the beast since its last flight on 31 May. But by Monday 23 June, the wind had abated to 8-10 knots of cross-wind. I was comfortable with this cross-wind strength and decided to launch a sortie.

After hauling the metal bird out of its roost, I took a picture of its massive paddle blades to remind me of their excellent speedbrake qualities when executing a forced landing.

Over three weeks, the main air tank maintained about the same pressure since the last flight. But the emergency air tank had lost about 30% of its normal pressure. Used for extending the landing gear in event of a main tank failure, the emergency tank would be re-pressurised as soon as the engine was started.

I was certain that the main tank would have no problem starting the engine since it had plenty of air. This was indeed the case when the engine started up on the first attempt (with the usual cloud of smoke).

Taking off from runway 29R, the bird reached 1000 ft just past the end of the runway. The bird's rate of climb still impresses me even after having flown it for about 5.5 hours.

As usual, I started the workout with some aerobatics. After a few manoeuvres, I noticed the beast having a slight tendency to roll right in straight and level flight. I made a mental note to adjust the aileron trim tabs later.

The next task was to descend to 2500 ft to practice some forced landings. I half rolled DZY onto its back and let the nose fall through the horizon to 45 degrees down and held it for the descent. Completing the roll to wings level and upright again, I prepared the aircraft for the practice forced landing.

It just so happened that today, there was a decent headwind along the St Mary's airstrip. Using the inboard edge of the aileron as my reference marker, and an extra 20 kph over the best glide speed of 150 kph, I flew the descent cone towards the target touchdown point.

Turning onto short final, it was time to extend the gear. With the gear down and locked, it became clear the Christmas turkey was going to nail the touchdown point. That was good enough and pleasing for me. So I opened the throttle and retracted the landing gear to head off home.

Mission accomplished.

How the big bird got its colours

2008-06-14T01:44:00.026+10:00

June 2008 Quite a few people have asked me if I designed the bird's paint scheme and why it has the colours it has. The answer will be a little lengthy but interesting to people unfamiliar with WW2 Soviet-era fighters and their designers.

During WW2, the most prolific and famous Soviet fighters were creations of the Yakovlev and Lavochkin Design Bureaus. In the USSR, aircraft design bureaus were named after their chief designer in part to acknowledge their leadership, and in part to differentiate one bureau from another with a name rather than a customary nondescript number.

So for example, Opytnoe Konstructorskoe Byuro 115 (Development & Design Bureau 115), was also semi-officially known as OKB Yakovlev; bearing the surname of the founding chief designer or engineer, Alexander Sergeevich Yakovlev.

Similarly, OKB MiG was named after its co-founders, Artem Mikoyan and Mikhail Gurevich, OKB Lavochkin was founded by Semyon Lavochkin, OKB Tupolev by Andrei Tupolev, OKB Sukhoi by Pavel Sukhoi and many more.

Since the dark days of WW2, just as the West has seen great consolidation of its aircraft industry with many famous companies closing their doors and switching off the lights, the same has occurred in the former Soviet Bloc.

Only OKB Sukhoi has an active production line for its extremely good Su-27, -30, -33, -35 and -37 combat aircraft. OKB MiG and OKB Yakovlev struggle to remain involved in serial production of frontline combat aircraft.

But I digress.

In the later years of WW2, Yak (common abbreviation) and Lavochkin fighters (principally the Yak-3, Yak-9 and La-7) were mostly painted in two-tone grey (dark grey on light grey) camouflage topside and light blue underside.

Depending on an aviation regiment's practice, additional trim colours adorned the nose and vertical tail of the aircraft. By far the most common trim colour was the obligatory "Communist" red so favoured by the USSR.

So the basic topside and underside camouflage colours of VH-DZY follow standard Soviet patterns in the latter years of WW2. The green nose and tail trim would have been "Communist" red back then.

Aside from red not being a favourite colour of mine, it also fades to black at a distance. I chose a bright green to increase visibility of the Yak-50 at medium range for safety reasons.

Another non-period addition to the paint scheme are the two blue bands around the aft fuselage. These too, were included to improve visibility especially when looking down onto the bird from above.

Against a green or brown background, the blue bands stand out better than the green trim. Without the higher visibility colours, the grey camouflage does indeed make the aircraft difficult to see.

The Soviet red stars on the tail, fuselage and under wing surfaces are authentic for the late WW2 period. A common practice with some WW2-style paint schemes used for other Yaks around the world today, is to paint the stars on the top wing surfaces instead of under wing surfaces, or to paint the stars on both top and under wing surfaces.

While not strictly correct, the stars on the top wing surfaces do add some colour at close range (they are difficult to see further away due to the fade to black effect of red objects). One minor but interesting detail about the red stars is worth highlighting.

Before victory was all but imminent in May 1945, the red star only had a thin white border along all the edges. Presumably, the white was to set off the red star clearly against a camouflage background.

But when victory was imminent, the white border was itself enclosed by a thinner red border along all the edges. So the red-edged red star used for VH-DZY is from the very late war period.

Gliding like a Christmas turkey

2008-06-02T21:58:00.029+10:00

May 2008 The last day of autumn, Saturday 31st May, was excellent flying weather; except when climbing up to 4500 ft to begin a workout session, I could see a layer of brownish light smog over the city and along the horizon. Nice!

On this sortie, one thing I wanted to do was use the big Russian attitude indicator to help me obtain the 45 degree inverted downline while flying a half Cuban 8. Competition aerobatic aircraft usually have angle sights mounted on each wingtip to assist pilots obtain the proper upline and downline angles.

But since no self-respecting warbird soils its wingtips with such untidy items, the non-tumbling attitude indicator comes in handy for obtaining the desired pitch angles when flying such manoeuvres. All it took was a quick glance to confirm the big bird was pointing 45 degrees downhill while inverted before stopping the pitch input and then rolling back to the upright wings level position.

I flew a number of consecutive full Cubans and reverse Cubans until I was comfortable using the instrument with its non-conventional (by western standards) reversed sky and ground display.

Next came flying a few Immelmans (roll off the top of a loop). While the Yak-50 manual nominates a 300 kph entry speed and minimum 150 kph at the top of the loop, it doesn't nominate a G loading for the initial pull up into the manoeuvre.

So I started with a 4G pull up and found that the airspeed at the top of the loop before rolling upright wings level was close to the 1G stall speed of 100 kph. The handling was mushy when rolling upright. It seemed clear the 4G pull up didn't deliver a sufficiently fast turn rate in the vertical plane before the bird lost energy at the top of the loop.

During the next attempt, I used a 4.5G pull up and it resulted in a 150 kph airspeed at the top of the loop. Handling was reasonably good when rolling upright wings level. With a 5G pull up, the airspeed at the top of the loop was about 170 kph. Satisfied with my findings, it was time for the main purpose of the sortie - determining suitable wing reference points for use during forced landings.

The previous weekend, I used a row of wing rivets (kept over the desired touchdown point when gliding to short final) between a third and a half wingspan inboard from the wingtip for my last partially successful attempt; which seemed to work until the landing gear was extended.

To compensate for the greatly increased descent rate with the gear down, I chose to start with another row of wing rivets at about half wingspan position. Conveniently, this corresponds to the inboard edge of the aileron. That's right, ailerons on the 50 cover slightly over half the length of each wing. On the Su-31, they span two-thirds of each wing!

Following Noel Kruse's advice, I also added 20 kph to the 150 kph best glide speed to provide better control and higher kinetic energy during the forced landing glide. I was pleased when the new reference row of rivets and higher glide speed resulted in a tight but successful arrival over the selected touchdown point.
t
tGeometrically, the 50 requires a narrower angled cone (compared to other less draggy birds) for a successful forced landing. Put another way, the Lift to Drag ratio of the beast is pretty poor due to the big paddle bladed prop! So the resulting geometry requires a tight spiral glide path to be flown to reach the touchdown point. And it becomes even tighter when a strong headwind is present.

For many years now, it has been standard practice for me to execute at least one practice forced landing during each sortie. With its Christmas turkey glide performance, the Yak-50 demands maintenance of this discipline. Being prepared is definitely better than being sorry.

Getting comfortable with the beast

2008-05-24T18:34:00.010+10:00

May 2008 Today, 24th May, turned out to be perfect flying weather. It was a contrast to last weekend with winds gusting to 25 knots - pretty much all of it cross-wind! Needless to say, few people ventured into the sky then.

While M-14P radials are in fact very reliable and rugged engines, I still wondered if there would be difficulties starting following a two week hiatus. So I was pleased the engine started immediately on the first attempt with the obligatory cloud of smoke.

Upon reaching 4500 ft over Warragamba Dam, it was time to run the bird through its workout session. On the previous sortie two weeks ago, DZY pulled a maximum of 4Gs during the workout. For this workout, the beast and I pulled first 5Gs, then later 6Gs, through a series of manoeuvres.

Following the workout, I rolled the big bird onto its back and let the nose fall past the horizon on descent from 4500 ft to 2500 ft. To avoid shock cooling the engine, I closed the engine shutters before throttling back while the bird descended. Approaching 2800 ft, it was time to roll back upright again in time to level off at 2500 ft.

The next task was to identify reference points on each wing for use while conducting a forced landing due to an engine failure. Taught to me by a former RAAF fighter pilot, Noel Kruse, this forced landing technique uses suitable reference points on the wing to fly a descent along the surface of an inverted cone whose tip is attached to the desired touchdown point.

I set up for the practice forced landing using an initial start point suitable for a Alpha (Robin) 2160. It didn't take me long to realise the beast wasn't an Alpha 2160 while gliding. I had to abandon my first attempt when the bird descending like an overfed Christmas turkey, couldn't even reach mid-base leg. Although I expected a fair amount of drag from the large paddle bladed propeller, I was surprised it had such an effect on glide performance.

On my second attempt, I used a row of rivets even closer inboard from the wing tip as my reference point. This had the effect of bringing the initial start point closer in to the desired touchdown point. Although I was able to make mid-base leg this time, the Christmas turkey still couldn't stay up long enough to make the touchdown point. So around I went to climb back up for another attempt.

My third attempt saw me choose a row of rivets even closer inboard from the wing tip - between a third and halfway in. This time, I was able to line up for a short final and so I extended the landing gear. That ruined things. The big bird seemed to have gained a ton when the descent rate picked up. So I abandoned the attempt and headed off for home and a later discussion with Noel.

Following an uneventful landing and exit from the runway, I called the tower to wish them good day. After a pause, the controller replied saying that he had been distracted while admiring my lime green helmet. He also warned me to keep the keys to DZY safe because it seemed that quite a few people wanted to take the bird for a spin!

Putting the beast through its paces

2008-05-11T23:39:00.004+10:00

May 2008 Sunday, 10th May. Feeling a little cheated of an opportunity to "work out" the beast during its ferry flight to Bankstown yesterday, I went out to fly DZY today. The weather was a little better than yesterday, with the cloud base at 4500 ft and some scattered pockets at 3500 ft.

After a (by now) normal 100 m takeoff run, the control tower called me on the radio as I turned to leave the circuit area. They wanted to know what sort of aircraft flew and made noises like the big bird! Only later, did I remember that while they were familiar with two-seat Yak-52, DZY is the only Yak-50 in the state.

Upon reaching my usual aerobatics area near Warragamba Dam, I began the bird's first heavy "work out" session in Australia. It handled extremely well through a series of Cubans, barrel rolls, rolling reversals, loops, aileron rolls, Immelmans, split-esses and four-point rolls.

Compared to the Marchetti SF260 I used to fly some years ago, the Yak-50's controls are nicely harmonised. When researching the Yak-50 before deciding to buy one, I had read a couple of articles commenting on the slightly heavier than ideal aileron control force. I actually didn't find them disproportionately heavy nor less than ideally harmonised. Perhaps servo tabs are necessary only for aggressive aerobatic competition flying.

Having had my fill of aerobatics for the day, I returned for an uneventful landing at home base; leaving me satisfied the big bird was fun to fly and looked nice to boot. Indeed, a Police Air Wing helicopter crew thought so too, when they circled DZY twice while I was cleaning it outside its hangar.

The big bird changes roost

2008-05-10T17:52:00.012+10:00

May 2008 Last Sunday, 4th May, I had intended to move the beast to Bankstown airport but instead decided to stay on an extra week to fly more demanding aerobatics. If any mechanical bugs surfaced, the local maintenance outfit happened to be available to respond immediately. As it turned out, the bird ran smoothly without any problems.

So today, Saturday 10th May, I pulled the bird out of its hangar at Camden airport for the last time. After five weeks at Camden, it was time to move DZY to its permanent roost at Bankstown airport.

Taking off under a cloud base at 2500 ft, I pointed the beast north to my usual aerobatics area near Warragamba Dam. Levelling off at 1800 ft and with the engine purring smoothly, I sat back to enjoy the ride. Passing a large house on a hill off my left wing tip, I noticed some kids waving at me, so I rocked my wings in return.

Overhead the dam with the cloud base still at 2500 ft and patches of mist in the area, there was no chance of aerobatics on this flight. Somewhat reluctantly, I rolled the big bird onto an easterly heading to follow the pipeline to Prospect Reservoir and then onto Bankstown airport.

Arrival in the Bankstown circuit was uneventful. Rather than land immediately, I decided to perform one touch and go to get reacquainted with the airport's runways as I hadn't flown out of Bankstown since January. With the touch and go out of the way, the full stop landing was equally uneventful.

As I taxiied DZY to its new roost and shut down the engine, I was a little surprised to see a few spectators gathered nearby. Soon after answering their questions, the fuel truck pulled up to feed the thirsty bird. Then Roy Fox and David Thiess (owners of the hangar) helped me push the beast into its new roost. Note the twin-engined biplane behind the Yak-50. It is Roy's pride and joy - a de Havilland Dragon Rapide.

Flying the big bird at last

2008-04-27T22:44:00.036+10:00

April 2008 After thirteen consecutive days of rain, Saturday 26th April dawned cloudless with light north-easterly winds; close to perfect flying weather. Test pilot, Steve Curtis, took DZY for the final phase of test flying to satisfy requirements of its airworthiness certificate. Following 50 minutes of flying, he returned satisfied that the bird was operating well.

Before I knew it, the time arrived for me to fly the beast for the first time. As I climbed into the cockpit and buckled up first the parachute, then the seat harness, I almost couldn't believe I was about to fly the beast at long last.

After taxiing out and lining up on the runway, I paused to lock the tailwheel and then opened the throttle. I had only advanced the throttle to about 50% and was still opening it when the big metal bird told me it wanted to fly by lifting off gently on its own accord. Retracting the landing gear, I turned onto the crosswind leg for a departure out of Camden airport.

On reaching the training area, I began exploring the bird's general handling with some simple stalls, steep turns and combat turns. Unsurprisingly, the Yak-50 handles quite similarly to its close relative, the Yak-52 with light, tight and harmonised control forces.

Reversing turns in one direction into the opposite direction required minimal stick movement. Pulling up and then rolling into combat turns was delightful and effortless. All the while, the big engine simply loped along at 65% power.

I was tempted to continue with more aerobatic manoeuvres. But I decided to save them for another day because of a fast approaching winter sunset and duly headed back to Camden to practice landing the beast.

For my first approach, I decided to skim the aircraft just above the runway without touching down, to gauge the flare height and view perspective before executing a go around to set up for the second approach. Touchdown on my second approach was smooth and so I felt ready for a full stop landing on the third approach.

As I touched down on the third approach, I slowly eased back the stick to lower the tailwheel to the runway. Then I noticed the aircraft had actually become airborne again. Rather than retrying to land well down on the remaining runway, I decided to be cautious and execute a go around.

Coming around onto my fourth approach, the big bird settled on the main landing gear gently. This time, I just let the tail lower onto the runway of its own accord. When I felt the tailwheel contact, I eased the stick full back, slowed the beast to taxi speed and exited the runway.

Feeling a mixture of elation and relief, the return taxi gave me time to savour the realisation of a childhood dream of owning a "warbird" aircraft. Indulgent perhaps, but then every boy needs his toys.

Having fun while working

2008-04-05T00:36:00.019+11:00

April 2008 Friday 4th April. VH-DZY's flight testing began in earnest after it was moved from Wedderburn airstrip to Camden Airport for the duration of its test program. At the conclusion of the test program, the beast will be moved to its home at Bankstown Airport.

With test pilot, Steve Curtis, at the controls, the bird rumbled out to the runway. Taxiing a Yak-50 requires full concentration. To turn, you have to apply rudder in the desired turn direction while carefully squeezing the brake lever attached to the joystick. e.g. apply right rudder while squeezing the brake lever generates greater force in the right wheel brake. Since the tailwheel castors freely when unlocked, it will happily swing the rear end of the bird to the left at the same time. To taxi straight ahead, you just straighten the bird with suitable differential braking, centralise the rudder pedals and then ease the joystick back to lock the tailwheel. To turn again, ease the joystick a little forward of neutral, and the tailwheel unlocks.

This time at Camden, I was unable to get as close physically to the aircraft during takeoff. So I had to use a large zoom to pick up the bird at a distance. Unfortunately, without a tripod or monopod, it was difficult to avoid some "jiggling" of the video.

A Yak-18T aircraft owner, Rob Mangan, kindly offered to assist with some air-to-air photography by flying formation with Steve. So with me as photographer, we had some fun while conducting the bird's test flight. In this short clip, Steve is joining up on the Yak-18T's right wing.

This clip shows the Yak-50 in a formation turn to the right and then eventually leaving the formation in a fun way.

Steve brings VH-DZY in for a smooth touchdown before opening the throttle and taking off again. Several circuits were flown this way to establish suitable power settings for use in the circuit, as well as the preferred landing technique for this bird.

All this flying leaves a big bird thirsty. So it came back to be refuelled and for Steve and I to discuss his findings so far.

The big bird takes to the sky

2008-04-02T00:49:00.020+11:00

March 2008 Sunday 30th March dawned nearly cloudless with a light north-westerly breeze. Perfect for the first flight of the beast in Australia; and also since its refurbishment in Lithuania. Yak-50 853101, also known as VH-DZY, was rolled out onto the grass for test pilot, Steve Curtis, to run through the pre-flight inspection.

Peeking past the engine cooling shutters, the nicely overhauled and repainted engine looks neat and tidy - as it should!

Pre-flight inspection completed and with Steve strapped in, the engine belched a few puffs of white smoke (visible below the wing, next to the right wheel) and rumbled into life.

Radial engines need to be warmed up properly before flight. This gives the pilot time to run through other items in the checklist, and of course, acknowledge admiring looks from bystanders. Once warmed up, it was time to taxi to the runway area for run up checks before finally lining up for takeoff.

With a short takeoff run of about 100 m, VH-DZY flashed past as it lifted off on its maiden flight in Australia. It was exciting to watch the big bird climb away rapidly into the blue sky and settle into its new life here.

The beast gets its paperwork

2008-03-28T00:34:00.016+11:00

March 2008 After a long eight week wait for the beast's airworthiness inspection to be conducted and its certificate of airworthiness to be issued, it was rolled out onto the grass; ready for a round of ground taxiing tests.

Business end of Yak-50 serial number 853101. Its large 2.4 m (7.9 ft) diameter propeller is connected to a 9 cylinder, 10 litre capacity, 360 hp supercharged Vedeneyev M-14P radial engine.

Starting a radial engine is show of noise, smoke and sound. The M-14P engine actually starts easily, despite the drama. The noise, smoke and sound are just to keep up the "warbird" image! I shut down the engine after completing the ground taxiing test and pronounced myself satisfied with the bird. Flight testing will follow in the next few days.

A poor man's warbird takes shape

2008-01-25T21:22:00.001+11:00

January 2008 It was very pleasing for me to cast my eyes on the assembled beast today. Like a boy in a toy store, I walked around the sleek Russian bird patting it and admiring its clean and perhaps slightly menacing lines.

Relative to modern day aerobatic aircraft, the Yak-50 is a big bird. It has a wingspan of 9.5m, length of 7.97m (including spinner) and height of 2.7m; similar dimensions to the famous wartime fighter, the Yak-3 (wingspan 9.2m, length 8.5m and height 2.39m).

At last, the instrument panel was completed by the addition of the flight hours meter. The panel layout is dominated by the large attitude indicator. Engine instruments are grouped on the right half of the panel, with flight instruments on the left half.

The simple and compact Becker VHF transceiver and transponder combination is housed in a small console below the switch bank. Rather than cramming a panel mounted GPS unit in a larger console in the same position as done in some other Yak-50s, I will use a portable moving map GPS unit such as the AvMap EK-IV.

After inspecting the beast and sitting in the cockpit amid the new leather upholstery, the grin on my face says it all.

Like assembling a (big) model airplane

2008-01-23T21:56:00.002+11:00

January 2008 After yet another round of delays clearing quarantine requirements, the beast was finally delivered to the assembly hangar and unpacked. I was pleased no damage had been incurred during its long journey from Lithuania. Its engine cowlings were removed for the quarantine inspection - in case any unwanted travellers had hitched a ride. Note the aircraft behind the beast is Lindsay Sinclair's Yak-52.

A small access hatch is visible on the top of the upper cowling. It provides access to the oil tank filler.

When I was a boy, I used to build plastic model aircraft. The disassembled vertical fin and fabric-covered rudder reminded me a lot about those plastic models. On occasion, I would end up with leftover parts after assembling a model. It wouldn't do for the same to happen with a real aircraft!

The horizontal fin and fabric-covered elevators are also reminiscent of a plastic model kit. Note the substantial greenish yellow arm with a large weight at the end of it. This is the elevator's mass balance. Its function is to change the natural frequency of the structure; which in turn, raises the structure's critical airspeed (at which flutter occurs) sufficiently far away from the operating speed range of the aircraft.

Looking from the front towards the rear, the massive bulk of the main wing spar to fuselage attachment point is testament to the need for the airframe to bear loads ranging from +8G to -5G. Note head of the wing attachment bolt at the left edge of the picture. The rest of the right wing is to the left.

In the foreground, the left rudder pedal's leather strap is visible. To its right, the black knob is for adjusting the rudder pedal position. Above the rudder pedal, the wing spar carry through with its layered doubler straps bolted together again gives some idea of the heftiness of the load bearing elements. Note the two yellow tanks in the background - they are the main and auxiliary fuel tanks.

Door opens to a new life in Australia

2008-01-10T21:31:00.002+11:00

January 2008 A New Year, and finally, after a transit lasting 8 instead of 5 weeks, my new toy arrived in Sydney. After clearing Australian Customs, the next step was to clear quarantine checks. As the container door was opened, it also opened a new chapter in the life of this Yak-50, serial number 853101.

Painted in a WW2 Soviet era paint scheme, this Russian bird attracted a number of compliments from a gaggle of port workers unloading other containers nearby. Then questions and comments came fast...how fast can it go...it's as big as a Spitfire, isn't it...where are the guns...you should fly it in the Red Bull race...man, it's real sick! "Sick means cool or awesome," a worker helpfully explained - in response to my puzzled look.

The Yak-50's forward, sliding and rear canopies are styled after the Yak-1, 3, 7 and 9 fighters produced by the venerable Yakovlev Design Bureau back in the dark days of WW2. Note the magnetic compass inside the forward canopy, on top of the instrument panel glare shield. The red knob at the top of the forward canopy is the emergency canopy release. Partially visible over the seat, is the 7-point Hooker harness.

For its long voyage from Lithuania to Australia, the bird was mounted on a steel cradle (dark frame in the lower right of the picture); which was itself attached to the container floor. Notice the hefty wing attachment points (painted part grey and part sky blue) on the side of the lower fuselage. Their heftiness is required for the +8G to -5G limit loads in aerobatic flight. Plastic covers pipes for supplying air to power the landing gear retraction/extension jack and the wheel brake.

Aft fuselage without the vertical fin and rudder, and the horizontal fins and elevators. Note the non-retractable tail wheel.

Underside of the left wing showing the aileron (secured with a locking pad) and the retracted landing gear. When finally delivered to the airfield hangar, it will still take time to reassemble the bird, weigh it, prepare documentation, inspect it and test fly it. These will be the subject of later posts.

Preparing for the Yak-50

2007-11-11T20:19:00.000+11:00

November 2007 Russian prop aircraft like the Yak-52, Yak-50, Su-31 and Su-26, are fitted with the supercharged M-14P radial engine and use a pneumatic system to start the engine and power the landing gear. The Yak-52 pictured here belongs to Mark McNicol. He very kindly allowed me to use his aircraft for conversion training. An equally kind Steve Curtis offered to conduct my conversion training to radial engined and pneumatic system equipped Russian aircraft.

Although equipped with tricycle landing gear and weighing 315 kg more than the 50, the 52 (1305 kg MTOW) is sufficiently similar for conversion training to the single seat 50. Note the tall landing gear used to provide sufficient ground clearance for the big 2.4 m (7.9 ft) diameter propeller.

In terms of seating position relative to the 50, the 52's front cockpit is further forward. But for initial engine and systems conversion training, I started off in the front cockpit. Later on, I will move to the rear cockpit to get used to flying aerobatics from the rear cockpit.

The rear cockpit has a limited instrument panel. Note the Russian style attitude indicator (top centre instrument) in which the light grey "sky" is below the black "ground." In flight, when the aircraft's nose is raised above the real horizon, the artificial horizon (dividing line between the light grey and black sections) moves up above the fixed aircraft symbol (visible along the -20 degree pitch marker).

Compared to the layout of the 50's cockpit, the 52 is similar but different. One major difference is the location of the engine cooling shutters lever and oil cooler flap lever on the right cockpit console (seen on left side of the photo above). The emergency air valve (red knob) is also on the right cockpit console.

The left cockpit console contains the switch bank, flap lever, throttle and pitch levers. Another key difference between the 50 and 52 are the flaps - the former has none. Consequently, my flying in the 52 is conducted without flaps. I did make one landing with flaps and found they made very smooth landings easy.

From lonely storage to renewed life

2007-11-10T22:37:00.004+11:00

Yak-50 in flight. Its classic lines echo Alexander Yakovlev's WW2 fighter design heritage.

February 2007 Yak-50 serial number 853101 stored inside Yak UK's hangar in Little Gransden. Registered as G-CBPO, the aircraft had not flown since 2002. Prior to restoration and life in the UK, 853101 had been noted as a derelict aircraft (by an aviation enthusiast) at an airbase in Odessa-Lyman, Ukraine, after serving as 59 Blue with DOSAAF (USSR military flying club). I bought the aircraft from Mark Jefferies (Yak UK), who in turn had bought it from the UK-based owner.

The original cockpit layout was unchanged from the time of manufacture. Note the Russian Baklan 5 VHF radio beneath the switch bank.

April 2007 Out of a dark and dusty hangar and into the light. The Russian registration RA-44476 remained on the aircraft from the time it had previously been on the Russian register. The UK registration G-CBPO had not been painted on - presumably because the owner hadn't bothered to do so.

Note how far the cockpit is set back from the nose; limiting forward visibility while taxiing on the ground. The cockpit position is similar to that of the Spitfire and Corsair.

June 2007 The bird was disassembled for an overhaul and complete repaint in Lithuania.

September 2007 In Lithuania, 853101's wing feathers were removed and the paint stripped for a complete structural inspection and repair as necessary exercise.

Similarly, the bird's fuselage was stripped of equipment and paint. No major structural problems were found during the non-destructive testing and inspection of the airframe.

Some rivets around the undercarriage attachment box were found to be loose and were replaced. A small skin crack was also repaired with a doubler strip as seen in the photo.

The engine was completely disassembled for cleaning, overhaul and repainting. Note the patches of rust on some components. Mark's comment was that it's important for scheduled annual inspections to be performed even though an aircraft may not be flown much.

October 2007 Fuselage in the paint shop with the primer coat applied.

Fuselage after the dark grey on medium grey camouflage pattern was applied.

Then the WW2 era Soviet red star was applied. Other markings were to follow.

Underside view of completed wing feathers with the undercarriage wheel recess visible.

Fuselage with the rest of its markings applied. Note the mechanic inside the cockpit area. He is assembling the various electrical lines, mechanical controls and pneumatic lines leading into the cockpit. Another mechanic is working on the remounted engine.

Repainted tail feathers. All the control surfaces (ailerons, elevators and rudder) were re-covered with Ceconite fabric. Note the hefty flanges and bolts attaching the rear base of the vertical fin to the rear end of the fuselage.

The business end of 853101. A nine cylinder, 10 litre capacity, 360 hp radial engine, the Vedeneyev M-14P and its other 400+ hp versions are popular aerobatic engines of choice today. Note the big brown container mounted on the engine firewall. It's the engine oil tank!

Overhauled and repainted engine with the propeller, spinner and cooling shutters attached.

Twin fuselage fuel tanks located between the engine firewall and cockpit. Total capacity is 127 litres.

Two air bottles, one for normal use and the other for emergency undercarriage extension. The pneumatic system is used for starting the engine and powering the retractable undercarriage.

Undercarriage uplock mechanism. The rectangular reddish block is the microswitch to detect undercarriage position (retracted or extended), while the grey and black cylindrical block is the actuator for releasing the undercarriage uplock.

This is my all time favourite office. Note there is a hole (left of control stick) for one more instrument to be fitted - an air-switch flight hours meter. I changed the cockpit and panel layout by replacing the Baklan radio with a Becker radio and transponder combination in a new housing (below switch bank), adding the flight hours meter, moving the accelerometer (G-meter) from the top of the glare shield (left of the compass) to the right side of the instrument panel (above the primer's oval knob). This cleared the view over the nose.

853101's nose with the top engine cowling attached and the bottom cowling in the foreground.

Yak-50 serial number 853101 out of the workshop and before being shipped to me in Australia.