An extended rest ends

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.

Getting comfortable with the beast

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!

Preparing for the Yak-50

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.