The Yak-55M is a beast of an airplane. Dwarfing the Pitts and Extra on the ramp, the big M-14P 9-cylinder radial engine makes a distinct impression. The first step in this airplane is to check the oil. The minimum allowable is 8 liters, but depending on how hot it is outside I like to fly with between 11 and 13. Once taken care of, I open one of two engine access doors and move the manual oil cutoff switch inside the cowl to “on”, removing the remove before flight ribbon attached. A quick look in the compartment to make sure it’s relatively dry and everything is in place, I secure the door and move to the cockpit.
The key here is checking that the mags and shower of spark switches are off. With a radial engine, before starting, you need to pull the propellor through about 12 blades to make sure there is no excess oil in the cylinders. Failing to do this could lead to expensive damage. Since we’re pulling the prop through, it’s important to make sure the ignition is off. The alternative can be very hazardous to your health.
With the ignition off and the airplane chocked, I pull through twelve blades, pausing if I get any oil out of the exhausts or the intake drain. It’s not unusual to have a little oil dripping out of the exhausts if the airplane has been sitting for more than a week. If I get any excess resistance on a blade, it means there may be oil trapped in the cylinder – requiring a different procedure to get the oil to drain out the intake and through the intake drain. I take special care when pulling the prop through to make sure my body is always clear of the plane of the propellor.
Once this chore is complete, we do the rest of the preflight inspection. Since this is an aerobatic aircraft, we pay special attention to looking for foreign objects that might jam controls. The preflight itself is fairly straightforward – there isn’t much to this airplane but engine and airframe. The preflight also gives any oil that has collected in the intakes as a result of pulling the prop through some time to drain out the intake drain.
Hopping up onto the front of the wing from the tire (there is a technique to this you’ll have to master), we are again in the cockpit. Six shots of prime puts fuel in the intake, priming for start and also diluting any remaining oil and making it easier to drain. We don’t want oil in the intakes, and these procedures help ensure there is none.
Hopping down, we pull six more blades and wait for the intake drain to stop dripping. We close it, remove the chocks, and are ready to fly.
Hopping back up on the wing, it’s time to put on the parachute and helmet. The cockpit is relatively roomy. Hook up the five point harness, ratchet it tight, and we are ready to start!
This airplane starts easy. Another few shots of prime, a few pumps of the manual fuel pump, shower of sparks, master, and gauges on, throttle cracked, starter engaged, and the engine will fire. As soon as it fires, mags to both and set RPM to 25%.
The sound of the M-14P will turn heads. It’s a unique, throaty, glorious rumble. And that’s just at idle.
Taxiing is a breeze. This airplane has Cleveland brakes, so the only trick is seeing over the nose. There is a lot of engine in front – it’s kind of like flying an F4U. S turns are recommended and the airplane is stable and honest on the ground.
After a flight control check, we wait for temps and do a quick runup. 70%, mags checked, prop cycled, engine instruments good. We check air pressure (the starter is pneumatic). If we’re at 600PSI, turn off the compressor. If not, no problem, it’ll get there soon. A relief valve let’s go at about 620 PSI, and it’ll startle you (but it’s harmless). Once it fires, you lose about 150 PSI, so you’ll have to wait for it to fill up again. The trick is turning off the compressor at 600 PSI (on the ground or in the air).
With the prop full forward, and brakes set, it’s time for some fun. Smoothly advancing the throttle, the airplane will push you back in the seat. Somewhere around 80%, the big three blade prop will start to bite air, and you’ll really feel the acceleration. By the time the throttle is in, you are airborne. The airplane tracks smoothly on the ground and is honest throughout.
I like to hold the airplane level a few feet off the ground up to about 220 KPH (this is a russian airplane). Then a smooth, but aggressive pull and the airplane will rocket up. An initial 45 degree deck angle looking for about 130KPH in the climb will have you at 2000 ft before you clear the airport fence. From there, 130 to 150KPH, bringing the RPM back to 94% for the climb. If you are out for acro, you’ll be at full throttle and 91-94% throughout (you can fly it at 99%, but as Vladimir says, the engine last longer dialed back a bit. You won’t notice the difference).
I like to practice high, so around 6000 ft I’ll level off and reratchet the belts. A quick flick and you are inverted. Check engine instruments, make sure nothing is loose in the cockpit, and then roll back over. One more ratchet and you are good to go. I think hanging in the belts is one of the most awesome feelings in all of aviation.
From an aerobatic standpoint, the Yak will do just about anything. The knock on the airplane in competition circles focuses on three qualities. First, since this is a Yak-55M, it has a short wing. This means that with any kind of wing loading you get lots of drag. If you are used to flying an Extra and pulling 6-7G in the corners, you’ll kill energy quick in the Yak-55M. This means it requires a little extra finesse in order to maintain energy through a sequence.
Second, the ailerons are big and the airplane has a lot of roll inertia. Control forces are light, but once the Yak is rolling you really have to work to stop in where you want it. It forces good technique. As a positive, master the Yak and point rolls in other airplanes become a piece of cake. This also makes snap rolls more challenging, but again, once perfected, you’ll be spoiled flying another airplane.
Finally, the aircraft is big. This means that small errors that wouldn’t attract a judges attention in other airplanes get called out in the Yak. You’ll also draw some “low” calls simply because the aircraft looks lower because of it’s relative size to other competitors.
Having said all of that, it doesn’t mean the airplane can’t be competitive. Sportsman and Intermediate are the sweet spot. Advanced is a challenge but doable, and it has the performance for Unlimited, but it will take a special pilot to be competitive.
Once you’ve had enough acro, it’s time to land. This airplane is one of the easiest taildraggers I’ve ever flown. Downwind at 200KPH, base and final at 180KPH, flare the airplane to a three point attitude with the power coming off, and an easy three point landing. You can wheel land the airplane, but the big steel gear legs have lots of bounce and the prop arc is pretty big. The rudder maintains authority throughout the landing – small, but constant adjustments keep the airplane tracking straight, and once the tailwheel is on the ground you are safely on the ground.
You’ll have a big grin on your face and be a little mad you quit so early. But that’s alright, it’s your airplane and you can go again anytime you want.