Hi,
anyone have already fly a yak 55 ..how its like...and what you think about this aircraft?
Yak 55M
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Re: Yak 55M
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Last edited by Hedley on Thu Apr 07, 2011 6:33 am, edited 1 time in total.
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Re: Yak 55M
I can't believe the size of the ailerons on that thing! 
http://www.youtube.com/watch?v=5m3yka8C ... re=channel
http://www.youtube.com/watch?v=5m3yka8C ... re=channel
Re: Yak 55M
Deleted.
Last edited by Hedley on Thu Apr 07, 2011 6:34 am, edited 1 time in total.
Re: Yak 55M
yeah...i was looking to some airplane and i saw the yak55....never hear about it before...and I discover its look like a little beast for about 50 000$, 345 degree/sec, 360 hp possiblity of 400 with the M14PF....cheap for the maintenance...about 15-20 gallons hours can leave it outside where its very a good things and can save a lot of money!
Re: Yak 55M
More less what Hendley said. My 2 cents:
-weight is not really a problem - it’s within 100lbs of the Sukhoi and can be easily reduced. What sets it apart from the Sukhoi is drag, especially under Gs. Sukhoi loves Gs and carries energy under high load very well. Yak 55M- not at all. If you make a mistake and pull more then 6Gs into your first figure, you have just blown your whole sequence. Yak 55 corners somewhat better then 55M, as it has more wing area, but has slower roll rate. They are also quite rare.
-Yak has much heavier ailerons then Sukhoi. They are powerful and big shovels reduce aerodynamic loads, but the inertia is huge. That makes point rolls and crisp, clean stops difficult.
-sitting position is absolutely horrendous, especially if you are over 5 feet tall. Their idea of increasing G tolerance was to shove pilot’s knees into his face and cut off flow of blood. It makes 25 min aerobatic flight uncomfortable, anything longer becomes a torture. Factor hiring a ferry pilot into cost of ownership. He won’t come cheap more then once.
- very easy to fly ,good visibility, more predictable and then Sukhoi. One of the best tumbling aircraft ever made.
-affordable and pretty much bulletproof. You will never break it unless you hit the dirt. Simple (cheap) maintenance. Best aerobatic engine ever made. It is possible to win Gold at the world level in Advanced category (AWAC).
It will fly Unlimited figures, but it’s very difficult to get thru the whole Unlimited sequence due to energy limitations. Big engine (M14PF, or similar) , lower weight, and aerodynamic cleanup could possibly fix that. Pilot seat could be modified for more comfort. Custom composite ailerons could cure the inertia problem.
-lots of airplane for the $$.
Jerz
-weight is not really a problem - it’s within 100lbs of the Sukhoi and can be easily reduced. What sets it apart from the Sukhoi is drag, especially under Gs. Sukhoi loves Gs and carries energy under high load very well. Yak 55M- not at all. If you make a mistake and pull more then 6Gs into your first figure, you have just blown your whole sequence. Yak 55 corners somewhat better then 55M, as it has more wing area, but has slower roll rate. They are also quite rare.
-Yak has much heavier ailerons then Sukhoi. They are powerful and big shovels reduce aerodynamic loads, but the inertia is huge. That makes point rolls and crisp, clean stops difficult.
-sitting position is absolutely horrendous, especially if you are over 5 feet tall. Their idea of increasing G tolerance was to shove pilot’s knees into his face and cut off flow of blood. It makes 25 min aerobatic flight uncomfortable, anything longer becomes a torture. Factor hiring a ferry pilot into cost of ownership. He won’t come cheap more then once.
- very easy to fly ,good visibility, more predictable and then Sukhoi. One of the best tumbling aircraft ever made.
-affordable and pretty much bulletproof. You will never break it unless you hit the dirt. Simple (cheap) maintenance. Best aerobatic engine ever made. It is possible to win Gold at the world level in Advanced category (AWAC).
It will fly Unlimited figures, but it’s very difficult to get thru the whole Unlimited sequence due to energy limitations. Big engine (M14PF, or similar) , lower weight, and aerodynamic cleanup could possibly fix that. Pilot seat could be modified for more comfort. Custom composite ailerons could cure the inertia problem.
-lots of airplane for the $$.
Jerz
Re: Yak 55M
thanks a lot for the info, love to talk with experienced pilot who know alot about aerobatics!
Re: Yak 55M
I've competed against them many times and helped judge and watched them fly of course quite a bit. Flown well they are great to watch. Kind of like a tractor motoring its way methodically along through a sequence. Similar to a Sukhoi but of course a bit slower .. but the sound is oh so cool.
i've contemplated several times getting rid of the S-1T and getting a Yak and of course parking it outside. That cost savings alone would be pretty interesting.
They do however burn a wack load of gas and oil and you see people that fly them will carry lots of extra oil in the baggage compartment.
Peter
i've contemplated several times getting rid of the S-1T and getting a Yak and of course parking it outside. That cost savings alone would be pretty interesting.
They do however burn a wack load of gas and oil and you see people that fly them will carry lots of extra oil in the baggage compartment.
Peter
Re: Yak 55M
Baggage compartment Peter? There isn't one. That's another shortcoming I forgotten about. You visit Woolymart alot flying one of those. Fuel and oil burn is about twice that of S1, but on par with 540.
Re: Yak 55M
I stand corrected Jerzy, it was an SU29 front seat that i saw occupied with a big pail of oil for the days practice flightsBaggage compartment Peter? There isn't one. That's another shortcoming I forgotten about. You visit Woolymart alot flying one of those. Fuel and oil burn is about twice that of S1, but on par with 540.
Hey question .. will those MP's run on automotive fuel or are they 100LL limited also... because that would be a big advantage.
Peter
Re: Yak 55M
Peter
The required Octane, even for M14PF (400hp) is 91, so they run on car gas, I was told. You would have to change your fuel system to synthetic rubber seals, hoses, carburetor diaphram, flop tube, and so on. Otherwise the ethanol in car gas will eat the natural rubber and you will have a glider with glide ratio of about 1:1. The vapour locking of blended gas is another consideration. To do it properly, you would change to Airflow Performance FI, with a high pressure electric fuel pump, and special considerations for fuel system temps, pressures, and fuel/air separator return lines. Big expense and makes the whole idea much less attractive from saving $$ point of view. Of course with possibility of 100LL disappearing soon, we may have no choice. I run FI on my Suk already for performance reason, but haven’t tried the car gas yet.
I find myself less and less willing to experiment with gliding in aerobatic airplanes at my old age.
So true about carrying the pail of oil with you, but top end overhaul with better rings can fix that. Also, my Extra 300 with factory reman engine was even worse on oil consumption. Oil was just going out the breather tube at a rate of about 2-3 l per short flight. That was flying Advanced and Unlimited with lots of positive to negative G transitions. Flying just gentle loops and rolls wasn’t burning any oil at all, so it was due to inverted oil system limitations, not so much the engine itself. In that respect, the Russian oil system is much better, providing you address the slopy pistons and rings to reduce the blowby.
I don't think Yak 55 is a big upgrade from the soupped up (roll rate) S1S or similar, other then much cleaner lines for this extra 0.01% score it takes to win a bigger contests.
Stepping up from Pitts to Yak is difficult for most pilots, especially westeners not familiar with metric system, opposite direction prop rotation, air start, etc. They also fly totally differently , and take at least 100hrs, just to get use to one. I know a very competent Pitts pilot who tried the switch in preparation for an AWAC, and went back after a year or two. His biggest complain was the sitting position with pilot's head way outside the roll axis.
The required Octane, even for M14PF (400hp) is 91, so they run on car gas, I was told. You would have to change your fuel system to synthetic rubber seals, hoses, carburetor diaphram, flop tube, and so on. Otherwise the ethanol in car gas will eat the natural rubber and you will have a glider with glide ratio of about 1:1. The vapour locking of blended gas is another consideration. To do it properly, you would change to Airflow Performance FI, with a high pressure electric fuel pump, and special considerations for fuel system temps, pressures, and fuel/air separator return lines. Big expense and makes the whole idea much less attractive from saving $$ point of view. Of course with possibility of 100LL disappearing soon, we may have no choice. I run FI on my Suk already for performance reason, but haven’t tried the car gas yet.
I find myself less and less willing to experiment with gliding in aerobatic airplanes at my old age.
So true about carrying the pail of oil with you, but top end overhaul with better rings can fix that. Also, my Extra 300 with factory reman engine was even worse on oil consumption. Oil was just going out the breather tube at a rate of about 2-3 l per short flight. That was flying Advanced and Unlimited with lots of positive to negative G transitions. Flying just gentle loops and rolls wasn’t burning any oil at all, so it was due to inverted oil system limitations, not so much the engine itself. In that respect, the Russian oil system is much better, providing you address the slopy pistons and rings to reduce the blowby.
I don't think Yak 55 is a big upgrade from the soupped up (roll rate) S1S or similar, other then much cleaner lines for this extra 0.01% score it takes to win a bigger contests.
Stepping up from Pitts to Yak is difficult for most pilots, especially westeners not familiar with metric system, opposite direction prop rotation, air start, etc. They also fly totally differently , and take at least 100hrs, just to get use to one. I know a very competent Pitts pilot who tried the switch in preparation for an AWAC, and went back after a year or two. His biggest complain was the sitting position with pilot's head way outside the roll axis.
Re: Yak 55M
The inverted oil system in the S-1T is not that great either when you do lots of transitions especially in the very low +/- G range. If I do rolling turns, vertical rolls, or especially a kind of nifty avalanchy thingy with about 3 rolls or snaps off the top of a loop I lose 1.5 quarts or so in a 10 minute flight. .. lots of fun thoughSo true about carrying the pail of oil with you, but top end overhaul with better rings can fix that. Also, my Extra 300 with factory reman engine was even worse on oil consumption. Oil was just going out the breather tube at a rate of about 2-3 l per short flight. That was flying Advanced and Unlimited with lots of positive to negative G transitions. Flying just gentle loops and rolls wasn’t burning any oil at all, so it was due to inverted oil system limitations, not so much the engine itself.
