FAQs


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Here are answers to the questions most frequently asked about the operation of imported aircraft.

 
bullet How are YAK and Sukhoi aircraft registered in the U.S. ?
bulletHow restrictive is "Experimental Exhibition category" ?
bulletWhat about spare parts ?
bulletWhat piloting experience do I need to safely operate a YAK ?
bulletWho can work on an Exhibition category aircraft ?
bulletWhat is the typical fuel/oil consumption and how fast does a YAK52 cruise ?
bulletIs there a way to carry more fuel ?
bulletDo the Russian avionics work in the USA ?
bulletIs the YAK52 competitive in Aerobatic Competition ?
bulletHow about insurance ?
bulletIs the Engine TBO really only 500 hours ?
bulletWhat is all this I hear about spar modifications?
bulletHow is the YAK52 ADF used?
 
bullet What do the Russian Language Annunciator lights mean ?

 

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How are YAK and Sukhoi aircraft registered in the U.S. ? 

Contrary to popular belief, there is no such thing as "straight experimental" category.  There are, in fact, several categories, such as experimental amateur built, experimental racing and experimental exhibition.  It is the latter category in which Yaks and Sukhois are generally operated.

Within the experimental exhibition category, aircraft are divided into 4 sub categories: Warbird, Turbine, Aerobatic and Other. Basically, the four categories offer similar restrictions except that turbine aircraft have to be maintained in accordance with an FAA approved maintenance schedule and "Other" aircraft can only land at the airport from which they took off. (This is the FAAs way of preventing you from importing a utility aircraft, such as the AN2, and using it simply to bypass the expense of operating a standard category (non-experimental) aircraft).

 

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How restrictive is "Experimental Exhibition category" ? 

All of the YAKs and Sukhois operating in the USA are in the Aerobatic sub category and enjoy restrictions similar to these:

  1. The pilot needs to hold an appropriate certificate

  2. The aircraft must be inspected each year in accordance with the scope and detail of FAR 43 appendix-D (Annual inspection) The inspection must be carried out by an A&P. (I.A. not required)

  3. You may not fly over densely populated areas except for the purpose of takeoff and landing.

  4. You may not operate the aircraft for compensation or hire. (ie, no commercial operations)

  5. The aircraft may only be operated for the purpose of exhibition, maintenance and proficiency.

  6. Exhibition is defined as: attending a school or shopping mall exhibition, fly-in, airshow, aerobatic competition or organized practice session.

  7. For flights other than those listed above, the aircraft may only operate within a specified geographical area, usually a circle of 300 NM based on the airport at which the aircraft is based.   NEW or REVISED Operating Limitations eliminate the 300 NM proficiency area.  In other words, NO RESTRICTIONS WHERE YOU CAN FLY, EXCEPT FOR CLASS B AIRSPACE.

  8. At the beginning of each year, the operator must submit a list of the events he/she intends to attend that year (program letter).

  9. For any flights not listed in the program letter and which lie outside the 300 NM radius, the FAA must be informed in advance by FAX or post card. (Inform, NOT ask permission).  THIS DOES NOT APPLY IF YOUR OPERATING LIMITATIONS DO NOT STATE A 300 NM PROFICIENCY AREA.
     

Clearly there is a lot of latitude here. The FAA has carefully avoided defining the term "organized practice session" and they will accept a FAX on the day of your departure.   However, it is best to fax your Program Letter updates at least 48 hours in advance.  So plan ahead.

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What about spare parts

I can assure you it much easier to get parts for a YAK52 than it is for my Piper Comanche! Not only are there at least 5 companies in the USA that stock spares for the aircraft, but it is still in production and all parts are being made. Further, although Romania may seem a long way away, remember that there is a UPS and a FedEx office in almost every town in the world now. If the part you need is not in this country (unlikely) and not in England (Extremely unlikely) a FAX to the factory will have the items you need in the UPS box right away. I know of no parts problems with these aircraft at all. Furthermore, when you get the bill, it will be for a fraction of the amount the equivalent US part would cost. My main alternate source in the US is George Coy at Gesoco Industries (802) 868 5633.
 

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What piloting experience do I need to safely operate a YAK ?

None! These aircraft are basic trainers for goodness sake. In W.W.II, pilots we sent to war in P51s with, in some cases, less than 100 hours in their log books. It is attitude that counts. Professionalism and a willingness to learn will have you safely operating the aircraft in a very short time.

If you have never operated a "complex" aircraft, that training, and the logbook endorsement required will be provided.

I have taught several private pilots with between 100 and 200 hours total time and no complex time at all. In a few hours of thorough, organized flight instruction and plenty of classroom time, they are able to safely operate and enjoy the YAK52.

Of course, if you want to buy a green flight suit and tell everyone at the fly-ins you attend just what a hot-shot a person needs to be to fly an aircraft like this, I won't tell a soul! - Honest.

 

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Who can work on an Exhibition category aircraft ?  By: Dennis Savarese

According to FAR Part 43, which covers the maintenance of aircraft, 43.1 says:
43.1 Applicability.

            (a) Except as provided in paragraph (b) of this section, this part prescribes rules governing the maintenance, preventive maintenance, rebuilding, and alteration of any --

                (1) Aircraft having a U.S. airworthiness certificate;

                (2) Foreign-registered civil aircraft used in common carriage or carriage of mail under the provisions of Part 121 or 135 of this chapter; and

                (3) Airframe, aircraft engines, propellers, appliances, and component parts of such aircraft.

           (b) This part does not apply to any aircraft for which an experimental airworthiness certificate has been issued, unless a different kind of airworthiness certificate
                 had previously been issued for that aircraft.

At annual inspection time though, it does require an A&P certificate to perform and sign off the annual condition inspection, but not an I.A.


 

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What is the typical fuel/oil consumption and how fast does a YAK52 cruise ? 

As they say in the race car business, speed is money - how fast you wanna go? In the YAK business, we tell people you can make the fuel burn just about whatever you want. Just set the throttle.

Seriously though, a YAK52 at aerobatic power, being flown hard will burn as much as  24 gallons per hour. On the other hand, on a long delivery flight with the power set to optimum range settings, I have measures as low as 11.5 US gph. A more typical fuel burn, at 70% power, the setting most commonly used in training and just flying around having fun is about 15~16 gph. At this speed, the rather draggy YAK will be cruising along at 125 to 130 knots.

The oil consumption is harder to quantify. This is because during aerobatics, each time the inverted oil valves operate, a small amount of oil is lost overboard. Also, the top half of the oil tank is really only good for ferrying.

This is how it works: If you don't fly upside-down (shame on you!), the engine will burn about the same as any other  engine of this size. Perhaps a quart every few hours. If you fly upside down, and oil in excess of 8 quarts will be vented overboard quite quickly. Thereafter, it will burn just a little more that it does right side up. The rumors about YAKs burning more oil than fuel came about because people kept topping up the tank to 16 quarts (litres), doing a couple of slow rolls and then finding there were only 8 quarts left. The secret is that if you are going to fly aerobatics, don't put much more than 8 quarts in it.

 

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Is there a way to carry more fuel by: Dennis Savarese

Go to the FUEL BLADDERS page.
 

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Do the Russian avionics work in the USA ? 

Not only do they work, but they probably work better than any radios used in western light aircraft. The Comm radio has 760 channels, the ADF has 8 presettable stations (download the instructions here) and the intercom is excellent.

 

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Is the YAK52 competitive in Aerobatic Competition ?  by: an aerobatic instructor

Most certainly it is. You will have to work very hard (and have luck on your side) to win at unlimited but look at it this way: The difference in price between a YAK 52 and an Extra 300 is about $240,000. Can you imagine how good you would be if you put $240,000 worth of gas in a YAK 52? Curtiss Pitts once said (or so it is reputed) that the most cost effective way to increase the performance of an aircraft is to put gas in the tank.

The fact is, a YAK 52 can very easily perform the Sportsman and the intermediate sequences and it can do so with grace and elegance. It is big enough to be seen easily by the judges and makes a very impressive sound. It has great "presence".

I have often read that the YAKs are very poor at rolling circles but I have not found this to be so. The YAK 50 does great rolling circles and the 52 does them quite well.

In advanced category, the weight of the aircraft and it's flat bottom wing begin to make life more difficult.

 

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How about insurance By: Dennis Savarese

It will vary with experience and location of course, but the insurance rates seem  reasonable for this type of aircraft.  Expect to pay somewhere between $2000 and $3000 for the normal coverage's depending upon insurance agents and underwriters.  Rates vary quite a bit from company to company though.  Don't be surprised if you are told you will need 10-20 hours of dual instruction by a CFI and 10-20 hours of solo before you can carry a passenger.  

One of the best agencies writing insurance policies for Yak 52's is Cannon Aviation Insurance in Scottsdale, AZ.  Contact Tom  Johnson for a quote and tell him Dennis Savarese recommended you call him.

 

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What is the Time Between Overhauls for an M14P engine ? 

The official time between overhauls on an M14P engine is 750 hours. Until recently it was 500 hours.  Does this mean that like a Lycoming, at the end of that time, they are pretty well worn out and must have all the major components replaced and be recertified?

No it does not! To understand the engine (and the airframes they are installed in) you must first understand the culture and the system in which they were designed to be operated.

In the former Soviet Union, the aircraft were all government property. (You know how carefully people look after government property). If one broke, you requisitioned another.   There were no annual inspections and little if any preventative maintenance. - When I first asked how frequently I should change the oil I was told that they did not bother since after aerobatics, they had to add oil anyway so It was constantly being changed!    In short, the aircraft were designed to be operated in rather agricultural circumstances where technical resources were few. A further difficulty is that Russian oil is rather crude and does not benefit from the additives we are used to.

Under these circumstances, it is easy to understand why the factory wanted to take a look at each engine every 750 hours or 5 years. If you on do an "annual" every five years, you'd better make it a good one!

When the engines are returned for overhaul, they are often not overhauled as we understand the word, it is more like Inspect And Replace if Necessary (IRAN). The engines are measured and checked. Any worn or defective parts are replaced. The engine is then tested and returned to the field.

When you consider that in the West, we have excellent oil, regular maintenance, annual inspections and we tend to look after what we own, it is clear that a much longer TBO is practical. Pompano Beach Air Center, at one time the importers of Sukhoi aircraft, offered a 2200 hr. guarantee on the engines and I have personally disassembled and inspected an engine with 1000 hours of hard use that had no measurable wear other that a few frayed high tension leads.

I feel quite confident in predicting that when properly looked after, these engines will easily provide at least 2000 hours of reliable operation.

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YAK52 Wing Spar Modifications  by: a YAK expert

The modification state of YAK52s has been the subject of much misinformation, much of it emanating from a person seeking to discredit the YAK52 to help bolster sales of a competing (and now discontinued) aircraft.

The YAK52 was designed as a +7/-5 G aircraft. In 1982, new limits were established for the YAK52 limiting it to +5/-3 G until an up-grade was fitted increasing the strength of the Spar carry through.

Since all YAK 52s in service in the east block were required to be overhauled every five years, by 1987,  all the aircraft in existence should have been upgraded. By the time they started to appear in the USA,  there should have been no unmodified aircraft left. In fact, there were a few aircraft that did not receive the upgrade. It is easy to tell these aircraft since when the modification was made, a "pie slice" shaped bump was added to the underside wing root fairings under the main spar.

If you have one of these aircraft, there is nothing to worry about at all. They are perfectly fine aircraft, just respect the load limits and don't pull more than 5 G.

The most recent aircraft produced in the factory (in Romania) have a further level of modification which is designed to increase the aerobatics life to 5000 hours!  Please look at the Bulletin page for details of all the modifications available for the YAK52. 

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Using the YAK52 ADF system by: a contributor

There are two frequency selector controls. The horizontal switch under the glare shield marked A & b (sort of) and the rotary knob on the right hand control panel marked 1- 4 & "pi".

The A/b switch allows you to select one of two banks of 4 frequencies. It always seemed odd to me that half the controls were on the right and the other half on the top-left but then I learned that the Russians fly instrument approaches based on two NDBs at each airport. On on the extended center line of the runway about five miles out and the other on the airfield. The rotary switch (1 ~ 4 & "pi") selects one of four airfields. The A/b switch, which is located close to your instrument scan, selects "outer marker" or "airfield beacon" Now as you can see, it makes some sense.

To program the frequencies, download the file ADF.DOC from the download page. It explains all the details.

The "pi" position means "variable frequency" and requires a variable tuning unit which is not fitted to the YAK52 so that position does nothing.

On the face of the control panel are two small toggle switches, as I recall, one of them is marked "ANT" (or something close in Cyrillic) and "RAD". This is the ADF/ANTENNA switch. In the forward (toward the nose) position, the ADF needle will point to the NDB. In the rear position, you just hear the station ident. The pointer does not operate.

The second silver switch is the BFO switch. Again, normal position if forward (BFO off) if you need the BFO to help make out the ident, move it rearwards.

Next, alongside the adf control unit, between it and the fuselage wall is a green light and a pushbutton. The control panel is only active if the light is on. If it is not, press the button and it will come on. If the rear pilot presses his button, his green light will come on and yours will go off. Now he has control of the ADF and your controls are disconnected.

The black rotary knob is the volume control (more later) and the small red button is the "test" button. It will swing the needle away from the station for a while.

Finally, to make use of the ADF, you need to understand the intercom/radio/adf volume control set-up:

There are four radio controls in the YAK 52, two on the intercom panel (below the primer) one on the ADF and one on the radio. I'm doing this from memory but I think this is how it works.

Audio from the ADF is controlled by it's own volume control, mounted on the ADF control panel. From there it goes through the small silver toggle switch at the bottom right of the intercom, through the right most, white volume control knob on the intercom panel and thence to the headphones.

To hear the ADF, you must have the ADF volume turned up, the right most intercom volume turned up, the rightmost intercom toggle switch in the UP position and have both the ADF and intercom power turned on. You will also need at least one of the rotary converters running I think.

The radio audio is controlled by the radio volume control. from there it goes through the rightmost intercom volume control and thence to the headphones.

Intercom volume is controlled only by the leftmost intercom volume control.

In theory, you can set each device to the level you prefer but what an odd way to do it.

bulletThe Annunciator panels above each instrument panel are interpreted as in the following tables:

 

Stall Warning Approaching Stall Metal Chip In Oil Generator Fail
Excess 'G' Gyro Compass Unusable Stall Warning Heater ON Pitot Heat ON

Front Cockpit

 

Excess 'G' Stall Warning Low Airspeed
Generator Fail Left Tank < 12 L Right Tank < 12 L
Battery ON Gyro Compass Unusable Metal Chip in Oil
Pitot Heat ON Stall Warning Heat ON

 Rear Cockpit