Paul Sharp replied
Well, this site is bound to have aficionados like myself, who will give glowing reports, but I'm sure you know that. I'm not personally familiar with the C model, since I have a T337B made in 1967. I believe strongly that Skymasters in general are excellent buys, with some caveats (which I will explain). The plane took some heat because in the beginning it wasn't that fast and didn't have any better overall accident rate than other twins at first and over the years it got a reputation as requiring more maintenance than usual. I believe that all of the negatives are behind them now except possibly the speed issue. The normally aspirated models in truth are generally slower than other twins with comparable size/engines/etc. But they are not that much slower, and there is compenation in terms of the control issue in case of an engine- out -- the largest issue in my opinion. They are also roomy airplanes and comfortable to sit in, with good headroom, etc.
Some others who own the normally-aspirated models can jump in here and talk about speeds for those. My case is an exception in a few ways, but I will give you the dope on it. The early turbos were certificated to wonderful heights - so high you could get in trouble if not careful. Mine is certificated up to 33,000 feet. It has factory O2 and I also have a portable backup system, as I wouldn't want to be making an emergency dive if I had any problems with the O2 in the 20's. I found that the POH was accurate when it said that you could establish climb settings of 28" and 2600 RPM at 14.5 GPH and climb from sea level to 24,000 feet without touching a thing except perhaps the trim. My aircraft has full deice (although none of them are certified for KNOWN ice - something I have heard was given up on because after a certain amount of time in icing conditions the tailplane, of which there is so much area, finally got to where even the deice boots couldn't keep it all off) except for a hot windshielf plate (I have seen and heard of very few models with the hot plate - rare in my opinion). Almost all of the aircraft have the aux. fuel tanks, which gives you plenty of gas even for long trips.
Mine also has dual hydraulic gear pumps and King avionics with dual glideslope receivers, and as with all others I also have dual vaccuum pumps, dual alternators, and dual regulators - besides dual engines. The electrical system is 28 volts, and I've never had a problem, even with the boots, prop deice, and all radios going. My heater is a Janitrol; normally-aspirated models have the usual muffler-based heating systems.
In the 10,000 foot range, I get 165 knots groundspeed in no-wind conditions at 75% power, and burn about 24-25 GPH (measured by what fuel it takes for the time flown when I get it topped off after arrival). If I take the aircraft up high, I can get as much as 190 knots out of it, and that's fast enough to keep me happy. My aircraft will also hold 20,000 on EITHER engine in standard conditions. (I don't know about the normally- aspirated models, but show me another twin that will do that...) The later turbo models were limited by certification to 25,000 feet, but that takes care of most people quite well.
When I bought my airplane, I had the front engine (it was past TBO) overhauled for $14,000. The turbo hoses did not need replacing, and I had to get the newer VAR crankshaft (did I spell that right?). That price is really about normal for all but the smaller/lighter-engined aircraft. I figure that I fly for about $65 per hour (I seldom fly at less than 75% power) in direct costs, with ongoing maintenance about equal to that amount for 100-200 hours per year. Annuals run from $2000 to $4000 each year. I think you will find these costs fair and favorably comparable to other twins.
They have also been called noisy, but those who ride in mine (not pressurized) have remarked about how quite it was; these are other, conventional, twin flyers. I always fly with an ANR headset (and provide all passengers with headsets, too), so this issue never entered my mind anyway.
They have excellent load-carrying capabilities, although like most airplanes, you can't really carry as many people as claimed and still have full fuel. Six seats are commonly advertised, although most of us don't use the two, smaller rear seats much, if at all. We put luggage there anyway. A baggage pod is available, but not many have used those.
The airplanes are built like tanks and very strong - another plus. The POH docs are excellent (Cessna has usually gotten high ratings for this). Cessna parts are high, but most of us get them from other sources for most things, and save a lot doing so; in effect when we do, we pay about the same as anyone else not buying directly from Cessna.
They make excellent IFR platforms - one of their best characteristics. Just be sure to get one with newer avionics, as the early Cessna ARC stuff, as with all Cessnas, is not very high in quality and the older it gets the worse it gets. Most airplanes that are actively flying have lots of avionics replacements (usually good choices).
The pressurized Skymaster is probably the best buy of any pressurized airplane available. They are limited to 20,000 feet, but can be very nice aircraft to own and fly.
The model's record for safety has improved, and I got insurance ($2100 year) for less than I paid for the Twin Comanche I formerly owned (which is also a great aircraft, but I wouldn't trade my Skymaster for another one of them).
I believe that one of the reasons the aircraft got a bad maintenance reputation is that because their prices were down historically, pilots thought when they bought a cheap twin they could fly it cheap, and that just ain't so. It costs as much as any other comparable twin to fly, maintain, and operate. So when they buy one cheap, often it hasn't been maintained, and they have to put a lot of money into it to get it up to snuff. So my advice to you if you buy one is to shop carefully and get a good pre-buy inspection from an A&P or IA who knows the model.
Because I live and fly in the west high mounainous terrain and in all kinds of weather, I wouldn't want a normally-aspirated model. But the turbo model I have is absolutely wonderful and I am a most satisfied and happy owner.
Hope this information helps. You might ask about any specifics you want to know about. This site is as good as I've found for Skymaster info.
GMAS 337Skymasters Club replied
Simply put... don't believe all the articles on how bad they are... because most of them are written by people who are writers and not owners.. and either only know what people have said ... or they compile what they read... but either way... they not know much of what they speek..... Most of the centerline thrust planes like the skymaster.... are ... safer than most of the single high power or side by side twins.... loss of power and control of aircraft is still the biggest killer... and in the case of hi power singles... loss of the engine.. results in the plane going down... in side by side twins... it is the Vmc that get most of em... when one engine quits... but, in the skymaster.. if one engine quits... because it is centerline thrust... all it does is slows down... with little or no change in flight dynamics... I would recomend the skymaster...
E.M. Hitchcock added
I do not pretend to be an expert so will comment only as an owner for about 10 years. The 337 with the engine driven gear pumps have given me no trouble but do watch the oil level and for sure check the gear at least once a year on the ground. A friend with a later 337 with the electric pump did have gear problems but it was due to bad seals on the electric valves. This was reported to be a known condition which his inspector did not know about. He did have two gear up landings and the aircraft received rather minor dammage. Minor but costly.
As to safety well two are better than one when you experience a single failure. I can maintain over 6000 feet alt. on either engine and have had two experiences where I shut down an engine for possible problems. Both cases were quite minor and did not involve much cost. Had I been flying a single we would have been in the ocean. In a single engine configuration the aircraft did perform well just operated at a reduced speed. For pilots that do not spend a lot of time in the air it does make things easier when you experience an engine out. In the hands of a well experienced pilot I do not think there is much difference between center line and normal twins.
Dennis A. Butler also added
Yes the gentleman above makes very good points that are well taken. Most of the authors that are writing magazine articles today are younger than my son and have absolutely no experiance with 337's or any other airplanes, for that matter. Unfortunately the insurance industry takes airplanes like the P337's and rates them as cabin class twins. Cabin class twin you say? Yes, they don't know where to put the airplane because it's in a class of it's own. The biggest thing over the years that has hurt the Skymaster is the mechanics working on them. They didn't understand them and couldn't seem to make as much money on them as the 310, because the engines are not as accessable. It took longer to perform maintenence because it was a little more crowded in the engine compartments. Working on the Skymaster is like working on two single engine airplanes. In stead of modifying themselves to the airplane and charging accordingly they got mad at the airplane and began to bad mouth it and provide punative billings to the customers. At the same time Piper had this new airplane called the Seneca. It had the same engines as the Skymaster but it was a real twin because it had the engines on the wings and it was cheeper. Wow! Down went the Skymaster sales from 500 units a year to 250 to oblivion. Go fly a Skymaster and then fly a Seneca, you won't like the Seneca. Remember also that the Skymaster comes in three flavors. Normally aspired, turbo and Pressurized turbo. They all look the same but they are distictively different animals. As far as them being unsafe: Later in life as I began to fly jets I came across an ex air force pilot that knew I had a Skymaster. He began to tell me about the Skymaster that he had to fly in Vietnam for a year. Oh boy, I figured he would have hated the airplane, NOT SO! He started out, "I flew KC 135's then was assigned the Skymaster for close air support for the year. I flew that airplae 800 hrs of combat, heavy aerobatics, we loaded that airplane with rockets, bombs and every kind of ordenance that we could think of and always came home. Guys were even shot by ground fire in the Skymaster and always came home". Remember those 700 Skymasters that were built for the Air Force were not beefed up. They were the same airframes that went into the civilian market. Absent spinners, with bug eye doors for observation, they were the same. Should you get a Skymaster? Yes. But only if you find the right person to maintain it, the right person to teach you the airplane, or it will bite you, and only if you want to fly an airplane that has the roll rate of a fighter jet and will get you into and out of places that you would never think of in another aircraft. This airplane cannot be compared to anything else it is unique and in a catagory all of its own.
Paul Sharp added
Actually, I believe it is correct that there were some changes to the airframe on the Air Force versions, the O2's or O2A's as they are known. The guy that does the airshow aerobatics routine with a former O2 model said that, as near as I can remember, the wing roots and gear were beefed up and that he definitely recommended that you not do rolls in the normal Skymasters. Of course, I don't think we normal owners would consider it anyway since the airplanes are not approved for such maneuvers, etc. (I suspect that the non-Air Force model frames could handle rolls, but am not interested in finding out.) It is true that the airframes are very strong, nevertheless; I believe they are much stronger than most other models of aircraft.
Bob McGrath added
Your English is very good. In fact, it is better than the English of some native English speakers that post things here from time-to-time! As a pilot for 43 years, a Skymaster owner for almost 13 years and an A&P mechanic with Inspection Authorization, I can recommend a Skymaster very strongly with a couple of reservations. First, it is absolutely necessary to find a mechanic who knows, or is willing to learn, the airplane. Second, it is necessary to allow this mechanic to do what needs to be done without "cutting corners". If you cannot do some of the maintenance yourself it could be very expensive to own a Skymaster. But it is a wonderful airplane and should serve your purposes well. You might also want to consider a 336 which will not cost you much in performance and will eliminate any potential problems with the gear and will be lighter. Finally, my observation over my many years of flying and fixing is that airplanes do not kill people; pilots kill people. The vast majority of Skymaster accidents with which I am familiar were not the result of problems inherent in the airplane but, rather, deficiencies in pilot technique. Good luck!!
Michael Zinn replied
Some general advice. I've had a 1979 P337 for 10 years, and at purchase I had Jack Riley to a partial conversion to include intercoolers. I have my own maintenance crew and FBO shop, so take that into consideration. I've had long periods of reliability, and long periods of constant annoying squawks. The plane I bought sat for a long time prior to my purchase, but had only 300 hours in 1989. I think reliability is a function of prior maintenance. If you can get a P337 up to snuff, its really no different than any other complicated plane in terms of reliability. Maintenance cost is another matter. Because so much stuff is packed in so small a package it takes more labor to do almost anything. More labor means more down time, depending on the job. I just put two factory remans on and zero timed both front and rear everything. Sorry, I'm keeping it. My one complaint is lack of air conditioning. Ventilation is not the greatest in hot weather, but if unpressurized you can open a window for a quick air change. Venting is better when unpressurized. I'm presently reseaching retrofit of airconditioning, and am planning installation pursuant to an FAA 8110 DER this spring. If this works, I'll keep the board informed. There might be many others interested in putting air in their 337's. Pressurization is great. I use it almost all the time (except for blazing hot weather). That's why I'm putting air in, so I can fly pressurized all the time. High altitude and pressurization don't affect TBO, just baby the engines on climb. The Riley intercoolers have served me well. I have no basis for comparison. I've flown for years with two adults, a teenager, two big german shepards, and luggage. A little cramped, but the plane is so easy and comfortable to fly that I wouldn't trade it in, even for a new Seneca. (I looked).