Questions about Skymasters

I am new to the group....very impressed so far. Checking out the 337 and P337 for the first time for a purchase. I'm a low time multi IFR pilot. Anyone out there owned both types or have knowledge of both? Is the P model a big maintenance project. @ Annual costs to maintain? Are the turbos finnicky?

[kevin]

Colin,

I have owned both. The P model has not been a big maintenance project for me. I had only one abnormal expense relating to pressurization, and that was when we discovered that my windows had been stripper damaged in painting 10 annuals and 2 owners before me. I had to replace all the windows, which was very expensive, about $15K. But that fate should not befall you. Other than that, it has been no different than any other turbocharged twin, like a Seneca for example. I have hand no maintenance expenses directly related to pressurization (as differentiated from turbocharging) in 5 years of ownership, except the windows. Labor costs in generar are perhaps 10% more because maintenance access is more difficult than a Seneca. Another way to look at it is it costs about the same as a turbocharged Cessna single, like a 210, with all the engine related expenses doubled.

The turbos have not been finnicky for me.

Kevin

[Bob Cook]

Colin

I concur with Kevin. The P has much better suited for comfort and range. IF you mission is typically 600-1000 miles range then the P starts to shine. It lets you run around on top rather than banging around below. Consequently you do pay somewhat more for turbos and maintenance. It does add to the annual costs, however, like power steering..... once you have it you would not want to go back. There is a drawback in that you do need aircondioning at times due to the pressurized air temp. Again, dependent on mission.

If you do look for a P then find one with boots. You do experience more ice or at least exposed to more ice in the northern latitudes. I question if I would ever consider a P without boots unless living in california or New mexico. It's hard to avoid.

I have a feeling that the advantage of running at higher altitudes with greater ground speeds helps to reduce the cost differencial. Kevin is the record holder for GS but two weeks ago I was running 230 knots over four hours whereas at 10k ft I would have been down to 140 knots !!!! The fact you have more options gives you an edge.

In the summertime dodging CBs "VFR" at mid teens is better than trying to find them when they are embedded.

If you catch up on the history with this board and the UNO board there are copious discusssions related to this question. The real killer is trying to find an aircraft that has been well treated and maintained. If not you can get into trouble like Kevin and unknowingly end up with additional expenses that were not planned. Low time AC is can be a real drain on your pocketbook. This stands for any aircraft not just a 337/

I am sure there are many others on the board that can assist you in labelling all the pitfalls. Do not skimp on a pre purchase regarless of the type. Find someone that knows skymasters, not your local A&P.

337's are exceptionally safe and are no more expensive to operate or maintain than any other twin. Not necessarly less but not any more. The 337 is a unique aircraft that has exceptional flying qualities including an exceptional smooth ride. Great IFR platform... When you lose an engine the good one takes you to the airport. What is the only aircraft that made it around the world nonstop..... and what did it look like ? 337 was before it's time....

hope this helps.

Bob

[WebMaster]

I think that there are some things to consider.
1. Fuel flow will be higher for a P, 27 gph vs 22-23.
2. The turbos, and controllers, require ongoing maintenance, as well as the magnetos, and sparkplugs. If you get non pressurized magnetos, you have to service them more often, as well as the plugs. Otherwise, the mags start crossfiring, and the engine runs rough, won't make power, etc.
3. Insurance will be higher, and there will be a requirement to go to RTC on an annual basis for recurrent training.

Jerry Desantis owned a non-P, then bought the P, and makes the comment that a P is a much more serious airplane.

It boils down to what do you want to do with your plane.

[Mark Hislop]

Colin:

Where are you located. I'm sure you are close to one of the members of this group who would be happy to take you for a ride. That way you could get a better idea of just what you are getting in a P or T or normally aspirated 337.

If you are any where near Aurora, Il, (ARR) I would be happy to take you up in my 73 P337.

I have owned two Seneca II's and now my 337. the maintenance costs have been just about identical. I have never had a pressurization system related expense. I have not had any more expense with the turbos or controllers. I loved my Senecas, but I get about 5-10 knots more airspeed from the 337 at the same fuel flows. (For that airspeed, I trade off baggage space and a little bit of cabin space.) The P or T models give you a great deal more flexibility on weather avoidance and flight planning. All of them are easy to fly.

Mark

[kevin]

I don't completely agree with Larry's comments about turbo maintenance. I have owned a normally aspirated and now a P337. I have also owned other turbocharged airplanes, including a T210 and T182RG.

In my experience with all of the Cessna turbocharged airplanes, the turbos and controllers do not require ongoing maintenance, *except* in that they offer an additional thing to break. So yes, once in a while I have had problems with turbochargers and controllers, but once in a while I have a problem with most everything on an airplane. My read of Larry's comment (and maybe I read it wrong) makes it sound like your mechanic will frequently be fiddling with these things to keep them going, and that has not been the case for me. Only exception is the need to lubricate the wastegates frequently (I do it at every oil change) to keep them from getting sticky. The turbochargers themselves don't require any maintenance at all, until they get damaged (FOD) or fail.

As Larry said, if you buy and install the quite inexpensive pressurized mag kit, you do not need to do any additional sparkplug or magneto maintenance. If you do not, as I have not (yet), you will need to clean and gap your sparkplugs every 100 hours OR your mags will misfire. If you do the maintenance every 100 hours on the plugs, you do not need to do any additional magneto maintenance.

Big differences between P and normal for me:

1.) P's cost a LOT more to buy.
2.) Fuel flow is higher, as Larry said. But they are 20 to 40 kts faster too. But it does not make up the difference.
3.) P's give you vastly more weather capability, for the additional cost.

All the comment about would apply to T337s interchangeably with P337s. T337s can be a bit less expensive to buy, have a much higher service ceiling (30,000 plus), and are scarce as hen's teeth to find for purchase.

Both P's and I think T's have a gas-fired heater (fire-breathing monster) to maintain, which IS an expense, as there is an AD to be complied with periodically. The normals use manifold heat for the cabin.

The only P related (not turbo related) ongoing expense I can detect are the extra time removing the floor panels every year (they are sealed, and have to be removed with a heat gun and profanity) . Someday I will have to replace the door seal I suppose, but I have been very careful not to cut it when entering and exiting, and have not had to do that yet (knock on wood).

Kevin

[WebMaster]

Since I fly NonP, my comments are based on jerry and don and he who is without a name, who have had fits, occasionally with their turbos, and the infamous gook in the controller, that comes from the oil, causing problems. Some people never have that problem, and others have it, it seems, on an ongoing basis.

Thanks you for this very prompt and informative reply. The plane sounds great - with the usual caveats. Are you guys always this helpful?

Part Two: My plane partner and I have argued long into the night about the virtues of certified known icing vs. de-icing. I don't see any P337's cert. for known ice. In fact, I haven't seen a photo of one that even has boots on the vertical stabilizers. Have any of you had any experience with this type in ice? I do not plan to fly more than 5 minutes in ice ever, but I live in Toronto and this is a BIG consideration 6 months of the year.

[WebMaster]

No skymaster is certified for FIKI (Flight Into Known Iceing). In fact, few planes are. Many planes have deicing equipment on them. There are some Skymasters that do have boots on them, mine, for instance. Apparently, with the way that the tail works, they decided that boots were not necessary on the vertical stabilizer. Now, I have flown into accumulating airframe ice, and it is a scary experience. As it should be. When we landed, we had 4 inches of ice on the front of the radar pod. That was after shedding most of it during descent.
The plane will carry a lot of ice, and continue to fly. In my most recent long trip, back from NYC, we picked up some ice on the wing, and were able to shed it using the boots. Not the same as accumulating airframe ice, just light rime ice.
You really don't want to continue to fly in accumlating ice. Last winter, a Caravan, which is certified for FIKI, crashed because it accumulated to much ice.
Bob Cook and Jerry DeSantis have P models with boots. It is good to have boots, because it gives you time to think about how bad it is, and where will you land. The alternative, no boots, means you are in a jam, as soon as it starts to form. On the www.superskyrocket.com site, there is an article about a SuperSkyrocket, and they talked about climbing through clouds, and picking up ice, and watching it melt in the sunshine. It takes a lot longer to melt off than it does to accumulate.
By the way, Bob lives someplace near you, at least part of the year, and I live in Kalamazoo, MI, and Jerry DeSantis lives in Battle Creek, about 15 miles east of me.

Yes, we are generally this helpful for anyone who asks a question.

[Bob Cook]

Colin

If you live north or RDU you are always in jeopardy of finding ice... at almost any altitude. Last friday passing ERI enroute to IAG the controller cleared me from 14 to 7k at "pilot's discrestion". Interesting the controller's always seem to try and tell you something. When I acknowleged ,he then indicated there was reported icing between 9k and 3k. You could see it coming up to the lake. Surface temp was 0 deg. C and winds were 240 at 24 gusting 30 ( southerly flow). You knew that there was going to be ice. You would NEVER consider doing this decent flight with the forcast without boots. It is interesting that very few pilots report icing as it spoils it for other aircraft travelling the same route. Also interesting that the controllers "hint" but never seem to come out and "declare" icing unless a pilot has reported moderate or greater. This case it was moderate. Hmmmmm....

Although the 337 is not certified with known ice, there is no question any aircraft needs to monitor the situation very closely and know beforehand there is a way out. Freezing rain or percip is no option. I hand fly in ice and i haven't found the tail is accumulating any more ice than the rest of the AC. The trim position seems to hold it's position. You do notice a reduction in airspeed and you definately know when the alternate air door opens! The mp takes a big bump .... downward.

With a turbo you have a real good chance of climbing out of it without getting into trouble. Just keep the climb angle reduced when ice is encountered so it doesn't build up other than the leading edge. At night there is very little room to dodge ice especially when you are transitioning a cold front. I have seen it at -10 to -15 deg OAT.

Word to the wise.... make sure you hand fly it in ice and soon as you see that you need more forward trim then it is time to find a route out ... quickly. BTW The hot plate works extremely well.

I have clear ice on a couple of occasions but it never lasted more that a few seconds... luckily.

If you live in Toronto you will need boots if you intend to fly IFR... with any form of reliability.

Larry -- re turbo gunk

I have never experienced any form of turbo gunk. They are extremely reliable. I did go pressurized mag mod to get rid of the pre-ignition problems. They are gone as well. Leaning the engines and changing oil every 30 hrs seems to avoid the problem so far. Having the furnace (janitrol) is more maintenance but it also appears to be very reliable so far.

As far as fuel flow I burn 26 gph at cruise and 30 on the climbs... no doubt more than normally aspirated.

bob

Thanks, Bob and Larry. Bob has just described a typical winter arrival into CYYZ perfectly. What rate of climb will a booted P337
give you?

[Mark Hislop]

Colin:

I normally climb at about 120 mph indicated. This speed keeps the nose down low enough to see over it, and gives plenty of cooling. At these speeds, with full fuel and two or three people, I get 750 to 900 fpm, depending on the outside temps. The plane will climb faster, but the nose is so high you can't see other traffic.

Mark