337 or 337p

JamesC · #1 06-28-17, 12:13 PM

Hi Greg. The P337 pressurization is very easy to operate, but these birds get leaky with time, especially if they have had some damage like this one. I would take it for a test flight and among other things see what the pressurization diff is at altitude. The bird doesn't have to be perfect but you would still like to have no wing drop in the power off stall (take your instructor) and see if she flies straight and level hands off. Turbo management is obviously critical and takes more planning ahead. Also you have to see how much your insurance is going to be and even if you can get it depending on eg. how many hours retractable time etc. you have. One more thing – this model is actually a T337G (ie not a P337 even though its serial number begins with P) so the Flint tip wing spar AD could be an issue. There are some great bargains out there but be careful. My first Skymaster seemed like an awesome deal but had plenty of costly hidden nightmares. My mechanic did an import last year for a new Skymaster owner and things were so bad he would not could not see ever signing it off as airworthy. The owner had to get a special flight permit and took it to another shop for lengthy repairs – I don’t think it is flying yet.
Take your time!
Jim

fsnewton · #2 06-28-17, 12:32 PM

Jim,

As a point of comparison, what were the maintenance gotchas you had with your first Skymaster? For me, I right off the bat had a bad fuel sender, some prop governor work and getting the cabin psi to 3.35 (work in progress). But since the annual in December, all systems have been working great and the engines (about 700 SMOH) have been flawless (knock on wood).

Scott

JamesC · #3 06-28-17, 01:57 PM

Same as you plus DG issues (installed an Aspen PFD), hidden hydraulic system corrosion, needed pressure controller overhaul, had turbo failure in flight, diode board issues, belly drain issues and water getting in the belly. Plus a bunch of other stuff, all fixed for $$$ - my wife was really impressed.

Jerry De Santis · #4 06-30-17, 08:29 PM

Hi, I own N34EC, a 1975 P337G unit. This is my second Skymaster having owned a 1971F unit earlier. I purchased N34EC in 1997....20 years now. My yearly annual runs between $2300 and $3500 depending on extra things I want done. If you plan to fly high, I highly recommend the P unit. The 1975 model has a 150 gallon total fuel capacity (148 gallon useful). Three tanks in each wing and unless you want to cross feed, you don't have to switch tanks. My plane is equipped with spoilers so I don't worry about shock cooling engines to make quick alt. Changes. In fact, i don't even change throttle or MP when using spoilers. I also have A/C and highly recommended for the P model. Can get warm in cabin. One factor you should be aware of, I generally burn 25 to 27 gallons per hour with the rear engine using about 1 o 1.5 gallons more per hour. I am a believer of operating rich of peak so engines stay cool. About cylinder head temperatures in the range of 340 to 375 degrees. Exhaust temp. In range of 1100 to 1350 with the higher temps in the rear engine. N34EC is equipped with TSIO 360 CB engines. Have any other questions on the P unit feel free to send me an e-mail.

Good luck on your choice!

Cheers
Jerry

LostKiwi · #5 07-04-17, 10:51 PM

I agonized over the same thing. Once I'd decided I needed a Skymaster, I really did go back and forth over buying a P model, and ended up buying a Normally aspirated 337G.

My reasoning was much the same as yours, I live in the rockies, and for me to go anywhere requires some serious altitude. Having the second stove when flying over tiger country gives me a warm fuzzy feeling.

Happy to report that the NA Skymaster has no real problems with that mission. Climbs like a missile if you want it to, and it'll hold a 500 ft/min cruise climb all the way up to 12,000 ft. Goes in and out of short strips, big, roomy, comfortable cabin for us "husky" gentlemen, and it has more useful load than you can shake a stick at. Absolutely the right airplane for the job.

It does hurt seeing the P model boys up at 17 or 18k with 250 knt ground speeds though - I want a piece of that! Maybe my next airplane......

Leighton.

Jerry De Santis · #6 07-05-17, 10:30 AM

Something to keep in mind when over the mountains, by book values, the P unit will hold 18,500 feet alt on either engine should you experience an engine out. The NA unit will hold about 5,500 feet on the front engine and 7,500 feet on rear engine. Those values were taken from the 1971 F unit. This is why I chose the P unit years ago.