What to look for in a prebuy?

[mshac]

Originally Posted by ljmolina

 CABIN PRESSURE CHECK
-Take Plane upto 17,500 ft and ISOLATE each engine and check to see if
the cabin pressure can maintain max differential pressure (3.25psi)

You don't need to go to 17.5 to verify the pressurization system. You could do it at 8.5, just be sure the differential gauge on the pressurization control panel is at max.

That said, taking the plane to 17.5 will expose bootstrapping, weak mags, and weak wastegates/turbos. Its well worth it to fly that altitude during the prebuy if at all possible! If one engine can't hold manifold pressure or starts to miss up there, you know you have an issue.

These airplanes were designed to fly high. They are both faster and more efficient the higher they go. I find 17.5 to be a "sweet spot" on a lot of trips. You're VFR, but with flight following at that altitude, you get great service from controllers, almost as if you were an IFR flight. Also, there is very little traffic at that altitude. I'll go hours without ever seeing another aircraft sometimes. My father once complained that it was "boring" flying so high because he couldn't see anything, so I flew him from Nashville to Dallas at 2500 ft - he loved every minute of it! Kept me out of a strong headwind too

[ljmolina]

Thanks for all the info... Im kinda nervous and excited as this will be my first plane I own...the skymaster has always been my childhood dream plane...and now I can afford one...I hope it goes well Monday.

Luis

[mshac]

Best wishes for Monday.

Remember, make the decision with your mind, not your heart. It can be very hard to do in these types of situations, but you will be better off.

If you do buy it, you can always get great support here.

[ljmolina]

I understand...As much it will hurt, I am willing to walk away.

[JeffAxel]

Max pressure differential on the P337 is 3.35psi. Should hold a 10000ft cabin at FL200 with either engine running. Check the flap cables, they make a sharp bend and the damage is hard to see, Cessna put out a SB on this a while back. Use every radio, autopilot and piece of avionics and make sure they all do what they are supposed to do. Make sure the pitot heat works, hard to find replacements.

[mshac]

Let us know how it went today!

[mshac]

Well did you buy it or not?

After all the help we gave you, we want to know what happened!