When to retract the gear?

[Rickskymaster]

Since I am new to the Skymaster ownership, I have heard a couple of different ideas as to when to retract the gear.
The first holds to retract as soon as positive rate of climb is established.
The second states that because of the gear doors openings etc, and the drag created, that at least 500 feet should be the point that the gear is retracted.
I have to say that I have tested both and it seems that number one wins out from my point of view.
I am very interested in what the rest of you all do as SAP, and I think this might be a potential discussion for the get together latter next year?

Rick Galvin
N48AT

[Mark Hislop]

Rick:

As far as I'm concerned, it depends on how many engines you have running. With both engines running, the drag factor is pretty much a non-event, and I put my gear up as in any other twin...when there is no chance of putting the plane back down on the runway. During single engine operation, I would never raise the gear. At gross weight, my 73 P337 will only climb 350-375 fpm on one engine with gear up (according to the book). With gear down, it will climb about 250 fpm. During transition, with the gear doors open, it will not climb.

Mark

[Don Hickman]

I agree with Mark. I raise the gear as soon as there is no chance of getting the plane back onto the runway, assuming both engines are running. If one should quit during climbout, I wouldn't raise the gear at all.

[kevin]

I had two different procedures, one for my normally aspirated '65 337 that I owned before, and one for the '73 P337 I have now.

On the '65, the gear was run by a hydralic pump on (if I remember right) the front engine. If that engine failed during the retraction cycle, and did not continue to windmill enough to keep pumping fluid, I'd be down an engine with the doors hanging out. As I recall, the single engine rate of climb on that airplane with the gear doors open (not with the gear down, with the doors open) is something like -200 fpm. Guess I should call it rate of descent. Anyway, on that airplane I waited until I had a good amount of altititude, maybe 800' or so, before I put the gear up. And pumping the gear up during an engine failure at less than 800' AGL is too much to ask of someone single pilot, or at least of this pilot.

I use to have a running argument with John Killeen at Recurrent Training Center about this. Cessna's official approved training (from RTC) says "positive rate, gear up" on all Skymasters. But I tried it both ways, and the gear being down with the doors closed has very little actual effect on climb performance. But if the gear doors stuck open, you are going to land soon.

For my '73 with the electric power pack, I use "positive rate, gear up" as my procedure, just as RTC teaches. If the electric power pack on this airplane fails at the same time as an engine, it will be a very bad day indeed...

Kevin

[Rickskymaster]

If it depends on how many engines you have running, what happens if you retract upon having positive VSI, both engines are running, gear is in transition and then engine failure.
The gear doors are open, gear is somewhere in coming up.
It would seem safer to wait until 500 or 1000 feet to retract.
I would love to hear everyone's opinior on this.

Rick

[Kevin McDole]

I'm with Rick on this. Since the gear retraction cycle is something like 13 to 18 seconds, an engine failure during retraction would result in a negative rate of climb.

I wait until I'm at least a few hundred feet up before I retract the gear. When it finishes, I then retract the flaps. At 500 feet I then do the power reduction.

I suppose there might be an argument for raising the flaps earlier - perhaps one a positive rate of climb is achieved.

Incidentally, I once had a squat switch fail in such a way that when I retracted the gear, the doors opened, but the gear did not retract. And using the gear switch, there was no way to alter this configuration. I simply stayed in the pattern and landing this way. Had an engine failure occured in this time, it might have gotten interesting.

[hharney]

WITH ALL THE CONCERNS ABOUT THE GEAR DOORS AND RETRACTION DURING AN ENGINE FAILURE THERE IS ANOTHER SOLUTION.

TAKE THE DOORS OFF. I HAVE THE RTA DOOR REMOVAL MOD AND IT IS A GREAT PEACE OF MIND. IT ALSO ELIMINATES A LOT OF SWITCHES AND ACUATORS. MY GEAR RETRACTION AND EXTENSION TIME IS MUCH QUICKER WITHOUT ALL THE EXTRAS HAPPENING.

ANYBODY ELSE HAVE THIS MOD?

I REALLY LIKE IT.

[Paul Sharp]

I retract the flaps after about 100 feet, and the gear at about 300 or 400 feet. I figure it can't hurt to have some altitude before putting them up and there's nothing I can see that you lose by waiting a little bit. Why even risk a problem if you can avoid it or better the odds?

[Bob Cook]

I don't think there is a precise rule that fits all circumstances. Generally speaking I retract when I hit 1000 ft. There is no reason to do it sooner. I prefer to get over to departure and making sure all is working smoothly. Gear is on the bottom of the "to do list". Flaps come up soon as I settle into a climb attitude.

This gives me a chance to monitor the gear retraction and insure the pump does not burn itself out.

Bob

My decision as to when to retract the gear depends on runway length and what configuration I want to be in if I have to put the airplane back down.

Coming out of typical airports in So. Florida (6000-10000ft runways) I'll hold off on the gear till I know I can't put the aircraft back on the runway.

Coming out of North Captiva which is 2000 ft with water on both ends, the gear comes up as soon as I break ground and have positive rate. If I have to go into the water, I want the gear up.

Granted I've got the gear door mod on my airplane. Back before the gear door mod I wouldn't touch the gear till I had 500 ft.

Ray Torres