Gear Retraction on Take Off

[aldoradave]

Going through the familiarization with the (new to me) N84E and I am now compiling my own check lists, both normal and emergency. Ernie Marin helped a lot with his "generic" list but I am still going to have a lot of questions!

First one is the issue of gear retraction in the case of an engine out right after take off. I am well award of the extreme drag of the gear doors in transit and the reluctance to use them in such a situation.

But N84E has the gear door mod from RT Aerospace and my guess is that it is much less of an issue. It may be that gear retraction should be one of the first acts if airborne. The book on my 73 P337 says it is the last thing.

Your comments are appreciated.

Dave Dillehay

[Ernie Martin]

My gut feeling is that you are right, put the gear up, but I haven't given the matter enough study to comment (even though my first 337 had the mod). Hopefully, others will. Ray Torres, the brilliant engineer (and FAA DEA) who invented these mods, is often reluctant to post on this Board for fear that others may think that he's pushing his products. Perhaps he'll make an exception here and offer his views.

Ernie

[Skymaster337B]

Even with a gear mod the wheels turn flat face into the wind...and must increase drag? Unless there's an owners manual suppliment that says otherwise? As part of the STC there's usually a suppliment that is mandatory to add into the owner's manual. If this STC dosn't have a suppliment then you must, by law, follow the owner's manual which says keep the gear down.

[tropical]

Also consider when the nose gear doors open the drag created along with the nose wheel turning sideways as it retracts.

There is really no need to rapidly retract the gear. Follow the manufacturers recommended guidelines.

[billsheila]

My 1965 has somewhat unclear instructions on this point in the POH or rather "Owners Manual". However when you put all the pieces together, I think the better approach is to leave the gear down until well clear of obstacles or establish a SOP (which I have done) of 1000' AGL before gear movement. Some things to consider:

1) I only have a pump on the front engine, so if I lost the front engine or the pump on the front engine on take-off, gear transit will be slow and manual, not a good time to be trying to pump a handle.
2) The transit time on a skymaster gear overall is pretty long -- there is lots happening down there -- something like 12 to 15 seconds. Again, if you lose climb ability or begin to descend at this moment, these seconds could be very critical and seem very long.
3) The airplane will still climb (not swiftly but still upward motion) with the gear fully extended and operating on one engine.
4) Not always, but generally, things have a greater chance of going wrong when you change something. Said another way, if you are climbing which is the most important thing to have happen right after take-off, don't change anything until you gain a comforting altitude.

When I consider all of the above, my SOP is simply to do nothing but climb (ie no configuration changes) until I reach 1000' AGL. Then I can move flaps (which carries some risk in the skymaster...see other threads re risk of flap cable breakage) and move the gear, and adjust throttles and pitch for cruise climb. In the event something does go wrong before 1000' is reached, then the decision making can proceed from there depending on what has happened.

It drives most twin pilots nuts to see the gear handle not get touched for so long after take-off (in fact many re-current instructors or safety pilots I fly with from time to time often query me on what I am doing, or not doing!!) but I remain convinced the above approach, in a skymaster anyway, is the right one.

[rhurt]

Last month I took off into 300 overcast and did not like the attitude changes from retracting the gear in the clouds on climbout. It was another distraction at a critical time. On the return flight that day, the ceiling was 500 overcast and it felt much better to have the gear retraction done before going IMC.

Obviously I'm willing to accept the risk of losing an engine in IMC on a low ceiling day, and I'm betting the pilot (me) will fail before the engine will while the gear is in transition.

[Mark Hislop]

Why not experiment both ways and see how much reduction in performance you get? Climb up to a safe altitude and level off. Then set one engine to "zero thrust" just like you would do when you are simulating engine out scenarios. Then try climbing with the gear down and locked, and with the gear in transit. It's a safe way to find out, and then you'll know for sure.

Mark