When to put the gear up...

M

meritflyer

Well-Known Member
As the subject of much debate and now, a recent article in a popular flying magazine, I thought it would be appropriate to discuss this subject.

The ongoing debate amongst CFIs, corporate operators (PC-12, TBM, Meridian), and now magazines questions whether to retract at 'no more available runway' or at a positive rate.

So the question for discussion is -

Q: When do you put the gear up on a single engine airplane and why?
 
meritflyer said:
As the subject of much debate and now, a recent article in a popular flying magazine, I thought it would be appropriate to discuss this subject.

The ongoing debate amongst CFIs, corporate operators (PC-12, TBM, Meridian), and now magazines questions whether to retract at 'no more available runway' or at a positive rate.

So the question for discussion is -

Q: When do you put the gear up on a single engine airplane and why?
Click to expand...

I do it when there's little chance of landing on the remaining runway. Its not like in the fighter I used to fly where I'm accelerating so fast that I need to get the gear in the wells the second after liftoff.
 
When the student reaches cruise and wonders why we're 25 knots slower than his estimate.
 
meritflyer said:
When do you put the gear up on a single engine airplane and why?
Click to expand...

It depends on where you plan to have your next engine failure. If you plan to have it right after lift off, then you'd better leave the gear down until there is no more runway; if you plan to have it a couple of minutes later, then you'd better make it a habit to raise the gear once you get a positive rate of climb, so you'll have more altitude to play with when the engine fails.

Since we never know when the engine will actually fail, nor do we have good statistical info on this, there isn't a demonstrably correct answer.
 
Seems to me that retracting the gear at "positive rate" only really applies when the decision to continue the flight has already been made (e.g., V1). In most light aircraft, that decision point comes only when setting the aircraft back down on the runway is no longer feasible--which is when I retract the gear in such aircraft.
 
I was taught the gear goes up when you will no longer be landing on the runway after a failure. That was for both the cessna and the seminole. The first place I heard 'positive rate, gear up' was in the erj since you wouldn't go diving back at the runway after a failure on climbout.
 
MikeD said:
But you fly a multi.......

:D
Click to expand...

Wish I could say that were true, but sadly not for a few more months (stuck with the Rolls royce weed wacker for now)
IMG_1890.jpg


I guess the difference for us is that if we lose the engine on t/o, either we have the runway remaining to put it down and drop the tailhook for the long field gear, or we are ejecting (offroading in the Goshawk has been notoriously fatal for most involved) Neither of these scenarios are options for the average single engine turbine a/c....so maybe disregard my advice :) But I agree with holding it until you can't land anymore without running off the end
 
tgrayson said:
It depends on where you plan to have your next engine failure. If you plan to have it right after lift off, then you'd better leave the gear down until there is no more runway; if you plan to have it a couple of minutes later, then you'd better make it a habit to raise the gear once you get a positive rate of climb, so you'll have more altitude to play with when the engine fails.

Since we never know when the engine will actually fail, nor do we have good statistical info on this, there isn't a demonstrably correct answer.
Click to expand...

The discussions of late have dealt specifically with -

1) Raising the gear at positive rate as there simply isn't performance data to support the 'no more available runway' idea; and

2) If the engine does fail at an early point in the takeoff, which gear position is most desired to mitigate/minimize the impact of the airframe and occupants alike.

The author presented the gear, in a down position accompanied by an early engine failure, may pose a far greater control issue upon returning to the ground rather than a belly landing.
 
Positive rate.

If I end up having to return to the runway with my gear up then fine. I've got nothing but hate for a plane that just tried to kill me. It's getting the gear up treatment.
 
MikeD said:
Thought you moved up!
Click to expand...

Soon, so soon......though I still may not have afterburner if I get my #1 choice :p

As for the runway remaining argument, we have had similar discussions re: abort speed. The thinking is that as soon as you rotate, your max abort numbers go out the window as things now depend on pilot skill and technique, ie test pilot stuff. The demonstrated numbers are for a jet still on the runway using max braking/speedbrakes. If I'm at 200 ft, lose the engine and see myself passing the 5 board, I don't really know for sure how things are going to go after that. I do think there is a reasonable distance where you are familiar enough with your aircraft to know that you can get it stopped, but on shorter runways that of course can be more or a guesstimation. I'd say a bigger factor would be how well or poorly your particular aircraft does potentially offroading with gear down. As I said previously, mine does not do well, so if I had to slide off the end, I'd much rather be gear up and using the belly to slow down than digging in and cartwheeling. We've had rollovers where the pilot had to sit there (for what I would imagine would seem to be an eternity) while JP leaked into the cockpit and pooled in the canopy after the rear bulkhead broke and the centerline fuel cavity started spilling, while waiting for the crash crews to cut him out. Not my idea of a good day at least!
 
I know there is a lot of "cool" factor for the students getting into the 182R/G. They want to get the gear up now!



As roger said, it is either at the end of the runway or in cruise. :D
 
///AMG said:
Soon, so soon......though I still may not have afterburner if I get my #1 choice :p

As for the runway remaining argument, we have had similar discussions re: abort speed. The thinking is that as soon as you rotate, your max abort numbers go out the window as things now depend on pilot skill and technique, ie test pilot stuff. The demonstrated numbers are for a jet still on the runway using max braking/speedbrakes. If I'm at 200 ft, lose the engine and see myself passing the 5 board, I don't really know for sure how things are going to go after that. I do think there is a reasonable distance where you are familiar enough with your aircraft to know that you can get it stopped, but on shorter runways that of course can be more or a guesstimation. I'd say a bigger factor would be how well or poorly your particular aircraft does potentially offroading with gear down. As I said previously, mine does not do well, so if I had to slide off the end, I'd much rather be gear up and using the belly to slow down than digging in and cartwheeling. We've had rollovers where the pilot had to sit there (for what I would imagine would seem to be an eternity) while JP leaked into the cockpit and pooled in the canopy after the rear bulkhead broke and the centerline fuel cavity started spilling, while waiting for the crash crews to cut him out. Not my idea of a good day at least!
Click to expand...

It's called E-28 gear. :)

But thats why I made the differentiation between a light single, and a jet. They're different cats when it comes to what works better. And even within the light single's, there's different techniques depending on what you're end-goal is.
 
MikeD said:
It's called E-28 gear. :)

But thats why I made the differentiation between a light single, and a jet. They're different cats when it comes to what works better. And even within the light single's, there's different techniques depending on what you're end-goal is.
Click to expand...

Haha, yes that would obviously be my first kneejerk response at a mil field, though it comes into play when we are flying out of unequipped civilian fields.

Makes sense about the differentiation though....I'm going to guess here that a TBM or Meridian probably wouldn't need too much excess runway to stop if they put it back down; assuming modern brake tech would help here
 
meritflyer said:
Raising the gear at positive rate as there simply isn't performance data to support the 'no more available runway' idea; and
Click to expand...

If what you mean by performance data is that the aircraft isn't likely to be able to land in the runway remaining, there are clearly runways in which that is not true. The question is "how much time"? The shorter the runway, the less time, obviously. And the higher the density altitude, the less time.

If the engine does fail at an early point in the takeoff, which gear position is most desired to mitigate/minimize the impact of the airframe and occupants alike.
Click to expand...
Gear down, most likely. But a nice gentle landing on the runway is optimal.

The author presented the gear, in a down position accompanied by an early engine failure, may pose a far greater control issue upon returning to the ground rather than a belly landing.
Click to expand...
Perhaps. Again, I think it would depend on what short of pitch attitude has been achieved when the engine fails. High pitch, it will take a pretty aggressive push down to maintain airspeed. But I do think by this time there would be no more runway remaining anyway. Most people have a relatively shallow climb angle just after lift off and I think a straight ahead landing is doable, assuming the pilot is paying attention.
 
Long answer: Once I'm flying, the gear is useless to me. I want the drag out of the way so I can get as much altitude as quickly as possible. If the engine quits, then it goes on the belly. My main focus is staying alive if the engine goes.

Short answer: Positive rate, gear up.

Greg
 
tgrayson said:
If what you mean by performance data is that the aircraft isn't likely to be able to land in the runway remaining, there are clearly runways in which that is not true. The question is "how much time"? The shorter the runway, the less time, obviously. And the higher the density altitude, the less time.
Click to expand...

There is no published data by the manufacturer on such a situation. Anyone who attempts to argue the whole long runway vs. short runway idea in my mind, is volunteering to be a test pilot.
 
You must log in or register to reply here.
Back
Top