When do you retract flaps after take-off?

[Bob_Belville]

12 minutes ago, 201er said:

Looks like the left one stopped but the right one is still going. I don't like tapping the brakes because I inadvertently end up tapping the rudders too and don't like distractions down low.  There's no brake on the nose wheel so everyone has that one spinning regardless.

I was watching the right one, didn't notice that the left had stopped. I really don't think it is important and I do not "feel" any inertia in the JBar. 

The next time you have your plane up on jacks you might check to see if the left one won't coast as far as the right when you spin it by hand. One of our A&Ps may correct me, but I think Lynn trained me to adjust the axle nut so that the wheel would only coast about one revolution when spun by hand.

[N6758N]

12 minutes ago, Bob_Belville said:

The next time you have your plane up on jacks you might check to see if the left one won't coast as far as the right when you spin it by hand. One of our A&Ps may correct me, but I think Lynn trained me to adjust the axle nut so that the wheel would only coast about one revolution when spun by hand.

I would say that might be a little tight Bob. The general rule of thumb is to snug the axle nut and then back off the nut until you've reached  the cotter pin hole. You might only get one revolution out of a freshly packed bearing full of grease, but too tight will cause premature bearing failure, too loose will cause play in the wheel and a potential shimmy. 

[Alan Fox]

When I cant figure why my plane is still in the white at cruise power ......  Then I raise the flaps....

[N201MKTurbo]

16 minutes ago, Alan Fox said:

When I cant figure why my plane is still in the white at cruise power ......  Then I raise the flaps....

And retract the gear....

[jetdriven]

Or if it's only indicating 150 MPH instead of 175....

[M20F]

20 hours ago, bonal said:

Until you wait too long and can be a bit difficult to get them stored especially if your not that strong.

If you are below flap speed they go up no problem.  I see guys slamming the gear up at times 5’ off the runway.  I don’t think Clarence or me are advocating waiting till 5000’.   This is one of those common sense things where slowing down a bit probably does more for you.  

[Brian Scranton]

I'm flaps up at 500' AGL...every time. Boost pump off, landing light off and prop back to 2550 as well. That's my 500' checklist. 

[Mooneymite]

1 minute ago, Brian Scranton said:

That's my 500' checklist. 

By 500' I probably just figured out I forgot to turn my boost pump on.

I definitely need a co-pilot!  

[Gone]

16 hours ago, gsxrpilot said:

Yep, I'm with you Bob. But to me, even more important than running off the end of the runway, is having the most altitude possible when I'm out of useable runway. I know my Mooney climbs much better with the gear tucked up rather than with it hanging out. So the quicker I can get it put away, the quicker and higher I can climb. Altitude is safety and the more I can get quicker, the safer I am.

That is me too.  Gear up (less than 2 seconds on a manual J bar) as soon as establishing positive rate and runway no longer a factor.  

Flaps up when I am no longer worried about where to put it down if the engine quits (normally 1000' AGL).

 

[steingar]

I really don't like the idea of climbing below flap speed, especially because, like I said, its really easily blown through.  So flap retraction is part of the takeoff drill.

[Hank]

It's simple for me:  once I'm sure I'm climbing, gear up! Around 20-50'agl or so, I'm moving that switch.

Flaps don't usually need to be raised, as I don't usually use them for takeoff. When I'm heavy or have less than 3000' to an obstacle, i deliberately add Takeoff flaps and raise them when I'm above the obstacle. Hold that toggle up til they don't move any more. If the climb isn't so hot, I'll take them out in steps. But not normally a concern of mine.

I leave WOT /2700 to whatever my desired altitude is, whether it's pattern work at 1200 msl or a 500 nm trip at 10,000 msl.

[kpaul]

@Bob_Belville Stepping on the brakes is recommended to stop precession torque.  A spinning wheel when tipped creates a significant amount of torque which stresses the retract mechanism.  It is a checklist step in every aircraft I have flown that has gear the retracts perpendicular to the direction of roll.

[Alan Fox]

9 hours ago, kpaul said:

@Bob_Belville Stepping on the brakes is recommended to stop precession torque.  A spinning wheel when tipped creates a significant amount of torque which stresses the retract mechanism.  It is a checklist step in every aircraft I have flown that has gear the retracts perpendicular to the direction of roll.

If you think that the gyroscopic force of a 12 lb wheel , puts any "real" stress on a system that can sustain the full weight of the aircraft , bouncing on it , you are misguided.... And I say that respectfully , 

[kpaul]

Just now, Alan Fox said:

If you think that the gyroscopic force of a 12 lb wheel , puts any "real" stress on a system that can sustain the full weight of the aircraft , bouncing on it , you are misguided.... And I say that respectfully , 

Trust me in the fact that I am not misguided.  if you were to hold a bicycle wheel/tire <2lbs at the hub and have someone spin it to our take off speed and then rotate it 90 degrees, it would rip itself from your hands.  Spinning objects changing planes have significant torque, hence the reason the engineers include it in checklists to step on the brakes prior to retraction.

[jetdriven]

But it's not on the checklist for this airplane type and there's no documented evidence of any harm to the airplane for it.  I'm not a fan of adding more procedures to prevent something that doesn't happen. 

Edited October 17, 2017 by jetdriven

[MIm20c]

56 minutes ago, kpaul said:

Trust me in the fact that I am not misguided.  if you were to hold a bicycle wheel/tire <2lbs at the hub and have someone spin it to our take off speed and then rotate it 90 degrees, it would rip itself from your hands.  Spinning objects changing planes have significant torque, hence the reason the engineers include it in checklists to step on the brakes prior to retraction.

Probably just one of many reasons why aircraft wheels/tires are small diameter units. 

[MIm20c]

1 hour ago, Alan Fox said:

If you think that the gyroscopic force of a 12 lb wheel , puts any "real" stress on a system that can sustain the full weight of the aircraft , bouncing on it , you are misguided.... And I say that respectfully , 

I don’t bounce it...

 

 

...on every single landing. Just those where bystanders, controllers, or passengers are watching. 

[Skates97]

1 hour ago, jetdriven said:

But it's not on the checklist for this airplane type and there's no documented evidence of any harm to the airplane for it.  I'm not a fan of adding more procedures to prevent something that doesn't happen. 

It is step one in the POH for retracting the gear after take off in my plane. 

[Bob - S50]

13 hours ago, kpaul said:

@Bob_Belville Stepping on the brakes is recommended to stop precession torque.  A spinning wheel when tipped creates a significant amount of torque which stresses the retract mechanism.  It is a checklist step in every aircraft I have flown that has gear the retracts perpendicular to the direction of roll.

While it's not a bad idea, it's not in the POH for my J.  It wasn't in the operations manual for the T37, T38, T33, F106, F15, 727, DC9, 757 or 767 either.

[Marauder]

Finally a topic other than ROP versus LOP, flaps up versus flaps down or skinny women versus fat women. Refreshing to say the least. And, oh, I am a brake stomper - guilty as charged. 

[PMcClure]

14 hours ago, kpaul said:

@Bob_Belville Stepping on the brakes is recommended to stop precession torque.  A spinning wheel when tipped creates a significant amount of torque which stresses the retract mechanism.  It is a checklist step in every aircraft I have flown that has gear the retracts perpendicular to the direction of roll.

But, only when turned against the spinning axis. The rational plane of the Mooney nose gear doesn't change much if any in retract. Not like turning a bicycle wheel 90 degrees. In fact the spinning wheel will help maintain alignment in the plane. 

 

PS  - gear up once I have positive rate, then flaps. 

[kpaul]

44 minutes ago, PMcClure said:

But, only when turned against the spinning axis. The rational plane of the Mooney nose gear doesn't change much if any in retract. Not like turning a bicycle wheel 90 degrees. In fact the spinning wheel will help maintain alignment in the plane. 

Correct - I was only talking about the mains.

[PMcClure]

21 minutes ago, kpaul said:

Correct - I was only talking about the mains.

well duh! senior moment - would be interesting to do the math on stresses. I'll put one of my engineering students to the test. 

[kpaul]

Just now, PMcClure said:

I'll put one of my engineering students to the test. 

Nice, I would not be able to do the math, but I am glad there are folks out there that can and even enjoy that kind of thing.

[Mooneymite]

1 hour ago, Bob - S50 said:

......It wasn't in the operations manual for the T37, T38, T33, F106, F15, 727, DC9, 757 or 767 either.

Because most of those planes apply brakes automaically upon gear retraction.   No need to apply pedal brakes