Flap Retract on Takeoff

[moontownMooney]

For folks that have the manual/hydraulic pump flaps, I'm curious what speed you retract your flaps on take-off. We used to wait until reaching Vx (94 mph) because retracting at lower speeds seems to cause a breif drop (or perhaps it is just a pitch up that feels like a drop?). However, it does seem like the plane accelerates (to get to Vx or Vy as quickly as possible) much more quickly if you get the flaps up sooner. We just noticed (not sure how we'd missed it before) that the manual prescribes retracting between 80-90mph. Is this where most folks actually retract? Is there a noticable pitch or drop for you?

 

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[ShuRugal]

If there's no obstacle to worry about, I retract at the top of white arc. If there is an obstacle, or if there are no good landing spots dead ahead, I climb with takeoff flaps at 100 MIAS to pattern altitude, then retract them and accelerate further.

[Jim Peace]

Whatever it takes:

 

[carusoam]

Moontown,

Keep in mind the speed that your flaps move is adjustable...

If they retract too quickly you might fall out of the sky when they dump all the lift...

Every Mooney also has a flap speed... to not exceed.

If you exceed that speed with the flaps down...

Fixing the cracks in sub spars has expenses related to it... 

Unlike a C152, you don’t get a free 15° of flap to work with...

If you notice the loss of lift, your flaps are probably moving too quickly...

If you are wiggling the flap valve trying to modulate the flap movement... they are set too fast...  they should be moving slowly counting the seconds... you won’t be able to sense the change in lift over that amount of time...

Unless your butt is extra sensitive... 

PP thoughts only, not a mechanic...

Best regards,

-a-

[ShuRugal]

My butt must be extra sensitive. I don't notice any loss of lift, but I do feel the pitch try to change. I can usually control it with extra yoke pressure so that my passenger doesn't notice, though.

[MooneyMitch]

Just now, ShuRugal said:

My butt must be extra sensitive. I don't notice any loss of lift, but I do feel the pitch try to change. I can usually control it with extra yoke pressure so that my passenger doesn't notice, though.

Smooth yoke adjustments in conjunction with smooth trim wheel adjustments too...... it’s all about smoothness and precision...... precision will result in smoothness.  

[Hank]

31 minutes ago, ShuRugal said:

My butt must be extra sensitive. I don't notice any loss of lift, but I do feel the pitch try to change. I can usually control it with extra yoke pressure so that my passenger doesn't notice, though.

The pitch does change as the flaps move--nose up as flaps go down, nose down as flaps go up. I just don't use Takeoff Flaps very often for taking off, but I do frequently land with them!  

[carusoam]

With electric trim and flaps... they operate at the same slow speed...

And the trim cancels out the movement of the center of lift as the flaps change...

 

So... with the manual system... trim and flap adjust at the same time as if you are the Long Body motors...
 

the slower the flap retract, the better off you will be...

For the OP... you have a checklist after departure... probably includes brakes, gear, flaps and fuel pump...

For practical purposes...

1) brakes are optional...

2) gear as quick as practical... after verify positive rate...

3) wait until you are 1k’ above the ground climbing at Vy to turn off the Fuel pump, and put flaps away... note this altitude... it is not how fast you are going... it is how high above the ground you are....

Changing configuration close to the Ground for any reason, just because I hit a speed... would be bad form... 

4) then accelerate to 120 for cooling climb at speed...
 

There is a X-Mooney engineer that teaches this set of details... getting away from the ground is what it is all about... safely and quickly...

PP thoughts only, not a CFI...
 

Best regards,

-a-

[MooneyMitch]

9 minutes ago, carusoam said:

With electric trim and flaps... they operate at the same slow speed...

And the trim cancels out the movement of the center of lift as the flaps change...

 

So... with the manual system... trim and flap adjust at the same time as if you are the Long Body motors...
 

the slower the flap retract, the better off you will be...

For the OP... you have a checklist after departure... probably includes brakes, gear, flaps and fuel pump...

For practical purposes...

1) brakes are optional...

2) gear as quick as practical... after verify positive rate...

3) wait until you are 1k’ above the ground climbing at Vy to turn off the Fuel pump, and put flaps away...

4) then accelerate to 120 for cooling climb at speed...
 

There is a X-Mooney engineer that teaches this set of details... getting away from the ground is what it is all about... safely and quickly...

PP thoughts only, not a CFI...
 

Best regards,

-a-

Gear up as quick as practicle....... man, my instructor would gasp out loud!

She says keep gear out till you’re out of runway, in the event of a possible return trip the the runway with an engine out ....one less thing to think about/perform in a rapidly deteriorating situation.

I’m trying this new to me method as I’ve always been a quick retractor ! 

Oh yes, I’m trying the offset departure too..... I can be retrained, I think....

[carusoam]

In the event you put the gear away, and then change your mind...

Put it back down...  quickly if needed.

Its a Manual Mooney.... not one of those ancient hydraulic disaster machines... 
 

Same for electric gear Mooneys... it happens so fast.

I still hit the brakes whether it is needed or not... inertia, rubbing, good feeling, whatever...

Best regards,

-a-

[MooneyMitch]

1 minute ago, carusoam said:

In the event you put the gear away, and then change your mind...

Put it back down...  quickly if needed.

Its a Manual Mooney.... not one of those ancient hydraulic disaster machines... 
 

Same for electric gear Mooneys... it happens so fast.

I still hit the brakes whether it is needed or not... inertia, rubbing, good feeling, whatever...

Best regards,

-a-

I do all that when taking off, unless she’s watching me out of her hangar door...

It IS hard to teach an old doggie new tricks ....

[Ragsf15e]

I put the gear up quick too!  If I blow an engine and land straight ahead, I may get it back down, maybe not.  If not, at least I’ll stop fast!  I want to get airspeed and altitude quickly after takeoff to increase options. 
 

To the OP, I have hydraulic flaps too.  My technique is to retract them at 100mph.  I feel the “settle” slower than that a bit uncomfortable.

[MooneyMitch]

2 minutes ago, Ragsf15e said:

I put the gear up quick too!  If I blow an engine and land straight ahead, I may get it back down, maybe not.  If not, at least I’ll stop fast!  I want to get airspeed and altitude quickly after takeoff to increase options. 
 

To the OP, I have hydraulic flaps too.  My technique is to retract them at 100mph.  I feel the “settle” slower than that a bit uncomfortable.

Oh yes indeedie it stops super fast........ ask me..... no, never mind.......don’t ask me how I know ! 

[Hank]

46 minutes ago, carusoam said:

With electric trim and flaps... they operate at the same slow speed...

And the trim cancels out the movement of the center of lift as the flaps change...

So... with the manual system... trim and flap adjust at the same time as if you are the Long Body motors...

Anthony, you've been spoiled by your R! The hydraulic Mooneys, just like my electric C, use the pilot's right hand up by the throttle to retract flaps, and the pilot's right hand down on the floor to spin the trim wheel. I can't, and have never heard any pilot without electric trim buttons on the yoke claim to move flaps and trim at the same time!

As for raising the gear, I make sure I'm in control, verify positive rate (thank you, IVSI!) and raise the gear. They're usually stowed by treetop level. If needed, they come down in about 2 seconds. My Flight Review CFI this year was shocked by how quickly they move. See the photo for my typical departure, but realize the photographer was looking up at me so I'm not really above the trees as it appears. 

[ShuRugal]

 

 

 

 

My Flight Review CFI this year was shocked by how quickly they move.

 

Always fun to introduce a seasoned GA pilot to a Mooney. "You put your gear up too... Oh, they're back out again? And there they go away again. Right, I get the picture."

 

 

 

[carusoam]

@Hank,

Nice documented truth..!  

Thanks for sharing that...

 

I have to go back and do some reading...

raising flaps will definitely try to raise the nose

 

What is your flap Vfe?

They are making the point in an interesting way...

• Any slower, we risk stall under various added conditions...
• Any faster, we risk exceeding Vfe...
• Doing it above 1k’ adds room for recovery, gives extra time, and coincides with fuel pump off...

Nothing like flying around with flaps extended, fuel pump running, and staring at the J-bar in the wrong place... 

Best regards,

-a-

 

[RLCarter]

13 minutes ago, Hank said:

They're usually stowed by treetop level. If needed, they come down in about 2 seconds. My Flight Review CFI this year was shocked by how quickly they move. 

When me and the IA did my 1st annual, he had me retract the gear wile he was watching from a creeper. He yelled retract them and I did, then he was standing at the storm window laughing and said "can you go slower so can see if anything binds?). H e was like a kid, had me raise and lower the gear a bunch just so he could see how fast it was

[ShuRugal]

When me and the IA did my 1st annual, he had me retract the gear wile he was watching from a creeper. He yelled retract them and I did, then he was standing at the storm window laughing and said "can you go slower so can see if anything binds?). H e was like a kid, had me raise and lower the gear a bunch just so he could see how fast it was

My IA has me unlock them and put the bar in the middle of the travel, then moves them himself to check for anything binding at each wheel. Then concludes with one slow as I can move it retract, and one equally see extension.

[McMooney]

3 hours ago, moontownMooney said:

 

For folks that have the manual/hydraulic pump flaps, I'm curious what speed you retract your flaps on take-off. We used to wait until reaching Vx (94 mph) because retracting at lower speeds seems to cause a breif drop (or perhaps it is just a pitch up that feels like a drop?). However, it does seem like the plane accelerates (to get to Vx or Vy as quickly as possible) much more quickly if you get the flaps up sooner. We just noticed (not sure how we'd missed it before) that the manual prescribes retracting between 80-90mph. Is this where most folks actually retract? Is there a noticable pitch or drop for you?

 

Sent from my LM-V405 using Tapatalk

 

 

 

I don't bother to use the flaps on takeoff, figure a few extra feet of runway vs worrying about flaps while taking off is a fair trade.

[RLCarter]

10 minutes ago, ShuRugal said:

My IA has me unlock them and put the bar in the middle of the travel, then moves them himself to check for anything binding at each wheel. Then concludes with one slow as I can move it retract, and one equally see extension.

That's how we did it as well, had 1 MLG door that was a little too tight and 1 NLG door that stuck out in the wind about an inch

[Ragsf15e]

4 minutes ago, RLCarter said:

That's how we did it as well, had 1 MLG door that was a little too tight and 1 NLG door that stuck out in the wind about an inch

Heck, that probably cost you at least half a knot!  Tell me you fixed it?!

[skydvrboy]

Unless I’m heavy or on a short field, the flaps are generally up before I start my takeoff roll.  When I do use flaps they come up after all obstacles are cleared.  And yes, I notice the change in pitch.  Until I rebuilt the flap pump, my flaps retracted in about 0.1 seconds and would certainly get your attention! (They work fine now, but the change in pitch is still noticeable.)

On landing, it depends whether I’m landing to the North or the South.  When landing to the North, my hangar is 1400’ from the threshold... full flaps so I make my turn-off.  When landing to the South, my turn-off is 11000’+ from the threshold, so flaps are optional and a long landing is requested. 

[RLCarter]

3 minutes ago, Ragsf15e said:

Heck, that probably cost you at least half a knot!  Tell me you fixed it?!

lol...you would have to meet my IA, this was his 1st Mooney he had worked on, while he doesn't have the experience that M20Doc has, he does have those same eagle eyes. So yes it was corrected before he left that day

[Ragsf15e]

56 minutes ago, Hank said:

Anthony, you've been spoiled by your R! The hydraulic Mooneys, just like my electric C, use the pilot's right hand up by the throttle to retract flaps, and the pilot's right hand down on the floor to spin the trim wheel. I can't, and have never heard any pilot without electric trim buttons on the yoke claim to move flaps and trim at the same time!

As for raising the gear, I make sure I'm in control, verify positive rate (thank you, IVSI!) and raise the gear. They're usually stowed by treetop level. If needed, they come down in about 2 seconds. My Flight Review CFI this year was shocked by how quickly they move. See the photo for my typical departure, but realize the photographer was looking up at me so I'm not really above the trees as it appears. 

I think my current retraction technique is similar.

I have to admit that when I was a young buck I got to takeoff in front of a (small) crowd once in the Mighty Strike Eagle.  Full afterburner was the norm and I planned to be at 30’ and 450kts by the end of the runway for the pull into the vertical.  I yanked it off the runway early, maybe 120kts, sucked up the gear and had that sinking feeling... apparently, 50,000lbs of thrust only goes so far.  Somehow didn’t scrape it back down (like the F-22 at Fallon a couple years ago).  When I cleaned out my shorts later, I remembered that the gear goes through significant gyrations during extension/retraction (Including turning the mains sideways) and increases drag a lot!  Oops!

[moontownMooney]

Thanks for all the good thoughts. I hadnt considered that perhaps our flaps are retracting too quickly and need adjusted. It is slower on the ground, but in the air they seem to substantially retract in a second or less and completely retract in under two seconds. What should it be? Our Vfe is 125 mph so that isn't a concern. For the folks talking about keeping flaps until 1000' and not changing configuration low... Vx and By are specifically with no flaps and I need that performance. Our home base (at least until a hangar opens up at a nearby field) is 2600' grass surrounded by 500-700' hills. This is why I care about being able to accelerate to Vx as quickly as possible. We currently derate our max gross by 200 or 300 lbs in the dead of summer to maintain reasonable safety margins.

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