Takeoff Flap Setting - zero degrees?

[joepilotmooney]

Folks! I've been taking off with no flaps for some time now, thinking, let's save important parts from wearing out .  I am wondering though, I will have a few mor knots at liftoff speed, which might put even more overall force on the airframe? Maybe this all sounds silly, but!! What' the group think on this?

[Nico1]

Wear is likely negligible. More important to make sure rigged and lubed regularly. And not over-speed of course.

Also, you are worsening your safety margin in case of an engine failure on takeoff. Because kinetic energy is proportional to V squared, a 10 percent increase in speed results in roughly a 21 percent increase in impact energy. Could be the difference between walking away from an accident or not. Thats one reason why cirrus recommends pulling the chute rather than landing in a field since it has slightly higher approach speed (from a cirrus expert on a podcast I heard a while ago).

Building it as a habit can be problematic in cases you are taking off from short runways or higher DA.

Don't think the cost/benefit calculation passes on this one for me.

[bradcarr]

so far I've been all zero flaps takeoffs.  

[Slick Nick]

First of all, worrying about speed putting “stress” on a Mooney is a little strange. That’s what they’re built for!

Second, you do lose some takeoff performance with flaps up vs at T/O. Normally you’d retract them around 400’ anyway and accelerate to cruise climb airspeed. I can’t think of a good reason to leave them up for takeoff. “Wear and tear” on a flap motor seems silly. Might as well just leave the gear down too.

[N201MKTurbo]

I have been doing no flap takeoffs for 30 years. I use them for short and soft field takeoffs. The amount of additional runway needed is negligible. It takes off a lot smoother with zero flaps. The only way you know you have left the ground is it gets smoother.

[oisiaa]

What speed to you rotate at with no flap vs takeoff flaps? I rotate my C at 60 knots with flaps and would probably go for 65 no-flap unless someone else has a different idea.

Edited Monday at 10:14 PM by oisiaa

[Hank]

5 minutes ago, oisiaa said:

What speed to you rotate at with no flap vs takeoff flaps? I rotate my C at 60 knots with flaps and would probably go for 65 no-flap unless someone else has a different idea.

The Owners Manual for my C says to pull on the yoke at 65-75 mph, so I usually do so at 70 mph, no flaps.

Most of my takeoffs are no flaps, but when loaded near gross I use Takeoff Flaps and pull back at the same speed.

[Note:  60 knots = 69 mph, so functionally the same.]

I may have used Takeoff Flaps departing a 2000' grass strip, but I moved and don't go there anymore. 

[N201MKTurbo]

12 minutes ago, oisiaa said:

What speed to you rotate at with no flap vs takeoff flaps? I rotate my C at 60 knots with flaps and would probably go for 65 no-flap unless someone else has a different idea.

With a no flaps takeoff, I don’t rotate. It just flys off.

[Caleb]

Been testing flaps and no flaps myself. Extra ground speed makes my front tire get a little squirrelly before lift off. Does everybody have that issue, or is it just me?
And where do you set your takeoff trim? Flaps and no flaps.


Sent from my iPhone using Tapatalk

[N201MKTurbo]

25 minutes ago, Caleb said:

Been testing flaps and no flaps myself. Extra ground speed makes my front tire get a little squirrelly before lift off. Does everybody have that issue, or is it just me?
And where do you set your takeoff trim? Flaps and no flaps.


Sent from my iPhone using Tapatalk

You should trim up a bit more. On my plane, I find it works best about 1/8 inch above the top takeoff mark.

[McMooney]

I got out of the habit of using flaps during my IR training.  My then cfii framed it as, one less thing to worry about.   my guess, takeoff flaps would get me flying 20 feet sooner.  now, full flaps, that's a difference, plane is in ground effect almost as soon as you hit full throttle, don't know how i know this.

[PT20J]

On the Mooney, most of the increased lift and stall speed reduction comes from full flaps. Takeoff flaps only make a knot or two difference in stall speed. The main effect of takeoff flaps is to reduce the deck angle.

"Rotating" is really a misnomer for piston airplanes (See John Deakin's description under Takeoff Roll in the article https://avweb.com/features/pelicans-perch-86-where-are-the-eyes-part-2/)

The best way I've found to take off in a Mooney is with trim set for climb (a couple of flights will allow you to figure out where this is on your trim indicator) and hold a slight pull on the yoke against (Bob Kromer - former Mooney test pilot - suggests about 5 pounds force) and let it fly off when it's ready reducing back pressure as it lifts off for about a 7 deg nose up attitude. This will work with flaps or without flaps, but the initial trim setting will be different.

[GeeBee]

Flaps get you shorter ground rolls, but they impede the first and second segment climb. Zero flaps get you longer take off rolls but improved first and second segment climb. The problem with zero flaps on a Mooney is you may not have take off data within the manual to point to if something happens. I've rolled big airplanes to the end of the runway with minimum flaps to get improved climbs in mountainous terrain and I've rolled them with maximum takeoff flaps out across the beach and over the ocean where they were heavy for the runway length, but climb rate was not an issue. It is always a balance.

[BDPetersen]

Funny. In 60 years flying Mooneys my only no flap takeoffs were because of an oversight and I thought it felt crumby. Two pumps for me.

[joepilotmooney]

2 hours ago, BDPetersen said:

Funny. In 60 years flying Mooneys my only no flap takeoffs were because of an oversight and I thought it felt crumby. Two pumps for me.

You are right it does feel a little crumby!! I think it's a smoother takeoff with flaps. My main reason for not using flaps on takeoff is less mechanical activations, less wear and tear, even if it's only a little.

[joepilotmooney]

9 hours ago, PT20J said:

On the Mooney, most of the increased lift and stall speed reduction comes from full flaps. Takeoff flaps only make a knot or two difference in stall speed. The main effect of takeoff flaps is to reduce the deck angle.

"Rotating" is really a misnomer for piston airplanes (See John Deakin's description under Takeoff Roll in the article https://avweb.com/features/pelicans-perch-86-where-are-the-eyes-part-2/)

The best way I've found to take off in a Mooney is with trim set for climb (a couple of flights will allow you to figure out where this is on your trim indicator) and hold a slight pull on the yoke against (Bob Kromer - former Mooney test pilot - suggests about 5 pounds force) and let it fly off when it's ready reducing back pressure as it lifts off for about a 7 deg nose up attitude. This will work with flaps or without flaps, but the initial trim setting will be different.

I will try adjusting the trim for my no flap takeoffs. Don't know why I didn't think of that. My J needs a good little pull to get it off the ground.

[SKI]

I always use takeoff flaps. I just hold slight backpressure and let it fly off. Positive rate and the gear comes up. As soon as the gear is done moving, I immediately retract the flaps. I imagine anything will work and in IFR I could see how having one less thing to worry about would be helpful. I'm just a lowly VFR pilot so that flow works for me. More importantly is do the same thing every time. For me anyway flying is about repetition. I try and do the same thing at the same time so it's second nature. 

[bluehighwayflyer]

In a Mooney with electric gear, I say do it either way you want, although I generally preferred using them in my previous J, but in a manual gear Mooney takeoff flaps seems to make it easier to keep the speed down and to get the gear up after takeoff.

In my current C, two pumps usually does it.  I use a fully downward deflected aileron as my guide.  

[Hank]

1 hour ago, SKI said:

I always use takeoff flaps. I just hold slight backpressure and let it fly off. Positive rate and the gear comes up. As soon as the gear is done moving, I immediately retract the flaps.

Wow, my gear is up around treetop height, but when I use flaps, they come up when I'm looking down on the obstacle that made me use them, or if I'm just heavy, then when I feel good about initial climb.

[Will.iam]

On my gear retracts especially if no flap takeoff i apply the brakes before gear retraction as the higher ground roll will have a longer and higher speed spin that will put extra load on the gear retraction motor if it’s retracting while the wheels are still spinning. 

[Yetti]

For the mid body no flaps is the way to go.   As explained to me by a Mooney Safety Instructor.    The Mooney wing really needs some airspeed over it to make if fly.    So fly it off and gear up, then hold the plane level in ground effect for a couple of seconds.  You will feel the plane accelerate. This will get you to 100-105 MPH really quick.   Now the wing is flying start going up.   

[LANCECASPER]

12 hours ago, joepilotmooney said:

My main reason for not using flaps on takeoff is less mechanical activations, less wear and tear, even if it's only a little.

In my opinion if that's your reason it's not a good one.

If that's a good argument maybe just shutting off your engine in descent and not using it the last ten minutes of flight will save on wear and tear on your engine. On a one hour flight that's a 16.7% savings. Or just leave the airplane in the hangar  . . .  no wear and tear on anything. It will just rot out.

Most systems in our airplanes fail because they sit too much, not because they get used too much. You're the first Mooney pilot in the 33 years I've been around Mooneys to use that as an argument for not using flaps. You're over-thinking this. Whether you choose to use them is your decision, based on performance data in the POH. But I wouldn't spend any time thinking about whether using them will shorten their life - they are made to be used.

 

[Hank]

21 minutes ago, LANCECASPER said:

... just shutting off your engine in descent and not using ...

That's how the early planes worked, didn't have much of a throttle. Kill the engine and glide to a landing, all airfields were large enough to make every landing into the wind. 

Haven't seen much discussion if this strategy in almost a century . . . .

[Andy95W]

7 hours ago, joepilotmooney said:

My main reason for not using flaps on takeoff is less mechanical activations, less wear and tear, even if it's only a little.

I’m not giving advice one way or the other.

From a wear and tear perspective, I look at it that maintaining the flap system is relatively inexpensive, but maintaining the landing gear is potentially VERY expensive.  Lifting off at a slower ground speed produces less wear and tear on the landing gear, especially the nose gear bushings/pivot points/ etc.  I fly from an airport that is fairly rough, so you can guess what I prefer.

[M20F]

I do full flap take offs so I can comply with 14 CFR § 91.117(a)