Flaps on take-off?

[ncdmtb]

The guy I bought my '66 M20E from is a CFI. He checked me out in the plane and I did my complex endorsement with him.

He told me, that as a rule he never used flaps on take-off and recommended I do the same. I have now almost 50hours in the airplane and followed his advice. I never really felt, that I was missing out by doing no flaps take-offs. I have only been flying on paved runways. One of the shortest runways I have taken off from was a 2.800' paved, slightly up hill, at sea level, with trees and a sloping hill on extended. (so nothi g too demanding so far) For that T/O I briefly considered setting flaps, but the decided to go w/o and had no issues.

What do others do? Advice/recommendations?

[fantom]

What do others do? Advice/recommendations?

 

Read your POH....those factory test pilots must have known something more than your CFI

[Danb]

POh and 300+ hours in Mooneys say and you should use flaps. Cfi is clueless. Sing up for a Mapa training weekend you will enjoy and get useful help from some of the best mooney drivers there is. Be safe have fun

[mike_elliott]

The guy I bought my '66 M20E from is a CFI. He checked me out in the plane and I did my complex endorsement with him.

He told me, that as a rule he never used flaps on take-off and recommended I do the same. I have now almost 50hours in the airplane and followed his advice. I never really felt, that I was missing out by doing no flaps take-offs. I have only been flying on paved runways. One of the shortest runways I have taken off from was a 2.800' paved, slightly up hill, at sea level, with trees and a sloping hill on extended. (so nothi g too demanding so far) For that T/O I briefly considered setting flaps, but the decided to go w/o and had no issues.

What do others do? Advice/recommendations?

 

 

Why extend your take off roll? Why raise your Vso speed on takeoff? If you have a good reason to do this, then don't use take off flaps. Otherwise, take advantage of the capabilities of your E and use them like the Owners manual instructs. I would be very interested in why the guy told you not to. Maybe he knows something I don't about this and I would be interested in that knowledge if so.

[Bob_Belville]

2500 pic in M20Es - I can't remember ever taking off w/o t.o. flaps per POH (15 deg,, ~2 pumps.)

 

And I almost always land with full flaps. Only exception might be on a 10,000' runway with some model Boeing in trail or fighting a 25k cross wind.

[Shadrach]

You certainly don't need flaps for take off, but you will not get the book numbers in the POH without them (good chance you won't with them either). There is absolutely no logical reason for your CFI to instruct you not to use flaps. Some pilots prefer the way the aircraft rotates sans flaps (I believe Bob Kromer is in this camp). Whatever floats your boat...

Flaps do add lift to the equation, but more importantly IMO, deploying flaps changes the wing chord line, which in effect increases the angle of incedence. This means that at a given angle of attack, all other things being equal, the pilot gets better forward visibility ove the nose.

Here's a good exercise: go out and slow to flap speed with no flaps, take note of your sight picture, and then add "take-off" flaps, re-trim for level flight. I think you'll find that you're flying along slightly nose down compared to flaps up. You could do the same thing in a no flaps climb. Either way, adding flaps brings the nose down because it increases angle of incedence.

I've done no flap take-offs (occasionally even on purpose). I personally see no benefit from doing them. I think the plane rotates beautifully with flaps, and I'll take all of the forward visibility I can get...especially in an airport environment!

[aaronk25]

You certainly don't need flaps for take off, but you will not get the book numbers in the POH without them (good chance you won't with them either). There is absolutely no logical reason for your CFI to instruct you not to use flaps. Some pilots prefer the way the aircraft rotates sans flaps (I believe Bob Kromer is in this camp). Whatever floats your boat...

Flaps do add lift to the equation, but more importantly IMO, deploying flaps changes the wing chord line, which in effect increases the angle of incedence. This means that at a given angle of attack, all other things being equal, the pilot gets better forward visibility ove the nose.

Here's a good exercise: go out and slow to flap speed with no flaps, take note of your sight picture, and then add "take-off" flaps, re-trim for level flight. I think you'll find that yourself flying along slightly nose down compared to flaps up. You could do the same thing in a no flaps climb. Either way adding flaps brings the nose down because it increases angle of incedence.

I've done no flap take-offs (occasionally even on purpose). I personally see no benefit from doing them. I think the plane rotates beautifully with flaps, and I'll take all of the forward visibility I can get...especially in an airport environment!

Very nice write up. Agree.

[Jamie]

Directed at no one in particular...

 

I think it's funny how the POH the LOPers ignore for leaning advice suddenly becomes the One True Way when it comes to stuff like flaps. Either the test pilots "knew what they were doing" or they didn't.

 

Or...

 

The POH is like any other technical document... part truth, part "we've always done it that way", part "It's dumb, but it's required by CFR...", part "the lawyers made us say that", and part "no, you don't have to, but it can't hurt and an inexperienced operator won't know when you can do it and when you can't so..."

 

I found a paper from years ago, which I posted to a previous thread on this that had lots of math to essentially say "flaps help you rotate sooner". On the runways of the time, this probably made a big difference. And, I suppose, getting the wheels up and into ground effect sooner could be an advantage on a soft field. But they're obviously not required for take off, and you're not going to die if you don't have them down in normal situations, so the advantage is less clear.

 

The "visibility over the nose" aspect is interesting, and now I'm going to feel like a Concorde pilot every time I set take off flaps.

[N201MKTurbo]

I have over 4500 hours in Mooneys and I only use take off flaps on very short or soft runways.

 

The plane fly's better without them. IMHO

 

Didn't we argue endlessly about this in another thread some time ago?

[Bob_Belville]

I have over 4500 hours in Mooneys and I only use take off flaps on very short or soft runways.

 

The plane fly's better without them. IMHO

 

Didn't we argue endlessly about this in another thread some time ago?

Everybody has one department...

[Shadrach]

Directed at no one in particular...

I think it's funny how the POH the LOPers ignore for leaning advice suddenly becomes the One True Way when it comes to stuff like flaps. Either the test pilots "knew what they were doing" or they didn't.

Or...

The POH is like any other technical document... part truth, part "we've always done it that way", part "It's dumb, but it's required by CFR...", part "the lawyers made us say that", and part "no, you don't have to, but it can't hurt and an inexperienced operator won't know when you can do it and when you can't so..."

I found a paper from years ago, which I posted to a previous thread on this that had lots of math to essentially say "flaps help you rotate sooner". On the runways of the time, this probably made a big difference. And, I suppose, getting the wheels up and into ground effect sooner could be an advantage on a soft field. But they're obviously not required for take off, and you're not going to die if you don't have them down in normal situations, so the advantage is less clear.

The "visibility over the nose" aspect is interesting, and now I'm going to feel like a Concorde pilot every time I set take off flaps.

The visibility over the nose is real. It may not be terribly dramatic at take off setting, but it's very dramatic when comparing no flap to full flap landings. There are reasons to stray from the POH. Instrumentation, information sharing and understanding have come a long, long way since 1966. Think about how difficult it would be to seek out the appropriate, digestible information on say combustion science in 1966 or even 1986 for that matter. Things have changed, every time an answer gives birth to another question, the new answer can be found almost immediately. Society has become far more sophisticated/savvy in many ways due to the inter webs. So much so that many if us have learned to do comfortably things that a handful of folks (like say R. Lopresti) were doing comfortably in the 70s (you brought up LOP ops, not me).

I guess the question one has to ask is: What is the reasoning behind the deviation from the conventional wisdom or POH in this case? If the reasoning is compelling, then one has a reasoned choice to make. As far as I can tell, the CFI did not offer any technical reasoning behind the recommendation (incidentally, neither have you), just a "because I said so". Much to my parent's chagrin, that type of explanation didn't work when I was 2 and it certainly doesn't work now... I think most adults are the same in that way, at least until it comes to politics...

[robert7467]

I am on a 8,000' runway. The only time I use flaps during takeoff, is when I am fully loaded, or on a hot day on a shorter field. For me, on takeoff, it’s just one less thing I have to mess with. I have about 130hrs in my Mooney and I am still trying to break bad habits I learned from my training.

There was a time, when I could not even have a good landing with flaps, and I landed without flaps. Then the guys on this board start busting my chops, and a light bulb went off in my head and I use full flaps on every landing except for heavy crosswinds where I need that extra speed for a more stable approach.

My main issue that I now have to overcome is trimming on final, which will probably help me better maintain my final approach speed at night. Not saying your instructor is bad, in fact he might be a good stick and rudder pilot. I think now is a good time to take a couple steps back and get to know your airplane by what the book says, especially if you are going to work on higher ratings. Instrument training requires precision and flying by the numbers, and your POH will help you along the way.

[ncdmtb]

Thanks for the quick and excellent feedback! I am very glad to have found such a knowledgeable group.

He told me that flaps are not really required (runway lemgth) and - if I recall correctly - he also told me something about the plane rotating smoother; he does most his flying in Pilatus, King Airs and Challengers, and claims that the Mooney w/o flaps has a flight profile more similar to the bigger iron.

I am definately going to give the "flaps" / "no flaps" comparison test to see the difference in forward visibility.

[Jamie]

were doing comfortably in the 70s (you brought up LOP ops, not me).

 the CFI did not offer any technical reasoning behind the recommendation (incidentally, neither have you),

 

You're all over the place with the "you", but if you're addressing me, I'm not taking a position on this. I don't care what anyone else does. Just commenting on the blind spot some have with the POH. It's either authoratative, or it's not.

 

And actually, I did give reasoning behind the use of flaps in the technical paper that was an attachment on a post in a previous thread about this.

 

 

[Hank]

The Owners Manual for my C says "FLAPS--TAKEOFF or as desired" so I use "as desired." I use Takeoff flaps when loaded near gross or on short fields, like the nearby 2000' grass strip (max load 2 souls, half tanks, Flaps for takeoff). At my 3000' home field with trees at both ends, only when heavy (near gross).

Forward visibility with flaps helps a lot flying the pattern and landing. But on takeoff, the OM says to raise flaps when clear of obstacles. Does visibility over the nose make a huge difference when climbing below 100-150 agl?

As for rotation, she rotates just like the OM says without flaps--pull back to break ground, then relax some back pressure. With Takeoff flaps, there's not enough rotation to notice, she stays pretty much in the same attitude as on the ground and levitates into the air.

Short bodies handle differently than the others. My C lands very well over the trees with Takeoff flaps, but I have flown an F several times and it is much more stable and repeatable with Full flaps. But then again, the F had only three positions available--Up, Takeoff and Down, while they are infinitely adjustable on my C. Wind makes a difference with my flap setting, I use more flaps for less wind.

The MAPA PPP is who taught me to set Trim so the bottom of the indicator is at the top of the Takeoff stripe when not heavy. I highly recommend new Mooney pilots go, my first was five weeks after I finished insurance dual, and I hit 100 hours in my logbook flying to it.

[Shadrach]

You're all over the place with the "you", but if you're addressing me, I'm not taking a position on this. I don't care what anyone else does. Just commenting on the blind spot some have with the POH. It's either authoratative, or it's not.

 

And actually, I did give reasoning behind the use of flaps in the technical paper that was an attachment on a post in a previous thread about this.

 

Rubbish,  There are sections of the POH that are clearly codified as "limitatations", those sections are athoritative. Sections that are codified as "recomendations" are just that.

 

Previous post edited to qualify the "you" I was referring to in parentheses.

 

Also, could you link the thread or paper you posted?  Like you I don't really care what anyone else does, but I do enjoy learning why they do it

[Marauder]

Didn't we argue endlessly about this in another thread some time ago?

Yes, if you haven't figured it out yet, this is the twilight zone and you just happen to be in another episode. The last episode was whether not we should fly ROP or LOP.

[Shadrach]

I have over 4500 hours in Mooneys and I only use take off flaps on very short or soft runways.

 

The plane fly's better without them. IMHO

 

Didn't we argue endlessly about this in another thread some time ago?

 

 

I'm don't want to argue, just seeking the why. 

 

You have a great deal more Mooney time than I do, and you've stated that it's your opinion "that the plane flys better with out them".  I appreciate your experience. The difference between your statement and the ones that I find frustrating is that so many folks omit the IMO part and sustitute the 4500 hours of experience as a technical or subjective explanation.  

 

I appreciate your preference, but I'm still curious what "the plane flys better without them" means.

[DrBill]

WOW, what a mistake.   If you take off of 5000 ft runways all the time, sure but that's surely not my case. At my home field (3400 ft) , I use flaps when I am not alone.  ALL THE TIME.  Two pumps make a big difference.  If you take off loaded on a short field w/o flaps, you WILL sooner or later have an issue.  I finally got the landing sequence down for full flaps each time too. With or without a load.  Makes my run out a lot shorter.

BILL

 

[Shadrach]

Actually Hank, I believe the majority of Fs made have haudraulic flaps, which can be set anywhere within the range of the actuator.

[Shadrach]

Forward visibility with flaps helps a lot flying the pattern and landing. But on takeoff, the OM says to raise flaps when clear of obstacles. Does visibility over the nose make a huge difference when climbing below 100-150 agl?

It's likely not a huge difference, but what are you gaining by giving it up? If I understand you correctly, you simply have a personal preference for the way the AC rotates without flaps. I'd not try to convince you to do otherwise. However, I do think that telling a student pilot that it's better without explaining that you just like it, may cause them to interpret it as technical gospel as opposed to just subjective preference.

[Jamie]

WOW, what a mistake.   If you take off of 5000 ft runways all the time, sure but that's surely not my case. At my home field (3400 ft) , I use flaps when I am not alone.  ALL THE TIME.  Two pumps make a big difference.  If you take off loaded on a short field w/o flaps, you WILL sooner or later have an issue.  I finally got the landing sequence down for full flaps each time too. With or without a load.  Makes my run out a lot shorter.

BILL

 

From the paper, flaps apparently allow you to rotate sooner, and (I'm guessing) Vx is improved. Flaps allow you to land more slowly => less kinetic energy => shorter roll out.

 

OTOH, I have 10,000ft. I'd rather go faster, sooner, and start accelerating to cruise climb. Flaps add lift, sure, but also drag. Also, one less thing to be messing with in the transition from tower to departure, one less thing to distract during touch and goes (wow, I'm just hitting all the soft spots today), more graceful transition to cruise (I hate that little burble as the flaps retract), etc.

 

Flaps help shorten take off and landing distance, but the effect isn't free. If you understand the trade offs, you don't need to use them for each and every take off (or landing).

[Shadrach]

Pure speculation on my part, but I think a lot of guys don't like TO flaps because the airplane can wheelbarrow with just the front seats loaded if there's not sufficient back pressure on the yoke (about 5lbs of pressure seems right and is often quoted), or proper nose up trim. The trim indicator on the older planes is not very precise in terms of mechanics or readability. Inadequate nose up trim will indeed make the plane feel nose heavy with take-off flaps.

[Hank]

Actually Hank, I believe the majority of Fs made have haudraulic flaps, which can be set anywhere within the range of the actuator.

I thought they went all-electric in 69, like the others. I'm not up on annual production rates, but I flew an F that, like my C, is all electric. Different actuators, but electric.

I was also taught when transitioning that flaps aren't needed for every takeoff, and it was confirmed at the PPP shortly afterwards.

Flaps are a tool to use, and every takeoff, like every landing, is slightly different (wind speed/direction, weight, CG, distance to & height of obstacles, runway surface condition, runway slope, etc.) . Sometimes a different tool works better. I don't treat everything like a nail just because I have a hammer--I also have wrenches and screwdrivers.

[Bob_Belville]

Pure speculation on my part, but I think a lot of guys don't like TO flaps because the airplane can wheelbarrow with just the front seats loaded if there's not sufficient back pressure on the yoke (about 5lbs of pressure seems right and is often quoted), or proper nose up trim. The trim indicator on the older planes is not very precise in terms of mechanics or readability. Inadequate nose up trim will indeed make the plane feel nose heavy with take-off flaps.

When I bought my '66E neither the flap indicator nor the trim indicator were indicating the actual position. One cable was broken the other out of adjustment. The retired airforce pilot who had had the plane 6 years just ignored the indicators, which as you say aren't much. OTOH, it was not a big deal to fix them the first time we had the belly panel off.