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Flaps on take-off?


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I'LL STIR THIS POT!

On the cover it says:

Mark 21, Model M20C

OPERATE THIS AIRCRAFT ONLY 1. after reading owners manual 2. with owners manual on board 3. after you are fully qualified & understand all of the aircraft operating characteristics & limitations

Owners Manual

1965 [1962-1963-1964 data included]

Mooney Aircraft, Inc

On page 17-18 it says:

PRE TAKEOFF CHECK

6. Set wing flaps to take-off setting (see indicator).

I'm done here ...

(Don't know how many gloomy NTSB accident report films about catastrophes involving no-flap take-offs I have watched year after year in my career? But one should be enough! Yeah, it's just a little Mooney. Yeah, I can fly the crap out of an airplane, a jet, a helicopter ... I know I can ... and low to the ground too, but there's a big difference between "cowboyin'" and flying tactical or training maneuvers to prescribed standards. It's a thin line when one crosses over to the "cowboy" side. It's not to be done lightly. We all know the rhetoric about aviation inherintly having severe consequences for complacency, lack of vigilance, judgement and situational awareness. I am not calling anyone a "cowboy" ... But I am just saying ... Do you really want to live close to the line? Ever do that "risk versus benefit" risk-assessment stuff?)

Well, Dave, there you go. Mine says "Mooney Ranger Owners Manual 1970" with the same disclaimer on the cover.

Inside, under "Before-Takeoff Check" on p.3-12 it says:

11. Wing Flaps--SET for TAKEOFF or as desired.

Further down it says

Before applying power for takeoff, quickly recheck for:

3. Flap Indicator--TAKEOFF or as desired.

So the book for your 65 and my 70 C-models are not the same. If our books for different years of the same model are different, the books for different models of different years won't be the same either.

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You mean.......these planes come with a book........telling you how to fly it?????  I will have to look for mine! All I was ever told was that if you pull up on the yoke the houses get smaller and if you pull up more on the yoke the houses get bigger!

There, I corrected the deficiencies in your education. (Wish this stinking Apple product would let me bold the changes, but they don't see the need for a Ctrl key.)

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There are many who fly with absolutes. I have some too. Taking off without take off flaps at my primary airport wasn't one of them, but as I said in a previous post on this thread I will do from now on like a good boy. Maybe I will stick my tongue out my open pilot window at 10,ooo in December and pretend there is a flag pole out there...if my wife triple dog dares me.

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I usually don't use flaps unless short strip or heavy. Not sure about this but there was a Mooney that crashed in Arizona about two years ago on take off and killed both occupants. I think it was a high altitude strip and was thinking that they stalled shortly after takeoff and hit nosefirst. Could it be that they used flaps and didn't have the trim set right. When they retracted flaps shortly after takeoff the pitch went up and they stalled. Not sure if that is what happened but I saw the pictures and it sure came in on its nose. Flaps are probably the way to go but need to watch out for the sudden up pitch when they are retracted. I also wonder how many people forget to retract the flaps and over speed them. I know of some people that forget to retract the gear until they wonder why it doesn't go fast.

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I usually don't use flaps unless short strip or heavy. Not sure about this but there was a Mooney that crashed in Arizona about two years ago on take off and killed both occupants. I think it was a high altitude strip and was thinking that they stalled shortly after takeoff and hit nosefirst. Could it be that they used flaps and didn't have the trim set right. When they retracted flaps shortly after takeoff the pitch went up and they stalled. Not sure if that is what happened but I saw the pictures and it sure came in on its nose. Flaps are probably the way to go but need to watch out for the sudden up pitch when they are retracted. I also wonder how many people forget to retract the flaps and over speed them. I know of some people that forget to retract the gear until they wonder why it doesn't go fast.

 

Do you understand why an AC pitches up when the flaps are raised?

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from somewhere in the internet.........

 

Lowering the flaps in flight generally will cause a change in the pitching moment. The direction and degree of the change in pitch depend on the relative original position of the centre of pressure and the centre of gravity. The factors that contribute to this are

1. The increase in lift created by the increased wing area and chamber will lead to a pitch-up moment if the centre of pressure remains in front of the centre of gravity.

2. If the associated rearward movement of the centre of pressure is behind the centre of gravity, then this will produce a nose-down pitch.

3. The flaps will cause an increase in the downwash, and this will reduce the angle of attack of the tailplane, giving a nose-up moment.

4. The increase in drag caused by the flaps will cause a nose-up or nose-down moment depending on whether the flaps are above or below the lateral axis.

The overall change and direction in the pitching moment will depend on which of these effects is predominant. Normally, the increased lift created by extending the wing chord line when the flaps are extended is dominant and will cause a nose-up pitching tendency because the centre of pressure normally remains in front of the centr of gravity

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Cruiser,

 

That is a very detailed explanation. A simple way of stating it is that the flaps in effect, change the chord of the wing and thereby change (increase) angle of incidence (angle of wing to horizontal axis of fuselage). A given AOA with no flaps will result in the fuselage being at a higher angle when compared to TO flaps.  My point is that I don't think one would see a significant degradation in airspeed from the "apparent" pitch up when raising flaps because the "pitch up" is due mostly to a reduction in AOI...the actual AOA of the wing is likely very close to what it was with flaps, but just appears higher because the fuselage axis is closer to parallel with the wing.

 

Besides, I think the accident Skybrd is referring to was an engine failure caused by a corroded fuel servo in an F model departing Winslow-Lindberg Regional Airport and had little to do with take off procedure.

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Interesting reading. When it comes to Performance Planning (in any airplane) it's probably good to always keep in mind the goal. If the goal is to never put the airplane in a situation where the loss of an engine will result in an injury/serious accident we are going to be much more restricted than if we view an engine failure as an "acceptable" risk. 

 

After 40+ years in this business I have become an even stronger advocate of the former philosophy - and I assume most of my passengers would agree. Yes, it restricts me to much larger airports, longer runways, better clearways, more friendly surrounding terrain, etc. It restricts me (in my Mooney) to day/"soft" ifr and even what routes I fly to some degree. But if it saves me and my passengers from serious harm even once in my career I figure it is worth it.

 

If the airplane doesn't fit the mission change the mission or change airplanes.

 

M20C, DC9, B727, B757/767, B747, B777, B787

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I never dreamed flaps on takeoff would be as controversial as ROP/LOP or Camguard.

That's because this post was correctly answered by fantom on the very first reply. I can understand the discussions on ROP/LOP and Camguard (and I enjoy them) since these don't come with a POH, but I don't understand this. Too many opinions and not enough direct quotes from the POH. In this case of a '66 M20E. The answer is page 20, item 6.

Mooney_M20_21_OM.pdf

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That's because this post was correctly answered by fantom on the very first reply. I can understand the discussions on ROP/LOP and Camguard (and I enjoy them) since these don't come with a POH, but I don't understand this. Too many opinions and not enough direct quotes from the POH. In this case of a '66 M20E. The answer is page 20, item 6.

My 76' F POH says to set flaps "TO TAKEOFF or AS DESIRED". Now, that's settled.

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