M20J Takeoff Flap Question

[kevinw]

40 minutes ago, Bob - S50 said:

"If forward CG set trim to upper portion of band and to lower portion when at aft CG."  So make sure when you only have people up front that the trim indicator is at the top of the band.

+1. A Mooney CFI taught me this the day I picked up the airplane. Good advice.

[peevee]

3 hours ago, N201MKTurbo said:

When I was ferrying that Rocket recently I did no flap takeoffs. It was little different than my J except I was milking the throttle up and by the time I got to 32 inches I was airborne. Oh well, I didn't need all that power anyway.

I've been doing no flap takeoffs for so long, taking off with flaps seems weird.

To each his own...

Unless I'm climbing high and intend to be at full power I'll just use 30ish inches. 25 if I'm repoing to a close in airport. It's plenty.

[Yetti]

15 hours ago, Shadrach said:

Have you had your tail rigging checked? Same airframe and I do not cruise anywhere near almost all nose down. 

I match Marauder..... maybe you should have your tail checked :-)

 

[Shadrach]

57 minutes ago, Yetti said:

I match Marauder..... maybe you should have your tail checked :-)

 

I don't think so for Several reasons.

1)  My plane is a one owner aircraft. I know that no one has monkeyed with the rigging other than the factory.

2) given the front seats are in front of the CL and CG, your's and Chris's "large" stature should help to reduce the amount of trim needed.

3) if you're cruising near full nose down when alone, how in hell do you load the plane with rear passengers and luggage?...all of which would require more and more nose down trim in cruise.

4) When I am solo (180lbs) and low on fuel <15gals, I run out of aft trim during full flap approaches.

5) the tail rigging specs for long, mid and short bodies are different, but some mechanics are still perplexed by this and use the wrong settings when rigging an aircraft. There indeed was a recent thread about this occurring on a vintage mooney.

[N201MKTurbo]

It is almost impossible to rig the trim wrong. The range of motion is from the tail binding up on the nose down side to the hing in the tail being fully extended on nose up. The full range of the jack screw barely fits in that range. If you can run your trim from full up to full down it is pretty close to the mark.

As far as take off setting, after a few takeoffs you should know where to set it. The mark on the indicator is for non Mooney pilots to have a good starting place.

[Bob - S50]

3 hours ago, gsxrpilot said:

Sorry, but that instruction seems about as obvious as "push throttle forward to go." I can't imagine any pilot needs the POH to tell where to put the trim. Trim as required.

The indicator for takeoff trim on my J is not a mark, it is a band (or range) of trims.  I think the POH is just telling us that we should not blindly put the trim into the middle of the band each time.  It is telling us that it can vary from top to bottom of the band depending on CG.  It is also telling us that if loaded within the allowable CG, takeoff trim should be somewhere in that range.

[201er]

On 4/25/2017 at 8:55 PM, planeflyer4u said:

(New to the 201)  Is it Normal to experience pitch up of the nose when retracting  take off flaps during  climb out? Im new to the 201 (1977M20J ) but when preforming normal take off using take off trim position and take off flaps, rotating at approx 70 mph it requires additional back pressure to liftoff,once breaking ground it climbs well,gear retraction has no pitch or trim change but when I retract the flaps the nose pitches upward requiring considerable down nose trim . Ive flown M20E models etc and didnt get this reaction any thoughts ? Thanks for any Input ...

I haven't had a chance to read all of the responses but here's my take.

Yes, there is a noticeable pitch change with flap change. When extending flaps prior to landing, I offset the pitch change with the electric trim. 

When it comes to retracting takeoff flaps, I usually avoid the pitch up (bad when you're already at high aoa) by preemptively pitching down prior to retraction. This offsets the pitch change and maintains angle of attack. There is a momentary loss of lift during which time the climb rate is stunted. Then I repitch for my desired climb aoa and the climb improves.

[Hank]

Yep. And that down pitch and loss of lift csn be disconcerting, especially if you aren't expecting it. It is quite noticeable even in my C, and i don't pitch down any. That's why, when I use Takeoff Flaps, i retract them only when I am looking down on the obstruction (usually trees).