takeoff problem - right crosswind, 1978 M20J

[daansley]

When the crosswind is coming from the right, during the takeoff run prior to liftoff speed, the aircraft feels like it is slightly pitching forward and the right wing tip is lowering toward the pavement. It's an odd and uncomfortable sensation. Is it normal? I've tried increasing the elevator trim UP setting (normally set @ TAKEOFF) and various positions of the ailerons from full-right-aileron to neutral. I'm still getting the pitch & lean to right before liftoff. I never pull back on the elevator until reaching liftoff speed (71 MPH). Should I?

The Mooney likes to turn to the right (weathervane) more than turn to the left (P-factor). That seems odd considering that the plane sits with its nose so high in the air. I've checked the leveling per the manual and it is correctly leveled.  Nose tire pressure is 50 psi and mains are 40 psi.

I'm relatively new to Mooneys (~ 150 hours) but have several thousand hours in a Beech Debonair (straight-tail Bonanza) and Piper Comanche 250. Thank you for your advice.

David Ansley

[KSMooniac]

I'm not sure what to say about this behavior!  I'll note that you should check your specs for tire pressure as my 1977 J is 49 in the nose and 30 in the mains and I don't believe it would be any different for a 1978.  Perhaps the later models with 2900 lb. gross weight might be higher, though.

Does your plane track straight on the ground with the pedals neutral?  How about flying hands-off?  Perhaps your nosewheel/rudder rigging is not correct, and the problem only manifests itself as you described.

[daansley]

Thanks

 

 

[daansley]

I increased the main tire pressure to 40 psi (shortly after I started flying the M20J two years ago) because the outer rib on the main tires was worn; the right tire has more wear than the left.  Higher pressure in the main tires gives a little better visibility in front.  But I'm happy to reduce the main tire pressure back to 30 psi if that's what is recommended.  Thanks.

[KSMooniac]

I think Mooney (and other) main tires can wear faster on the outer edges, so it is good practice to rotate the tires every year or two.  I haven't done that by the way.   

Definitely play a little with your trim settings.  Mooneys are sensitive to trim, and there is a huge difference flying solo vs. at gross with weight in the back.  I tend to set my trim more nose-up if solo, and more aligned with the takeoff mark if heavy.

[fantom]

It's 30 lbs. for the mains, and 49 for the nose on my '94 as well. Be careful with extra pressure in your mains, because you don't want the wheels to get bound up in the wells. Also sounds like it's time for new tires.

Have you checked the play in your rudder. About 1/4" is good. More is, of course, not so good.

[Piloto]

Next time try taking off with no flaps. You may have an asymetrical flap condition. Also verify actual flap deflection with a protactor. I normally takeoff with no flaps to avoid the ground effect air cushion and to ensure no porpoising on uneven runways, it also gives you more controllability on crosswinds.

José

  

[jlunseth]

What you say actually makes sense.  The Mooney - my Mooney anyway - has a tendency to come off the mains and onto the nose wheel during the takeoff roll.  You will see some articles, I believe the one's I read were on the mapa site, that recommend applying about 5 lbs. of back pressure to the yoke during takeoff to keep the plane firmly planted on the mains. 

I am assuming that since you are having a consistent feeling that the right wing is lowering, you fly from a field that has a persistent wind quartering from the right, is that so?

I would first just try the back pressure on the yoke and see if that keeps the plane from pitching forward as you describe.  But also, proper taxi and takeoff technique requires "turning into" a quartering headwind, in other words, turning the yoke to the right so that the right aileron comes up and the left goes down, in order to prevent the wind from getting under the right wing and flipping the plane.  If the right wind is strong enough, you want that wing down on the right side.  If you come off the left main first, so what.  Same on landing, you will need a crosswind correction to slip to the right with the nose straight down the runway.  That crosswind correction with the yoke should be held after landing in order to prevent the same thing, the wind getting under the wing and flipping the plane.  Read an NTSB report where that very thing happened last summer.

[daansley]

Thanks for the suggestions. I'll experiment with changing the trim and flap settings and apply back pressure on the yoke during the takeoff run. The plane flies fine once it becomes airborne and landings (even in crosswinds) are uneventful. Home airport (KVNC) is on the Gulf of Mexico. It's a rare day that it's not windy. The foot pedals are tightly connected to the rudder. But the pedals move a lot (~ 1 - 2") before I feel pressure on the nose gear steering arm. Unless I hear differently, I will assume that's normal for a M20J.  Service Kit SK-01 (Nose Gear Truss Oversize Replacement Bushing) was installed at the last annual. I haven't noticed much improvement. 

[alun]

ive taken off in some pretty heavy crosswinds and dont have the problem you descibe. i have a 78 J.

[fantom]

Same way....we walked down a row of Mooneys at MAPA, and many had too much play, maybe from flapping around in heavy winds.

Issues could be in trim link mechanism, hinge bolts or heim bearings. Best to have a real Mooney savvy A/P check it out.

[Parker_Woodruff]

For what it's worth, Remember that an airplane will always turn easier to the left.  Unless it's Russian.

This could be part of the [asymetrical?] feeling.

[duke]

NO SLIGHT BACKPRESSUE UNTILL ROTATION IS PROBABLY THE ISSUE. AIRCRAFT IS PROBABLY WHEELLBARROING AND BECAUSE OF

A LOT OF RIGHT RUDDER--P FACTOR + X WIND AND BEING THAT RUDDER AND AILIRONS ARE LINKED VIA SPINGS, THE LEFT MIAIN IS LIKELY OFF THE GROUND AND NOSE AND RIGHT MAIN STILL ON THE GROUND UNTILL ROTATION, MEANIN THE AIRCRAFT IS IN A NOSE LOW, RIGHT WING LOW ATTITUDE. 

[gregwatts]

Next time try taking off with no flaps. You may have an asymetrical flap condition. Also verify actual flap deflection with a protactor. I normally takeoff with no flaps to avoid the ground effect air cushion and to ensure no porpoising on uneven runways, it also gives you more controllability on crosswinds.

José

 

Ditto, what Jose said......and once you correct the main tire pressure, this may cure your issue.

[Marauder]

This threads looks to be 2 years old. But I do agree with today's comments. If I don't apply some back pressure just before rotation and use too much rudder, I will get this sensation as well. Was there ever any final outcome on this topic?

[Jake]

Again, I see that this thread is old but here goes. With only the pilot in the plane the best setting for takeoff trim is significant up trim for best neutral controls at takeoff speeds. If you have set the trim per the trim markings for takeoff you will have to apply significant back pressure. This may translate to a feeling of nose down as you approach takeoff speed. I have over 3500 hours in 3 different models of Mooney.

[wishboneash]

I have to set the trim half way between the neutral and fully up position. I also use some back pressure. Makes it much smoother for take offs.