elevator trim rigging

[scottfromiowa]

I am shopping Mooneys, specifically the M20J and I flew one (first time flying a Mooney) that was rigged such that full nose trim down resulted in level flight at a "normal" cruise setting.  (I don't remember the specific RPM and MP, but let's assume it was a square setting of 2300 RPM and 23 inches).  Is it normal to have to set the trim full nose-down in cruise? 

I also noticed I had to set the trim all the way nose-up for landing, but I have read this is "normal."

Comments?

[1964-M20E]

I’ve only flown a 20B model once and my current E model and neither of these had that odd quirk.  During my annual in February / March the mechanic and I went through re-rigging all controls on the aircraft.  Most were very close to factory settings.  The most ambiguous instructions were for the elevator but after talking with several folks the mechanic and me, we got it right.  When in cruise flight I do not need to have the rim full nose down.

[Shadrach]

Quote: scottfromiowa

I am shopping Mooneys, specifically the M20J and I flew one (first time flying a Mooney) that was rigged such that full nose trim down resulted in level flight at a "normal" cruise setting.  (I don't remember the specific RPM and MP, but let's assume it was a square setting of 2300 RPM and 23 inches).  Is it normal to have to set the trim full nose-down in cruise? 

I also noticed I had to set the trim all the way nose-up for landing, but I have read this is "normal."

Comments?

[Hank]

Similarly, my C does not require full trim in cruise or when landing. Cruise trim will vary with power settings and with loading--as CG moves aft, more down trim should be needed. Power generally creates lift, so the more power you are making, the more down trim should be required. My trim position in cruise tends to be near the center or slightly down; often my trim is near the takeoff mark after touchdown, but I generally ignore the marker when coming in, I'm too busy looking out the window, maintaining glideslope and adjusting power/trim to stay where I want to be to notice the location of the trim marker.

A visit with travel boards should clear up any questions.

[Piloto]

Trim setting varies with load on the plane. Did you check the baggage compartment? The more stuff you put in it the more you have to trim down.

José

[richardheitzman]

ditto the remark on CG, I have not flown any aircraft that requires max trim to maintain level flight.

[Bill_Pyles]

OK; I appreciate your responses.  Sounds like the plane I flew may be a little odd, but not completely off the chart. 

There was nothing in the baggage compartment, btw.

[OR75]

Anyone has an idea on how much it costs or how many hours it takes to get all the riggings done in an MSC ?.

 

[Hank]

Quote: Bill_Pyles

There was nothing in the baggage compartment, btw.

[Shadrach]

Quote: Hank

 In my plane, 2 people and full fuel is pretty close to the forward CG limit. If flying there takes full down trim, what will you do with 100 lbs or more in the baggage compartment, or people in the back seat, or both? Those situations will require more down trim, but you're already maxed out . . .

[Hank]

D'oh! My bad, sometimes I forget the obvious.

I prefer carrying as much as possible behind the seats for a reason, now what was it???  :-)

[kujo806]

Scott,

What has you shopping?  Just curious...it looks like you have a nice setup with your current Mooney.  I think I have seen yours parked behind the IowaFlighttraining planes.

[carusoam]

Viewed differently....

While on the ground, make sure that the tale is actually moving with all of the trim input.  Something (Short ADF wire)  may bind the tale and hold it in position, while the pilot exercises the full down trim.

Trim all you want, but something can keep the tale from going there.  My example is of the ADF wire is what happened when a too short spring was used.  When trimmed down, the tale was hung in place by the ADF wire.

In summary, make sure the tale is going from full forward to full aft with the rotation of the trim wheel.  Count the total rotaions of the trim wheel to make sure that it is not stopping short of actual "full down"

Best regards,

-a-

[Clarence]

There is clearly something mis rigged in the trim system.  In all the Mooneys I have rigged I have never heard of anyone running out of nose down trim.

It should take several hours (once the belly panels are removed) with the proper tools and knowledge to re set the trim to the correct values.

Clarence

[OR75]

a bit confused and asking for input:

On descent from cruise level to pattern altitude at relatively high speed at say -300 to -500fpm and ~ 160 - 170knots, I have to apply quite a bit of forward pressure on the yoke to maintain the rate of descent and with trim all the way down.

How will the plane loading help ?

I rarely have to trim the plane all the way up. Is my plane off - rigged ???    

[Ned Gravel]

Quote: OR75

a bit confused and asking for input:

On descent from cruise level to pattern altitude at relatively high speed at say -300 to -500fpm and ~ 160 - 170knots, I have to apply quite a bit of forward pressure on the yoke to maintain the rate of descent and with trim all the way down.

How will the plane loading help ?

I rarely have to trim the plane all the way up. Is my plane off - rigged ???