Heavy elevator authority...common to M20J?

[Davo]

My friend just purchased a 1989 M20J and couldn't wait for me to fly his new plane. There is a lot to like about this plane and I was excited to fly it. I have about 750 or so hours on various Mooneys but that was 30+ years ago so my recollection of the flight characteristics is nill. I was a bit surprised on the force needed to take off and land. Trim was set properly and manual trim moves free and easy. W&B  is good. I know saying it is "heavy" is a subjective description but, it just seems to take way more effort than is expected or remembered. The plane had a pre-buy, but that means little as I found the oil filter safety wired wrong and the landing light disconnected. I'm thinking a systematic approach to the controls with cleaning and/or lubrication may be of some benefit. I just wanted to get some feedback from those of you much more familiar and current in M20J model whether the plane is characteristically heavy in pitch of not. Thanks for your time and experiences.

 

[N201MKTurbo]

There was a recent thread about this exact subject.

[Davo]

Yes, I read it, thanks. 

[David Lloyd]

My M20C has a the blade prop that adds considerable weight to the nose.  With only the front seats occupied, despite nose up trim it takes a pretty good pull at takeoff to get the nose off the ground.  Once flying, it needs to be trimmed nose down for any speed more than about 70 knots.  The elevator does seem much heavier at the end of the ground run and the first few seconds of flying than I remember from 40 years ago.  Feels great any other part of the flight. Does this match your experience or question?

[N201MKTurbo]

Take off with no flaps, it will just fly right off with no elevator pressure at all.

[Ragsf15e]

Additionally, start the t/o roll with some back pressure (say “5lbs”).  Speed and front weight conspire to push the nose down if you don’t hold some back pressure during the roll.  If done properly and still takes a strong pull, try 1/2 turn nose up trim.  Front weight needs to be on the nose up side of T/O trim.

[mcarterak]

19 minutes ago, Ragsf15e said:

Additionally, start the t/o roll with some back pressure (say “5lbs”).  Speed and front weight conspire to push the nose down if you don’t hold some back pressure during the roll.  If done properly and still takes a strong pull, try 1/2 turn nose up trim.  Front weight needs to be on the nose up side of T/O trim.

Yep, I have started to trim just on the top of the nose up line when it's just front seat passengers. Makes a big difference in the pull required. 

[Hank]

56 minutes ago, mcarterak said:

Yep, I have started to trim just on the top of the nose up line when it's just front seat passengers. Makes a big difference in the pull required. 

That makes all the difference in the world!

[Davo]

Great stuff, everyone. Thanks for sharing your experience. I will try those tips and see. It's likely I'm just older and weaker!

[Utah20Gflyer]

The only time I feel like my plane is heavy in pitch is when rotating on takeoff, as soon as I'm in the air the pitch feels light.  Out of trim it can feel heavy but I don't experience that much as I am constantly trimming to keep things where I want it.  I have flown a J model before and it didn't seem much different than my G model.  Maybe the elevator travel is not set correctly?  Maybe check your planes elevator with the travel boards make sure everything is to spec.  If the travel is set incorrectly that could make your trim settings incorrect.   Check all linkages for free movement, potential obstructions, good condition and clean and lubricate everything.  Check the hardware between the elevator and horizontal stabilizer and make sure everything is in good shape and lubricated.    That's about all I got.  I find the control pressure to be about the same as a 172/piper Cherokee, etc.  So something is probably not right if control pressure is consistently heavy.  

[PT20J]

M20J and earlier models have trim assist bungees which act as centering springs on the elevator with the center (zero force) point variable according to trim setting. This system has two effects. First, it assists the trim system reducing the amount of stabilizer incidence change necessary to trim out stick force. Second, it improves airspeed stability by increasing the stick force when off trim speed. The effect is especially noticeable at low airspeeds where the dynamic pressure is lower and the aerodynamic control forces are reduced. The springs make the airplane appear more stable, but if you are out of trim it will make the control forces seem heavy compared to say a Cessna or Piper and it will seem heavier in rotation and flare as you are pulling against the springs. This is the reason starting the takeoff roll with about 5lb of pull helps make the transition to flight smooth because you don't have to pull to rotate; the airplane takes off by itself and you relax pressure to prevent over rotation as it breaks ground.

Starting with the M20K the trim system was changed to a variable down spring and bob weight presumably to improve maneuvering stability by increasing stick force per g due to the effect of the bob weight (the weight pulls down with increased force as the g load increases which is felt as a nose down pull by the pilot).

Skip

[carusoam]

Summary-ish…

1) Trim near the top of the T/O range if only front seats are full…. (See note from Hank below…)
2) Don’t over trim… that can lead to a different problem later on…. Like, the next five minutes….

3) Breaking ground uses the 5 LBs of force for most Mooneys from short to long body…. The nose gear leg length relative to main gear legs sets the attitude on the ground…  LBs have a much longer nose leg for additional nose up attitude… 

4) Once rotation begins, expect to relax the pull… or expect over rotation… 

5) Off the ground…  (things to consider)

• Positive rate check…
• hit the brakes for aviation tradition…
• End of useable runway check… Vx decision…
• clear the 50’ tree..
• Stow the gear…
• Trimmed and climbing… Vy decision…
• Stow the T/O flaps
• Electric Fuel pump off
• Cruise climb… CHT control decision…
• Post T/O checklist…

6) Each time the flaps change, trim will change…

7) Max flaps, comes with max trim change…

8) Trim changes with speed as well, but not that  noticeable during the T/O phase….

PP thoughts only, not a CFII….

Best regards,

-a-

[Hank]

Correction:  front seat only, no baggage--put trim the width the the indicator above the Takeoff mark, still a long, long way from the top of the range.

[Davo]

Y'all are great. This helps much. Thank you!

[Tx_Aggie]

I have a J model and yes the pull on the yoke to break from the ground seems unusually heavy. I tend to set my trim just above the “take off” setting during acceleration and on the roll - I’m still trying to master a smooth transition! Once in climb I have to trim down to pitch for 500 fpm climb. I’ve owned the plane for almost 2 years and flown about 130 hours fwiw. 

[Davo]

Follow up to everyone's advice. The bungee's were quite dirty, caked with old lube. I cleaned and sprayed/soaked with dry silicone then turned my attention to the yoke, cleaning the push rods and controls then spraying with silicone as well. Now everything is smooth as silk. Thanks for the guidance. This aircraft will definitely need some TLC to get her where she needs to be. 

[LANCECASPER]

20 minutes ago, Davo said:

Follow up to everyone's advice. The bungee's were quite dirty, caked with old lube. I cleaned and sprayed/soaked with dry silicone then turned my attention to the yoke, cleaning the push rods and controls then spraying with silicone as well. Now everything is smooth as silk. Thanks for the guidance. This aircraft will definitely need some TLC to get her where she needs to be. 

Just make sure that you use the lubricants called out in the Mooney Maintenance Manual. If people in the past have used the wrong lubricant it can result in the stiffness over time that you earlier describe.

[Davo]

Thanks.