Flaps issue at 100kts

[Ken_CT]

I am curious to see if anyone had this issue before. The aircraft is a M20J 1998 and if on a pattern and the flaps are engaged for landing at 100kts or above, the 5A breaker pops. The flaps works perfectly at both positions if the speed is 90Kts or below. We have changed the breaker and it was not the issue.

Any thoughts or similar experience?

Thanks.

[PT20J]

The air load will be higher at the higher airspeed. So, if there is too much friction in the flap system, the added air load from the higher airspeed might be enough to stall the motor and trip the breaker. Or, if something is wrong with the motor so that it doesn’t generate enough torque to operate the flaps, that might trip the breaker. 

[MikeOH]

Did this just start happening suddenly, or did it start out intermittently and get worse?

As PT20J said, too much friction; I'd look to see if everything is properly greased and not binding.

Not likely, but could be the circuit breaker going bad; you could 'shot-gun' and replace it, or use a clamp-on DC (NOT AC) ammeter to see what the current draw really is.

[N201MKTurbo]

I would take the flap actuator apart, clean it all up and reassemble it with the moly grease specified for the Dukes gear actuator. While you have it apart check the bearings and brushes in the motor.

I would check the amount of current it takes to spin the motor with no load on it. If it is more than 1/2 amp or so your armature is probably fried.

[IvanP]

Sounds like the actuator may need some care. I agree with Skip's suggestion above. May need new brushes.

[Ken_CT]

Thanks a lot. I will have the maintenance folks cleanup and grease the actuator assembly. Will see what shakes out. 

[Utah20Gflyer]

Sounds like your flap system might need some attention and as an owner of a hydraulic flap Mooney I don’t have much to add on troubleshooting an electric flap Mooney.  
 

I would however question why you would put out flaps at 100 kts or even higher.   Seems like that’s a bit fast.  90kts is a nice pattern speed for a mid body Mooney, and also works well as an approach speed.    Putting out flaps and gear at higher speeds creates a lot of extra wear and tear on the systems.   Ultimately it’s your plane so it’s your choice and I’m not saying people are wrong if they choose to operate their airplane differently than I operate mine.  There are however benefits to slowing down in the pattern and one of them is less wear and tear on the airframe.  

[dzeleski]

2 hours ago, Utah20Gflyer said:

Sounds like your flap system might need some attention and as an owner of a hydraulic flap Mooney I don’t have much to add on troubleshooting an electric flap Mooney.  
 

I would however question why you would put out flaps at 100 kts or even higher.   Seems like that’s a bit fast.  90kts is a nice pattern speed for a mid body Mooney, and also works well as an approach speed.    Putting out flaps and gear at higher speeds creates a lot of extra wear and tear on the systems.   Ultimately it’s your plane so it’s your choice and I’m not saying people are wrong if they choose to operate their airplane differently than I operate mine.  There are however benefits to slowing down in the pattern and one of them is less wear and tear on the airframe.  

The early Js have a Vfe of 125mph (108kts) and a Vlo/le of 150mph (130kts). The later Js I believe are even higher than that.

[Fly Boomer]

1 hour ago, dzeleski said:

The early Js have a Vfe of 125mph (108kts) and a Vlo/le of 150mph (130kts). The later Js I believe are even higher than that.

POH 1233 says 15 degrees at 132, and full flaps at 115.  Doesn't seem like 100 is "too high".

[dzeleski]

6 minutes ago, Fly Boomer said:

POH 1233 says 15 degrees at 132, and full flaps at 115.  Doesn't seem like 100 is "too high".

That’s what I was trying to get at. I agree with you, nothing wrong with putting them in at the top of the range.

[Fly Boomer]

1 minute ago, dzeleski said:

That’s what I was trying to get at. I agree with you, nothing wrong with putting them in at the top of the range.

Understand.  I don't really know if POH 1233 is early or late.  It was just another data point I had available.

[dzeleski]

1 hour ago, Fly Boomer said:

Understand.  I don't really know if POH 1233 is early or late.  It was just another data point I had available.

My 77 doesn’t have that, I have one speed and that’s it. I believe that later POH is from the 205 specifically.

[Ken_CT]

According to POH 3203, the max Vfe KIAS with flaps extended is 112 and 109 (KCAS) - White Arc.

One observation was that when the flaps were put in above 90 kts, the flaps barely travelled to the TO position but 2-3 secs later the breaker pops. It’s like the motor is trying and in the process drawing more current. 
At 90kts or below, they work perfectly fine.

Will have the Maintenance folks take a look at the actuator assy for grease hardened or other build up

[PT20J]

All the M20Js have a max full flap speed of 110 KIAS per the TCDS. The maximum speed for 15-degree flap deflection is not specified EXCEPT for S/N 24-3000 through 24-3078 (which were the short-lived 205s) where it is listed as 126 KIAS. There appear to be minor unexplained differences in some of the POH.