Stall Warning

[kpaul]

2 minutes ago, Marauder said:

I wish for your sake it wasn't. Now you have a different challenge to find the issue causing it. I think someone else mentioned the pitot static system or airspeed indicator being involved. Something isn't adding up.

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Yes, I guess it's off to the avionics shop...

[N201MKTurbo]

Have you manually moved the switch with the master on to see how it is working? It shouldn't turn on until it is pushed all the way up. If it comes on when barely moved, it isn't working correctly. Remove it from the plane, and hose it down with Tri Flow or red brake parts cleaner. That will usually get it working. You don't want to buy a new one $$$...

if it beeps when you push it up, there is nothing the avionics shop is going to do about it.

BTW it is impossible to bend that vane from outside the plane without breaking the switch.

[kpaul]

Just now, N201MKTurbo said:

Have you manually moved the switch with the master on to see how it is working?

I didn't, but will next time I'm at the hanger.

[N201MKTurbo]

I'm actually at the hangar, and I just tried mine. It comes on when moved about 1/8 inch up from the bottom position. It is about half way through its stroke. It is working properly, it just chirps before the wheels touch down on landing.

IMG_0030.MOV

[kpaul]

Just now, N201MKTurbo said:

I'm actually at the hangar, and I just tried mine. It comes on when moved about 1/8 inch up from the bottom position. It is about half way through its stroke. It is working properly, it just chirps before the wheels touch down on landing.

IMG_0030.MOV

Thanks for the video.

[Marauder]

2 minutes ago, Marauder said: I wish for your sake it wasn't. Now you have a different challenge to find the issue causing it. I think someone else mentioned the pitot static system or airspeed indicator being involved. Something isn't adding up.

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Yes, I guess it's off to the avionics shop...

Please let us know what you uncover to fix it. My bet is a partial blockage in your static line.

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[peevee]

On 1/17/2016 at 7:44 PM, Yetti said:

 cut your hand while cleaning bugs off the wing.

every.flight.

[takair]

On January 17, 2016 at 8:54 PM, DonMuncy said:

These vanes are a very stiff stainless steel. They don't ben easily. And definitely do not try to adjust it by bending. They are adjustable by loosening the fasteners and moving the switch/vane. It is my understanding they are tough to get to.

As discussed, the photos look like the vane is not bent.  I just looked at the POH for my E.  Straight ahead stall is listed as 67 clean, 64 TO flaps and 57 full flaps.  Per my manual, the stall horn is set for 5-10 mph before actual stall.  That would put me as high end at 77, 74, and 67 for the horn.  If we assume that the F is similar, then your horn may be as little as 6mph high.  Most airspeed indicators have more error at the low end, but if we assume that the error is 3-4 mph, you may be even closer.  Long story short, you are likely within range of a vane adjustment.  I looked at an old one and they have large adjustment slots.  The hard part is getting it to contour to the leading edge as you move it down.  Note the slight gap in yours already.  They likely got it as low as it would go for the current profile.  Your best bet might be to get the avionics shop to calibrate your ASI...at least provide you the corrections.  Then perform stalls either clean or dirty and have your mechanic adjust accordingly.  It is a huge pain to get at the nuts on the back, ideally two person job.  I added adjustable nut plates to make it easier. Take the usual precautions doing stalls.  It is easy to get complacent if you have to go out multiple times to get it dialed in.  My maintenance manual is at the hangar, so couldn't verify, but I think they may have more details on how to correctly adjust.  

[carusoam]

Even new Mooneys have a stall switch that can misbehave.  Mine went silent after about six months of my ownership.  It didn't tell me.

My preflight now includes an electronics on preflight long enough to hear the warning.

Best regard,

-a-

[StinkBug]

7 hours ago, kpaul said:

Yes, I guess it's off to the avionics shop...

Sounds to me like you've narrowed it down at least. The plane seems to actually be stalling at a pretty normal indicated speed, meaning the ASI isn't acting up. I wonder how much change in angle it really takes to effect the stall vane. The pictures look pretty close, but if it only takes a couple degrees of "adjustment" then it'd be damn near impossible to see via pictures on the internet that are not at precisely the same angles.

[druidjaidan]

I've got the opposite problem with my F.  Tested on the ground all good.  Then up with my CFI for transition training.  Start setting up slow flight, slower, slower, slower hitting about 65 MPH and it's getting really mushy, but no horn.  Pull it back a little more getting to the bottom of the white arc, no horn but I'm feeling buffeting in the ailerons.  I tell my CFI what I'm feeling and he's kinda like "yeah right, we're pretty light we just aren't there yet let me try".  He takes over and pulls it through the bottom on the white arc and a bit under that we stall.  No horn =(

 

[Marauder]

The best way to see where it is actually going off is to do slow flight to the point the horn is going off constantly or at least is chirping.

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