0TreeLemur Posted Monday at 08:01 PM Report Posted Monday at 08:01 PM Having difficulty adjusting my lift detector. Despite the fact that it passes ground-test, it does not signal stall condition in the air. Thinking it might be an internal issue. I'm guessing that Mooney put that hole in the wing where it is for a reason. This poll will help me confirm that most are installed in the middle and that adjustment should not be necessary. Thx. Quote
MikeOH Posted Monday at 08:03 PM Report Posted Monday at 08:03 PM Hmm, I can't say for certain without looking at mine, but my 'visual memory' is that yours is pointing down way too much; might just be your camera angle. I'll try and get out to the hangar today and take a couple of pictures of mine. 1 Quote
EricJ Posted Monday at 08:10 PM Report Posted Monday at 08:10 PM Yours appears to be in the least sensitive (lowest airspeed) position, so moving it higher may make it start to trip. It may take a few iterations to get it in a useful spot if it has been moved. I marked mine before taking it out to rehab the switch, but it turns out that mine has very little adjustment room, anyway. I wound up pushing it up as far as I could and it is still only just working reasonable well. 1 Quote
0TreeLemur Posted Monday at 10:07 PM Author Report Posted Monday at 10:07 PM Thanks Eric. 1 hour ago, EricJ said: Yours appears to be in the least sensitive (lowest airspeed) position, so moving it higher may make it start to trip. Thanks for the photo. My switch is intermittent so it needs to refurbed. The good news is I think the switch installed in my J is the one that was manufactured by Mooney to be serviceable. It doesn't look like the FlightSafety version at all. 1 Quote
A64Pilot Posted Monday at 10:39 PM Report Posted Monday at 10:39 PM Stall warnings are adjustable, often by moving the assembly up and down, sometimes by bending the vane. If yiu bend the vane make sure the switch still clicks when yiu move it. As part of my production test flights I had to adjust them where they would go off 5 to 10 mph prior to stall in the landing configuration. A has been said moving them up increases the speed / decreases the angle of attack they will alert, down lowers it. They are very commonly bent by people walking by and snagging it or a fuel hose etc. If it works on the ground repeatedly, almost certainly it’s just out of adjustment or bent. Quote
MikeOH Posted Tuesday at 12:24 AM Report Posted Tuesday at 12:24 AM Here are photos of mine. It is an F so could be different. Quote
Fritz1 Posted Tuesday at 12:38 AM Report Posted Tuesday at 12:38 AM My TKS stall warning would not go off when I bought the Bravo, Brian Kendrick test flew the airplane and we moved the entire stall warning assembly up by about 1/8", had to install new rivnuts, perfect thereafter, bottom line airplanes came out of the factory with stall warning in need of adjustment 1 Quote
carusoam Posted Tuesday at 01:00 AM Report Posted Tuesday at 01:00 AM Before attempting to bend the vane… know that Mooney hardened it… expect it to break before it bends… also know that the vane pretty much marks where the split line occurs… at high AOA… the split line descends the face of the leading edge…. when the air going above the wing, includes the vane in its path... the vane trips the switch and sounds the alarm… The assembly has ordinary Honeywell micro switches in it… getting to the assembly is quite a hassle… ancient PP memories only… not a mechanic. testing the stall indicator prior to flight became part of my usual check list after I went months without hearing a peep from it. best regards, -a- 1 Quote
carusoam Posted Tuesday at 01:17 AM Report Posted Tuesday at 01:17 AM When comparing stall vane locations… keep in mind we all fly the same wing… but, the higher MGTW of the mid and long bodies… may show a different location of the vane… the construction of the vane location definitely got a different mounting hole as aerodynamics became more importanter… if you make a few flights while adjusting the vane location… see if you can chart mm vs. Speed(alarm) may need to bracket a couple of speeds… Check the maintenance manual to see if there is a procedure for this??? Best regards, -a- Quote
0TreeLemur Posted Tuesday at 01:19 AM Author Report Posted Tuesday at 01:19 AM Comparing mine with the photo that Skip posted above, I don't see an obvious difference in terms of the location. The vane on Skips (top) seems to be bent down a bit more than the vane on mine (bottom). But the position on the wing seems quite similar. I'm really starting to suspect that the problem with my stall warning is in the mechanism rather than its set point. Like I wrote previously it does sound when I lift the vane during a ground check. I does not sound when doing a stall aloft or in the landing flare. The S&MM does have an entry. It is posted above. I'm not at that stage yet- trying to determine if it is a setting error or an internal switch mechanism problem. Plus the Phillips heads on the two adjustment screws on my bird are just about stripped. Quote
carusoam Posted Tuesday at 01:23 AM Report Posted Tuesday at 01:23 AM 45 minutes ago, Fritz1 said: My TKS stall warning would not go off when I bought the Bravo, Brian Kendrick test flew the airplane and we moved the entire stall warning assembly up by about 1/8", had to install new rivnuts, perfect thereafter, bottom line airplanes came out of the factory with stall warning in need of adjustment We have an interesting thread regarding the heated stall vanes… around here somewhere… this device becomes more important as ice changes the shape of the wing…. And the weight of the plane climbs into an unknown regime… where expected stall speeds may be higher than ever experienced before… Go FIKI! Best regards, -a- Quote
carusoam Posted Tuesday at 01:30 AM Report Posted Tuesday at 01:30 AM 6 minutes ago, 0TreeLemur said: Comparing mine with the photo that Skip posted above, I don't see an obvious difference in terms of the location. The vane on Skips (top) seems to be bent down a bit more than the vane on mine (bottom). But the position on the wing seems quite similar. I'm really starting to suspect that the problem with my stall warning is in the mechanism rather than its set point. Like I wrote previously it does sound when I lift the vane during a ground check. I does not sound when doing a stall aloft or in the landing flare. The S&MM does have an entry. It is posted above. I'm not at that stage yet- trying to determine if it is a setting error or an internal switch mechanism problem. Plus the Phillips heads on the two adjustment screws on my bird are just about stripped. I have seen pics of the stall vane and switch assembly around here before… probably has part numbers of the switch itself included in the discussion… and what was used to clean the switches. having a spark plug hole camera will probably be helpful to determining the best route of action… iirc… it’s a long way from the access panel to the leading edge area… Best regards, -a- Quote
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