Aspen2013 Posted July 6, 2020 Report Share Posted July 6, 2020 This sound occurs when airspeed gets in the yellow arc and sometimes in moderate turbulence when the plane drops. What is making that sound and where is sensor? Or could it be an air leak around door seal? These models have terrible door seals. Wish I had inflatable seal. Quote Link to comment Share on other sites More sharing options...
Hank Posted July 6, 2020 Report Share Posted July 6, 2020 My little C makes a pretty good whistle above 180 mph indicated (yellow starts at 175). It may just be airflow around the cabin / antennas at high speed. Quote Link to comment Share on other sites More sharing options...
carusoam Posted July 6, 2020 Report Share Posted July 6, 2020 Somebody mentioned nose wheel doors the other day... a particular attitude was the initiator... Since an Acclaim has electronic sounds for the stall and gear horns... I wouldn’t expect a buzzer to be in the design. Take a look at all the gear doors... see if they have any obvious marks where the closed position is... This is a free take a look kind of thing... if you discover any funny wear marks... put the plane up on jacks to adjust the gear doors... PP thoughts only, not a mechanic... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
MIm20c Posted July 6, 2020 Report Share Posted July 6, 2020 Imperfections in the skin, like hail damage for example, could possibly produce unusual noises. Quote Link to comment Share on other sites More sharing options...
Aspen2013 Posted July 6, 2020 Author Report Share Posted July 6, 2020 I noticed that the nose wheel doors had the seals falling apart. Some of it was hanging down and i had to cut that piece off. Anyone have a suggestion for replacement seal? I was going to get some thin weather strip from Home Depot. Quote Link to comment Share on other sites More sharing options...
carusoam Posted July 6, 2020 Report Share Posted July 6, 2020 Sounds like you may have just found your source of vibration... See if you can find the same dimension of seal... the gear door tightening may require adjustment if a new seal is a different dimension... PP thoughts only, not a mechanic... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Aspen2013 Posted July 6, 2020 Author Report Share Posted July 6, 2020 not really vibration but sounds like an air horn at low volume. Today was first time I heard it after takeoff and climbing out and during turns. Went away after straight and level flight. The only time before that is in some rough turbulence and when I dipped into yellow arc on a smooth cool air morning in a rapid descent. Quote Link to comment Share on other sites More sharing options...
MooneyMitch Posted July 6, 2020 Report Share Posted July 6, 2020 7 minutes ago, Aspen2013 said: not really vibration but sounds like an air horn at low volume. Today was first time I heard it after takeoff and climbing out and during turns. Went away after straight and level flight. The only time before that is in some rough turbulence and when I dipped into yellow arc on a smooth cool air morning in a rapid descent. Sound is vibration. As Anthony stated, you possibly have found your horn sound (vibration). Quote Link to comment Share on other sites More sharing options...
Aspen2013 Posted July 6, 2020 Author Report Share Posted July 6, 2020 Very true that sound is vibration by an acoustic wave propagating through a medium (in this case air) vs that from vibration of say two metal surfaces that may be felt or heard from propagating through metal. Like something loose. Thanks though so we are clear.:) Quote Link to comment Share on other sites More sharing options...
carusoam Posted July 6, 2020 Report Share Posted July 6, 2020 Going on prior experience... Some MSer reported a very similar challenge... They found the gear doors had become loose and the attitude of the plane during the climb had them make noise... It wasn’t that long ago either... It will be interesting to see if this experience is similar to that experience... We can also search for the other experience to see what else may have been found... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
jlunseth Posted July 6, 2020 Report Share Posted July 6, 2020 An induction leak can play like a flute. Really loud if it is in the right spot. Quote Link to comment Share on other sites More sharing options...
Aspen2013 Posted July 12, 2020 Author Report Share Posted July 12, 2020 Update. Didn't realize how bad the nose gear landing door seal was. Only the long edge had some remaining. I saw it hanging down and had been removing it slowly. The leading and trailing edges had nothing. I found this rubber type strip. It flattens well to about the same thickness as original (which is probably worn out flatter). Same width. Cleaned to bare metal and applied. It has self adhesive backing. Flew it and went for nose dive. Not a sound. I played with the vents as well opening and closing them with the main control knob and the fish eye ones. Nothing. I believe the nose gear doors were the culprit. Someone was a genius!! This material I think will me more durable. I will check fit more next time the plane is up on jacks. Thanks everyone! Ken Quote Link to comment Share on other sites More sharing options...
carusoam Posted July 12, 2020 Report Share Posted July 12, 2020 Somewhere along the way... Mooney is going to hire a polymer engineer just for their seals... Might take a week of work. Doors baggage Landing gear... 3M makes some good products. Nice pics, Ken! Best regards, -a- Quote Link to comment Share on other sites More sharing options...
ArtVandelay Posted July 12, 2020 Report Share Posted July 12, 2020 My J parts manual only shows the seal on leading edge, of course mine doesn’t have a seal, I don’t remember seeing any on other Mooney I’ve looked at. Am I missing a 5 knot speed mod? Quote Link to comment Share on other sites More sharing options...
Aspen2013 Posted July 13, 2020 Author Report Share Posted July 13, 2020 All 3 edges had remnants of door seal. This is on Acclaim Type S. The doors are different than on my K model. Sure they changed things. Quote Link to comment Share on other sites More sharing options...
bradp Posted July 13, 2020 Report Share Posted July 13, 2020 Might be useful to stop chafing too Quote Link to comment Share on other sites More sharing options...
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