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Inner gear doors on 231?


Austintatious

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Hello everyone.... I know this has been discussed before, but when I search for info I do not find what I am looking for.

I have year models 79 and 84 M20k (231's)  with Rocket conversions.  Neither of them have inner gear doors.  And the plastic fairings that mount below the wings and behind the wheels are also missing.  Both have brake calipers on the rear (I think that was a mod.)

The thing is, when I search on the interwebs, I find pictures of M20K 231's that both have and do not have the inner gear doors.  Yet when I search for gear doors I find no source for M20k 231 replacements. 

So what gives, did 231's have inner gear doors or not? 

Can they be added?  Will the M20k doors fit?

Are there replacement plastic fairings available? (the conical trailing plastic that sits under the wing behind the tire)

If you are wondering WHY I am asking this....  My aircraft both have every speed mod that can go on them.  In fact one of them even lacks a step.  Yet they do not make the published rocket speeds.  I know those speeds are probably a bit optimistic.  However, I can feel/hear the rumble of tumbling air coming from somewhere in the aircraft.   I was trying to figure out where is is coming from and the only 2 places I think it could be coming from is either the cowl flaps, or the open wheel wells.  The sound does not change when the Cowl flaps are opened/closed.  So I started exploring the wheel well situation.

It would be fun to add these and note any differences they make, noise and speed wise.  I have a good grip on how these perform so I could make a pretty solid comparison if I did it.

 

Lo Profile Gear door mod, in flight.jpg

 

 

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The 231's did come with inner gear doors. I think some people take the inner gear doors off to make it more convenient to access and inspect/replace the brakes and other things that live in that area. The fairings are also available through Mooney or as suggested above you could make them yourself or find someone on here that has made them and may be willing to help you out by making you some replacements.

When I purchased my 231 the inner gear doors had been removed and after a month or two of flying one of those fairings behind the gear departed while in flight. When the fairing came off there was definitely more wind noise and in certain attitudes vibrations that hadn't been present prior to the fairing coming off. I was able to order the fairing through an MSC and when I took it in for the repair I also had them add the inner gear doors back to my aircraft. The inner gear doors did improve my speed by one or two knots and of course the fairing being put back on eliminated the noise and vibration.

I'm pretty sure you could score some inner gear doors through an MSC or from an aircraft salvage yard. 

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Hard to tell from the picture but looks like it already has the modworks fiberglass doors so the rear fairings are removed. Might need to check how the doors are rigged at annual. Any gap in the leading edge let’s air in and it pulls them open even more in flight.

To make it quieter supposedly the wheel well liners help but they don’t do anything for speed.

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I wonder if the OP planes had the modworks IG doors and they were taken off at some point - if you already had the caliper  rotation this would be the best route forward. 
 

IG doors are often removed if the plane operates from an unimproved field. 

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I had to replace one of my inner gear doors a few months ago. Mooney/Lasar said it'd take at least a month and $1200.  I found a replacement at Wentworth salvage for $500 - got them in less than week. Here: http://www.wentworthaircraft.com/

I believe the part numbers are 550060-001 (lhs) and 550060-002 (rhs)

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56 minutes ago, Austintatious said:

Thanks everyone,  Yes the pic in my OP is just an example of what I would like to put on my mooney.

I hear those CF lower doors are sort of an orphaned STC.  Surprised Laser didnt pick it up.

LASAR hasn’t even maintained a lot of their own STCs. I suspect there’s not enough money in mods anymore. 

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