M20J Inner Gear Doors

[Bartman]

I was doing some cleaning and my springtime detailed inspection this past weekend and found a broken inner gear door bracket. It was the rear one that has 2 caged nuts and is U-shaped. No new damage to the inner or outer door, but they do have some previous repairs and appear to be fairly delicate. We removed both inner doors and we have started looking for a replacement bracket. The IA says he can probably just fabricate one if I can't find one easily. I know the POH states the inner doors can be removed for grass strips, and have considered just leaving them off.

Has anyone measured the difference? What is the ACTUAL speed penalty with just leaving the inner gear doors off ? (I think the POH says about 5 knots)

Jamie

[Cruiser]

for reference on the M20J 201 models I believe inner gear doors were first introduced on the 1987 205 then on all 201s in 1989 and thereafter.

I assume the Ks were similar.

My 1984 J does not now nor ever had inner gear doors.

 

5kts ? Hmmmmmm. I wonder if there is an upgrade?

[Bartman]

Not sure what to say about the 205.

My 1977 J Model POH is at the hangar, but i do remember reading that the doors can be removed for grass operations. The pages are all yellowed and came with the bird when she was hatched. I did not look in the logs, but i figure the POH reference is evidence that they were original equipment on 1TF ???

[201er]

I can tell you for sure that my '78 201 has inner gear doors and all other vintages of 201 that I've seen have them as well. I think they just changed the layout of the gear doors a little in those later models.

[Cruiser]

Sorry if I caused any confusion. I am taking the information from a spreadsheet that I got long ago. I don't know the source so I guess it's accuracy may be in question as well.

It lists the model years down the the page and the changes across the page. It shows "lower gear doors" on all models but starting as I listed above there were also "inner gear doors" listed.

I checked the parts catalog and the "lower gear doors" are called DOOR, INBD and identified as -18 in the diagrams.

there is also a diagram labeled Figure 2 - Main Landing Gear Door Assy (Enclosed) that shows a third door (-41) called PANEL, DOOR and the DOOR INBD (-18) is called MIDDLE DOOR Assy but these are only for serial number 24-3000 thru 24-3078

So, do the newer 201 model Js have completely enclosed wheel wells? What does the inner gear doors look like on newer planes?

attached is a picture of my plane that clearly shows the inner part of the wheel well exposed in flight.

[201er]

Yours totally has inner gear doors. Have you ever seen a piper from below? Their entire wheel is exposed!

[Jeff_S]

I had the leading edge of one of my inner gear doors crack so badly last summer that we had to just replace it. So I flew several trips with it missing, and I can't say that it impacted speed all that much. Nor did I feel any excessive drag on that side of the airplane. I think 5 knots would be an extreme example of speed loss, but that's just a gut feeling.

[Magnum]

See pictures 5-7, there you can see the inner gear doors of the 205 in operation:

http://www.mooneyspace.com/index.cfm?action=gallery&userGallery=22

 

 

[201er]

That closes up beautifully! Shame it only gives 4mph at most! I can see why they didn't standardize it on most models.

[PTK]

Quote: Bartman

I was doing some cleaning and my springtime detailed inspection this past weekend and found a broken inner gear door bracket. It was the rear one that has 2 caged nuts and is U-shaped. No new damage to the inner or outer door, but they do have some previous repairs and appear to be fairly delicate. We removed both inner doors and we have started looking for a replacement bracket. The IA says he can probably just fabricate one if I can't find one easily. I know the POH states the inner doors can be removed for grass strips, and have considered just leaving them off.

Has anyone measured the difference? What is the ACTUAL speed penalty with just leaving the inner gear doors off ? (I think the POH says about 5 knots)

Jamie

[Jeff_S]

Quote: JimR

I'm not suggesting that the terminolgy that I used is correct.  I just wanted to let you guys know that you were talking about two different things.  IMHO the 205's fully enclosed landing gear is the coolest thing ever.  I think that MAC abandoned it, though, in later models.  I read a comment once on either the MAPA or Mooney Tech List that it is difficult to rig. Perhaps that is why?  See gallery picture number 18 below for a photograph of the 205's landing gear door system.  In it it almost looks like you can see the inboard gear on the right main hanging open. 

Jim 

http://www.mooneyspace.com/index.cfm?action=gallery&userGallery=114

 

[Bartman]

Allsmiles,

0.180 AMU.....i dont know how they sell this stuff so cheap. 

Seriously, I figured that little $10 part would be at least $250. And if there is little or no speed penalty I considered just flying the way it is.

[Bartman]

Tried to create a new thread but the message didn't show up. Must be something to do with using the Ipad so here goes a try at responding to an existing thread.

we decided to go on a trip to Florida for our anniversary. Using the Garmin 430 our calculations consistently showed that we were about 6 knots slower than we used to fly. This is unacceptable so we will be getting a bracket and installing the inner gear doors as soon as practical.

On a side note, we were married on 5/5/05 at 5:55 exactly 7 years ago. The squawk code we were assigned was 5557 for our leg down the Florida coast....and NASA even shot off a rocket for us in celebration.

[Bennett]

I had forgotten about the third doors. About 20 years ago (time passes way too quickly) Paul at LASAR, and I, worked out a third door system to comletely enclose the wheels, and LASAR installed them on my 261 conversion.  I don't think that it used the same parts as the later MSE Js use. (Although the factory might have adapted it for the these later Js - I don't recall the time sequence) I really don't recall whether Paul created an STC for them, or if it was done on a 337 form. I do recall that they worked perfectly, and was just one more speed mod installed on that aircraft. With all the mods she was way faster than most, and she won the Sun and Fun sprint in the 1990s, and then the Columbus 500 (yes, 500 miles of WOT racing against about 40 aircraft) in that same year.  If you want those doors, you might contact Paul at LASAR and ask him about them.

[INA201]

I'm looking under my relatively new to me J and noticed marks where inner gear doors used to be. Looked it up in the parts catalog and sure enough I'm suppose to have them.  What do you guys think the effect of not having these are?  It seems like there would be a lot of turbulence where the opening is left along with the rear fairing there.  While looking around I found what looks like carbon fiber doors on a modded up 201 but I couldn't find where they are sold.  Does anyone have a solution that may be an improvement over stock or any other suggestions?  I've attached some pictures. Thanks gang!

[carusoam]

See the name TestWest?

You can send him a PM from here.

He is one of our resident aviation efficiency gurus.

The name he attributed is LoneStar Lo Profile Main doors.  That may be more of a challenge to find.

Of course, if you are looking for Mooney parts.  The Mooney factory still makes parts.  MSCs are the local source to supply Mooney parts.

what are the other two pictures from?

One shows a large bump that is behind the wheel when it is stowed.

The first photo shows a one pice gear door that looks the same as my ’65C had, no inner door for her either...

hope that helps some.

Best regards,

-a-

[PTK]

I looked into those inner gear doors as well. Those are composite gear doors. It was a Mod Works STC and then went to Lone Star Aero. Today it's orphaned.

[Jeff_S]

The effect of having the inner gear doors removed on a J is supposed to be about 5 knots, so it's significant.  When I had my J, I had trouble with the inner doors cracking and ended up having to replace both of them. I used LASAR and ordered refurbished units and then had them repainted to match at a local body shop. As I recall, the reforms were still ~$400 and change to buy, but once I got them on they were fine.

[INA201]

Thanks guys for your responses! The hump is a fiberglass fairing that is indicated in the parts manual. Without the inner gear doors I bet that fairing is slowing me down some.  I'm currently seeing around 145 knots in cruise and felt that I shoujd be in the 150 range or a little more.  I will PM test west and have e-mailed LASAR and see what comes out of that.  If I can go carbon/glass versus metal I'm thinking it might be better.  Lasar also sells some kind of wheel well baffle too.  While we are at it might just go ahead and put that in too and see how it all works out.  

[Marauder]

Thanks guys for your responses! The hump is a fiberglass fairing that is indicated in the parts manual. Without the inner gear doors I bet that fairing is slowing me down some.  I'm currently seeing around 145 knots in cruise and felt that I shoujd be in the 150 range or a little more.  I will PM test west and have e-mailed LASAR and see what comes out of that.  If I can go carbon/glass versus metal I'm thinking it might be better.  Lasar also sells some kind of wheel well baffle too.  While we are at it might just go ahead and put that in too and see how it all works out.  

Your 1978 J should be at least doing 155 KTAS. If you are seeing 145, something is slowing you down a lot.

Sent from my iPad using Tapatalk

[jetdriven]

155 at 75% power 2500 RPM . Some can only do 152 or so but 145 is slow.

i have the wheel well liners and the plastic gear doors.  I'd guess 2 knots for both.  

[Steve Dawson]

When I bought my J it didn't have the inner gear doors and after I bought a set from Scott and installed them. The plane picked up 5 knots. With a bit of rigging work and lifting the engine so the spinner wasnt lower than the cowling I can normally true out at 157-158 at 2500 RPM and 25MP or lower depending on altitude. 

[aviatoreb]

what do the inner gear doors look like?

[jetdriven]

Which ones 

[aviatoreb]

23 minutes ago, jetdriven said:

Which ones 

I don't know / if I knew I wouldn't be asking / something where I could look at my airplane and figure what I have?  I guess I have with whatever came stock on an 81'k which I presume is same gear stuff as an 82j.

 

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