M20C Spar Corrosion - options?

[westbrookgolfer]

Hello Mooneyspace members, as a new registered member, I'm looking for a little help from more knowledgeable mooney owners about my options in relation to my newly found issue relating to excessive corrosion around the spar.  I've owned my "C" model for about 4-5 years and have relied on a local AP to provide service and keep me out of trouble when it came to catastrophic issues regarding this plane.  After I bought out the FBO owner (and co-owner) of this plane, an inspection was done indicating no non-repairable issues relating to corrosion.  After a slight weep in one of the tanks (which was repaired by my AP about 1 year ago) it was weeping again and had another AP perform the annual AND fix this weep.  When the corrosion was discovered on the spar.  I simply don't have the funds to repair what will amount to nearly full value of the plane in spar/wing repairs.  I guess I can sell parts off the plane but this would amount to basically giving up on flying and I love it too much to do this.  I have a wonderful engine with about 450 hr (2000 TBO) and re-configured the panel and added a G430.  Is it better to just purchase different wings? repair the spar? or just part out and call it a learning experience....anyone know of a place who buys plane for parts?  I appreciate any assistance from this knowledgeable group - thanks.

[Sabremech]

I guess I'll be the first to jump in here. I have a 66 C model as well. First, where on the spar is the corrosion? Not all corrosion is condemning of the aircraft or the spar. Do you have any pictures of the area of concern? There are a lot of Mooney knowledgeable people and mechanics on this forum that I'm sure will weigh in that it's not necessarily the death of your airplane. If you'd rather not post pictures on a public forum, I'd be happy to try and help you make a determination as to whether it's repairable or not. My e-mail is sabremech_gmail.com ( just change the _ with a @)

David Staffeldt

[westbrookgolfer]

Thanks Sabremech - Yes, I have pics but they are at the AP offices.  I've done a bit of research and seen some photos of some really bad corrosion and my issue doesn't look anywhere near the extreme of what I've seen on the net but I'm not in a position to make that call.  I'll gather them tomorrow and post them...thanks again, I appreciate your assistance.

[carusoam]

Where is the plane located?

I like David's idea for assessing what you have.

I sold my 65C after my MSC condemned it. You don't want this. This just happens to you....

There are a couple of planes in the parts for sale area of this website. But that would be very expensive as well.

Assess what you've got. Take it to a place that will be able to fix it.

Typical of spar corrosion is taking it appart layer by layer resolving the corrosion then reassembly.

Often the corrosion looks worse than it is and can be properly treated at the visible surface.

Good luck,

-a-

[Alan Fox]

I've seen spar corrosion repairs done on stringers and splice plates , anything other than splice plates , and you are removing the wing and jigging it......probably starting around 15K + Personally I would really have to love a plane a lot to go that far........from a strictly dollars and sense point , its probably a part out.......  A used wing , is in the 5 to 8 K price point.....and a lot of labor.... The Pressleys in Morristown Tenn. buy Mooneys in all different states of dissarray.....

[jetdriven]

120-150 hours labor can swap a whole wing on a M20C.  Also, AC43.13 gives you 10% of thickness reduction for various reasons. If you are over that amount, its bad news.  However, I can see buying a used wing for 8 grand and swapping it out. It will take time, but it can be done.

[carusoam]

Jerry would be a source if you need to sell...

[Piloto]

When I was based at TJIG I saw plenty of plane and boat corrosion on the main structure. None was a reason to condem a plane. From what you describe your corrosion location is probably on the wheel well area on the spar web. This type of corrosion is repairable without  major disassembly. Very important that you check the center spar cap splice located on the back seat floor. This location get wet when it rains from water entering the access covers in front of the windshield that runs through the carpet all the way to back. The splice is repairable (replace) but more labor is required.

 

José 

[Alan Fox]

When I was based at TJIG I saw plenty of plane and boat corrosion on the main structure. None was a reason to condem a plane. From what you describe your corrosion location is probably on the wheel well area on the spar web. This type of corrosion is repairable without  major disassembly. Very important that you check the center spar cap splice located on the back seat floor. This location get wet when it rains from water entering the access covers in front of the windshield that runs through the carpet all the way to back. The splice is repairable (replace) but more labor is required.

 

José 

I saw a guy do the lower splice plates in the plane , looked like a lot of work.......I cant remember what they are called , but mooney uses a lot of fasteners that are not rivets , that make it a lot easier to work on the spar , They are a stainless headless bolt with a breakaway nut .....They are a lot more expensive than rivets.....

[N601RX]

Where are you located?  If I were in your situation I would want to fly it to one of the better known MSC that have had to deal with this before and get their opinion.  If a large length of the spar is involved, you may not have any choice but to replace the wing or spar cap.  If it is just a small section, it may be possible to get a DER to draw up and approve some form of local repair to the damaged area.  I know someone who replaced the wing in their C model several years ago.  Some of the bolt holes did not line up exactly and they had to ream and use oversized bolts.  I also read about a shop up in the northeast somewhere that had replaced a couple of spar caps without replacing the entire spar.

[westbrookgolfer]

thanks everyone, I appreciate your input.  if I can figure out how to post pictures here, I'll have two pics of the corrosion for everyone's perusal.

[westbrookgolfer]

Here are two of the pics coming from my A&P - any feedback would be appreciated.

[Alan Fox]

That is not actually the spar , that is the stringer that works like a spar cap.... It doesnt look that bad , I think any older mooney would have a little somewhere under the old sealant , can it be scotchbrited and alodined??? It doesnt look that deep....  

[M20F-1968]

I have a nice 1967 wing which is available for purchase.  It has no damage or corrosion.  This may be your cheapest option.  You can e-mail me at johnabreda@yahoo.com or call me at (617) 877-0025

 

Thanks,

John Breda

[N601RX]

It looks to me like there may be additional corrosion between the spar cap and wing skin that the picture is not showing. In one of the pictures the skin appears to be pushed down from the spar cap. When you see this it is usually an indication of corrosion between 2 parts.

[carusoam]

John B,

Can you post a photo of the wing you have available? Specifically, the area in question showing no corrosion vs. the golfer's indicated corrosion...

Best regards,

-a-

[KSMooniac]

Hard to tell from the pics IMO, and I'd say a second educated opinion is definitely in order!  The areas on the outside don't look awful to me, but I would be concerned what is lurking between the pieces and that of course is hard to inspect.  

 

Nothing is impossible, but you might be looking at a lot of work and/or expense to make it right.  It sounds like an otherwise great plane that is worthy of saving IMO, so I sure hope you can do so.  A wing swap might be the least labor, but could be expensive.  At least with the wing off you'll get a great opportunity to clean and seal the tanks and paint the wing to match while it is easier to manipulate.  If the corrosion is very localized, then some in-situ disassembly and repair would feasible too.

 

FWIW, I'm parting a 1981 J model currently with a damaged wing, but the spar appears to be pristine.  It would be a good candidate for a spar-ectomy if that is even possible, but I fear the labor required would be scary.  If some donor pieces could be useful, then let me know.

[Alan Fox]

No sparectomy , Those stringers run half  the whole lenghth of the wing........A huge undertaking , used will be the way , if it needs to be replaced...

[OR75]

I once inquired about what it takes to ship a Mooney overseas. I was at an FBO and saw many  Cessnas in containers ready to go.

The answer was that it  was probably best (cheaper) to fly a Mooney to its destination or hire a ferry pilot.

 

Cessnas: wings are easily taken off and tied to the container wall while the main frame sits tied town in the middle

 

Mooneys: too much work to do it the Cessna way.  If you really want to put it in a container, probably best to remove the tail cone.   

[Alan Fox]

I watched the guys at Airmods do it once , wasnt too bad , but didnt look as easy as most , I think the determining factor is the wing is basically one piece, you cant split it........I hope I never have to take a wing off my beech , but if I do its 4 nuts , wires and cables.....

[KSMooniac]

I watched two Mooney factory mechanics disassemble a complete Ovation and put it on their special trailer and haul it back to Kerrville.  They did the job and were on the road in less than 8 hours, so it is quite possible.

[westbrookgolfer]

I once inquired about what it takes to ship a Mooney overseas. I was at an FBO and saw many  Cessnas in containers ready to go.

The answer was that it  was probably best (cheaper) to fly a Mooney to its destination or hire a ferry pilot.

 

Cessnas: wings are easily taken off and tied to the container wall while the main frame sits tied town in the middle

 

Mooneys: too much work to do it the Cessna way.  If you really want to put it in a container, probably best to remove the tail cone.   

not sure where this international destination came from but this is a michigan based plane and will remain so - thanks for your input anyway...much appreciated.

[rbridges]

just out of curiosity, was the corrosion discovered when they were sealing the tanks?  Is it something that would have been seen when they installed my bladders?

[Hank]

I once inquired about what it takes to ship a Mooney overseas. I was at an FBO and saw many  Cessnas in containers ready to go.

The answer was that it  was probably best (cheaper) to fly a Mooney to its destination or hire a ferry pilot.

 

Cessnas: wings are easily taken off and tied to the container wall while the main frame sits tied town in the middle

 

Mooneys: too much work to do it the Cessna way.  If you really want to put it in a container, probably best to remove the tail cone.   

 

That's because Cessna gear is mounted to the fuselage, and the wings and tail feathers are individually removeable. Mooney gear is mounted to the wing, so two cradles are needed:  one to support the fuselage, and one to stand the entire wing on the leading edge [the whole thing is one big piece]. Tail feathers are removed by drilling out the rivets just behind the baggage door, removing a couple of tiny bolts and disconnecting the trim jack screw. That also takes some sort of cradle for support, to say nothing of a huge crate if that is your option.

 

Lots of things to do removing a wing--power to the lights/strobes in the wingtips, fuel lines, disconnect the gear mechanism, aileron control rods, flaps, static lines to the pitot, my VOR antennas are also in the wingtips.

 

Lots of things to check a donor wing for besides corrosion:  proper wingtips; lighting and strobes; antennas; condition of fuel tanks & sealant; condition of landing gear, actuation mechanisms, wheel bearings, Heim bearings; condition of flaps and ailerons, control rods, linkages, bearings; condition of the static lines and pitot tube; etc., etc.

 

Good luck with your C! They are really great planes.

[westbrookgolfer]

That's because Cessna gear is mounted to the fuselage, and the wings and tail feathers are individually removeable. Mooney gear is mounted to the wing, so two cradles are needed:  one to support the fuselage, and one to stand the entire wing on the leading edge [the whole thing is one big piece]. Tail feathers are removed by drilling out the rivets just behind the baggage door, removing a couple of tiny bolts and disconnecting the trim jack screw. That also takes some sort of cradle for support, to say nothing of a huge crate if that is your option.

 

Lots of things to do removing a wing--power to the lights/strobes in the wingtips, fuel lines, disconnect the gear mechanism, aileron control rods, flaps, static lines to the pitot, my VOR antennas are also in the wingtips.

 

Lots of things to check a donor wing for besides corrosion:  proper wingtips; lighting and strobes; antennas; condition of fuel tanks & sealant; condition of landing gear, actuation mechanisms, wheel bearings, Heim bearings; condition of flaps and ailerons, control rods, linkages, bearings; condition of the static lines and pitot tube; etc., etc.

 

Good luck with your C! They are really great planes.

thank you hank, really great info.  I hope I can keep my plane in the air, one of the great joys