Fabric Wings how long are they expected to last

[Steve Smith]

Question what is the thought on the life span of fabric wood wings? From what I can tell the fabric on the wings of my 59 A is the original material is that possible ? The log books go back to hour 1 and there is nothing on a recover beyond flaps and alerions... It is certified and just recently had its annual. Interested  to hear what others think  

 

 

[Hank]

Wooden Mooney wings are a special case. The typical fabric-covered wing uses fabric that is tightly stretched between ribs, with nothing under it, and uses a combination of tension and coatings (dope, paint, etc.) for strength. If the fabric tears, the wing surface literally disappears. 

A wooden Mooney wing is covered in beautifully patterned plywood that is laid atop the ribs, and will fly just fine with no fabric. My guess is that the fabric, paint, etc., lends a little strength but is mainly to protect the wooden surface from damage, chemicals, UV rays, etc.

The lifetime of the two is likely drastically different, the former being shorter is my official engineering estimate. But so much depends on the thickness and condition of the coatings, how well it absorbed into the fabric vs. laying on top of it, etc. Cracks in the paint are especially worrisome, as I would expect localized degradation of the fabric and wood from water ingress.

Maybe someone here could provide actual experience . . . .

[BKlott]

There are many variables involved with this. Is the covering material Grade A fabric or one of the newer, synthetic materials that have been developed over the decades. I’ve been told by those from that era that Grade A fabric could go bad in just a year or two. The newer coverings have demonstrated 25 years or longer when properly maintained.

Most experts recommend that wood and fabric aircraft must be hangared. Being left out in the weather, sun, UV exposure,  rain, etc. is not conducive to long life for wood and fabric. Additionally, we are told that these planes need to be flown regularly to “air them out” and you need to keep the drain holes open in the wings as well, otherwise the moisture in the wings can lead to deterioration in the structure.

How the previous owner(s) of the wood and fabric airplane you are interested in, used and maintained the airplane, will impact how long the wood structure and fabric covering will last. As a buyer, I don’t know how you can readily evaluate all of that.

[AerostarDriver]

So something I saw recently on an A model was fiberglassed wings in place of the fabric. I have no idea on the legality of such a configuration but interesting. Depending on what fabric was used, what process and how the covering has been maintained, I have seen fabric airplanes last 50-60 years with proper care. However, sun, rain, snow, dust are not friendly to fabric, neither is siting but that means flying in sun, rain, and encountering dust and rocks.

[carusoam]

Expect changing from one material to another to require an STC... often the material suppliers do this effort to sell their product...

For any M20A enthusiast (and Steve, the OP)... find pics of the wooden wings... pre-paint... they are a form of industrial art... 

Yes, the wood can last forever, but having a mechanic with wood working and inspection skills is really important...

For any natural material.. keeping them out of the weather, moisture, UV light, and rats... can be good  for your investment...  More for storage, than for operation...

For more info about fabric coverings....  these are not the fabrics you are familiar with... they are more a composite covering... with fantastic UV proof paint...

 

Search the trade name Ceconite for more details...
PP thoughts only, not a mechanic...

 

Best regards,

-a-

 

[kerry]

1 hour ago, AerostarDriver said:

So something I saw recently on an A model was fiberglassed wings in place of the fabric. I have no idea on the legality of such a configuration but interesting. Depending on what fabric was used, what process and how the covering has been maintained, I have seen fabric airplanes last 50-60 years with proper care. However, sun, rain, snow, dust are not friendly to fabric, neither is siting but that means flying in sun, rain, and encountering dust and rocks.

It's probably a Razorback covering.  The fiberglass fabric goes through the same dope process.  Supposedly Razorback has a life time warranty.  My understanding is that Razorback is difficult to work with and it much heavier.  If I ever redo my wing I would like to use Oratex.  No dope or chemicals.  Fabric comes painted and is lighter.  Just needs to be glue on wing and shrink it.

[vorlon1]

14 hours ago, kerry said:

It's probably a Razorback covering.  The fiberglass fabric goes through the same dope process.  Supposedly Razorback has a life time warranty.  My understanding is that Razorback is difficult to work with and it much heavier.  If I ever redo my wing I would like to use Oratex.  No dope or chemicals.  Fabric comes painted and is lighter.  Just needs to be glue on wing and shrink it.

Being from Arkansas, and thus a Razorback, I can state emphatically that being a Razorback is a lifetime commitment!

[Greg Ellis]

The first photo in this thread is of a Mooney Mite down at the Lonestar flight a Museum in a Texas.  It is the wood wings and fuselage without fabric to give you an idea of how beautiful the woodworking was on these early Mooneys.

 

 

[59Moonster]

If you look back through my posts, I uploaded some photo's of when my M20A's wing was redone in 1997. Even though it is wood, it is covered in sheet metal. 

[mike20papa]

SHEET METAL?!  MERCY!  Are you sure?  The fabric is painted with aluminized dope - is that what you are seeing?  

As far as the "life expectancy" of dacron/synthetic coverings, UV exposure is the only variable.  Keep it painted & hangar'd  and it will out live the pilot.

Edited October 6, 2020 by mike20papa
add photo

[59Moonster]

On 10/5/2020 at 8:02 PM, mike20papa said:

SHEET METAL?!  MERCY!  Are you sure?  The fabric is painted with aluminized dope - is that what you are seeing?  

Well now that you say that, I have no idea. Just doesn't look like fabric I've seen and don't know what aluminized dope looks like. 

Edited October 7, 2020 by 59Moonster
typo fixed

[carusoam]

If it is sheet metal...

Expect to see a lot of rivets holding it in place...
 

Grumman’s are the only planes I am familiar with that hold aluminum together with glue...

The maintenance manual probably holds a few clues to what is used where...

Best regards,

-a-

[mike20papa]

In the picture is the mahogany veneer (poplar core) plywood wing the "metal" aluminum colored portion is the Polyfiber coating "polyspray" an aluminized coating to block UV.  The orange colored area is the "polybrush" a fabric glue/sealer (first applied before the polyspray.  The only "sheet metal" covering on the wings is on the lower surfaces just fwd of the gear that enclose the main fuel tank bays.  They are screwed in place with #8 MS's

Edited October 7, 2020 by mike20papa

[carusoam]

Great photographic details Mike!

Thanks for posting them.

Best regards,

-a-