The International Cessna^® 170 Association

i bet that metal skin comes up a 'little bit' too.
and, gee, it corrodes awful!!
dave

Its interesting as both the Stinson and the Citabrias use the rivets to attach the fabric instead of rib stitching. Maybe no conection just an observation. Bill K

Regardless of the attachment method, it can be done incorrectly. No question about it: when buying a fabric airplane, it takes a practiced eye to spot the problems. There are airplanes out there that look terrific at 30 feet, but which the particular mechanic I trust with my J3 would refuse to annual.

3958v wrote:Its interesting as both the Stinson and the Citabrias use the rivets to attach the fabric instead of rib stitching. Maybe no conection just an observation. Bill K

I wasn't specifically stating that the airplane I saw was stitched instead of rivetted. I frankly didn't notice ... The point was the fabric was not tightly shrunk and/or doped or whatever the process used called for . The fabric was so loose that it billowed up on top of the wing in flight.

In an article written by a Stinson owner, http://www.stinsonflyer.com/sf-97.htm it is stated:"Step 7 - Wing cover. With the wing I choose the envelope method. This is a personal choice which I made because I wanted the wingtip sewed. Many others prefer the blanket method I used on the fuselage. Once the fabric is attached the next step si to heat shrink the fabric to tighten. After heat shrinking the Poly Brush is applied. Next comes taping, and rib stitching.

Since the lift comes from low pressure on top of the wings, there is a requirement to fasten the fabric to the wing. There are actually several means by which different manufactures secure the fabric to the wing. AC 43 shows rib stitching as the primary method. Stinson 108's came from the factory using PK type self taping screws. "

This is just in case any of you fly airplanes that take parachutists up for jumping: 105.43 makes the pilot in command of an airplane carrying jumpers responsible for the type of parachute, who packed it, and when it was packed. The person conducting the parachute operation is also responsible but those folks do not always hold an FAA certificate and they may not be around to explain it if their parachute does not function. If something goes wrong and the parachute was not packed properly or within dates, who do you suppose the FAA is going to hold responsible? PICs are also responsible for tandem parachute systems 105.45 and foreign parachutists/equipment 105.49. Curiously, we (PICs) are not responsible for static line jump equipment 105.47.
I would never dare to argue with Gahorn or ole Gar but these are the facts and pilots who want to limit their liability should know them.

gahorn wrote:I wasn't specifically stating that the airplane I saw was stitched instead of rivetted. I frankly didn't notice ... The point was the fabric was not tightly shrunk and/or doped or whatever the process used called for . The fabric was so loose that it billowed up on top of the wing in flight.

.......

Since the lift comes from low pressure on top of the wings, there is a requirement to fasten the fabric to the wing. There are actually several means by which different manufactures secure the fabric to the wing. AC 43 shows rib stitching as the primary method. Stinson 108's came from the factory using PK type self taping screws. "

Just to clarify what I'm sure George already knows but others might not who are reading this thread.

On a fabric covered wing, shrinking of the fabric, glue and dope do not attach the fabric to the wing ribs and they alone will not hold the wings airfoil shape. A mechanical means such as rib stitching, rivets, PK screws or clips are used to accomplish this depending on what method has been approved for that particular aircraft.

voorheesh wrote:...I would never dare to argue with Gahorn or ole Gar but these are the facts and pilots who want to limit their liability should know them.

I didn't think we disagreed on the PIC's responsibilities...and therefore I didn't see us in any disagreement over that point. The condition of any airplane the PIC intends to take up is his responsibility and is normally part of his pre-flight activities. I'm certain there are good, airworthy airplanes that are used for skydiving. I've just not personally seen very many that were. As Miles might say, "your mileage may vary". (And never hesitate to disagree with me...or you'll be in a small group.)

N9149A wrote:..On a fabric covered wing, shrinking of the fabric, glue and dope do not attach the fabric to the wing ribs and they alone will not hold the wings airfoil shape. A mechanical means such as rib stitching, rivets, PK screws or clips are used to accomplish this depending on what method has been approved for that particular aircraft.

Thanks, Bruce. I may not have been very clear on that. The airplane I witnessed had very loose fabric between the ribs...and the only thing holding the fabric to the wings was the stitches, PK screws, or whatever... The thing had such loose fabric (due to insufficient shrinkage of the envelope onto the wing) that it billowed excessively between ribs.

Skydivers - I flew a C182 and several Beech 18s hauling jumpers some years ago. Since I owned the planes, I guess I took my own risks, but they were in pretty good condition. Always carried an extra ignition key -as the stories go, the last jumper out grabs the key! That and a sharp knife in case a student got hung up using a static line, but nothing ever happened. We finally got a procedure worked out where the 182 was touching down about the time the last jumper was getting on the ground. Beech 18 was fun - 13 jumpers and me. I remember the time at an airshow when I got to sit with Bob Hoover in the pre-airshow briefing. Even made a few night jump flights with the 18, (but always with a full moon) when all the jumpers had lights attached somewhere - looked weird when glancing back in the cabin. With handles on the outside so they could all group around the door and go at once, someone was always crawling up the wing and looking into the cockpit!

Jumpers live in the fast lane - they always wanted to train me for free so I would be a better jump pilot (positioning the plane correctly for the jump), but I never took them up on it and never regretted it! Jumpers always wanted to jump out of different airplanes and get that in their logbook - a local doctor had a PT-19 that took a few on jumps, but they were pretty hard on the old trainer, so he declined after awhile.

Not sure there are many old, bold jumpers around!

I'm sorry fellows I thought that you were implying that the fabric had come loose from the ribs. Obviously if the fabric were not shrunk properly it could billow between the ribs with any type of attachment used. I do know that Cessna clips for fabric attachment can be a problem as I found quite a few that were not doing their job when I remove the fabric on mine. While that was the case it had not reached the point where it was affecting the flying characteristics. Bill K

George,

If "the lift comes from the low pressure on top of the wings", how in the world does an airplane fly upside down?

After all, JoAnn Osterud (sp.) flew her aerobatic biplane from Vancouver to Vanderhoof, B.C. inverted. How she do that, huh?

blueldr wrote:George,

If "the lift comes from the low pressure on top of the wings", how in the world does an airplane fly upside down?

After all, JoAnn Osterud (sp.) flew her aerobatic biplane from Vancouver to Vanderhoof, B.C. inverted. How she do that, huh?

Mirrors?????

blueldr wrote:George,

If "the lift comes from the low pressure on top of the wings", how in the world does an airplane fly upside down?

After all, JoAnn Osterud (sp.) flew her aerobatic biplane from Vancouver to Vanderhoof, B.C. inverted. How she do that, huh?

The "Lift from low pressure" comment is not my own. It was part of that website that I quoted. (But ...if the surface facing "up" is the "top"...I'd imagine that if an airplane were flown upside-down....that the "top" of the wing would now be that previous "bottom" that is now "up".)
Did you know that the Chinese stand on their heads?

On fabric airplanes: I'm not sure of the veracity of the story, but legend around Tullahoma, TN when I lived in the area, tells of one of the locals ferrying a Cub or similar airplane. While in flight in smooth air, all of a sudden the airplane banked hard over to one side on its own, requiring full opposite controls to counter. Then a few minutes later the problem "corrected" itself. Upon inspection, it was discovered that mice had chewed some or all of the rib stitching in both wings. One wing cover let go (balooned out) before the other causing the asymetric lift.

I guess the moral of the story is if you don't have personal knowledge of a plane's recent history, an inspection somewhat more thourough than a preflight is called for before a ferry flight!

Miles

WAL I DINT MEEN TO START A EXTRY LONG DISCUSSIN BOUT LOOSE FABRIC OR MICE EATEN THRU THU STRING HOLDIN ON THE FABRIC BUT I DO REMEMBER THAT WING ON THAT PERTIKLAR JUNKER WASN'T TITE AN SMOOTH. LOTS OF RUMPLED LOOKIN SURFACE LIKE SOMEBODY LEFT THEYRE DIRTY UNNERWARE ON THE RIBS AN THEN PUT THE FABRIK OVER THEM.

IFN IDA HAD A WAY TO PEEK UP THAR WHILE I WUZ FLYIN ALONG I PROLBY COUDA SEEN THE SKIN FLAPPIN UP AN DOWN THEN IDA HAD TO JUMP OUT WITH A PARASHOOT THAT I HAN'T INSPEKT AN VIOLATE SOME FAA RULE BOUT DROPPIN THINGS FRUM AEROPLANES! SO IMA GLAD I DINT NO THAT.

AND GEORGE YOU HIT ON THE NAIL HED WHEN YOU SED SOME PLANE WERNT' ABLE TO GIT OUT O ITSA OWN WAY. THATSA GOOD DESCRIBE OF THAT CITABERYA. NOW IMA GONNA GIT OUT O MY WAY AN GO TO BED AN DOOO IT MYYY WAYYY DAA DAA DUMMM - - DAA DAA DUMMM YEH I GOTS A BROTHER AN HE CAN'T SING TOO