Ever wonder what a small aircraft's wing looks like? Now you know courtesy of a fuel sender leak!
Piper Spar, Ribs and Some Plumbing
- Thread starter wings&wheels
- Start date
Here is the spar in my Cessna Cardinal 177RG. There is an AD (airworthiness directive) that requires an inspection and Eddy Current of the spar lower web for cracks and corrosion. I treated and painted the spar back in 2007 after purchase, and had to strip the paint for the recent inspection as the Eddy Current was a bit wonky through the paint. There were no defects found, and I re-treated the spar per the AD, with Alodine, and corrosion inhibiting primer, along with the required CIC (corrosion inhibiting compound, like thick oil) on top.
The Cardinal spar is pretty much the same as the 1000 pound heavier Cessna 210, so it is very, very strong. The inside of the wing is similar. Very beefy.
Here is the spar with alodine on it, after the Eddy Current.
The Cardinal spar is pretty much the same as the 1000 pound heavier Cessna 210, so it is very, very strong. The inside of the wing is similar. Very beefy.
Here is the spar with alodine on it, after the Eddy Current.
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Brings back some memories nightmares.
I had a job early on in my A&P days replacing the fuel bladders in an Aztec. My knuckles were scraped and bleeding so much by the time I was done I looked like I had just come out of a horror movie. The guy I was working with, the most straight laced, laid back, non-profane person you would ever meet... was dropping low volume F-bombs like I had never heard. Kind of disturbing and hilarious all at the same time. The bladder had U-shaped clips on every corner that hooked onto the inner wing, and we had a couple that just did not want to snap into place. I worked on a few Pipers over the years but that one was the worst.
I had a job early on in my A&P days replacing the fuel bladders in an Aztec. My knuckles were scraped and bleeding so much by the time I was done I looked like I had just come out of a horror movie. The guy I was working with, the most straight laced, laid back, non-profane person you would ever meet... was dropping low volume F-bombs like I had never heard. Kind of disturbing and hilarious all at the same time. The bladder had U-shaped clips on every corner that hooked onto the inner wing, and we had a couple that just did not want to snap into place. I worked on a few Pipers over the years but that one was the worst.
I did an owner-assist annual on my old Tomahawk......treating and repainting the aft fin bulkhead from the inside. I'll put that up there w/ the Aztec effort!
The light aircraft are difficult to work on. They are not designed with service in mind, and the most simple of tasks can take weeks.
The larger, more professional built aircraft are made with a very different set of design criteria. Often with adequate access, and very high quality components.
A Gulfstream G550's horizontal stab lower skin replacement due to a tiny spot of corrosion. Notice there is no spar. Just stringers. The skin is very thick about 1/4 inch, and is the structure.
The larger, more professional built aircraft are made with a very different set of design criteria. Often with adequate access, and very high quality components.
A Gulfstream G550's horizontal stab lower skin replacement due to a tiny spot of corrosion. Notice there is no spar. Just stringers. The skin is very thick about 1/4 inch, and is the structure.
That "y" fitting is a thing of beauty.The light aircraft are difficult to work on. They are not designed with service in mind, and the most simple of tasks can take weeks.
The larger, more professional built aircraft are made with a very different set of design criteria. Often with adequate access, and very high quality components.
A Gulfstream G550's horizontal stab lower skin replacement due to a tiny spot of corrosion. Notice there is no spar. Just stringers. The skin is very thick about 1/4 inch, and is the structure.
Some more anatomy shots from the shop visit should anyone find this interesting:
1) engine w/ rocker box open to stake or lap intake valve in situ; low compression on that cyl despite low time engine
2) open floor w/ control runs and autopilot servo
3) fuel tank w/ leaking sender seal. interesting that the inboard and outboard senders are wired in series and the indicator reads total resistance.
1) engine w/ rocker box open to stake or lap intake valve in situ; low compression on that cyl despite low time engine
2) open floor w/ control runs and autopilot servo
3) fuel tank w/ leaking sender seal. interesting that the inboard and outboard senders are wired in series and the indicator reads total resistance.
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Interior appears original?
Recovered a few years ago in the same glorious antique goldish/tan velour and carpet as original, except for the dark brown floor carpet! I tend to keep things original, no matter how out of style. My Wife once described the interior as from a "...70's (adult movie) flick." Amazed that Piper carried this design into the late 80's.
Looks a bit dirty in the pics, but the interior is in excellent shape. Can't seem to source some of the original materials easily anymore, so will probably modernize at some point.
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I wouldn't touch it either if it's in good shape and it still matches the paint scheme besides. How about avionics? Yes GA design advances at a snail's pace.
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We updated the panel; Garmin 430, backup electric AH & skid/slip in the turn coordinator spot, had the remaining KX155 and KAP150 autopilot overhauled, transponder w/ ADS-b, etc. Considered the Aspen upgrade, but I do like the steam gauges...would be nice to lose the King horizon and dg though.
With the 210 spar issue they should have engineered it more redundant ,like 2 piece bonded and riveted or bolted so if one cracks there is still support. Cutting corners with materials for important aircraft structure is not a good idea. Even using struts like 172's etc. why not?
There is absolutely no strength shortcoming in the 210 or 177 spar, the only one in the world to have failed was both corroded and regularly severely overloaded in a cyclical manner. Not to mention it was never inspected or cleaned. From crack initiation to failure took 3,300 hours!
Note: The 177 spar has more than 110,000 pounds tensile strength and is loaded to 12,000 Lbs at 3.8G. The 210 spar is a bit thicker and has a similar safety margin.
However, I get your point that a single structural point of failure should never bring a plane down. Makes me think of the Extra 300L's carbon fiber spar. It is an extremely simple dual spar setup. Looks a lot like 2ea 2x8 boards glued together. Certified to +/- 10G, tested to 20G without failure.
It wasn't a spar but I worked on parts for a certain jet liner that were used as a hinge, it was made of titanium 2 plates with the proper holes, then they were bonded and a few rivets, sandwiched for redundancy from cracking. I would guess they as well could stand plenty of stress and high tensile strength as well. Its just the proper way to do things in the aviation world, bad things can happen if not done so.
Hasn't carbon fiber been known to delaminate? I trust it in aircraft just like I would on a submarine.
Hasn't carbon fiber been known to delaminate? I trust it in aircraft just like I would on a submarine.
Hasn't carbon fiber been known to delaminate? I trust it in aircraft just like I would on a submarine.
There is always the risk of composite delamination. The sub is a great example of what not to do, that being using carbon/kevlar/fiberglass in compression. In the example I gave, the Extra 300L aircraft, I am unaware of any spar failures, faults or delamination. They are very, very well built. Simple too. The good news is that a properly built composite structure does not suffer from corrosion or the type of fatigue failure that can cause an aluminum part to fail over time.
I can see composite if combined with metal, like some large helicopter blades are made.
Remembered to snap a pic of the interior in all its original material lurid detail....The panels and seats are in such good shape, even the Mylar piping, that I cannot justify updating them and I am a bit of a purist but gold/tan velour..
I did install Airtex brown carpets a while back that were quite an improvement and makes the rest of the interior a bit easier on the eyes.Yes we old guys fly w/ memory foam backside cushions and I need to remove the pen marks from the side panel...one guy I let fly does that!
Cherokee seats are some of the worst for your back...I don't blame you at all for the extra cushions! Looks ike you need to relegate your friend to First Officer and a pencil
Does carbon fiber laminate suffer from UV light deterioration like plastic does?
