172 / 170B wing change

[jatkins]

I know the wing is a 172 wing .
( the fuel vent behind the strut , is the give away )
seems no has picked up on that yet ?
Once I get through this I will get a STC for the fuel vent
behind the strut.
I REALLY like the vent there vrs above the cabin.

John

[GAHorn]

.( the fuel vent behind the strut , is the give away )
seems no has picked up on that yet ? ...John

Perhaps it's because you didn't offer that info as a clue. The early straight 172 had the same gooseneck fuel vent as the 170A/B. Just because you have a vent behind the strut still does not identify the wing as from a 172. You might have a 172 fuel system in a 170 wing, and THAT would indeed create a bit of a documentation problem.

[Bruce Fenstermacher]

OK in reality it would appear that you could have a 172 wing in the view of the casual observer.

BUT

If there is a reasonably priced, and available (read that currently being offered) STC for the 172 fuel vent system to be installed in a 170B wing,

THEN

I'd say you still have a 170B wing with a 172 fuel vent system installed that you need to document and obtain the approval (STC).

[n2582d]

John,
I recently went through an IA renewal course online. On the subject of field approvals they talked about AC 43-210 which says,

"105. What are the two ways that an ASI may approve an alteration or repair?

a. Examination of data only (one aircraft). This is the most common kind of field approval. ... .

b. Physical inspection, demonstration, and testing (one aircraft). This field approval is typically used when:

(1) A major alteration or major repair has been made to the aircraft by a person or persons unknown and no substantiating approved data or maintenance record exists; or

NOTE: When an alteration or repair is made by person(s) unknown and without substantiating data, the mechanic or repair station may correct this discrepancy by creating a data package based on the installation and equipment already installed in the aircraft and submitting it to the ASI for approval. When it is approved, the ASI may inspect the aircraft. If the data package is acceptable, the ASI will sign in block 3 of FAA Form 337, approving the installation or repair based on his or her inspection or testing of the alteration or repair. If an alteration or repair is made that can be approved by a physical inspection or demonstration and testing, rather than just data, or if creating a data package is not practical, the ASI will perform the inspection and then sign off in block 3 of FAA Form 337.

(2) An alteration is installed, tested, and the ASI witnesses that test."

The course gave the example of an IA who when checking the records "finds that the (wrong model) engine has been in the airplane for 8 years and has 1100 hours on it -- this would be an example of an alteration that has been thouroughly flight tested. In a case like this testing would be complete and it would be just a matter of signing block 3 (of the 337 form) approving the alteration by physical testing."

I'm not sure how Canadian regulations compare to our FAR's. If something like this is not allowed north of the border could you fly south and have it your 172 wing installation approved in the US?

Although the O-300B is not approved for the C-170B mine has been on my plane for years. If the FAA doesn't see that it is the same thing as a C-145-2H which is approved for the C-170 I plan on getting the engine approved going this route.

[jatkins]

THANKS Gary,
Good post. I will take that question to the AME, and see what the reply is.

John

[c170b53]

The field approval method via 337 is frowned upon up here. In reality after awhile we (170 club) probably have collected more data on our airplanes than most organizations. This information is very valuable, as most inspectors in regulatory positions must cover a variety of aircraft types and can hardly be expected to know it all. When presenting your case, investigate the problem, assemble the information and then present it in a concise package. I don't see a problem with using 337's as supporting data, when in most cases there's little other information to go on. The MOT may or may not agree but having a fist full of documentation can be a perspicuous and persuasive proposal.

[GAHorn]

...a perspicuous and persuasive proposal.

Ahhh. How sesquipedalian.

[Haydon]

Hmmmm........Not to beat the dead horse....but "A" model folks can squeek english....and don't have this wing problem....another feather in our sombrero.....not to mention flap rollers, dihedral or worrying about a balanced tail.....The simple life....

[GAHorn]

Hmmmm........Not to beat the dead horse....but "A" model folks can squeek english........

Yes, but can they speak (or spel) it?

[jatkins]

re: 172 / 170B wing change.

For those who, have offered help, and comments on this subject, here is an update.

I have researched the part numbers, The original C 170B L/H wing part number WAS 0523005.
The part number changed to 0523005-58, in the parts manual temp revision#1 dated 27 Jan. 1995.

Looking at the C 172, 1956 to 1962 parts book the L/H wing comes up as 0523005-58 ,
and states when exhausted use 0523005-201.

In the next series of C 172, parts book 1963 to 1974 the L/H wing comes up as 0523005-201,
and states when exhausted use 0523005-216, which IS MY wing part number, GREAT!
My wing part number is the 0523005-216.

However If the original part number 0523005, or 023005-58, are checked via,
Cessna or a Cessna dealer, the part on the COMPUTER comes up as 0523005-215 ????

I spoke to "Ross" at Williams Air motive, who seems very knowledgeable on 100 series wings,
He was able to say the difference between the -215 and the -216 is the placement of the door, catch / stop.
Sure enough they are in different locations.

I then spoke with Cessna Engineering Tech support, who were VERY helpful. A second engineer called me back the next morning. They told me the guys at Williams Air motive are the "GURUS" on the 100 series wings. The engineer told me the wings are interchangeable however, before they could send out a letter stating as such they would have to run it past engineering, for a cost of $576.00.

Looks like my engineering rep. is going to accept the above,
combined with the letter from Bruce (THANK-YOU so much), covering the 5 key points.

I will provide a final update.

John

[alaskan99669]

My wing part number is the 0523005-216.

John

Where exactly on your wing did you find this part number, or was it referenced in paper work?

[jatkins]

On the release tag in paperwork

[Bruce Fenstermacher]

John this is great news and all very interesting information about wing part number history.

The $576 Cessna wants would be cheap if you knew the outcome would be favorable. To be honest with the information you have dug up combined with the FREE Cessna letter I have, I don't understand what else would be needed or what else Cessna could add.

Like Corey, I'm curious where you found your wing part number on your wing?

[jatkins]

The wing part number is in my records, as is the release tag, which has the
part number and the serial number and the registration of the C 172 it came off.


This L/H wing is in MUCH nicer condition then the R/H 170B wing on the other side,
mainly because it is newer.

When I get through this I make look at either getting the Right one changed or rebuilt,
if I go the rebuilt route, I will definitely go to Williams Air motive, after speaking with these guys,
and after the engineering tech reps comments.

[lowNslow]

The $576 Cessna wants would be cheap if you knew the outcome would be favorable. To be honest with the information you have dug up combined with the FREE Cessna letter I have, I don't understand what else would be needed or what else Cessna could add.

Bruce, just curious what your letter says and when it is dated. I would think that if Cessna engineering would sign off on this it would carry some weight with SOME local FSDO offices and grease the skids so to speak. I agree that $576 would be a cheap investment.