logbook entry/337/approval for further flight

zero.one.victor · Post by **zero.one.victor** » Mon Mar 17, 2003 6:48 pm

I posted recently (on a generator topic) asking about requirements for doing a 337 versus a simple logbook entry. This seems like kind of a grey area,with different opinions from different people. One opinion is that if it is listed on the TCDS,it is an approved part and just needs a logbook entry. For example, replacing a 20amp generator with a 35A model. I can see where maybe this just needs a logbook entry,but it is an "alteration",as in "major repair or alteration" on the top of a form 337.
How about replacing the landing gear with a set of EDO-2000 floats? They're listed as approved equipment for the A & B models,but I would sure think that a 337 is required, along with a revised W&B,of course.
How about replacing early gear legs with late-model "lady legs"? They are a 170 part,I don't see where the gear legs themselves are actually listed on the TCDS but they obviously must be an approved part for the airplanes the factory put them on. W & B issues aside-- and assuming the gear leg replacement was an "upgrade" and not a "repair"-- would this be a logbook entry only,or would it require a 337? If it does require a 337, who can approve this alteration-- must it be an FAA inspector,or can an IA do it? Is it a field approval,or a previously-approved alteration like an STC?
I welcome everyone's opinions,of course,but if someone wants to state their opinion as "fact" it'd be nice to see some backup for same--FAR's,AC's,Cessna manual,etc. Sometimes we (A&P's and IA's,as well as us shadetree types) tend to blur that line between opinion and fact---present company excluded,of course

Eric

ak2711c · Post by **ak2711c** » Tue Mar 18, 2003 7:36 am

My FAA inspectors opinion is that if it is on the TCDS it doesn't need a 337. However he did say that if it is some thing big like floats, skis, or a different motor for example, that it would be a good idea just to cover your bases and get it field approved. Inspectors can't very well turn down a field approval if it is listed on the TCDS. My two cents.
Shawn

funseventy · Post by **funseventy** » Wed Mar 19, 2003 12:04 am

What do you mean cover yourself with a field approval? The floats are on the type certicate which is approved data. Maybe you are confused about field approvals, they are approving the data in which the mod was done not the actual work accomplished. The IA's signature at the bottom of the 337 is the return to service. The TC or an STC are all approved data, you can even use someone elses field approval as approved data. That is why it is sometimes hard to get the FAA to buy off on a 337, because even though under your controlled conditions it is a good idea they want to cover the next guy who sees this in the logs and wants to do it to another and is under different circumstances. The lady legs were never tested by the factory on an early airplane and that is why that would be a field approval. It is not a 170 part it is a 170B part. Other wise I could argue that I could install a 170 flap on my 170B, but I think its very clear why the FAA would want to be involved with that decision, Yikes!

Kelly

Tom Downey · Post by **Tom Downey** » Wed Mar 19, 2003 3:44 am

Quote
"The TC or an STC are all approved data, you can even use someone elses field approval as approved data."

This is not true.
You can use a approved 337 on the same make and model to show it has been done sucessfuly before, but it is not approved data.

funseventy · Post by **funseventy** » Wed Mar 19, 2003 4:11 pm

Tom,

This is how my PMI has explained it to me. However, in my attempt to make it short and sweet I did not mention that it must be same make and model, which was an important thing to mention.

Kelly

Tom Downey · Post by **Tom Downey** » Thu Mar 20, 2003 12:01 am

The 337 that was approved on a different "N" number with the same make and model, is not approved data, it shows the Approving FSDO rep that it has been done successfully, that makes it easier to get their approval, when they sign the 337 that you submitted THAT becomes the APPROVED DATA. --- NOT the 337 for the other "N" number.
FSDO COULD ask for the engineering on the first aircraft, or they can ask for new engineering on your aircraft. A prior approval on a different aircraft is not an automatic sign off on your aircraft.

Dave Clark · Post by **Dave Clark** » Thu Mar 20, 2003 12:48 am

Tom is exactly right with the exception that there have been some "multiple" 337 field approvals in the past. Under revision 15 they are specifically excluded for use from now on.

ak2711c · Post by **ak2711c** » Thu Mar 20, 2003 8:04 am

Kelly, my mistake what I ment to say was. However if it is some thing big like floats, skis or a different engine it would be a good idea to file a 337. It all comes down to an interpritation of regs. For example the javilin fuel tank in a 170. One reg says in so many words if it is on the TCDS you don't need a 337. Another reg says if you install an aux fuel tank inside the plane that you must file a 337. One thing I did just learn though on field approvals is just because it is stamped and signed doesn't mean the coast is clear. There have been a few cases were other inspectors have looked through an aircrafts 337's and found one that in there opinion should have never been field approved and revoked it. But they didn't stop there, they tried to sight the pilot for flying an unairworthy airplane. The didn't make it stick obviously but the guy did loose that 337.

Tom, you are right. That is a very common misconception.
Shawn

Post by **GAHorn** » Sat Mar 22, 2003 4:41 pm

Tom is correct (as usual). This is all about "approved" data such as Tom listed, and "acceptable" data, which can be used to obtain approval. A previous field approval can be used as "acceptable" data to obtain a field approval.

AR Dave · Post by **AR Dave** » Tue Feb 01, 2005 11:40 pm

I tend to put documents, like the "Wheel Landing" write up, on file. Today I put a stack of the files onto a disk, so that I'll have them if something happens to the computer. That got me to thinking about my pilots log book and the airplane logs. Would be ashame to loose these for some reason.
Have any of you techies put your log books on computer or something like that?
I was thinking about scanning all the documents and putting them on file on a disk. Sound like a good ideal?
Now that I've built a website I'm feeling pretty smart!

zero.one.victor · Post by **zero.one.victor** » Wed Feb 02, 2005 4:21 am

Seems like I've seen ads for electronic logbook programs for aircraft records. Check TAP. Or are you talking about just scanning your logbooks,337's etc & burning them onto a CD?

Eric

mvivion · Post by **mvivion** » Wed Feb 02, 2005 5:02 am

Sorry, guys, but what Kelly said was "if its listed on the TCDS or an STC, it is approved data" He did NOT address that to field approvals, and as far as I can tell, he is precisely correct on that. I think we are mixing apples and oranges here, as in approved data, vs field approvals.

Installation of an STC requires a form 337 be submitted to the FAA, but it DOES NOT REQUIRE FURTHER APPROVAL. It is based on approved data. In other words, the FAA inspector cannot deny a 337 for installation of a legal STC, if the work was done properly, yada, yada.

If its on the TCDS, it is most certainly approved data. For floats, as an example, an IA has to do the initial installation, primarily because it will require some cutting and fitting, attachment of cables, etc, and it will require a new W & B, which an owner can't do. But, once done, the IA simply makes a logbook entry to the effect that EDO floats were installed per the TC, on this date, and new weight and balance calculated. That's all that's required-no 337 required, or desired.

Note that PeeKay 2300 floats, however, are approved on an STC, not the TC, so they require submission of a 337.

Fer cryin out loud, don't even suggest to the FAA that we should submit 337's for TC approved equipment.

As noted earlier, though, the equipment has to be approved on the TCDS for the appropriate model of airplane.

Field approvals are a whole different ball game, as noted, but they are different from STC's and TC approved equipment.

Mike Vivion

zero.one.victor · Post by **zero.one.victor** » Wed Feb 02, 2005 5:23 am

Still seems like a grey area to me-- of course, I'm no A&P or IA either. The 337 sez "major repair or alteration"-- even if floats are listed on the TC, that installation still seems like a alteration. Same with (for example) hanging a Franklin 165 on the nose--listed on the TC, but still an alteration. I would say that either of these mods require a 337 but that 337 would not require any FAA approval, just the mechanic's signoff. But I believe that an A&P can't sign off a 337, even for a TC'd or STC'd alteration-- it must be an IA. Not sure if a Certified repair Station can sign them off either.
What about 337's for avionics installations? Another grey area.......

Eric

Tom Downey · Post by **Tom Downey** » Wed Feb 02, 2005 6:26 am

The Type certificate has a list of equipment that was approved to be used on that make and model, these are listed by number.

If say, you removed equipment number 101 and replaced it with number 102 this is a log book entry.

If that item 101 is approved on certain aircraft serials numbers, and not others, it may take a 337 to prove the engineering on the item is safe to use on that serial number.

Floats as your example, Could be a STC on some aircraft, and approved equipment on others.

The type certificate could say that EDO floats model number 2200 are number 104 on the type certificate, but require a 337 to place areocet floats on the aircraft.

Engines listed as alternate equipment such as the Franklin 165 C-145, can be swapped as a log book only, because the manufacture listed them on the type certificate, because the testing was done at the factory.

See me the next time your over, we''ll talk some more.

AR Dave · Post by **AR Dave** » Wed Feb 02, 2005 6:03 pm

Eric, yes i'm just talking about scanning logbooks, 337's etc & burning them on to a CD?
I didn't mean to restart a discussion on STC / 337's that stopped on Mar 22, 2004.