Landing light and PMA parts questions.

[dhillier]

Whilst rebuilding the wings of the Clipper I would like to install a right hand side landing light. I have the parts from a wreck and I think the addition of wig-wag lights in conjunction with the left hand side lights would be a great safety feature.
I know there are various threads on the subject but none appear conclusive - perhaps purposely so. Does this modification count as minor and thus be recorded as a logbook entry “fitted as per Piper drawing 12534 etc”? It does appear to fit in this category as does not reach an criteria of a major modification, the approved data is the Drawings and AC43-13 describe the methods used.

Secondly - PMA parts. Take for example DakotaCub part DC41291 - Aileron pulley cable cage.
http://dakotacub.com/index.php?optio...id=447&cat_id=


It is PMA’ed for various PA18 models and is the same part number that is used on the PA16. Now I don’t know the reason that DakotaCub did not include the PA16 on its PMA list - maybe it’s a cost per model issue at certification or maybe they just didn’t bother with such a rare model.
Would my IA be at liberty to say “ it’s a PMA part made to a certified standard. The part does not know if it’s on a PA18 or PA16 - but they both require the same part number - thus it is safe to fit”?

I appreciate my IA has the solution and final say but I am asking for discussion on the subject. Here in the UK, not all IA’s are so experienced in these matters as many of you guys.

As always any input is appreciated.

[Paul Watts]

In my opinion (which carries zero weight) adding the landing light to the left side would be a minor mod, as a matter of fact I did the same thing while restoring my PA22/20. No ramp checks yet, so I can't definitively say what the FAA would say - except I have no doubt that if you ask 6 FSDO inspectors, you will get 10 different answers; or in the case of DFW FSDO, no answer at all. "Call engineering, apply for a STC"

As for the pulley guard, maybe Dakota Cub only lists parts for "Cubs"? I really don't know, but why not just tell everyone you "found" the guard at the bottom of your "assorted clipper parts box"(scuff it up a little first)--you just knew that guard would eventually 'show up'! It's just a bent piece of sheet metal...not exactly cutting edge technology...it either fits, or doesn't.

I guess I've rambled on without really telling you anything! My recommendation would be to talk it over with your IA... his (hers) is the only opinion that really counts.

EDIT: oops, I just realized your from the UK. Sorry, I have absolutely no knowledge of laws/regs etc governing the Brits!! I should just delete my post, I really don't want to guide you down a path that I have no idea where it leads! (Still,,,who could possibly know where the pulley guard came from?? How do you know where the pulley guard for the other wing came from??)

[Jeff J]

The best bet on the lights is talk it over with whomever has to sign it off in your area. My first reaction is to treat it as a major alteration for 2 reasons. First, a sizable hole must be cut into the leading edge and properly filled. I had to run a 337 for a leading edge repair that would be very similar to installing a light (cut out a section and replace). Second is the redesigning of the lighting system to add rather long and potentially high amp circuit to the electrical system. I don't think they would be hard to get field approvals for but I would run the paperwork or at least ask my PMI if he wanted to see paperwork for it before I started.

I wouldn't give the pulley cage a second thought. PMA'd with the same part number. I can't imagine anyone having a problem with that and if they did I would claim "owner produced part". I don't know if that rule applies over there.

[pilot]

I just posted a picture of N9615D in "cover photos" here - with right side light showing. Easy install in existing wing, spent more time screwing with fishing the wire and fixing the headliner than anything else. I dropped in 4 Aeroleds (2 landing 2 taxi) already had a two position switch (up for landing down for taxi) and added a wig-wag switch. AWESOME lighting setup, less amps than the original pair of GE bulbs to boot. All 4 Aeroleds on at landing position really lights up the night, plus the wig-wag is built it, no additional controller needed. Duplicated the light installation with factory parts, minor mod in my non-professional but highly researched opinion. http://www.shortwingpipers.org/photo...29-27s&cat=501

[dgapilot]

Like I’ve said before, the installer makes the major/minor decision. Use AC43.210A flow chart, and document the decision process if you decide it’s a minor. Even if you decide it’s a major, between the drawing, AC43.13-1B and AC43.13-2B I suspect there is sufficient “approved data” that no field approval would be required.


Sent from my iPhone using Tapatalk

[Steve Pierce]

As an IA I would sign the light off as minor but document the installation per the drawing. Look at the definition of major and minor in the FARs. I would make a logbook entry for replacing the pulley bracket. If it causes heartburn buy it from Univair. Dakota Cub uses a bearing type pulley instead of the bushing pulley so you will need the new pulley and pin as well.

[Gilbert Pierce]

Using AC 43-210A flow chart listing those items that effect airworthiness and cause the intended action to be a major repair in my opinion makes a lot of action deemed major to be actually minor repairs.
Those items that you say are not effected by the proposed action; weight, balance, structural strength, performance, power plant operation, flight characteristics, and the typical bureaucratic catch all , other qualities affecting airworthiness says to me a lot items regarded as major are really minor, depending on how interup other qualities affecting airworthiness.

For example, the battery called out in PA16 type certificate data sheet is not available, installing an FAA/PMA Odessey J16 battery in the original battery case is considered a major modification by some on this forum and requires an STC.

Using the 7 items above, no to each one of them says to me it is a minor alteration.
Actually the J16 battery STC is to modify the electrical system, the battery install is just a minor part of that STC.

I would also argue that replacing two 30 amp fuses in that STC with circuit breaker does not alter the BASIC DESIGN OF THE ELECTRICAL SYSTEM. Again referencing the aforementioned flow chart.

[dhillier]

Thanks for the replies. It’s useful for me to have background before I get to discuss with my IA. The example of the pulley bracket was just that, an example - it was more the principle that could be extended to other part numbers that I was interested about.
Thanks again.

[dgapilot]

Using AC 43-210A flow chart listing those items that effect airworthiness and cause the intended action to be a major repair in my opinion makes a lot of action deemed major to be actually minor repairs.
Those items that you say are not effected by the proposed action; weight, balance, structural strength, performance, power plant operation, flight characteristics, and the typical bureaucratic catch all , other qualities affecting airworthiness says to me a lot items regarded as major are really minor, depending on how interup other qualities affecting airworthiness.

For example, the battery called out in PA16 type certificate data sheet is not available, installing an FAA/PMA Odessey J16 battery in the original battery case is considered a major modification by some on this forum and requires an STC.

Using the 7 items above, no to each one of them says to me it is a minor alteration.
Actually the J16 battery STC is to modify the electrical system, the battery install is just a minor part of that STC.

I would also argue that replacing two 30 amp fuses in that STC with circuit breaker does not alter the BASIC DESIGN OF THE ELECTRICAL SYSTEM. Again referencing the aforementioned flow chart.

Gilbert, that’s why I stress that we should document the decision process when we call something a minor. If we document using the FAA policy and regulations, they can’t file a violation against us for using their words! Makes life much easier.

I remember years ago arguing with FAA inspectors. It’s just not worth it. Consider that based on FAA guidance, making a clipping J3 (Reed) is a minor alteration. Think about that!


Sent from my iPhone using Tapatalk

[Jeff J]

I looked through the flow chart in AC 3-210A and didn't see anything that would change my mind on the light unless cutting that size of a hole in the leading edge would have no effect on the structural strength of the wing or negatively affect the flight characteristics. The definitions in the FAR are pretty clear that if it is improperly done and could affect either then it is a major alteration and/or repair.

The electrical part is more ambiguous because a person must decide if it is a redesign of the system to add that circuit. It is great that Aeroleds were used in the example above but if the mod is done with that low amp draw in mind and for some reason an incandescent bulb gets installed because it is $400 cheaper there will be problems. Hopefully just a tripped breaker but could result in cooked wires and even fire. I had an owner come to me a while back who had installed a 100w bulb in the 50w taxi light position and couldn't figure out why his lights only worked about 30 seconds before the breaker tripped.