WSplit Cowl

[Hank Jarrett]

Re: WSplit Cowl

You design and evaluate all three and pick the one that works best.

Hint:
The vertical split has SERIOUS problems. I would prototype a horizontal split and a top cut out to allow the bowl to be dropped straight down with the lower cowl. Problem there is with loosing stiffness for the top cowling and hinges.

Yea, I have already looked at this quite a bit.

Hank

[Guest]

Re: WSplit Cowl

Well lets see, the change does not affect weight and balance (less than half pound), cooling or aerodynamics....Its non structural, soft aluminum, so I don't see a problem, but I find that a 6 ply tire is a change to the type certificate and a major...Tim

Tim and all,

You are not making a change to the Type Certificate, the FAA does that not us.

I was thinking about this after making the initial post (just the one line above) and want to suggest a way to approach the part of the reg that says "when not listed in the aircraft specifications issued by the FAA, are airframe major alterations".

Here is my suggestion,

If an item is listed in the TCDS then it is not possible for that specific item (alteration) to be a major alteration, it is an alteration but not a major one. (this makes the legitimate assumption that the item is implemented as the manufacturer prescribed not by some unapproved alternative)

If an alteration is not listed in the TCDS than it might be a major and to determine if it is we have to consider what the regs say (like Tim did for the cowl).

I think this approach is consistent with the FAA chief legal counsel approach.

Dave

[M Towsley]

Re: WSplit Cowl

Dave,

Not quite sure if this would matter. The L-2 does not use a hinged top cowl. It instead uses a horizontally split cowl, nose bowl and all.

I am still curious as to why the original poster wants to do this, we have not heard back from him since the original post.

[3Dreaming]

Re: WSplit Cowl

Hi Dave,

I understand your point, but there would not be a discussion if it were not for someone who apparently needs constant access to the front of the engine. I am curious as to why. I cannot even remember the last time I pulled the nose bowl.

I hope you have a short memory and it was removed at the last annual inspection. I know some will argue, but in my opinion it is required by regulation to be removed for the annual inspection.

[Hank Jarrett]

Re: WSplit Cowl

Only reason I wanted to was when i wanted to run the engine without the cowl to check the install out. Not exactly something you do every annual, much less more often.

Hank

[Guest]

Re: WSplit Cowl

I hope you have a short memory and it was removed at the last annual inspection. I know some will argue, but in my opinion it is required by regulation to be removed for the annual inspection.

Hi Tom,

I am not challenging or disagreeing but can you elaborate why it needs to be removed for annual?

I am thinking that I will be embarrassed by the answer so I will confess to short memory now!

Dave

[M Towsley]

Re: WSplit Cowl

I hope you have a short memory and it was removed at the last annual inspection. I know some will argue, but in my opinion it is required by regulation to be removed for the annual inspection.

I am curious, too. I greatly trust your opinion, Tom, and wonder why. That is not one of the requirements, (from what I remember??), in the original Taylorcraft annual inspection checklist, (the original, not a an updated/adapted list).

[Nefj40]

Re: WSplit Cowl

It never was that big of a deal to me, but my IA always has me remove the prop and nosebowl at annual. He's the one signing the book so I do what he asks. I'm guessing that he has his reasons.

[3Dreaming]

Re: WSplit Cowl

Appendix D to Part 43—Scope and Detail of Items (as Applicable to the Particular Aircraft) To Be Included in Annual and 100-Hour Inspections

(a) Each person performing an annual or 100-hour inspection shall, before that inspection, remove or open all necessary inspection plates, access doors, fairing, and cowling. He shall thoroughly clean the aircraft and aircraft engine.

For me I consider it necessary, otherwise how can I inspect the front of the engine and the front baffles.

[Hank Jarrett]

Re: WSplit Cowl

I am pretty sure I have inspected the front of my engine several times without removing the nose bowl. I DID remove the prop and nose bowl last time just because I saw some things I wanted to clean and look better at (it had been a LONG time since the last annual), but no IA has ever asked me to remove either the prop or the bowl. A small inspection mirror will let you see everything in and around the bowl.
What are you worring about missing? I am wide open to adding it to my annual list if needed.

Hank

[Robert Lees]

Re: WSplit Cowl

I don't think that Hank in the last post, and 3Dreaming in the post before, are too far away from the reality.

3Dreaming's post correctly highlights the bold "all necessary" words.

It is my humble view that who determines "necessary" is the IA at the time, at the aircraft and at that time. No more so than the word "thoroughly" with reference to cleaning.

Rob

[Guest]

Re: WSplit Cowl

I agree Rob.

A high level FAA maintenance guy (Bill O'brien) told me/us at an IA meeting about 10 years ago that often one A&P will think something is a major repair that another may deem it a repair (there are no minor repairs, just repairs).

He also said the FAA recognizes that such things occur and essentially said its ok and it happens.

Dave

[Guest]

Re: WSplit Cowl

Rob,

If appropriate feel free to move this post to another thread. This discussion got me thinking and I thought that this was interesting.

At the last IA meeting I attended one of the FAA PMI's discussed this part of the annual inspection checklist;

Appendix D to Part 43�Scope and Detail of Items (as Applicable to the Particular Aircraft) To Be Included in Annual and 100-Hour Inspections

(a) Each person performing an annual or 100-hour inspection shall, before that inspection, remove or open all necessary inspection plates, access doors, fairing, and cowling. He shall thoroughly clean the aircraft and aircraft engine.

I made some text red and some blue.

The blue text says "He shall thoroughly clean...", the PMI asserts that the IA himself must clean the airplane and that the cleaning is not merely to get it clean but in the process of cleaning one will notice things like leaks, loose rivets... that will not be identifiable later after the airplane was cleaned.

It was an interesting talk and I had never viewed the cleaning in that way but merely that items have to be clean to be inspected for some defects.

Also another thought.

The red text says "before that inspection". An IA cannot legally supervise an inspection, he may only conduct himself, he cannot supervise another doing it (I know that this goes on but its not legal). So the red text indicates that the removal of plates, doors... is prior (before) to the inspection so anyone can do that under his supervision and happens often during owner assisted annuals.


Dave

[Nefj40]

Re: WSplit Cowl

My first annual I had a nose bowl so eroded from baffle rubbing that it had made a hole. The felt was gone, as was a bunch of original baffle and it's staples. I was blessed with layers of JB weld and Duct tape. You wouldn't believe the names and number of years that where signed in my log book, at some point it became OK to leave the nose bowl on. It takes ten minutes. Take the damn thing off and look.

Edit to add.. If something happened to my AP/IA and I had to find a new one, if he didn't ask me to take the prop and nose bowl off, I'd find a new mechanic.

[Guest]

Re: WSplit Cowl

My first annual I had a nose bowl so eroded from baffle rubbing that it had made a hole. The felt was gone, as was a bunch of original baffle and it's staples. I was blessed with layers of JB weld and Duct tape. You wouldn't believe the names and number of years that where signed in my log book, at some point it became OK to leave the nose bowl on. It takes ten minutes. Take the damn thing off and look.

Edit to add.. If something happened to my AP/IA and I had to find a new one, if he didn't ask me to take the prop and nose bowl off, I'd find a new mechanic.

Hi Dave,

Are you certain that there was no other method of inspection that would have revealed these same issues/defects?

For example looking with mirrors, pulling/twisting/lifting to gain a view of it, flex-scopes ...

added at edit; I suppose what I am suggesting is that perhaps the folks that overlooked these things just didn't do any inspection at all of that area and their diligence is the issue not which parts to remove??

BTW- how do you know that they stopped removing the nose bowl at some point ?



Dave