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Stress manual
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Author:  zedzil [ Mon May 30, 2016 9:22 pm ]
Post subject:  Stress manual

Does anyone have a copy of the T-6/SNJ stress manual or knows where one can be looked at or obtained?

Jake

Author:  bdk [ Tue May 31, 2016 11:47 am ]
Post subject:  Re: Stress manual

North American Trainer Association may have access to it. I believe it was referenced in the AMOC for the wing attach angle AD.

Author:  zedzil [ Mon Jun 13, 2016 12:02 am ]
Post subject:  Re: Stress manual

Nobody knows where a stress report/analysis of the T-6 /SNJ can be located? I find it hard to believe. Come-on guys.

Author:  bdk [ Tue Jun 14, 2016 10:52 am ]
Post subject:  Re: Stress manual

You are going to have to do some additional research yourself. Have you asked NATA? Member "Stoney" on this board is intimately involved with NATA and was AFAIK involved in a recent AD note on the wing attach angles. Are you a member of NATA?

1. Contact Boeing (although I don't know why they would give you this info, it is a liability if they give you this report and you make changes to an aircraft based upon that info. They would get sued first)
2. Contact the FAA (who doesn't maintain a library of stress reports and asks Boeing for help in doing any needed stress analysis)

What exactly is your goal?

I doubt a fatigue or crack growth analysis was ever performed on T-6 parts during the design phase, so it wouldn't be in the stress reports if that is what you are after.

Nobody has a copy of this sitting on their shelf unless someone stole it. It is not public information. It would be contained in a number of a North American Aviation reports. The entire data set may not even exist any longer. Much was thrown out or misplaced.

======================
TCDS:

A-2-575 R-16.pdf

Revision Number:
16 Product Type:
Aircraft

Revision Date:
11/16/2009 Product Subtype:
Small Airplane

Responsible Office:
ANM-100L Los Angeles Aircraft Certification Office Tel: (562) 627-5200

TC Holder:
Boeing Company, The
=====================
AIRCRAFT SPECIFICATION NO. A-2-575
Aircraft Specification Holder The Boeing Company
4000 Lakewood Blvd.
Long Beach, California 90846
Aircraft Specification Holder Rockwell International transferred ownership to The Boeing Company on July 23, 2009
Record
North American Aviation transferred ownership to Rockwell International Corp. on
February 20, 1996

Author:  zedzil [ Thu Jun 16, 2016 9:20 pm ]
Post subject:  Re: Stress manual

bdk wrote:
You are going to have to do some additional research yourself. Have you asked NATA? Member "Stoney" on this board is intimately involved with NATA and was AFAIK involved in a recent AD note on the wing attach angles. Are you a member of NATA?

1. Contact Boeing (although I don't know why they would give you this info, it is a liability if they give you this report and you make changes to an aircraft based upon that info. They would get sued first)
2. Contact the FAA (who doesn't maintain a library of stress reports and asks Boeing for help in doing any needed stress analysis)

I don't think that I could get the document from any of the two sources for the reasons that you have indicated.

What exactly is your goal?

I am an aerospace engineer and ex-DER with many years experience in developing and designing major structural repairs, alterations and modifications on a wide variety of aircraft. I would like to develop an approved repair to the attach (bolting) angle that will eliminate the need to remove the wing and replace the whole angle if a damage is detected. To do it right I need original engineering data.

I doubt a fatigue or crack growth analysis was ever performed on T-6 parts during the design phase, so it wouldn't be in the stress reports if that is what you are after.

You'd be amazed to learn the small number of aircraft on which a fatigue or damage tolerance analysis or tests were ever done.

Nobody has a copy of this sitting on their shelf unless someone stole it. It is not public information. It would be contained in a number of a North American Aviation reports. The entire data set may not even exist any longer. Much was thrown out or misplaced.

Yes, I know that. The organization I was with in the 1970s threw away a complete set of drawings and engineering documents of the P-51. I still weep in sorrow… I am still optimistic - maybe in South Africa?

======================
TCDS:

A-2-575 R-16.pdf

Revision Number:
16 Product Type:
Aircraft

Revision Date:
11/16/2009 Product Subtype:
Small Airplane

Responsible Office:
ANM-100L Los Angeles Aircraft Certification Office Tel: (562) 627-5200

TC Holder:
Boeing Company, The
=====================
AIRCRAFT SPECIFICATION NO. A-2-575
Aircraft Specification Holder The Boeing Company
4000 Lakewood Blvd.
Long Beach, California 90846
Aircraft Specification Holder Rockwell International transferred ownership to The Boeing Company on July 23, 2009
Record
North American Aviation transferred ownership to Rockwell International Corp. on
February 20, 1996

Author:  bdk [ Fri Jun 17, 2016 2:59 pm ]
Post subject:  Re: Stress manual

All I can say is that you will have to take the drawing of the original angles, calculate their capability from the original materials, and then redesign. The bolt holes that join the wings are open holes, not interference fit. That is likely the problem.

I think the Harvard 4 angles may have an extra row of fasteners at the wing skin as well.

Not sure what the FAA might require (or whatever your local airworthiness organization is if you are outside the US), but you could do a side-by-side sub-element fatigue test of the original angle and your redesigned angle for comparison, with a detectable flaw already placed in a critical location.

I think the failure that resulted in the AD note was on the wing attach angle common to the fuel tank stress door (the tension side on the bottom of the wing). You would have both tension and some shear in the bolts there. I suspect most of the shear though is taken out in the vertical angle (4 or 5 bolts) at the front spar.

I think the crack growth was all calculated though. NATA has the AMOC so they must have had analysis to convince the FAA that their NDI method was adequate for the inspection interval they qualified.

So many parts were mixed and matched in service, at overhaul and during restoration you might have one wing with 2,000 hours and another with 10,000. You have to analyze from the perspective of a detectable flaw size.

7050 might be a good alloy for a redesigned attach angle I've always thought.

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