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Maintenance Handbooks or AC43.13-1B for Torque

BMC_Dave

Well Known Member
I ran across something I thought I should ask. AC43.13-1B shows the torque values for aluminum -6 AN fittings to be 110-130 in-lbs in table 9-2. The AMT handbook lists 75-125 in-lbs for -6 AL fittings in table 9-20.

The AMT is the more current document, but "is designed to aid students enrolled in a formal course for instruction preparing for FAA certification as a maintenance technician as well as current technicians who wish to improve their knowledge."

AC43.13-1B "contains methods, techniques, and practices acceptable to the
Administrator for the inspection and repair of nonpressurized areas of civil aircraft, only when there are no manufacturer repair or maintenance instructions"

Given that we're experimental we're not required to comply with AC43 strictly speaking, we use it as a guide for best practices. So in the case of conflicting information such as the torque values listed above which should we use? The more current reference or the 20 year old advisory circular?
 
How about posting a link to the the AMT handbook you are referencing.

I just download the three FAA-H-8033-30, -31, and -32 (V1 V2). Unable to find the table values you reference.

In the past, I tend to torque to the higher value when I found multiple torques in different reference material unless the lower value had a warning about using a higher value. I almost never go looking for differences in documents.
 
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I forgot there are several AMT Handbooks, I was referencing the general handbook, FAA-H-8083-30A.

https://www.faa.gov/regulations_policies/handbooks_manuals/aircraft/media/amt_general_handbook.pdf

Pg. 9-12 (378), figure 9-20, col 3, row 5.

It should be worth noting it's probably a good idea to be sure you're referencing the latest release not from some 3rd party site. I go to the FAA handbook main page: https://www.faa.gov/regulations_policies/handbooks_manuals/aircraft/ Single source data and all.
 
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Section 5 Torque Values

I'm not sure about other RV models, but I just use the guidance in Section 5 on Page 5-20 for torque values for AN bolts.
 
AN bolt values on aluminum hydraulic fittings?

Yeah you should certainly not be using that table for your AN flared fittings.

I also question the logic of torquing to the highest value you find given we're talking about soft aluminum flares...
 
AC43.13 has a problem. I once spent phone time with the responsible FAA office while doing article research, the subject being an obvious deviation from the manufacturer's revised instructions. Short version? There does not appear to be a practical process for review and change; the FAA representative seemed to be in despair about the necessary bureaucracy.

My opinion? Use the more recent source material. I no longer automatically trust AC43.13
 
AC43.13 has a problem. I once spent phone time with the responsible FAA office while doing article research, the subject being an obvious deviation from the manufacturer's revised instructions. Short version? There does not appear to be a practical process for review and change; the FAA representative seemed to be in despair about the necessary bureaucracy.

My opinion? Use the more recent source material. I no longer automatically trust AC43.13

Oh interesting, thanks for that bit of background. This is basically what I was figuring too.
 
AC43.13 has a problem. I once spent phone time with the responsible FAA office while doing article research, the subject being an obvious deviation from the manufacturer's revised instructions. Short version? There does not appear to be a practical process for review and change; the FAA representative seemed to be in despair about the necessary bureaucracy.

My opinion? Use the more recent source material. I no longer automatically trust AC43.13

I agree - I tell folks to use the AC if they have no newer reliable source material - but if they are fixing a T-6 or a Stearman, AC43.13 is perfect! :rolleyes:
 
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