Allowable Damage Charts!!!!!! 1

[ropethem]

In the military T.O.'s there are allowable damage charts. How would you look at this charts and figure out what they actually mean. I'm trying to get thru to some thick skulled individuals (the technicians actually performing the work), that the allowable damage charts are there for you to deciede whether or not you have to fix the aircraft. I had one of them actual tell me that is said it was not allowed, but it didn't tell me when to fix the part. By the way it was on an elevator control tab with 3 delaminations on the tab, and the allowable damage chart showed you the actual repairs to fix the aircraft part. Any suggestions!

Thanks,
Sincerely Confused!

 

[brin]

You're correct about definition of allowable damage limits/charts, but make sure you read all the text to go with the chart.

Without seeing the chart, I can only recommend to make sure the paper/approval trail is complete. The structural repair manual must link the part and damage limit chart/repair specifically, and the damage must be in specified locations on the part. And then the technicians must have adequate training to complete the repair.

I know I'm stating the obvious, but the responsibility is allways with whoever is willing to sign their name on the line that the repair is applicable (and approved).

 

[WKTaylor]

Hi... I am extremely familiar with this problem... +18yrs as an ALC and AFMC-Field engr [PACAF]; and (now) engrg work on military acft at a major contractor [KC-135].

Maintenance terms/definitions are poorly controled and enforced in the USAF vocabulary... and unfortunately poorly applied to T.O.s

I stressed the following:

Maintenance: act of removing, installing, calibrating, adjusting, cleaning, lubricating, inspecting, etc....

Repair: eliminating affects of physical damage to a component or "fixed" assembly, so as to restore the item to a serviceable condition, per established technical procedures/practices.

NEGLIGIBLE DAMAGE: minor nicks, scratches, dents, cracks, corrosion, etc that are acceptable with NO repair required [unlimited]. NOTE: these limits are usually different from part-to-part and/or acft-to-acft.

NON-NEGLIGIBLE DAMAGE: Damage that will require repair, since further deterioration is inetitable.

MINOR DAMAGE: NON-NEGLIGIBLE DAMAGE that does not immediately affect airworthieness.

MAJOR and CRITICAL DAMAGE: requires immediate evaluation and repair(s), and/or recurring inspection(s), due to airworthieness concerns.

DAMAGE LIMITS: accumulation of NON-NEGLIGIBLE DAMAGE [dents, scratches, corrosion, disbonding, cracks, etc], may, up to a specified maximum... when repair becomes MANDATORY. NOTE: this criteria allows continued safe and economical use of a part or assembly in-service with some damage... up to a point where either airworthieness, OR future repairability, is compromised.

REPAIR LIMITS: Specifies a MAXIMUM ammount of NON-NEGLIGIBLE DAMAGE [length and qty of cracks, area of corrosion, depth/area of dents, depth/length of gouges, etc...] that can be repaired using a specified method. Any damage exceeding this criteria requires:
(1) Repair per another procedure... or...
(2) Repair/overhaul by a higher-level repair organization [IE: Depot]... or...
(3) Engineering evaluation and disposition... or...
(4) Condemnation/replacement.

Regards, Wil Taylor