Sometimes I feel like I’m in an old “Twilight Zone” episode. And I don’t say that because I see space aliens serving man, or I get the creeps thinking about the cornfield, or even that I hear the voice of Rod Serling in my head … well, maybe sometimes. Every Friday night Mr. Serling did two things: 1) told stories that forced us to suspend our way of thinking for a different point of view; a vision that — no matter how farfetched — we needed to consider and understand its meaning; and, 2) often introduced the journey of disbelief with the words: “submitted for your approval.”
Now the inspector in the cubicle next to mine loves to pose random questions to test my knowledge of regulations or policy; he hasn’t learned yet that I usually don’t know the answer. But sometimes he’ll start a discussion on something that he’s working on that challenges the way I interpret how maintenance is conducted per the regulations. I’ve learned that I should suspend how I know the rules and work on how to reconcile them to questionable circumstances.
Submitted for your approval: A Brand-X Aerowidget (foreign manufacturer) goes off the runway incurring substantial damage; the aircraft is considered a total loss … or is it? Diagnosis: Replace the airframe from the wing root forward; Brand-X’s SWAT team assists the operator. The operator’s name is unimportant, but your mission is: determine if it’s a major repair/alteration or simple replacement … in the Aviation Zone (sorry, couldn’t resist).
From the manufacturer
Now seeing that the airframe sustained “substantial damage,” the answer is obvious: major repair. But the manufacturer’s version in this true story said: No. While reviewing the approved data it’s spelled out this work is not a major repair/alteration; no doublers were used, they were replacing part for part, rivet for rivet; case closed.
The structural strength of the new fuselage was never compromised. The replacement section was off the assembly line, technically the same down to the rivet. All structure is i-dent-i-cal, not even requiring more wiring. So again, is it a major repair/alteration?
According to the FAA
The FAA view on major repair/alteration says: Yes. It responded: the replacement of so much Primary structure and the use of fixtures and lasers to line up the hull are too involved to be just simple component replacements. Where are the 337s?
Meanwhile, the Part 121 operator is in the middle trying to work to the FAA standards while following the manufacturer’s approved data. I’ll bet Orville didn’t see this one coming. Let’s look at 14 CFR Part 1.1 for Major Repair/Alteration:
(In addition to an alteration not listed in aircraft, engine, or propeller specifications)
(1) That, if improperly done, might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness; or
(2) That is not done according to accepted practices or cannot be done by elementary operations.
The NTSB explanation
This is an example of when to read precisely what the regulation says. Considering how much structure was restored, the grey line darkens in favor of a major repair/alteration. With that much aircraft replaced, it can’t be an even swap as Brand-X suggests. But remember what I said about substantial damage? It was the NTSB explanation that drove the decision made by the FAA.
According to 49 CFR 830, the NTSB makes the call on whether the aircraft is involved in an accident; it determined this particular airframe suffered substantial damage (there’s that term again). The NTSB defines substantial damage as: “damage or failure which adversely affects the structural strength, performance, or flight characteristics of the aircraft and which would normally require major repair or replacement of the affected component (singular, not components).” When asked, the manufacturer said that it was repairing a broken aircraft, which in itself eliminated all doubt.
Although not specifically defined in the regulations, a repair is maintenance that takes place to restore a type-certificated product to "condition for safe operation." An alteration is maintenance...
Boeing CEO Alan Mulally declined to say by how much the plane was exceeding its target weight.