By Kenneth Jackson
APTN National News
It may have had nothing do with why the plane crashed but in a sad sense of irony the deadly First Air Boeing 737 that killed 12 people in August 2011 “theoretically” should never have been in the air.
That’s because the plane had incomplete airworthiness directives (AD).
But no one knew until after the crash according to the Transportation Safety Board.
With incomplete or incorrect AD reports the plane’s airworthy certificate was “not worthy” says Brian MacDonald, the lead investigator into First Air flight 6560 that crashed in Nunavut Aug. 20, 2011.
MacDonald said First Air had thought they completed two different directives but, in fact, hadn’t.
But he was quick to point out not completing them had nothing to do with the crash.
The report says so too.
The report also quotes Canadian Aviation Regulations: “when compliance with an AD is not met, the flight authority is not in effect and the aircraft is not considered to be airworthy.”
Chris Ferris, executive vice-president of marketing and sales at First Air, said they did full audit of its Boeing 737 fleet after the crash. The review in September 2012 spotted an issue with an AD inspection on the plane.
This AD in question from 2004 required “inspection of the horizontal stabilizer outer and inner pivot hinge pins for corrosion or cracking” according to the TSB report into the crash released Tuesday in Ottawa.
The report continues: “Failure of the outer and inner hinge pins could allow the pins to migrate out of the joint and result in intermittent movement of the horizontal stabilizer structure and consequent loss of controllability of the aircraft.”
MacDonald said “one step” was missed in the inspection but refused to say what that step was and when asked by APTN National News he said to file an access to information request.
Basically, it was an incomplete inspection.
“As a result of a records audit conducted by the operator in September 2012, it was determined that not all of the inspection requirements of AD 2004-19-10 had been completed,” says the report. “The service maintenance procedure created to comply with the AD did not contain sufficient information to accomplish all of the AD requirements.”
Ferris didn’t immediately know the step but the audit didn’t find any other AD inspection infractions in the Boeing fleet he said.
He said it was “hypothetical and speculative” that if the audit occured prior to the crash it may have prevented it.
When the TSB first began looking at First Air record’s between the December 2008 to August 2011, found on Transport Canada’s website, investigators saw all AD’s were recorded as completed.
Based on the finding by First Air TSB reviewed all AD inspection reports and found another wasn’t in compliance said MacDonald.
This one was from 2006 and involved the “elevator tab trailing-edge free play.”
The AD allowed for a bit of free play and inspection by First Air found it was in the allowed tolerance.
If it wasn’t in tolerance it needed to be fixed before returning to the air.
However, the TSB investigation found portions of the inspection were in “excess of the tolerances allowed.”
Again, however, TSB couldn’t find this played a role in the crash according to the report.
An AD is an instruction that specify special inspections, component replacements or modifications are required to ensure the continuing airworthiness of aircraft according to the TSB report.
“ADs are issued when experience reveals a functional or structural hazard affecting flight safety that requires immediate attention,” says the report.
