Aircraft Accidents and Lessons Unlearned VIII: Emery 17
I recently read an article titled: What the Loss of Emery 17 Taught Me, by Joe Yingst, from August 2016; I found it on a Google search and I located it on LinkedIn. Joe worked for Emery Air Freight at the time Emery 17 crashed in Sacramento-Mather airport, California, on February 16, 2000. The McDonnel Douglas DC-8-71, tail number N8079U, was trying to make an emergency landing at the departure airport, when its wingtip struck a building; the aircraft crashed into a used car lot just shy of the runway’s end; all three pilots were killed.
I started working for the NTSB in July 2001; this was the first major accident I worked for them. The investigation was already eighteen months-old before I became involved. What Mister Yingst learned from the accident was how to survive the downfall of your employer, post-tragedy, i.e. how to succeed in business. What I learned from Emery 17 was totally different.
The cause of the accident: someone unsafetied the right elevator tab arm-to-right elevator tab attach bolt – the elevators provide longitudinal control, e.g. aircraft nose up/nose down; the tab drives the elevator in an opposite direction, e.g. tab goes up, elevator goes down and vice versa. The attach bolt was found near Emery 17’s takeoff runway. The lock nut was missing; the bolt, with regular movements and vibrations, fell out. With the arm disconnected, the elevator moved to a ‘nose up’ position and could not be overridden in the air.
The airline industry would expect that a major commercial accident at a major commercial airport would require a proper National Transportation Safety Board (NTSB) investigation. In reality, the NTSB made little effort to investigate correctly. NTSB management stated, ‘there were only three pilots on the cargo aircraft;’ this view set the stage for major mistakes.
Obstructing an accident investigation happens all the time; it’s one of the lessons I hammer home to my students before they begin their careers. In this case, the NTSB’s management played a major role in allowing the obstruction to fester by not committing experienced resources to the February 16, 2000, accident; the NTSB’s experience-void was quickly filled by those trying to manipulate the information, to exploit the unfamiliar culture of a cargo airline versus the more familiar culture of a passenger airline.
In August 1999, a Repair Station called Tennessee Technical Services (TTS) was contracted to perform a heavy maintenance check on N8079U, which included replacement of the aircraft elevators. The elevators, considered a primary flight control, were inspected by a trained inspector who was not part of the team replacing the elevator. Instead, the Required Inspection Item (RII) inspector double checked the installation to assure the elevator system was properly installed, secured and the expected movements were full range of travel and were unrestricted.
From the paperwork, and by all evidence available, TTS did everything they were contractually required to do, including the RII inspection. That sounds cold, but a repair station is contractually obligated to provide work per the airline’s standards, which are per the aircraft manufacturer’s standards: to return an airliner in an airworthy condition. The RII inspector verifies his/her compliance with a signature; there are no tapes or videos, just signatures.
When I joined the investigation in August 2001, Emery was making the case that only TTS’s RII inspector had access to the elevator bolt; that only he could have failed to secure the bolt in a proper manner and that the bolt eventually, over the six months, ‘walked’, ultimately dropping out on the runway. As I sat though the interview with the TTS RII inspector, I reviewed the records and found that the ill-fated bolt had been touched only one other time: November 25, 1999, after N8079U arrived in Dayton, Ohio, for a package sort. The problem was – and this is what the Quality Control manager for Emery said – that N8079U was only on the ground for four hours on November 25, 1999; after loading and unloading the aircraft, Emery’s maintenance department could only have worked N8079U with two hours of ground time, not enough time to remove and replace the bolt.
And this is where the NTSB’s unfamiliarity with a cargo airline’s culture prevented them from seeing the forest for the trees. I asked the Quality Control manager a question during his interview in Dayton, Ohio; I asked him, “Do you fleet in on a Federal Holiday?” This question made no sense to the other fifteen people in the room; it, however, made perfect sense to the Quality Control manager and myself. He did not want to answer my question.
A cargo airline does not operate like a passenger airline; passenger airlines operate twenty-four hours a day, seven days a week. A cargo airline – especially in 1999 – only operates when domestic businesses are open. Businesses in the United States do not open on Federal Holidays; therefore, the cargo airlines do not fly on Federal Holidays; they fly the day before and the day after. The night before a Federal Holiday a cargo airline conducts a ‘fleet in’. This is where all the inbound flights are held over for the entire Federal Holiday and released the next night.
November 25, 1999, was Thanksgiving Day. N8079U arrived in Dayton, Ohio, at 10:00 PM on November 24th and departed 3:00 AM on November 26th. This gave the maintenance crews, not two hours to work the elevator as originally believed, but twenty-seven hours to work the elevator tab attach bolt; enough time to remove it, replace it … but not secure it.
Emery’s management tried to conceal the true cause of the accident; instead, they attempted to divert unwanted attention and unnecessary blame on the Repair Station, TTS.
Unfortunately, the NTSB learned nothing from the deception; they ignored the fact that Emery was not only responsible for circumstances leading up to the accident, but that Emery’s management thumbed their noses at the NTSB, exploiting the NTSB’s apparent lack of cargo airline cultural familiarity.
The cause of the accident was the bolt falling out, making the elevator uncontrollable; what caused the accident was Emery not following its own approved procedures. DC-8s are one of the dinosaurs of commercial aviation; no one flies them domestically anymore. But cargo airlines do fly Boeings, e.g. B737s, B757s, B777s, and Airbus aircraft, e.g. A300s; as do the passenger airlines … all the passenger airlines. The arrogance of ignoring a cargo airline based on the body count means that important factors affecting the safety of a cargo airliner will be missed; therefore, the same factors affecting the safety of a passenger airliner flying the same type airliner and utilizing the same repair stations will be missed. This puts passenger airliners in the same jeopardy experienced by the cargo airliner, with more devastating results as far as body count.
Joe Yingst learned valuable lessons about how to survive in his industry following his airline’s loss of certification. As for me, this was the first lesson unlearned I experienced as a new accident investigator. It would govern how I conducted accident investigations in the future; to trust no one and to look beyond the accident to the real cause.