Aviation Human Factors –
Eastern Airlines Flight 401 is a classic case study of aviation human factors that I’m sure many of you are familiar with but one that deserves revisiting.
Eastern Air Lines Aircraft 310EA (seen here) a Lockheed L-1011 crashed on December 29, 1972, 18.7 miles west-northwest of Miami International Airport, Miami, Florida enroute from JFK Airport. The aircraft was destroyed.
Aviation Errors can have Tragic Consequences
Of the 163 passengers and 13 crew-members aboard, 94 passengers and 5 crewmembers received fatal injuries. Two survivors died later as a result of their injuries.
More Experience = More Complacency?
The Captain was Robert Albin ‘Bob’ Loft, 55 a 30 year veteren employee who had 29,000 hours and was #50 on the Pilot seniority list. First Officer Albert Stockhill had 5800 hours and Flight Engineer (Second Officer) had over 15,000 flight hours and held commercial and Airframe & Powerplant Mechanic’s certificates.
Until the approach to MIA the flight was uneventful. The landing gear handle was placed in the “down” position during the preparation for landing, and the green light, which would have indicated to the flightcrew that the nose landing gear was fully extended and locked, failed to illuminate. The Captain executed a “Missed Approach” and climbed the aircraft to 2,000 feet proceeding on a westerly heading towards the Everglades.
It’s Just a Light Bulb
The first officer successfully removed the nose gear light lens assembly, but it jammed when he attempted to replace it. The captain then instructed the Second Officer to enter the forward electronics bay located below the flight deck, to visually check the alignment of the nose gear indicator stripes thus verifying that the gear was securely down and locked. Apparently the indicator stripes were not easily verifiable because the wheel well light was not operational.
Meanwhile, the flightcrew continued their attempts to free the nose gear position light lens from its retainer, without success. The Captain and the First Officer continued to discuss the lens assembly and how it might have been reinserted incorrectly.
Seemingly Minor Maintenance Tasks Actually Matter
Shortly after 2341, the second officer raised his head into the flight Deck and stated, “I can’t see it, it’s pitch dark and I throw the little light, I get, ah, nothing. ” We can only speculate on whether the wheel well light was operational and the optical tube was clean and visible.
The flightcrew and an Eastern Air Lines maintenance specialist Angelo Donadeo, who was occupying the forward observer seat discussed the operation of the nose wheel well light. Afterward, Angelo went into the electronics bay to assist the second officer to verify the gear was down and locked.
Tunnel Vision and Lack of Situational Awareness
The three flight crewmembers and the jumpseat occupant all became engrossed in the malfunction.
The National Transportation Safety Board determined that the probable cause of the accident was the failure of the flightcrew to monitor the flight instruments during the final 4 minutes of flight, and to detect an unexpected descent soon enough to prevent impact with the ground.
Preoccupation with a malfunction of the nose landing gear position indicating system distracted the crew’s attention from the instruments and allowed the descent to go unnoticed.
Distraction, confusion and lack of effective coordination amongst the crew led to the event.
It’s wise to reflect on the the lessons learned of how a seemingly simple procedure (replacing a light bulb and visually verifying the nose landing gear is down and locked) may have tragic consequences if done incorrectly.
It’s a Leaders responsibility to look at the whole process and monitor progress. It’s your team members responsibility to stay focussed and complete their individual responsibilities. It’s everyones responsibility to understand and not lose sight of the ultimate mission especially when multitasking and being stretched thin. In this case the mission was to land the aircraft safely and they failed.
Here’s a FAA training video recreating the final moments of flight 401 from the CVR transcript
A copy of the NTSB report is available here:
A review of the “Dirty Dozen” is here:
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