Aviation English Contributing Factors Related to Maintenance Planning
SofemaOnline - Case Study Eastern Airlines
Introduction
For many people in aviation today the events of Eastern Airlines Flight 855 are long forgotten, however, the memory does live on and on this fateful day many lives were saved thanks to the calm and professional approach of the pilots.
What happened?
On May 5, 1983, a Lockheed L-1011 TriStar, registration N334EA, en route from Miami International Airport to Nassau International Airport, experienced the loss of all three engines near Miami, Florida. Following a decision to return to Miami.
Initially assumed to be an indication error related to the “apparent” (but in reality, real) oil loss on all engines. Having elected to shut down the No 2 engine in accordance with Standard Operating Procedures (SOP’s) both wing engines subsequently failed which left the aircraft in a desperate predicament.
Heading back to Miami and with the aircraft on a controlled descent, the flight crew succeeded in restarting the number two engine at approximately 4000 Ft and went on to safely land the aircraft.
Why did it happen?
Please review the provided job card - How many errors can you identify?
During a routine “overnight” maintenance visit the previous night, the aircraft was scheduled for a magnetic chip detector replacement to enable inspection.
The task consisted of removing the master chip detector from each engine and replacing it with a new one.
The omission of all the O-ring seals on the master chip detector assemblies led to the loss of required Engine lubrication and ultimately the failure of the wing engines (remember the crew elected to shut down Engine No 2).
Note - Each chip detector had two O-rings, which served as oil seals. Unfortunately, the replacement chip detectors were not fitted with O-rings, a fact which escaped the mechanic who fitted them.
Incorrect Post Task Testing - After the chip detectors were fitted, each engine was run for 10 seconds to check for oil leaks. None were found.
The aircraft was signed off as serviceable and returned to service.
Outcomes and Conclusion
a) The mechanic failed to follow the correct procedures for the installation of master chip detectors in the engine lubrication system.
b) Lack of supervisory oversight to require mechanics to follow correctly the prescribed installation procedures.
c) The failure of Eastern Air Lines management to assess adequately the significance of similar previous occurrences and to act effectively to institute corrective action.
(This is where the role of Maintenance Planning enters the picture as the task card combined tasks on all 3 engines onto a single Task Card)
Note - In 1983 there were no HF procedures related to job card design - Discuss
d) Contributing to the cause of the incident was the failure of Federal Aviation Administration maintenance inspectors to assess the significance of the incidents involving master chip detectors and to take effective surveillance and enforcement measures to prevent the recurrence of the incidents.
Consider today the relationship between the FAA and industry is different from the European Model where far more emphasis is placed on the organizations' responsibility to self-manage (From 1993 under the JAA Independent Quality Assurance has been introduced - How effective is today's system to identify and address exposures?)
e) It was subsequently established that the engines needed to be run for at least 30 seconds with no O-rings fitted before an oil leak would become apparent.
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