THE ERROR CHAIN

A huge cargo aircraft was about to land. As the present fuel tank is low, the pilot chose another fuel tank. Suddenly the engines failed and the aircraft crashed into the nearby residential area. All people on-board were killed including the people in that neighbourhood.

The chain of errors for the above scenario are as follows:

1. A design flaw of the fuel NRV (Non Return Valve) as it could be fitted in the fuel supply pipe either ways.
2. A maintenance engineer fitted in a way against the fuel flow direction.
3. Failure to run a test on the system after valve replacement.
4. Lack of fuel due to the incorrect positioning of the valve subsequent in engine failure.
5. The pilot acted against the rules by selecting a different fuel tank on approach.
6. Not enough altitude and time to correct the mistake resulting to a major disaster

Let us analyse the events that led to this accident. It may be the fault of the designer or the design organisation to not structure a Murphy Proof policy. It may be the fault of the maintenance engineer who might be in a hurry or lack of concentration while on task or he may not have been properly trained. Pilot should have forgotten to check the fuel tanks before being used. So, if any link in this chain of errors had been broken, the accident would not have occurred.