MD-11
Maintenance Airframe; Maintenance Powerplant
Communication Breakdown; Confusion; Situational Awareness; Troubleshooting
Aircraft Equipment Problem Less Severe
Aircraft Aircraft Damaged; General Maintenance Action
Aircraft; Human Factors; MEL
Issued MEL 49-20-01 after Aircraft Maintenance Technician (AMT) stated this was an Oil Indication problem only. The Maintenance Release states that the ZZZ AMT noted the oil quantity was reading 0.0. The fire damage was noted two days later in ZZZ after ZZZ1 AMT had serviced APU to full and tried to start APU. The Damage could have been caused at that time. ZZZ AMT suspected an oil indication problem and called Maintenance Control for a deferral. Per MEL 49-20-01 Maintenance Step-3; I issued the Control number. [Recommend] inspecting the APU compartment every time we MEL an APU for failing to start. Routine Maintenance.
Reporter stated he is a Maintenance Controller. The original MEL 49-20-01 was applied to the MD-11 in ZZZ because of a pilot report for an APU Oil Quantity Indication malfunction reading zero. AMT in ZZZ did not look in the APU compartment to check the APU oil level due to turn around time constraints; they just decided to MEL the APU. An AMT in ZZZ1 actually checked the APU and found the APU oil completely gone; but did not see any leaks or oil residue and was unable to determine where the oil went. The earlier Pilot Report did not mention any odor or smells had been noted by the flight crew that would indicate the oil may have leaked into the pneumatic bleed duct from the compressor section. Suspicion was the oil had leaked out through the turbine section of the APU. He then serviced the APU oil to 'Full'. Reporter stated that after the MD-11 returned from ZZZ1; an AMT performing Routine Maintenance noticed heat damage to the APU Fire Containment Shroud; not fire damage. Repairs were made; but still not sure what caused the heat damage or oil loss. Looking back; MEL-49 probably should not have been issued until actual verification of the APU Oil Quantity level. Then perhaps; ZZZ Maintenance may have noticed the heat damage before requesting an MEL for APU Oil Quantity Indication.
A Maintenance Controller recommends that APU compartments be checked any time an APU is MEL'd for failing to start. He had previously issued an MEL for the APU Oil Quantity Indication on an MD-11 aircraft that was later found to have sustained heat damage to an APU Fire Containment Shroud and total loss of APU oil.