 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
A line mechanic requests clarification of add-on language to their MEL chapter-49 APU pneumatic issues for B757 aircraft; in order to understand the difference between that chapter and MEL chapter 36-12 APU shutoff valve. Concerns about applying an improper MEL for an APU pneumatic system deferral were also noted.
| Attributes | |
| ACN | 1084838 |
| Time | |
| Date | 201305 |
| Local Time Of Day | 0601-1200 |
| Place | |
| Locale Reference | ZZZ.Airport |
| State Reference | US |
| Environment | |
| Light | Daylight |
| Aircraft 1 | |
| Make Model Name | B757-200 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Parked |
| Component | |
| Aircraft Component | APU Pneumatic System & Ducting |
| Person 1 | |
| Function | Technician |
| Qualification | Maintenance Airframe Maintenance Powerplant |
| Events | |
| Anomaly | Aircraft Equipment Problem Critical Deviation - Procedural Published Material / Policy |
Narrative:
While reviewing the B757 MEL; I read [chapter] 49-xs [language add-on] for APU pneumatic issues and I then went to MEL 36-12; APU shutoff valve; and was trying to distinguish the difference between the two mels. They refer you to the same diagram; and [I] wanted to know exactly what APU pneumatic function meant. The second issue is that [MEL chapter] 36-12; paragraph-a; subsection-1; refers you to the APU shutoff air switch; of which does not exist on a B757. An APU bleed air switch; does however reside in the cockpit. Please clarify; as I would hate to use the wrong MEL for placarding an APU pneumatic system. On that note; which MEL would be proper to use when placarding the APU air?
Original NASA ASRS Text
Title: A Line Mechanic requests clarification of add-on language to their MEL Chapter-49 APU pneumatic issues for B757 aircraft; in order to understand the difference between that chapter and MEL Chapter 36-12 APU Shutoff Valve. Concerns about applying an improper MEL for an APU Pneumatic System deferral were also noted.
Narrative: While reviewing the B757 MEL; I read [Chapter] 49-Xs [language add-on] for APU Pneumatic issues and I then went to MEL 36-12; APU Shutoff Valve; and was trying to distinguish the difference between the two MELs. They refer you to the same diagram; and [I] wanted to know exactly what APU Pneumatic function meant. The second issue is that [MEL Chapter] 36-12; Paragraph-A; Subsection-1; refers you to the APU Shutoff Air switch; of which does not exist on a B757. An APU Bleed Air switch; does however reside in the cockpit. Please clarify; as I would hate to use the wrong MEL for placarding an APU Pneumatic System. On that note; which MEL would be proper to use when placarding the APU Air?
Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.