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A pilot reported a possible fire hazard relating to the standard-looking; 3-pronged; 400Hz electrical outlets in the cockpits of the B747-400's and B777-200's. The outlets accept standard household appliances; such as laptops and battery charges; rated at 50-60Hz; to be plugged into the 400Hz rated outlets. No use restrictions are noted in the flight manual nor are there restrictive placards near the plugs.
| Attributes | |
| ACN | 840998 |
| Time | |
| Date | 200906 |
| Local Time Of Day | 0601-1200 |
| Place | |
| Locale Reference | ZZZ.Airport |
| State Reference | US |
| Environment | |
| Light | Daylight |
| Aircraft 1 | |
| Make Model Name | B747-400 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Cruise |
| Component | |
| Aircraft Component | Electrical Wiring & Connectors |
| Person 1 | |
| Function | Pilot Flying |
| Experience | Flight Crew Last 90 Days 200 Flight Crew Total 10000 Flight Crew Type 500 |
| Events | |
| Anomaly | Aircraft Equipment Problem Critical Deviation - Procedural FAR Deviation - Procedural Maintenance Deviation - Procedural Published Material / Policy |
Narrative:
I have brought this problem to 747 fleet management in the past and now the same issue is occurring on the B777-200 fleet. The cockpit (electrical outlet) plugs are being used for items that are not rated for the power output of the plug. The cockpit plugs are indeed 115v; however; the frequency cycles are 400 versus the us standard of 60hz. The reason this is a problem is that the power adapters for computers; etc.; that are plugged into this outlet cannot accommodate these 400hz outlets. Computer power adapters are rated to accept 110-250v and 50-60hz. Maintenance control confirmed the cycles of 400Hz for these aircraft outlets and line maintenance confirmed that it is dangerous to use equipment that is not the proper 400 hz. (This was when I was on the B747-400). In june 2009; maintenance confirmed via ACARS that the B777 outlets are also 400hz and potential damage can occur to the aircraft and the equipment plugged in to it. This is a potential fire hazard (according to maintenance) and it needs to be addressed through the proper channels of company engineering; boeing or both. If all of the above related to me is true; these outlets need to be placarded as unsafe for use by cockpit crews; or anything other than maintenance use.
Original NASA ASRS Text
Title: A pilot reported a possible fire hazard relating to the standard-looking; 3-pronged; 400Hz electrical outlets in the cockpits of the B747-400's and B777-200's. The outlets accept standard household appliances; such as laptops and battery charges; rated at 50-60Hz; to be plugged into the 400Hz rated outlets. No use restrictions are noted in the flight manual nor are there restrictive placards near the plugs.
Narrative: I have brought this problem to 747 fleet management in the past and now the same issue is occurring on the B777-200 fleet. The cockpit (electrical outlet) plugs are being used for items that are not rated for the power output of the plug. The cockpit plugs are indeed 115v; however; the frequency cycles are 400 versus the U.S. Standard of 60hz. The reason this is a problem is that the power adapters for computers; etc.; that are plugged into this outlet CANNOT accommodate these 400hz outlets. Computer power adapters are rated to accept 110-250v and 50-60hz. Maintenance Control confirmed the cycles of 400Hz for these aircraft outlets and Line Maintenance confirmed that it is dangerous to use equipment that is not the proper 400 Hz. (This was when I was on the B747-400). In June 2009; Maintenance confirmed via ACARS that the B777 outlets are also 400hz and potential damage can occur to the aircraft and the equipment plugged in to it. This is a potential fire hazard (according to Maintenance) and it needs to be addressed through the proper channels of company Engineering; Boeing or both. If all of the above related to me is true; these outlets need to be placarded as unsafe for use by cockpit crews; or anything other than Maintenance use.
Data retrieved from NASA's ASRS site as of April 2012 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.