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|
Attributes | |
ACN | 1116792 |
Time | |
Date | 201309 |
Local Time Of Day | 1201-1800 |
Place | |
Locale Reference | ZZZ.ARTCC |
State Reference | US |
Environment | |
Flight Conditions | VMC |
Light | Daylight |
Aircraft 1 | |
Make Model Name | B737-300 |
Operating Under FAR Part | Part 121 |
Flight Phase | Takeoff |
Flight Plan | IFR |
Component | |
Aircraft Component | DC Generation Indicating and Warning System |
Person 1 | |
Function | First Officer |
Experience | Flight Crew Last 90 Days 101 Flight Crew Type 4200 |
Events | |
Anomaly | Aircraft Equipment Problem Critical Deviation - Procedural Published Material / Policy Deviation - Procedural FAR |
Narrative:
During the takeoff roll at ZZZ above 80 KTS; but below V1 and vr; the inertial reference system (IRS) recall light illuminated. It was noted that the dc fail lights were illuminated on the overhead IRS control panel. Both the captain and I acknowledged this and continued the takeoff. Once airborne; and above 1;000 ft; we called for and executed the QRH procedures for dc fail. The captain ran the QRH procedures and I focused on flying the aircraft and complying with ATC instructions. It wasn't until we were at our final cruising altitude of FL340 that we were able to fully diagnose the situation we were in. The QRH states that consideration should be given to landing at the nearest suitable airport. Since we were only 150 miles from our destination and overhead the busy ZZZ airspace; we elected to continue onto our destination. Thankfully we knew that we shouldn't expect thrust reversers; but we were unaware of many of the items we had lost (i.e. AFDS display panel and autopilot disconnect horn).because the autopilot disconnect horn was inoperative (inop); we were unknowingly non-rvsm compliant (this was not discovered until on final approach and I disconnected the autopilot at 1;500 ft AGL to execute the landing). I had expected the last page in the 'navigation' QRH tab to show all circuit breakers that could be affected by failures relating to the malfunctions in that tab. However; that is not the case here. The hot battery bus circuit breaker and the switched hot battery bus circuit breakers on panel P18-5 are not listed in this section. The absence of this information led us to never identify the actual cause of the dc fail light until at the gate. Maintenance discovered that the switched hot battery bus circuit breaker was popped. Once it was reset; the plane operated normally. The QRH should be updated to show the position and location of the hot battery bus and switched hot battery bus circuit breakers in the back of the 'navigation' tabbed section. The entire list of items that are on each bus should be listed; so that the crew will have a thorough understanding of what equipment is potentially lost. I firmly believe this incident could have been avoided and/or fixed in flight if the QRH would have been more thorough. Popped switched hot battery bus circuit breaker resulted in dc fail lights illuminating on IRS control panel.
Original NASA ASRS Text
Title: A First Officer reports about an IRS recall light and DC Fail lights that illuminated during takeoff roll on a B737-300 aircraft. Both pilots were unaware the aircraft had become RSVM Non-compliant due to the autopilot disconnect horn was inoperative and the lost of their AFDS display. Lack of reference in QRH to check Switched Hot battery Bus C/B also noted.
Narrative: During the takeoff roll at ZZZ above 80 KTS; but below V1 and VR; the Inertial Reference System (IRS) recall light illuminated. It was noted that the DC fail lights were illuminated on the overhead IRS Control Panel. Both the Captain and I acknowledged this and continued the takeoff. Once airborne; and above 1;000 FT; we called for and executed the QRH procedures for DC FAIL. The Captain ran the QRH procedures and I focused on flying the aircraft and complying with ATC instructions. It wasn't until we were at our final cruising altitude of FL340 that we were able to fully diagnose the situation we were in. The QRH states that consideration should be given to landing at the nearest suitable airport. Since we were only 150 miles from our destination and overhead the busy ZZZ airspace; we elected to continue onto our destination. Thankfully we knew that we shouldn't expect Thrust Reversers; but we were unaware of many of the items we had lost (i.e. AFDS Display panel and autopilot disconnect horn).Because the autopilot disconnect horn was inoperative (inop); we were unknowingly Non-RVSM compliant (this was not discovered until on final approach and I disconnected the autopilot at 1;500 FT AGL to execute the landing). I had expected the last page in the 'NAV' QRH tab to show all circuit breakers that could be affected by failures relating to the malfunctions in that tab. However; that is not the case here. The Hot Battery Bus circuit breaker and the Switched Hot Battery Bus circuit breakers on panel P18-5 are not listed in this section. The absence of this information led us to never identify the actual cause of the DC Fail light until at the gate. Maintenance discovered that the Switched Hot Battery Bus circuit breaker was popped. Once it was reset; the plane operated normally. The QRH should be updated to show the position and location of the Hot Battery Bus and Switched Hot Battery Bus circuit breakers in the back of the 'NAV' tabbed section. The entire list of items that are on each bus should be listed; so that the crew will have a thorough understanding of what equipment is potentially lost. I firmly believe this incident could have been avoided and/or fixed in flight if the QRH would have been more thorough. Popped Switched Hot Battery Bus circuit breaker resulted in DC fail lights illuminating on IRS control panel.
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.