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A BAE100 after takeoff in climb aircraft lost the attitude heading reference system and returned to the field. Failure caused by switching the power. No reference in the QRH warning that this power switching could cause failure of the attitude heading reference system.
| Attributes | |
| ACN | 400550 |
| Time | |
| Date | 199804 |
| Day | Tue |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | atc facility : dtw |
| State Reference | MI |
| Altitude | msl bound lower : 5000 msl bound upper : 10000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : dtw |
| Operator | common carrier : air carrier |
| Make Model Name | Jetstream 41 |
| Operating Under FAR Part | Part 135 |
| Navigation In Use | Other Other |
| Flight Phase | climbout : intermediate altitude other other |
| Route In Use | departure other |
| Flight Plan | VFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 270 flight time total : 5688 flight time type : 450 |
| ASRS Report | 400550 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : instrument pilot : commercial |
| Events | |
| Anomaly | aircraft equipment problem : critical other anomaly other |
| Independent Detector | other flight crewa |
| Resolutory Action | other |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Aircraft |
| Air Traffic Incident | other |
| Situations | |
| Publication | Unspecified |
Narrative:
During climb out, we experienced 2 EFIS problems. The TCASII fail light came on and the altitude select feature of the flight director would not work in manual or with autoplt. Referring to the QRH did not help since these failures were not idented or discussed. Since we were departing a high density airport area, both system were designed to ease pilot workload and assist in traffic avoidance. Without guidance from the QRH, we resorted to quickly checking circuit breakers and switch position. As we were doing this we also encountered some turbulence (jet wash). While wiggling the avionics switches to ensure they were 'on' the attitude/heading reference system heading system failed. Now with our bigger problem, we referred to the QRH and returned to departure airport. WX conditions at all times were VFR. I believe that moving the switches in turbulence caused a power interruption to the attitude/heading reference system. Later on the ground, I found a sentence in the flight standards handbook (system chapter) that mentions that recycling the avionics switch in-flight will cause loss of the attitude/heading reference system. However, recycling on the ground will not result in losing attitude/heading reference system. I am concerned that this fact is not a 'warning' in the QRH! The QRH should at least mention all the system pwred by the avionics master switch and include the warning about loss of attitude/heading reference system in-flight.
Original NASA ASRS Text
Title: A BAE100 AFTER TKOF IN CLB ACFT LOST THE ATTITUDE HDG REF SYS AND RETURNED TO THE FIELD. FAILURE CAUSED BY SWITCHING THE PWR. NO REF IN THE QRH WARNING THAT THIS PWR SWITCHING COULD CAUSE FAILURE OF THE ATTITUDE HDG REF SYS.
Narrative: DURING CLBOUT, WE EXPERIENCED 2 EFIS PROBS. THE TCASII FAIL LIGHT CAME ON AND THE ALT SELECT FEATURE OF THE FLT DIRECTOR WOULD NOT WORK IN MANUAL OR WITH AUTOPLT. REFERRING TO THE QRH DID NOT HELP SINCE THESE FAILURES WERE NOT IDENTED OR DISCUSSED. SINCE WE WERE DEPARTING A HIGH DENSITY ARPT AREA, BOTH SYS WERE DESIGNED TO EASE PLT WORKLOAD AND ASSIST IN TFC AVOIDANCE. WITHOUT GUIDANCE FROM THE QRH, WE RESORTED TO QUICKLY CHKING CIRCUIT BREAKERS AND SWITCH POS. AS WE WERE DOING THIS WE ALSO ENCOUNTERED SOME TURB (JET WASH). WHILE WIGGLING THE AVIONICS SWITCHES TO ENSURE THEY WERE 'ON' THE ATTITUDE/HDG REF SYS HDG SYS FAILED. NOW WITH OUR BIGGER PROB, WE REFERRED TO THE QRH AND RETURNED TO DEP ARPT. WX CONDITIONS AT ALL TIMES WERE VFR. I BELIEVE THAT MOVING THE SWITCHES IN TURB CAUSED A PWR INTERRUPTION TO THE ATTITUDE/HDG REF SYS. LATER ON THE GND, I FOUND A SENTENCE IN THE FLT STANDARDS HANDBOOK (SYS CHAPTER) THAT MENTIONS THAT RECYCLING THE AVIONICS SWITCH INFLT WILL CAUSE LOSS OF THE ATTITUDE/HDG REF SYS. HOWEVER, RECYCLING ON THE GND WILL NOT RESULT IN LOSING ATTITUDE/HDG REF SYS. I AM CONCERNED THAT THIS FACT IS NOT A 'WARNING' IN THE QRH! THE QRH SHOULD AT LEAST MENTION ALL THE SYS PWRED BY THE AVIONICS MASTER SWITCH AND INCLUDE THE WARNING ABOUT LOSS OF ATTITUDE/HDG REF SYS INFLT.
Data retrieved from NASA's ASRS site as of July 2007 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.