|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||0601 To 1200|
|Locale Reference||atc facility : hvq|
|Altitude||msl bound lower : 28000|
msl bound upper : 29000
|Operator||common carrier : air carrier|
|Make Model Name||Medium Large Transport, Low Wing, 2 Turbojet Eng|
|Flight Phase||cruise other|
|Route In Use||enroute airway : j85|
|Affiliation||company : air carrier|
|Function||flight crew : first officer|
|Qualification||pilot : atp|
|Experience||flight time last 90 days : 150|
flight time total : 7400
flight time type : 150
|Function||flight crew : captain|
oversight : pic
|Qualification||pilot : atp|
|Anomaly||aircraft equipment problem : less severe|
altitude deviation : excursion from assigned altitude
non adherence : clearance
|Independent Detector||other controllera|
other flight crewa
|Resolutory Action||flight crew : returned to intended course or assigned course|
|Primary Problem||Flight Crew Human Performance|
|Air Traffic Incident||Pilot Deviation|
After rotation from cak and prior to gear up (first officer flying) in IMC conditions, both airspeed indicators ceased to operate. They both indicated 0 airspeed. I continued the IMC climb out by reference to attitude and power setting. The erroneous airspeed indications activated both the overspd and stall warnings. Very distracting at a critical time! Upon reaching VFR on top conditions, the captain decided to fly the remainder of the leg. He instructed me to disarm both of the above warning systems by pulling their circuit breaker's. I had to leave my seat to do so. Shortly after leveling at our assigned altitude of FL290, the captain instructed me to contact company radio, initiate a phone patch with another ground facility, obtain WX for airports as possible alternates (VFR conditions), consult the aircraft systems manual and run the appropriate emergency checklists. While involved with the above, the #2 gen went off line. At this point the autoplt was deactivated and the captain was hand flying the aircraft. I looked up from the above assigned duties to scan the instruments. We were slowly deviating from altitude. I called 'altitude' to the captain, which he acknowledged. However, the captain misinterpreted the altitude readout and descend rather than climbed to correct. ATC inquired what altitude we indicated and the captain replied, then corrected from FL280 to FL290.
Original NASA ASRS Text
Title: PLT ALLOWED ACFT TO DESCEND BELOW ASSIGNED ALT.
Narrative: AFTER ROTATION FROM CAK AND PRIOR TO GEAR UP (F/O FLYING) IN IMC CONDITIONS, BOTH AIRSPD INDICATORS CEASED TO OPERATE. THEY BOTH INDICATED 0 AIRSPD. I CONTINUED THE IMC CLBOUT BY REF TO ATTITUDE AND PWR SETTING. THE ERRONEOUS AIRSPD INDICATIONS ACTIVATED BOTH THE OVERSPD AND STALL WARNINGS. VERY DISTRACTING AT A CRITICAL TIME! UPON REACHING VFR ON TOP CONDITIONS, THE CAPT DECIDED TO FLY THE REMAINDER OF THE LEG. HE INSTRUCTED ME TO DISARM BOTH OF THE ABOVE WARNING SYSTEMS BY PULLING THEIR CB'S. I HAD TO LEAVE MY SEAT TO DO SO. SHORTLY AFTER LEVELING AT OUR ASSIGNED ALT OF FL290, THE CAPT INSTRUCTED ME TO CONTACT COMPANY RADIO, INITIATE A PHONE PATCH WITH ANOTHER GND FAC, OBTAIN WX FOR ARPTS AS POSSIBLE ALTERNATES (VFR CONDITIONS), CONSULT THE ACFT SYSTEMS MANUAL AND RUN THE APPROPRIATE EMER CHKLISTS. WHILE INVOLVED WITH THE ABOVE, THE #2 GEN WENT OFF LINE. AT THIS POINT THE AUTOPLT WAS DEACTIVATED AND THE CAPT WAS HAND FLYING THE ACFT. I LOOKED UP FROM THE ABOVE ASSIGNED DUTIES TO SCAN THE INSTRUMENTS. WE WERE SLOWLY DEVIATING FROM ALT. I CALLED 'ALT' TO THE CAPT, WHICH HE ACKNOWLEDGED. HOWEVER, THE CAPT MISINTERPRETED THE ALT READOUT AND DSND RATHER THAN CLBED TO CORRECT. ATC INQUIRED WHAT ALT WE INDICATED AND THE CAPT REPLIED, THEN CORRECTED FROM FL280 TO FL290.
Data retrieved from NASA's ASRS site as of August 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.