 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Gulfstream iv aircraft during climb had a central air data computer and flight guidance computer fault. Altitude alert defaulted to a higher altitude and flight crew climbed through assigned altitude by 300 ft.
| Attributes | |
| ACN | 365600 |
| Time | |
| Date | 199704 |
| Day | Sat |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : dca |
| State Reference | DC |
| Altitude | msl bound lower : 17000 msl bound upper : 17300 |
| Environment | |
| Flight Conditions | Mixed |
| Light | Daylight |
| Aircraft 1 | |
| Operator | general aviation : corporate |
| Make Model Name | Gulfstream IV |
| Operating Under FAR Part | Part 91 |
| Navigation In Use | Other Other |
| Flight Phase | climbout : intermediate altitude |
| Route In Use | enroute airway : zdc |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | Other |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 95 flight time total : 11000 flight time type : 185 |
| ASRS Report | 365600 |
| Person 2 | |
| Affiliation | Other |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : commercial pilot : atp |
| Experience | flight time last 90 days : 100 flight time total : 16000 flight time type : 3000 |
| ASRS Report | 365599 |
| Events | |
| Anomaly | aircraft equipment problem : less severe altitude deviation : overshoot non adherence : clearance |
| Independent Detector | other controllera |
| Resolutory Action | flight crew : returned to intended course or assigned course other |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Aircraft |
| Air Traffic Incident | other |
Narrative:
Gulfstream iv aircraft departing washington national airport climbing out on a radar vector to the northwest. Assigned 17000 ft by center. While climbing through approximately 16500 ft MSL the #1 CADC and #4 flight guidance computer fail indicator appeared on the crew alerting system. The autoplt disengaged itself and the altitude alert preselect went to 24999 ft from original setting of 17000 ft. The aircraft was allowed to climb through 17000 ft to 17300 ft before the aircraft was descended back down to 17000 ft. In the meantime ZDC said they needed us to get back down to 17000 ft. I guess we exceeded our assigned altitude by 300 ft about 10-15 seconds. Our #1 CADC failure played havoc with our altitude reporting as we saw it fluctuate numerous times as we leveled at 17000 ft. ZDC never notified us of what he had us for altitude, until we asked when we were level at 17000 ft. He stated he had us at 17000 ft. We troubleshot the FMS system with no resolution using the checklist. After about 5 mins and climbing through 28000 ft MSL, the #1 central air data computer and #1 flight guidance computer alert disappeared. The autoplt system was reengaged and worked normally, for the next 50 mins. On descent to landing the problem reappeared and a manual approach to landing was completed at home base. The system was written up for repair. When #1 CADC and #1 flight guidance computer failed -- autoplt and autothrottles were in operation.
Original NASA ASRS Text
Title: GULFSTREAM IV ACFT DURING CLB HAD A CENTRAL AIR DATA COMPUTER AND FLT GUIDANCE COMPUTER FAULT. ALT ALERT DEFAULTED TO A HIGHER ALT AND FLC CLBED THROUGH ASSIGNED ALT BY 300 FT.
Narrative: GULFSTREAM IV ACFT DEPARTING WASHINGTON NATIONAL ARPT CLBING OUT ON A RADAR VECTOR TO THE NW. ASSIGNED 17000 FT BY CTR. WHILE CLBING THROUGH APPROX 16500 FT MSL THE #1 CADC AND #4 FLT GUIDANCE COMPUTER FAIL INDICATOR APPEARED ON THE CREW ALERTING SYS. THE AUTOPLT DISENGAGED ITSELF AND THE ALT ALERT PRESELECT WENT TO 24999 FT FROM ORIGINAL SETTING OF 17000 FT. THE ACFT WAS ALLOWED TO CLB THROUGH 17000 FT TO 17300 FT BEFORE THE ACFT WAS DSNDED BACK DOWN TO 17000 FT. IN THE MEANTIME ZDC SAID THEY NEEDED US TO GET BACK DOWN TO 17000 FT. I GUESS WE EXCEEDED OUR ASSIGNED ALT BY 300 FT ABOUT 10-15 SECONDS. OUR #1 CADC FAILURE PLAYED HAVOC WITH OUR ALT RPTING AS WE SAW IT FLUCTUATE NUMEROUS TIMES AS WE LEVELED AT 17000 FT. ZDC NEVER NOTIFIED US OF WHAT HE HAD US FOR ALT, UNTIL WE ASKED WHEN WE WERE LEVEL AT 17000 FT. HE STATED HE HAD US AT 17000 FT. WE TROUBLESHOT THE FMS SYS WITH NO RESOLUTION USING THE CHKLIST. AFTER ABOUT 5 MINS AND CLBING THROUGH 28000 FT MSL, THE #1 CENTRAL AIR DATA COMPUTER AND #1 FLT GUIDANCE COMPUTER ALERT DISAPPEARED. THE AUTOPLT SYS WAS REENGAGED AND WORKED NORMALLY, FOR THE NEXT 50 MINS. ON DSCNT TO LNDG THE PROB REAPPEARED AND A MANUAL APCH TO LNDG WAS COMPLETED AT HOME BASE. THE SYS WAS WRITTEN UP FOR REPAIR. WHEN #1 CADC AND #1 FLT GUIDANCE COMPUTER FAILED -- AUTOPLT AND AUTOTHROTTLES WERE IN OP.
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.