 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
An air crew descended below assigned altitude after passing the transition altitude. They confused the altimeter setting of 998 millibars with 29.98 inches.
| Attributes | |
| ACN | 1242194 |
| Time | |
| Date | 201502 |
| Local Time Of Day | 1201-1800 |
| Place | |
| Locale Reference | EDDF.Airport |
| State Reference | FO |
| Environment | |
| Flight Conditions | VMC |
| Aircraft 1 | |
| Make Model Name | Widebody Low Wing 2 Turbojet Eng |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Descent |
| Flight Plan | IFR |
| Person 1 | |
| Function | Pilot Not Flying Captain |
| Qualification | Flight Crew Air Transport Pilot (ATP) |
| Person 2 | |
| Function | First Officer Pilot Flying |
| Experience | Flight Crew Last 90 Days 143 Flight Crew Total 2739 Flight Crew Type 455 |
| Events | |
| Anomaly | Deviation - Altitude Excursion From Assigned Altitude Deviation - Altitude Overshoot Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy |
Narrative:
On descent into frankfurt cleared to descend to 6;000 feet. Transition level was FL070. The controller advised the crew that the altimeter was 998. 29.98 was read back to the controller at least three times without correction by the controller. Once passing through FL070 both the pilot flying and pilot monitoring (pm) set 29.98 inches in their altimeters. The controller noticed the aircraft was descending below 6;000 feet and advised the crew to set 29.47 inches. The aircraft descended approximately 350 feet below it's assigned altitude. The crew on this flight had experienced a maintenance delay [on departure] and had extended their duty day in order to complete this flight. Two factors contributed to this altitude deviation. First the crew was fatigued due to the delay and secondly the controller not specifying the altimeter setting in millibars or correcting the improper altimeter read back by the pm.
Original NASA ASRS Text
Title: An air crew descended below assigned altitude after passing the transition altitude. They confused the altimeter setting of 998 millibars with 29.98 inches.
Narrative: On descent into Frankfurt cleared to descend to 6;000 feet. Transition level was FL070. The controller advised the crew that the altimeter was 998. 29.98 was read back to the controller at least three times without correction by the controller. Once passing through FL070 both the Pilot Flying and Pilot Monitoring (PM) set 29.98 inches in their altimeters. The controller noticed the aircraft was descending below 6;000 feet and advised the crew to set 29.47 inches. The aircraft descended approximately 350 feet below it's assigned altitude. The crew on this flight had experienced a maintenance delay [on departure] and had extended their duty day in order to complete this flight. Two factors contributed to this altitude deviation. First the crew was fatigued due to the delay and secondly the controller not specifying the altimeter setting in millibars or correcting the improper altimeter read back by the PM.
Data retrieved from NASA's ASRS site 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.