 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
First officer of an MD88 overshot assigned descent altitude due to missetting the FMC mode control panel for an ATC requested speed reduction causing the autoplt to not capture preset assigned altitude. First officer recognized his mistake and manually returned the aircraft to assigned altitude. However, TCASII alert showed loss of standard separation with another aircraft.
| Attributes | |
| ACN | 410097 |
| Time | |
| Date | 199808 |
| Day | Wed |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : atl |
| State Reference | GA |
| Altitude | msl bound lower : 11700 msl bound upper : 12000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : atl |
| Operator | common carrier : air carrier |
| Make Model Name | MD-88 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other Other |
| Flight Phase | descent other |
| Route In Use | arrival other arrival star : star enroute airway : atl |
| Flight Plan | IFR |
| Aircraft 2 | |
| Make Model Name | Any Unknown or Unlisted Aircraft Manufacturer |
| Operating Under FAR Part | other : unknown |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 90 flight time total : 6000 flight time type : 170 |
| ASRS Report | 410097 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp pilot : private pilot : instrument pilot : flight engineer pilot : commercial |
| Experience | flight time last 90 days : 150 flight time total : 15000 flight time type : 4850 |
| ASRS Report | 410300 |
| Events | |
| Anomaly | altitude deviation : overshoot non adherence : clearance non adherence : far non adherence : required legal separation other anomaly other |
| Resolutory Action | flight crew : returned to intended course or assigned course |
| Consequence | Other |
| Miss Distance | horizontal : 9000 vertical : 700 |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
When descending to 12000 ft MSL I was given a speed reduction to 250 KTS and a heading change at approximately 12300 ft. I noticed that the altimeter was still at 29.92 and reset it to 30.16. That caused the altitude capture mode of the autoplt to cancel. I did not immediately catch the loss of altitude capture. I incorrectly pushed 'IAS' on the autoplt in an effort to change from the FMS speed to enable me to reduce to 250 KTS as instructed. I then caught sight of the aircraft altitude going through 11900 ft. To quickly gain aircraft control I clicked off the autoplt and proceeded to bring the aircraft back to 12000 ft MSL after dropping to approximately 11750 ft. There was an RA on TCASII for lower traffic while off altitude. I feel the events happened for several reasons. Not already having the altimeter set to 30.16. This, with being instructed to turn and change airspeed diverted my attention from the altitude. I pushed 'IAS' on the autoplt in error due to being new to the aircraft and its automation and being in a rushed situation. Solution: I should have called for descent checklist descending through 18000 ft. That would have reset my altimeter. More initial FMS training would have helped with not pushing 'IAS' on the autoplt. This caused a distraction. Having more flight experience in the aircraft would have increased familiarity.
Original NASA ASRS Text
Title: FO OF AN MD88 OVERSHOT ASSIGNED DSCNT ALT DUE TO MISSETTING THE FMC MODE CTL PANEL FOR AN ATC REQUESTED SPD REDUCTION CAUSING THE AUTOPLT TO NOT CAPTURE PRESET ASSIGNED ALT. FO RECOGNIZED HIS MISTAKE AND MANUALLY RETURNED THE ACFT TO ASSIGNED ALT. HOWEVER, TCASII ALERT SHOWED LOSS OF STANDARD SEPARATION WITH ANOTHER ACFT.
Narrative: WHEN DSNDING TO 12000 FT MSL I WAS GIVEN A SPD REDUCTION TO 250 KTS AND A HEADING CHANGE AT APPROX 12300 FT. I NOTICED THAT THE ALTIMETER WAS STILL AT 29.92 AND RESET IT TO 30.16. THAT CAUSED THE ALT CAPTURE MODE OF THE AUTOPLT TO CANCEL. I DID NOT IMMEDIATELY CATCH THE LOSS OF ALT CAPTURE. I INCORRECTLY PUSHED 'IAS' ON THE AUTOPLT IN AN EFFORT TO CHANGE FROM THE FMS SPD TO ENABLE ME TO REDUCE TO 250 KTS AS INSTRUCTED. I THEN CAUGHT SIGHT OF THE ACFT ALT GOING THROUGH 11900 FT. TO QUICKLY GAIN ACFT CTL I CLICKED OFF THE AUTOPLT AND PROCEEDED TO BRING THE ACFT BACK TO 12000 FT MSL AFTER DROPPING TO APPROX 11750 FT. THERE WAS AN RA ON TCASII FOR LOWER TFC WHILE OFF ALT. I FEEL THE EVENTS HAPPENED FOR SEVERAL REASONS. NOT ALREADY HAVING THE ALTIMETER SET TO 30.16. THIS, WITH BEING INSTRUCTED TO TURN AND CHANGE AIRSPD DIVERTED MY ATTN FROM THE ALT. I PUSHED 'IAS' ON THE AUTOPLT IN ERROR DUE TO BEING NEW TO THE ACFT AND ITS AUTOMATION AND BEING IN A RUSHED SIT. SOLUTION: I SHOULD HAVE CALLED FOR DSCNT CHKLIST DSNDING THROUGH 18000 FT. THAT WOULD HAVE RESET MY ALTIMETER. MORE INITIAL FMS TRAINING WOULD HAVE HELPED WITH NOT PUSHING 'IAS' ON THE AUTOPLT. THIS CAUSED A DISTR. HAVING MORE FLT EXPERIENCE IN THE ACFT WOULD HAVE INCREASED FAMILIARITY.
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.