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An MD80 flight crew, while shooting a fully automated approach with autothrottles, experience a malfunction in the autothrottle system.
| Attributes | |
| ACN | 600091 |
| Time | |
| Date | 200311 |
| Day | Tue |
| Place | |
| Locale Reference | airport : ord.airport |
| State Reference | IL |
| Altitude | agl bound lower : 300 agl bound upper : 500 |
| Environment | |
| Flight Conditions | IMC |
| Weather Elements | other |
| Aircraft 1 | |
| Controlling Facilities | tower : ord.tower |
| Operator | common carrier : air carrier |
| Make Model Name | MD-80 Series (DC-9-80) Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | ils localizer only : 27l other |
| Flight Phase | descent : approach |
| Route In Use | approach : instrument precision |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| ASRS Report | 600091 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Events | |
| Anomaly | aircraft equipment problem : less severe inflight encounter : weather |
| Independent Detector | other flight crewa |
| Resolutory Action | aircraft : automation overrode flight crew flight crew : overcame equipment problem flight crew : overrode automation |
| Supplementary | |
| Problem Areas | Aircraft |
| Primary Problem | Aircraft |
Narrative:
We were flying an ILS to runway 27L at ord. I was flying. At approximately 500 ft, we broke out of the clouds and it was clear and good visibility below. I advised my first officer that we were landing. The autoplt and autothrottles remained on throughout. I was flying visually (automation still on) on the VASI when at about 300 ft, I noticed the autoplt started easing the nose up a little. When I looked down to xchk the instruments, I noticed that the airspeed was 5 KTS below reference bug with no attempt from the autothrottles to recover. At about the same time, I glanced at the instruments. My first officer called out airspeed. I disconnected the autothrottles and the autoplt and continued down the VASI for an uneventful landing. First of all, I'm glad that my first officer stayed on the instruments instead of fixating outside, once we broke out. Lastly, I'm very confused as to why the throttles could have done that. I've never seen such a thing in my 13 yrs flying the S80.
Original NASA ASRS Text
Title: AN MD80 FLT CREW, WHILE SHOOTING A FULLY AUTOMATED APCH WITH AUTOTHROTTLES, EXPERIENCE A MALFUNCTION IN THE AUTOTHROTTLE SYS.
Narrative: WE WERE FLYING AN ILS TO RWY 27L AT ORD. I WAS FLYING. AT APPROX 500 FT, WE BROKE OUT OF THE CLOUDS AND IT WAS CLR AND GOOD VISIBILITY BELOW. I ADVISED MY FO THAT WE WERE LNDG. THE AUTOPLT AND AUTOTHROTTLES REMAINED ON THROUGHOUT. I WAS FLYING VISUALLY (AUTOMATION STILL ON) ON THE VASI WHEN AT ABOUT 300 FT, I NOTICED THE AUTOPLT STARTED EASING THE NOSE UP A LITTLE. WHEN I LOOKED DOWN TO XCHK THE INSTS, I NOTICED THAT THE AIRSPD WAS 5 KTS BELOW REF BUG WITH NO ATTEMPT FROM THE AUTOTHROTTLES TO RECOVER. AT ABOUT THE SAME TIME, I GLANCED AT THE INSTS. MY FO CALLED OUT AIRSPD. I DISCONNECTED THE AUTOTHROTTLES AND THE AUTOPLT AND CONTINUED DOWN THE VASI FOR AN UNEVENTFUL LNDG. FIRST OF ALL, I'M GLAD THAT MY FO STAYED ON THE INSTS INSTEAD OF FIXATING OUTSIDE, ONCE WE BROKE OUT. LASTLY, I'M VERY CONFUSED AS TO WHY THE THROTTLES COULD HAVE DONE THAT. I'VE NEVER SEEN SUCH A THING IN MY 13 YRS FLYING THE S80.
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.