 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
While on an autopilot coupled approach to sea runway 16L at 10 DME; the aircraft pitched up 5 degrees then down 6 degrees and accelerated to 170 kts exceeding the flap 30 speed for 2 seconds. An aircraft was taxiing across in front of runway 16L and another was on short final.
| Attributes | |
| ACN | 815829 |
| Time | |
| Date | 200812 |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | airport : sea.airport |
| State Reference | WA |
| Altitude | msl single value : 3000 |
| Environment | |
| Flight Conditions | IMC |
| Light | Night |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | B737 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | ils localizer & glide slope : 16l |
| Flight Phase | descent : approach |
| Route In Use | approach : instrument precision |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Experience | flight time last 90 days : 230 flight time type : 230 |
| ASRS Report | 815829 |
| Events | |
| Anomaly | non adherence : far non adherence : published procedure other anomaly other anomaly |
| Independent Detector | other flight crewa |
| Resolutory Action | flight crew : regained aircraft control |
| Supplementary | |
| Problem Areas | Aircraft Navigational Facility ATC Human Performance |
| Primary Problem | ATC Human Performance |
| Situations | |
| Chart | airport : sea.airport approach : il.s |
Narrative:
At approximately 10 DME on an autopilot coupled CAT I ILS into runway 16L in sea with the aircraft stabilized; fully configured; and at final approach speed; the aircraft pitched up 5 degrees then down 6-8 degrees while on glideslope. Once the aircraft pitched down; the airspeed increased quickly to 170 KIAS. The captain immediately disconnected the autopilot and corrected the unstable pitch attitude. We were at flaps 30 degrees at the time and exceeded the flaps 30 degree placard speed of 165 kts for about 2 seconds. The flaps did not blow back. The captain continued flying the approach and was stabilized by dglas. The weather at the time was 1500 ft broken and 9 SM visibility with the ILS critical area unprotected. There was a jet crossing runway 16L at the time of our pitch deviations and a heavy jet on a 4-5 mile final in front of us.
Original NASA ASRS Text
Title: While on an autopilot coupled approach to SEA Runway 16L at 10 DME; the aircraft pitched up 5 degrees then down 6 degrees and accelerated to 170 kts exceeding the flap 30 speed for 2 seconds. An aircraft was taxiing across in front of Runway 16L and another was on short final.
Narrative: At approximately 10 DME on an autopilot coupled CAT I ILS into Runway 16L in SEA with the aircraft stabilized; fully configured; and at final approach speed; the aircraft pitched up 5 degrees then down 6-8 degrees while on Glideslope. Once the aircraft pitched down; the airspeed increased quickly to 170 KIAS. The Captain immediately disconnected the autopilot and corrected the unstable pitch attitude. We were at flaps 30 degrees at the time and exceeded the flaps 30 degree placard speed of 165 kts for about 2 seconds. The flaps did not blow back. The Captain continued flying the approach and was stabilized by DGLAS. The weather at the time was 1500 ft broken and 9 SM visibility with the ILS critical area unprotected. There was a jet crossing Runway 16L at the time of our pitch deviations and a heavy jet on a 4-5 mile final in front of us.
Data retrieved from NASA's ASRS site as of May 2009 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.