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A B757-200 flight crew noted unusual sounds during descent. Postflight inspection identified a damaged honeycomb section of a leading slat suspected to be associated with frozen water.
| Attributes | |
| ACN | 1054367 |
| Time | |
| Date | 201212 |
| Local Time Of Day | 0001-0600 |
| Place | |
| Locale Reference | ZZZ.ARTCC |
| State Reference | US |
| Environment | |
| Flight Conditions | VMC |
| Aircraft 1 | |
| Make Model Name | B757-200 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Descent |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | Airframe Composite Structure |
| Person 1 | |
| Function | Captain Pilot Flying |
| Qualification | Flight Crew Air Transport Pilot (ATP) |
| Events | |
| Anomaly | Aircraft Equipment Problem Critical |
Narrative:
We had deiced the wings and tail before takeoff due to ice build up on the horizontal stabilizer. Takeoff and cruise were uneventful. Sometime after start of descent we noticed a change in the sound of the aircraft. The sound was slightly more pronounced somewhere between FL330 and FL260. No abnormal flying characteristics were noticed. Once we transitioned to knots I accelerated the aircraft slightly to discover if the sound was related to speed. That was inconclusive so I returned to the normal descent profile. We selected flaps one at approximately 210 KTS and an uneventful approach and landing followed. During postflight I noticed apparently damaged structure protruding from the top of the starboard inboard leading edge slat. We lowered the slat to observe the extent of the damage and maintenance verified a rupture of the honeycomb on the trailing edge of the slat.this aircraft suffered a similar event with the port leading edge slat some months prior to this incident. A perusal of the internet brought to light other similar incidents with B757s where water freezes in the honeycomb material causing the failure of the slat trailing edge.
Original NASA ASRS Text
Title: A B757-200 flight crew noted unusual sounds during descent. Postflight inspection identified a damaged honeycomb section of a leading slat suspected to be associated with frozen water.
Narrative: We had deiced the wings and tail before takeoff due to ice build up on the horizontal stabilizer. Takeoff and cruise were uneventful. Sometime after start of descent we noticed a change in the sound of the aircraft. The sound was slightly more pronounced somewhere between FL330 and FL260. No abnormal flying characteristics were noticed. Once we transitioned to knots I accelerated the aircraft slightly to discover if the sound was related to speed. That was inconclusive so I returned to the normal descent profile. We selected flaps one at approximately 210 KTS and an uneventful approach and landing followed. During postflight I noticed apparently damaged structure protruding from the top of the starboard inboard leading edge slat. We lowered the slat to observe the extent of the damage and maintenance verified a rupture of the honeycomb on the trailing edge of the slat.This aircraft suffered a similar event with the port leading edge slat some months prior to this incident. A perusal of the internet brought to light other similar incidents with B757s where water freezes in the honeycomb material causing the failure of the slat trailing edge.
Data retrieved from NASA's ASRS site as of July 2013 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.