 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
B767-300 flight crew reported difficulties with airspeed indications possibly as a result of in-flight icing.
| Attributes | |
| ACN | 1539950 |
| Time | |
| Date | 201805 |
| Local Time Of Day | 0001-0600 |
| Place | |
| Locale Reference | ZZZ.ARTCC |
| State Reference | US |
| Environment | |
| Flight Conditions | Mixed |
| Light | Night |
| Aircraft 1 | |
| Make Model Name | B767-300 and 300 ER |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Descent |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | Airspeed Indicator |
| Person 1 | |
| Function | Pilot Not Flying Captain |
| Qualification | Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Instrument |
| Person 2 | |
| Function | First Officer Pilot Flying |
| Qualification | Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine |
| Events | |
| Anomaly | Aircraft Equipment Problem Less Severe Deviation - Speed All Types |
Narrative:
At approximately 35;000 feet during descent; we had an IAS disagree EICAS message. The captain and first officer's airspeeds differed by varying amounts up to 50 knots. The captain's airspeed indicator was within 10 knots of the standby airspeed indicator. The checklist called for an abnormal landing configuration of flaps 20. With all this to deal with; we [advised ATC]; initially with center; and asked for emergency equipment to be standing by on landing. Descent; approach and landing all went smoothly. We told the ground control [that] we no longer needed the emergency equipment and taxied to parking. The fire crew met us at the gate to ask if hot brakes were an issue; which they were not. A good portion of the flight was in ice crystal conditions near a line of thunderstorms. I feel this may have been a factor but not sure. Flying at a lower altitude may have helped prevent this but my concern was with the thunderstorms first of all. The checklist calls for a flap 20 landing and provides pitch and thrust settings for various phases of flight. However; there is no settings for flaps 20 approach; only flaps 25 and 30.
Original NASA ASRS Text
Title: B767-300 flight crew reported difficulties with airspeed indications possibly as a result of in-flight icing.
Narrative: At approximately 35;000 feet during descent; we had an IAS Disagree EICAS message. The Captain and FO's airspeeds differed by varying amounts up to 50 knots. The Captain's airspeed indicator was within 10 knots of the standby airspeed indicator. The checklist called for an abnormal landing configuration of flaps 20. With all this to deal with; we [advised ATC]; initially with Center; and asked for emergency equipment to be standing by on landing. Descent; approach and landing all went smoothly. We told the Ground Control [that] we no longer needed the emergency equipment and taxied to parking. The Fire Crew met us at the gate to ask if hot brakes were an issue; which they were not. A good portion of the flight was in ice crystal conditions near a line of thunderstorms. I feel this may have been a factor but not sure. Flying at a lower altitude may have helped prevent this but my concern was with the thunderstorms first of all. The checklist calls for a flap 20 landing and provides pitch and thrust settings for various phases of flight. However; there is no settings for flaps 20 approach; only flaps 25 and 30.
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.