# Accident 20110729023949A: Boeing 747-422, July 29, 2011

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: July 29, 2011, 13:48 local time
- Damage: No damage
- Phase of flight: Takeoff: Climb Out
- Operating rules: Air carrier (Part 121)
- Operator: UALA
- Location: 39.5452° N, 118.1680° E: From the FAA
- Nearby events: https://openairdocs.org/map.md?lat=39.5452&lon=118.1680&mi=10
- Aircraft: N173UA, a cancelled registration (https://openairdocs.org/deregistered/N173UA-2012-01-09) (OpenAirDocs)
- Registry model: Boeing 747-422 (registry code 1384935, https://openairdocs.org/model/boeing-747-422) (OpenAirDocs)
- Registry engine: Pratt & Whitney PW4000 series (registry code 52119, https://openairdocs.org/engine/pratt-whitney-pw4000-series) (OpenAirDocs)
- Reported make and model: BOEING 747-422
- Reported engine: P&W PW4056
- People aboard: 385
- Fatal injuries: 0
- Other injuries: 1
- Pilot certificates: Airline transport
- Pilot flight hours: 18,500 total, 7,600 in this make and model, 75 in the last 90 days
- NTSB investigation: [NTSB DCA11FA091](https://openairdocs.org/ntsb/DCA11FA091) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/20110729023949A

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

PRIOR TO THE TURBULENCE EVENT, THE CAPTAIN HAD THE WEATHER RADAR ON AND DETERMINED THAT IT WAS SAFE FOR THE FLIGHT ATTENDANTS TO GET UP AND START THEIR SERVICE. THE SEAT BELT SIGN WAS REPORTED TO BE ON AT THE TIME.  APPROXIMATELY 3 TO 4 MINUTES AFTER NOTIFYING THE FLIGHT ATTENDANTS IT WAS SAFE TO GET UP THE FLIGHT ENCOUNTERED SEVERE TURBULENCE.   ACCORDING TO THE INVESTIGATION, WHILE IN CRUISE FLIGHT CLIMBING BETWEEN FL230-250 APPROXIMATELY 75NM WEST OF ANRAT NAVIGATION FIX, THE FLIGHT ENCOUNTERED SEVERE TURBULENCE FOR AN ESTIMATED PERIOD OF 30 SECONDS.THERE WAS ONE SERIOUS INJURY REPORTED TO A FLIGHT ATTENDANT WHO WAS THROWN TO THE FLOOR DURING THE TURBULENCE ENCOUNTER.  THE INJURY WAS REPORTED AS A RIGHT KNEE AND ANKLE.    THE FLIGHT ATTENDANT RECEIVED A 2CM FRACTURE TO HER RIGHT FIBULA REQUIRING A SUGAR-TONG SPLINT.FACTS:1. ONE FEMALE FLIGHT ATTENDANT RECEIVED A 2CM FRACTURE TO HER RIGHT FIBULA REQUIRING A SUGAR-TONG SPLINT. 2. NO REPORTS OF PASSENGER INJURIES.3. THERE WERE NO RETURNS NOTED ON THE WEATHER RADAR4. FLIGHT CREW REPORTED ENTERING RAIN SHOWERS AT TIME OF ENCOUNTER5. INITIAL WEATHER ANALYSIS INDICATED TURBULENCE WAS MOST LIKELY RESULT OF CONVECTIVE ACTIVITY 6. INITIAL FDR ANALYSIS SHOWS PEAK VERTICAL ACCELERATION OF POSITIVE .8G ABOVE THE NORMAL VERTICAL ACCELERATION.7. SINCE EVENT OCCURRED OVER THE CHINESE MAINLAND, THE EVENT WAS REPORTED TO CAAC WHO LATER DELEGATED THE INVESTIGATION TO THE U.S. NATIONAL TRANSPORTATION SAFETY BOARD.8. THERE WAS NO AIRCRAFT DAMAGE.

## The NTSB's investigation of this event (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB DCA11FA091](https://openairdocs.org/ntsb/DCA11FA091), Jul 29, 2011: Boeing 747-422 (N173UA), Tangshan, China, no damage. Probable cause: an inadvertent encounter with convectively induced turbulence likely due to radar limitations and convective weather developing upwards into the flight path.

## Other reports on N173UA (1)

Matched to the same aircraft by N-number and date.

- [Accident 20100219028409A](https://openairdocs.org/incident/20100219028409A), Feb 19, 2010: Boeing 747-422 (N173UA), Minor damage. Ua 897 iad-nrt encountered severe turbulence in the anchorage fir. The flight was experiencing moderate turbulence and asked for lower altitude due to a…

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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