# Accident 19990611046209A: Boeing 777222, Madison, WI, June 11, 1999

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: June 11, 1999, 21:30 local time
- Place: Madison, WI
- Damage: No damage
- Operating rules: Air carrier (Part 121)
- Operator: UALA
- Location: 43.0568° N, 89.4040° W: From the FAA, an estimate near the named town, within about 3 miles
- Nearby events: https://openairdocs.org/map.md?lat=43.0568&lon=-89.4040&mi=10
- Aircraft: N781UA, registered now (https://openairdocs.org/aircraft/N781UA) (OpenAirDocs)
- Registry model: Boeing 777-222 (registry code 1385219, https://openairdocs.org/model/boeing-777-222) (OpenAirDocs)
- Registry engine: Pratt & Whitney PW4000 series (registry code 52119, https://openairdocs.org/engine/pratt-whitney-pw4000-series) (OpenAirDocs)
- Reported make and model: BOEING 777222
- NTSB investigation: [NTSB CHI99LA184](https://openairdocs.org/ntsb/CHI99LA184) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/19990611046209A

## Narrative

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

(-23) UNITED FLIGHT 256 ENCOUNTERED UNEXPECTED CLEAR AIR TURBULENCE WHILE DESCENDING THROUGH FL180.  THE TURBULENCE LASTED 20 TO 30 SECONDS; THE REMAINDER OF THE FLIGHT WAS SMOOTH. THE SEAT BELT SIGN WAS NOT ILLUMINATED AT THE TIME OF THE ENCOUNTER.

## 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 CHI99LA184](https://openairdocs.org/ntsb/CHI99LA184), Jun 12, 1999: Boeing 777-222 (N781UA), Madison, WI, no damage. Probable cause: the pilot-in-command's inadequate evaluation of the weather conditions. Factors associated with the accident were the turbulence encountered and the seat belt sign was not illuminated.

## Other reports on N781UA (1)

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

- [Incident 19990731023439I](https://openairdocs.org/incident/19990731023439I), Jul 31, 1999: Boeing 777222 (N781UA), Newark, NJ. (-23) During climb pilot noticed smoke in cockpit and slight smoke in cabin. Shut down right air condition pack, smoke subsided. Landed at ewr. No evacuation…

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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.