- Date
- February 7, 1999, 08:27 local (15:27 UTC)
- Place
- Climax, CO
- Injuries
- 1 serious, 28 uninjured
- Damage
- No damage
- Phase of flight
- Enroute
- Aircraft
- N586UABoeing 757-222
- Weather
- Visual (VMC) · Day
- Status
- Completed · report October 13, 2000
- Report
- Approved by Office Director
- FAA report
- 19990207014579A
- Case key
- 45732
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
The flight's encounter with turbulence.
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Analysis
After departing from Denver, Colorado, United Airlines flight 553 was cleared to climb to FL350 via the Rockies Three Departure (DEN R-240). The captain radioed ahead to another United flight on the same departure course and altitude, requesting a weather report. The other United flight reported 'occasional light chop uh mostly smooth.' The captain released the flight attendants to move about the cabin. The captain reported that between FL340 and FL345, the flight encountered severe turbulence. One flight attendant received a fractured knee cap and a concussion.
Factual narrative
On February 7,1999, at 0827 mountain standard time, a Boeing 757-222, N586UA, was not damaged following an encounter with turbulence near Climax, Colorado. The 2 airline transport pilots, 5 flight attendants, and 22 passengers were not injured; however, 1 flight attendant was seriously injured. The airplane was being operated by United Air Lines, Inc., under Title 14 CFR Part 121. Visual meteorological conditions prevailed for this scheduled domestic passenger flight which originated from Denver, Colorado, approximately 30 minutes before the accident. An IFR flight plan had been filed with a destination of Santa Ana, California.
FAA records indicate that air traffic control cleared United Airlines flight 553 to an altitude of 35,000 feet via the Rockies Three Departure (DEN R-240). At approximately 0820, the captain of flight 553 radioed ahead to another United flight on the same departure course and altitude, requesting weather status. The other United flight reported "occasional light chop, uh, mostly smooth." The captain released the flight attendants to move about the cabin. The captain reported that between FL340 and FL345, the flight encountered severe turbulence. One flight attendant received a fractured knee cap and a concussion.
United Airlines records indicate that the flight crew had been notified of a Significant Meteorological (SIGMET) report for moderate to occasionally severe turbulence between FL300 and FL420. An FAA inspector with the Denver FSDO determined that United flight 553 was south of the SIGMET box at the time of the severe turbulence event.
Aircraft
- Registration
- N586UA
- Reported as
- Boeing 757-222
- Category
- Airplane
- Serial number
- 26710
- Airframe hours
- 19,634
- Engine
- P&W 2037M, 37,000 lbs thrust, turbo fan
- Damage
- No damage
- Flight
- Part 121
- Registered owner
- United Air Lines Inc.
- Airworthiness certificate
- Standard, Transport
- Last inspection
- Continuous airworthiness · March 6, 1998 · 3,330 hours before
- Departed
- DEN · Denver, CO
- Destination
- SNA · Santa Ana, CA
- Flight plan
- IFR
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 39
- Certificate
- Airline transport
- Airplane ratings
- Single-engine land, Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Class 1, Valid Medical--no waivers/lim.
- Seat
- Left
- Flight hours
- 9,000 total · 1,497 in this make and model · 3 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 160° at 8 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- 25,000 ft broken
- Temperature
- 36 °F, dew point 21 °F
- Altimeter
- 29.00 inHg
- Observed at
- DEN, 70 nm away
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.