- Date
- July 27, 1990, 18:00 local (Jul 28, 1990, 00:00 UTC)
- Place
- Cheyenne, WY
- Injuries
- 1 serious, 7 minor, 2 uninjured
- Damage
- No damage
- Phase of flight
- Enroute
- Aircraft
- N405MMGulfstream G-II
- Weather
- Visual (VMC) · Day
- Status
- Completed · report November 23, 1992
- Report
- Approved by Office Director
- FAA report
- 19900727029429A
- Case key
- 17977
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
An unforeseen encounter with clear air 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
The airplane was approximately 100 NM northeast of denver, deviating around thunderstrom activity, when clear air turbulence (cat) was encountered. The captain stated after the accident the flight attendant had left his seat to perform cabin duties and was squatting down in the galley when the airplane was buffeted by the turbulence. Th flight attendant injured his ankle while in this position. The airplane returned to englewood, CO., and the flight attendant was transported to the hospital. According to the denver ARTCC, there were no reports of turbulence by other aircraft prior to the encounter.
Aircraft
- Registration
- N405MM
- Reported as
- Gulfstream G-II
- Category
- Airplane
- Serial number
- 220
- Engine
- Rolls-Royce SPEY MK 511-8, 11,400 horsepower, turbo fan
- Damage
- No damage
- Flight
- Executive/Corporate · Part 91
- Operator
- Martin Marietta Corporation
- Registered owner
- Martin Marietta Corp.
- Airworthiness certificate
- Standard, Normal
- Departed
- APA · Englewood, CO
- Destination
- IAD · Centerville, VA
- Flight plan
- IFR
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Airplane ratings
- Multi-engine land, Single-engine sea, Single-engine land
- Instrument ratings
- Airplane
- Medical
- Unknown, Unknown
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 210° at 12 knots, gusting 16
- Visibility
- 50 statute miles
- Lowest ceiling
- 16,000 ft broken
- Temperature
- 81 °F, dew point 45 °F
- Altimeter
- 30.00 inHg
- Observed at
- DEN, 75 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.