- Date
- June 25, 1992, 08:33 local (13:33 UTC)
- Place
- Konawa, OK
- Injuries
- 1 fatal
- Damage
- Destroyed
- Phase of flight
- Enroute
- Aircraft
- N690JCRockwell 690B
- Weather
- Visual (VMC) · Day
- Status
- Completed · report January 4, 1994
- Report
- Approved by Office Director
- FAA report
- 19920625021739A
- Case key
- 18364
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 pilot's failure to maintain control of the airplane which resulted in an inadvertent spiral and subsequent rapid descent. The design stress limits of the airframe were exceeded resulting in an overload failure of the empennage. Factors related to the accident were: turbulence and the pilot's physical impairment due to drugs.
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
As the airplane was deviating around low intensity weather returns, and passing through 20,500 ft during climb out, it departed controlled flight and entered a right spiral. Descent rates exceeded 16,600 fpm during the descent from 18,300 ft to 3,900 ft and then slowed. Witnesses stated they saw the airplane descend from the clouds in a right flap spin. The empennage had separated from the airplane in pieces. Pieces of the wreckage were found up to 1.5 mi from the primary impact point. Both wings remained attached. The right engine was flamed out, and the prop was feathered at impact. No mechanical reason for the flameout could be determined. At no time did the pilot indicate he was having difficulties. The NTSB weather study indicated that moderate turbulence was present in the area. The pilot's toxicology tests found 0.151 ug/ml of chlorpheniramine in the blood; normal therapeutic concentration is 0.01 to 0.04. Effects of overdosage include sedation, diminished mental alertness, and cardiovascular collapse to stimulation.
Aircraft
- Registration
- N690JC
- Reported as
- Rockwell 690B
- Category
- Airplane
- Serial number
- 11479
- Airframe hours
- 3,355
- Engine
- Garrett TPE-331-5-251, 717 horsepower, turbo prop
- Damage
- Destroyed
- Fire
- On-Ground
- Flight
- Ferry · Part 91
- Operator
- Aircraft Sales International
- Registered owner
- Prime Inc.
- Airworthiness certificate
- Standard, Normal
- Last inspection
- 100 hour · March 27, 1992 · 28 hours before
- Departed
- OUN · Norman, OK
- Destination
- FLL · Ft. Lauderdale, FL
- Flight plan
- IFR
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 65
- Certificates
- Flight instructor, Airline transport, Military, Commercial
- Airplane ratings
- Multi-engine land, Single-engine land
- Instrument ratings
- Airplane, Helicopter
- Medical
- Class 2, Valid Medical--w/ waivers/lim
- Seat
- Left
- Toxicology
- Performed
- Flight hours
- 8,857 total · 98 in this make and model · 8,486 as pilot in command · 77 in the last 90 days · 15 in the last 30 days · 1 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 120° at 8 knots
- Lowest ceiling
- 3,400 ft broken
- Temperature
- 70 °F
- Altimeter
- 29.00 inHg
- Observed at
- ADM, 35 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.