- Date
- February 19, 1993, 15:45 local (22:45 UTC)
- Place
- Cochise, AZ
- Injuries
- 3 minor
- Damage
- Substantial damage
- Phase of flight
- Enroute
- Aircraft
- N9987MCessna Soloy TU206G
- Weather
- Visual (VMC) · Day
- Status
- Completed · report March 25, 1994
- Report
- Approved by Office Director
- FAA report
- 19930219002939A
- Case key
- 27928
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 continued flight into known forecasted icing conditions, in an airplane not certificated for such flight, which resulted in an engine flameout due to engine ice/water injestion, and the pilot's inability to restart the engine due to inadequate installation of the pneumatic air lines on the cowl door sequencing valves which prevented the alternate air doors to completely cycle open. The inadequate system design led to a blocked compressor inlet. Factors in the accident were: icing conditions, inadequate engine and induction anti-icing system design, failure of the manufacturer to perform adequate system testing to ensure adequate operation, and mountainous terrain.
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 engine flamed out after encountering forecasted icing. (The pilot had earlier used alternate air, but was unable to maintain altitude due to the power loss). During air restart, tot rose to about 520 deg, the engine would not accelerate, and quickly died away. A forced landing was made in mountainous terrain. The induction system has normal and alternate air paths. Normal path has two ram air scoops directing air to an air box, then down to the eng inlet. Selection of alt air path directs engine bleed air to close the ram air scoop doors, and open alt air door on bottom of cowl. Air then circulates around engine and through a spring loaded door on rear of air box. On site exam found ram air doors closed and cockpit lever on alt air. Alt air door open air line was found to have a loose b-nut fitting at the valve. Checklist calls for alt air during air start. STC holder could not produce any engineering or flight test data to validate that engine would produce sufficient vacuum to open air box spring loaded door during air start.
Aircraft
- Registration
- N9987M
- Reported as
- Cessna Soloy TU206G
- Category
- Airplane
- Serial number
- U20604636
- Airframe hours
- 1,304
- Engine
- Allison 250-C20S, 420 horsepower, turbo prop
- Damage
- Substantial damage
- Flight
- Ferry · Part 91
- Operator
- Hammonds Air Service
- Registered owner
- Daedalus Aviation, Inc.
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · February 3, 1993 · 32 hours before
- Departed
- MYF · San Diego, CA
- Destination
- ELP · El Paso, TX
- 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
- 42
- Certificate
- Commercial
- Airplane ratings
- Single-engine land, Single-engine sea
- Instrument ratings
- Airplane
- Medical
- Class 1, Valid Medical--w/ waivers/lim
- Seat
- Left
- Flight hours
- 6,042 total · 28 in this make and model · 5,933 as pilot in command · 103 in the last 90 days · 45 in the last 30 days · 3 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Visibility
- 5 statute miles
- Lowest ceiling
- 1,200 ft overcast
- Temperature
- 61 °F
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.