- Date
- July 15, 2009, 23:35 local (Jul 16, 2009, 05:35 UTC)
- Place
- Thermopolis, WY
- Injuries
- 1 serious, 1 minor
- Damage
- Substantial damage
- Phase of flight
- Enroute
- Aircraft
- N5461QCessna 172M
- Defining event
- Enroute-descent: Controlled flight into terr/obj (CFIT)
- Weather
- Visual (VMC) · Night/dark
- Status
- Completed · report September 30, 2009
- Report
- Approved by Office Director
- NTSB office
- Western Pacific Region
- Parties
- Casper FSFO
- FAA report
- 20090715011619A
- Case key
- 74303
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 instructor pilot's failure to ensure that his dual student maintained clearance from the terrain during a dark night visual flight rules descent.
Findings · 5
NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.
Sequence of events
The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.
Analysis
The student pilot and his instructor were returning to their home airport after a visual flight rules (VFR) night cross-country instructional fight. During the last segment of the flight, as the student was descending toward the airport, the airplane's wheels contacted the terrain on a ridge about nine miles from the planned destination, and about 1,650 feet higher than the airport elevation. Although the airplane initially rolled across the terrain at a high rate of speed, it soon encountered the elevated edge of a dirt road. The contact with the road edge resulted in a loss of control of the airplane and further contact with the terrain. The sequence of events resulted in substantial damage to the airplane's fuselage. Although the sky was clear with no restrictions to visibility, it was a dark night with no moonlight, and neither pilot saw the terrain prior to the accident. Although the instructor pilot did not specifically remember an unusual rate of descent or any sense of the airplane sinking, it was his opinion that a "mountain wave downwash" may have contributed to the accident.
Factual narrative
The student pilot and his instructor were returning to their home airport after a visual flight rules (VFR) night cross-country instructional fight. During the last segment of the flight, as the student was descending toward the airport, the airplane's wheels contacted the terrain on a ridge about nine miles from the planned destination, and about 1,650 feet higher than the airport elevation. Although the airplane initially rolled across the terrain at a high rate of speed, it soon encountered the elevated edge of a dirt road. The contact with the road edge resulted in a loss of control of the airplane and further contact with the terrain. The sequence of events resulted in substantial damage to the airplane's fuselage. Although the sky was clear with no restrictions to visibility, it was a dark night with no moonlight, and neither pilot saw the terrain prior to the accident. Although the instructor pilot did not specifically remember an unusual rate of descent or any sense of the airplane sinking, it was his opinion that a "mountain wave downwash" may have contributed to the accident.
Aircraft
- Registration
- N5461Q
- Reported as
- Cessna 172M
- Category
- Airplane
- Serial number
- 17261791
- Engine
- Lycoming O-320 SERIES, 180 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Instructional · Part 91
- Operator
- Round Top Flyers LLC
- Registered owner
- Round Top Flyers LLC
- Airworthiness certificate
- Standard, Normal
- Departed
- KLND · Lander, WY
- Destination
- KTHP · Thermopolis, WY
- Flight plan
- Unknown
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 · 2
As NTSB recorded them. NTSB leaves out names.
- Role
- Flight instructor
- Age
- 68
- Injuries
- Minor
- Certificates
- Commercial, Flight instructor
- Airplane ratings
- Single-engine land, Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Class 3
- Seat
- Right
- Flight hours
- 3,784 total · 1,800 in this make and model
- Role
- Student pilot
- Age
- 47
- Injuries
- Serious
- Certificate
- Student
- Medical
- Class 3
- Seat
- Left
- Flight hours
- 27 total · 27 in this make and model
Weather
- Conditions
- Visual (VMC) · Night/dark
- Wind
- 330° at 15 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 50 °F
Docket · 1
The files NTSB released with the investigation on July 28, 2009, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.9 MB in all.
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.
Other investigations on N5461Q · 1
Matched to the same aircraft by N-number and date.