Loss of Control in Flight: Cessna 172L Skyhawk, N7904G; accident occurred February 27, 2020 at Dubois Municipal Airport (U41), Clark County, Idaho

Aviation Accident Final Report - National Transportation Safety Board 

Additional Participating Entity:
Federal Aviation Administration / Flight Standards District Office; Boise, Idaho

Investigation Docket - National Transportation Safety Board:

https://data.ntsb.gov/Docket

https://registry.faa.gov/N7904G

Location: Dubois, ID
Accident Number: WPR20CA095
Date & Time: 02/27/2020, 0915 MST
Registration: N7904G
Aircraft: Cessna 172
Aircraft Damage: Substantial
Defining Event: Loss of control in flight
Injuries: 2 None
Flight Conducted Under: Part 91: General Aviation - Instructional 

Analysis

The flight instructor reported that, during the instructional flight, the student was making a low pass over the snow-covered runway when the airplane encountered a downdraft that decreased the airspeed and increased the descent rate. The instructor reported that he was too relaxed and should have added power at that moment but didn't. The wheels contacted the snow, and the airplane nosed over and came to rest inverted. The airplane sustained substantial damage to the wings. The instructor reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The student pilot's failure to maintain a proper airspeed and descent rate while conducting a low pass over a snow-covered runway after encountering a downdraft and the flight instructor's delayed action, which resulted in the wheels contacting the snow and the airplane nosing over. 

Findings

Personnel issues Aircraft control - Student/instructed pilot

Personnel issues Delayed action - Instructor/check pilot

Aircraft Airspeed - Not attained/maintained

Aircraft Descent rate - Not attained/maintained

Environmental issues Downdraft - Effect on operation

Factual Information

History of Flight

Maneuvering-low-alt flying Other weather encounter

Maneuvering-low-alt flying Loss of control in flight (Defining event)

Maneuvering-low-alt flying Collision with terr/obj (non-CFIT)

Pilot Information

Certificate: Flight Instructor; Commercial
Age: 26, Male
Airplane Rating(s): Single-engine Land
Seat Occupied: Right
Other Aircraft Rating(s): None
Restraint Used:
Instrument Rating(s): Airplane
Second Pilot Present: No
Instructor Rating(s): Airplane Single-engine
Toxicology Performed: No
Medical Certification: Class 1 Without Waivers/Limitations
Last FAA Medical Exam: 10/04/2018
Occupational Pilot: Yes
Last Flight Review or Equivalent: 06/23/2019
Flight Time:  715 hours (Total, all aircraft), 254 hours (Total, this make and model), 622 hours (Pilot In Command, all aircraft), 130 hours (Last 90 days, all aircraft), 39 hours (Last 30 days, all aircraft), 3 hours (Last 24 hours, all aircraft)

Student Pilot Information

Certificate: Student
Age: 26, Male
Airplane Rating(s): None
Seat Occupied: Left
Other Aircraft Rating(s): None
Restraint Used:
Instrument Rating(s): None
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed: No
Medical Certification: Class 3 With Waivers/Limitations
Last FAA Medical Exam: 07/09/2019
Occupational Pilot: No
Last Flight Review or Equivalent:
Flight Time:  53 hours (Total, all aircraft), 52 hours (Total, this make and model), 9 hours (Pilot In Command, all aircraft), 10 hours (Last 90 days, all aircraft), 9 hours (Last 30 days, all aircraft), 1 hours (Last 24 hours, all aircraft)

Aircraft and Owner/Operator Information

Aircraft Make: Cessna
Registration: N7904G
Model/Series: 172 L
Aircraft Category: Airplane
Year of Manufacture:1970 
Amateur Built:No 
Airworthiness Certificate: Normal
Serial Number: 17259604
Landing Gear Type: Tricycle
Seats: 4
Date/Type of Last Inspection: 02/01/2020, 100 Hour
Certified Max Gross Wt.: 2299 lbs
Time Since Last Inspection:
Engines: 1 Reciprocating
Airframe Total Time: 5262 Hours at time of accident
Engine Manufacturer: Lycoming
ELT: C126 installed, activated, did not aid in locating accident
Engine Model/Series: O-320 SERIES
Registered Owner: Right Rudder LLC
Rated Power: 150 hp
Operator: On file
Operating Certificate(s) Held: None

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: KRXE, 4862 ft msl
Distance from Accident Site: 27 Nautical Miles
Observation Time: 0905 MST
Direction from Accident Site: 138°
Lowest Cloud Condition: Clear
Visibility:  10 Miles
Lowest Ceiling: None
Visibility (RVR):
Wind Speed/Gusts: Light and Variable /
Turbulence Type Forecast/Actual: None / None
Wind Direction: Variable
Turbulence Severity Forecast/Actual: N/A / N/A
Altimeter Setting: 30.03 inches Hg
Temperature/Dew Point: -16°C / -13°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Rexburg, ID (RXE)
Type of Flight Plan Filed: None
Destination: Rexburg, ID (RXE)
Type of Clearance:None 
Departure Time: 0827 MST
Type of Airspace: Class G

Airport Information

Airport: Dubois Muni (U41)
Runway Surface Type: Dirt; Snow
Airport Elevation: 5123 ft
Runway Surface Condition: Snow
Runway Used: 16
IFR Approach: None
Runway Length/Width: 4600 ft / 100 ft
VFR Approach/Landing: Traffic Pattern

Wreckage and Impact Information

Crew Injuries: 2 None
Aircraft Damage: Substantial
Passenger Injuries: N/A
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 2 None
Latitude, Longitude: 44.162222, -112.220556 (est)