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WPR11FA117 · Cessna 172

31 Jan 2011 · Glendora, CA, United States

Cessna 172 · Accident: collision with terrain/object (non-CFIT) while maneuvering

From Brackett Field (POC) to Brackett Field (POC)

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Event

NTSB case
WPR11FA117
Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
Accident
InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
Completed
API-reported fatalities
0 · all aircraft and ground
Ground fatalities
Unknown
OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
General aviation
WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
Visual Meteorological Cond

Cessna 172

Aircraft type
Cessna 172
Category
Airplane
RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
N6922A
Operator
Gene A. Yu · private individual
Onboard fatalities
Unknown
Route
From Brackett Field (POC), La Verne, CATo Brackett Field (POC), La Verne, CA
Aircraft age
Not recorded
Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
Part 91: General Aviation
Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
Maneuvering
Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
Collision with terrain/object (non-CFIT)
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Substantial

Cause areas

  • Aircraft › Aircraft oper/perf/capability
  • Personnel issues › Action/decision

Approximate · Coordinates from the NTSB case API, not marked as estimated; no uncertainty radius is established.

NTSB narrative

The flight instructor reported that he and the commercially certificated student flew to mountainous terrain to practice using orographic lift. The flight instructor stated that the lift they were flying in began to dissipate so he took the flight controls and added full power to depart the area. Suddenly, they encountered a strong downdraft and moments later they impacted the terrain. It is likely that the airplane was not at a sufficient altitude for the pilot to recover from the downdraft encounter and clear the terrain. The flight instructor told local authorities at the time of his rescue that there were no problems with the airplane. A postaccident examination revealed no evidence of any preimpact mechanical anomalies with the airframe or engine that would have precluded normal operation.

Probable cause

The flight crew's failure to maintain adequate terrain clearance while maneuvering in downdraft conditions over mountains.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record WPR11FA117
Event ID
20110131X14558
Case number
WPR11FA117
Dataset
full-current
Source SHA-256
5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
  • Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
  • Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates. Values present in the bulk record are kept.
  • The date is the local date, which is the same as the UTC date the NTSB stores.
  • API snapshot SHA-256: f084d4eba9b581a60767c589043030a916902913cb9e89dac61b9ff7adac2ae5; retrieved 2026-09-15T15:43:36.915Z.