Aircraft Accident/Incident Report

Glendora, California 91740
Monday, January 31, 2011 15:25 PST

NTSB Narrative Summary Released at Completion of Accident

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.

NTSB Probable Cause Narrative

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

Event Information

Type of Event Accident
Event Date 1/31/2011
Event Day of the Week Monday
Time of Event 1525
Event Time Zone Pacific Standard Time
Event City Glendora
Event State CALIFORNIA
Event Country --
Zipcode of the event site 91740
Event Date Year 2011
Event Date Month 1
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 340939N
Event Location Longitude 1175245W
Event Location Airport --
Event Location Nearest Airport ID --
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness --
Investigator's weather source Weather Observation Facility
Time of the weather observation 1553 Pacific Standard Time
Direction of event from weather observation facility (degrees) 130
Weather Observation Facility ID CNO
Elevation of weather observation facility 635
Distance of event from weather observation facility (units?) 16
Time Zone of the weather observation PST
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height 4000
Sky/Lowest/Cloud Conditions Few
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 17
Dew Point at event time (in degress fahrenheit) 7
Wind Direction (degrees magnetic) 260
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 8
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 30.09
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury Serious
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor 1
Injury Total None --
Injury Total Serious 1
Injury Total All 2
Investigating Agency NTSB
NTSB Docket Number (internal use) 29086
NTSB Notification Source FAA ROC
NTSB Notification Date --
NTSB Notification Time --
Fiche Number and/or location -used to find docket information --
Date of most recent change to record Oct 17 2011 3:20PM
User who most recently changed record coos
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N6922A
NTSB Number WPR11FA117
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? No
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name CESSNA
Aircraft Model 172
Aircraft Series Identifier --
Aircraft Serial Number 29022
Certified Max Gross Weight 2200
Aircraft Category Airplane
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 4
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Jan 30 2011 12:00AM
Airframe hours since last inspection --
Airframe Hours 2796
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site No
ELT Type Unknown
Aircraft Owner Name Gene A. Yu
Aircraft Owner Street Address --
Aircraft Owner City Loma Linda
Aircraft Owner State CA
Aircraft Owner Country USA
Aircraft Owner Zipcode 92354
Operator is an individual? No
Operator Name Gene A. Yu
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address --
Operator City Loma Linda
Operator State CA
Operator Country USA
Operator Zip code 92354
Operator Code --
Owner has at least one certificate None
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation --
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Instructional
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code POC
Departure City La Verne
Departure State CA
Departure Country USA
Departure Time 1432
Departure Time Zone PST
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code POC
Destination City La Verne
Destination State CA
Destination Country USA
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Oct 17 2011 3:34PM
User who most recently changed record coos
Since inspection or accident Last Inspection
Event Location Runway Number and Location N/A
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --