Aircraft Accident/Incident Report

Montgomery, Texas 77316
Tuesady, December 7, 2004 10:20 CST

NTSB Narrative Summary Released at Completion of Accident

While maneuvering during an upset recovery training flight, the left wing separated from the airframe, which resulted in an uncontrolled descent and impact with terrain. A review of an on-board video revealed the instructor and student were performing training maneuvers which included steep turns, stalls, accelerated stalls, unusual attitudes and recoveries from these to a wings level attitude using several techniques. During the final maneuver, the instructor asked the student to lower the nose to "about a hundred and forty knots", and afterwards told the student to slowly pitch the nose upward "until we're pointed straight up." The airplane was seen climbing vertically up and visual contact with the ground disappeared. The instructor then told the student to "pull the way we just did a minute ago and pull the airplane into a stall." A brief stall occurred, and then the airplane continued to pitch in the same direction, and its path resembled the remainder of an inside loop. As the ground reappeared into the view, the aircraft was inverted and descending. There was a slight roll to the left as the airplane was descending while its pitch attitude continued in the same trend toward a vertical nose down attitude. While in a steep nose down attitude (no sky visible in the view), the instructor told the student to "pull it into a stall right now." At that moment, the recording ended. The main wreckage came to rest on the side of a hard surface gravel road, and the left wing, left horizontal stabilizer, inboard section of left elevator, aft canopy frame, and a portion of the left wing skin were located in a wooded area approximately 0.4 miles southwest of the main wreckage. The true history of the airframe could not be substantiated. All applicable Federal Aviation Administration Airworthiness Directives had been complied with at the time of the accident. Examination of the wing and carry-through structure revealed the structure failed as the result of extensive and widespread fatigue cracking in the -31 and -33 channels and the -3 and -85 webs. The cracks in the channels were in hidden areas and probably could not have been directly detected without extensive disassembly of the structure. However, the cracks in the webs would have been easily detected, and the crack in the forward web apparently was detected, based on the stop-drilled hole and the notes in the maintenance records. The materials of the structure were in compliance with required specifications. However, the workmanship was poor as indicated by the trapped debris and damaged holes. This may have been acceptable standards of workmanship at the time of manufacture, but have since been recognized as having a large negative impact on fatigue life of the structures. The fractured hole in the rear spar was recently inspected with no indication of cracks. It is highly unlikely that the cracks initiated and grew to the current sizes in less than 40 hours of flight time since the inspection. The localized damage and enlargement of the hole could have reduced the effectiveness of the inspection. The fatigue cracking in the carry-through, the rear wing spar, and the horizontal stabilizer indicate that the fatigue life of the entire aircraft structure has been expended. It is strongly suspected that these conditions may exist in other T-34 airframes.

NTSB Probable Cause Narrative

the in-flight separation of the left wing as a result of extensive fatigue cracking throughout the wing carry-through structure.

Event Information

Type of Event Accident
Event Date 12/7/2004
Event Day of the Week Tuesday
Time of Event 1020
Event Time Zone Central Standard Time
Event City Montgomery
Event State TEXAS
Event Country --
Zipcode of the event site 77316
Event Date Year 2004
Event Date Month 12
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 303035N
Event Location Longitude 0953855W
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 25
Degrees magnetic from airport 345
Airport Elevation 152
Weather Briefing Completeness Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 953 Central Standard Time
Direction of event from weather observation facility (degrees) 280
Weather Observation Facility ID CXO
Elevation of weather observation facility 245
Distance of event from weather observation facility (units?) 10
Time Zone of the weather observation CST
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions Clear
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) 16
Dew Point at event time (in degress fahrenheit) 8
Wind Direction (degrees magnetic) 340
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 8
Wind Velocity Indicator --
Wind Gust Indicator Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30.06
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury Fatal
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal 2
Injury Total Minor --
Injury Total None --
Injury Total Serious --
Injury Total All 2
Investigating Agency NTSB
NTSB Docket Number (internal use) 19153
NTSB Notification Source FAA
NTSB Notification Date Dec 7 2004 12:00AM
NTSB Notification Time 1100
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Feb 28 2006 12:35PM
User who most recently changed record NTSB\JOHB
Basic weather conditions Visual Meteorological Cond
FAA District Office Houston, Texas

Aircraft Involved

Aircraft #1

Aircraft Registration Number N141SW
NTSB Number DEN05FA032
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? No
Damage Destroyed
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Beech
Aircraft Model A45
Aircraft Series Identifier --
Aircraft Serial Number G-13
Certified Max Gross Weight 2900
Aircraft Category Airplane
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 2
Number of Engines 1
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Aug 3 2004 12:00AM
Airframe hours since last inspection 36.2
Airframe Hours 9316.3
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name PRVNY PLUK, LLC
Aircraft Owner Street Address 2803 Sackett St.
Aircraft Owner City Houston
Aircraft Owner State TX
Aircraft Owner Country USA
Aircraft Owner Zipcode 77098
Operator is an individual? No
Operator Name Texas Air Aces
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 8319 Thora Ln. Hangar A5
Operator City Spring
Operator State TX
Operator Country USA
Operator Zip code 77379
Operator Code --
Owner has at least one certificate None
Other Operator of large aircraft? --
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) Business
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code DWH
Departure City Montgomery
Departure State TX
Departure Country USA
Departure Time 945
Departure Time Zone CST
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code --
Destination City --
Destination State --
Destination Country --
Specific Phase of Flight Maneuvering
Report sent to ICAO? No
Evacuation occurred No
Date of most recent change to record Nov 16 2005 10:12AM
User who most recently changed record MCBM
Since inspection or accident Time of Accident
Event Location Runway Number and Location NA
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --