Air Tractor AT-502A N948BB

Summary

On 3 June 2003 at about 14:30 local time, a Air Tractor AT-502A registered N948BB was involved in an accident near Raywood, Texas, United States. One person was on board and one had minor injuries. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

3 June 2003 at 14:30

Classification

Accident

Location

Raywood, Texas, United States

Nearest airport

Tri-County Air Service Airport (XS58)

Coordinates

30.0000, -94.5500

Aircraft

Air Tractor AT-502A

Registration

N948BB

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Raywood → Unknown

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

LAX03LA180

1 person had minor injuries.

the pilot's encounter with a stall/mush condition in the takeoff initial climb due to his inadequate preflight/pretakeoff procedures and failure to set the wing flaps to the proper takeoff configuration before beginning the takeoff ground roll.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The airplane collided with trees while departing from a private grass airstrip. The departure surface was a grass strip that stretched about 2,000 feet long, with trees located at the end. The Airplane Flight Manual for the AT-502A states that 10 degrees of flaps should be set for takeoff. The pilot reported that his takeoff procedure consisted of starting the takeoff roll with the wing flaps in the retracted position until rotation, where he would he would start the initial climb by pulling back on the control stick while simultaneously lowering the flaps to the 10-degree extended position. The pilot stated that he used this procedure in an effort to decrease the ground roll. Following his procedure, the pilot applied full engine power and the airplane started the takeoff roll down the grass strip. As the airplane's groundspeed increased, he moved the flap control to extend the wing flaps and rotated the airplane to a nose high attitude. The airplane lifted off the grass surface, but the wing flaps failed to extend. The airplane climbed to about 15 feet, flew down the runway in ground effect, and collided with tree branches, then descended into the terrain. During an examination of the cockpit, a Federal Aviation Administration inspector observed the flap circuit breaker to be in the "out" position. The airplane's manufacturer stated that applying the wing flaps after starting the departure roll is an improper takeoff procedure. The manufacturer further stated that the drag created by the wing flaps at 10 degrees is negligible during takeoff roll phase of operation, and keeping them retracted will not decrease the takeoff distance by a measurable amount. An examination of the flap system failed to find a problem with the system operation or determine why the circuit breaker was in the open position.

Quoted verbatim from the NTSB record.