Ayres S2R N4009M

Summary

On 18 February 2005 at about 16:11 local time, a Ayres S2R registered N4009M, operated by Vance Ag, was involved in an accident near Firebaugh, California, United States. One person was on board and one died. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

18 February 2005 at 16:11

Classification

Accident

Location

Firebaugh, California, United States

Nearest airport

Firebaugh Airport (F34)

Coordinates

36.8597, -120.4644

Aircraft

Ayres S2R

Registration

N4009M

Category

Airplane

Engines

1

Operator

Vance Ag

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Firebaugh → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

LAX05LA100

1 person died.

the loss of engine power during takeoff climb resulting from the fatigue failure of one of the compressor turbine blades; the cause of the fatigue failure could not be definitively determined.

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

Read the full NTSB narrative

The airplane impacted soft muddy terrain during a forced landing following a loss of engine power shortly after departure. The pilot departed with a full load of fertilizer and climbed above several transmission wires before the engine lost power. The airplane pitched down in a nose-low configuration and dove toward terrain. The engine's most recent inspection occurred about 2 months prior to the accident. The logbook entry for that inspection stated that the mechanic performed a hot section inspection at which time the compressor turbine (CT) disk was reinstalled with 3,595 cycles remaining. A post accident examination of the engine revealed that a CT blade had failed in fatigue initiating in the fir tree root. Near the fatigue origin, no surface damage was observed and no material anomalies were found on the fracture surface; the reason for the fatigue failure was never definitively determined. The blade was likely manufactured under a Parts Manufacturer Approval (PMA). The Safety Board Materials Laboratory reported that the chemistry of the fractured blade appeared to be consistent with the PMA specified alloy and not to the material specification the original equipment manufacturer (OEM) utilizes. A review of the Safety Board database revealed an instance of a very similar failure on an OEM manufactured CT blade. Evidence of recent marijuana use was found on toxicological evaluation, and the pilot might have been impaired ..." It is not clear whether this impairment adversely affected the pilot's actual actions during his response to the loss of engine power.

Quoted verbatim from the NTSB record.