DFW06LA198

NTSB accident investigation · Ayres S2R-T34 · Parkdale, AR · August 11, 2006

Accident · No injuriesLimited investigationFinal report
Date
August 11, 2006, 11:30 local (16:30 UTC)
Place
Parkdale, AR
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N444HFAyres S2R-T34
Weather
Visual (VMC) · Day
Status
Completed · report January 31, 2007
Report
Approved by Office Director
Parties
FAA/FSDO
FAA report
20060811017839A
Case key
64338

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The failure of a compressor turbine blade for undetermined reasons, which resulted in a total loss of engine power. A contributing factor was the lack of suitable terrain for the forced landing.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of engine power(total) - mech failure/malfManeuvering - aerial application
Compressor assembly,blade - failureCause
Forced landingEmergency landing
On ground/water encounter with terrain/waterEmergency descent/landing
Terrain condition - crop
Terrain condition - none suitableFactor

Analysis

The 6,000-hour commercial pilot made a forced landing to a cotton field after the turbine engine installed on his agricultural airplane stopped producing power. The pilot landed in a field and subsequently collided with trees. An inspector with the Federal Aviation Administration performed an on-scene examination of the airplane. According to the inspector, the airplane sustained structural damage to the wings. Examination of the engine revealed a compressor-turbine blade had failed causing extensive damage to the vein ring, segments and small exit duct. This failure also resulted in debris contacting the power-turbine blades, which subsequently damaged all of the power-turbine blades and disc. The failed blade was never located and the mode of failure could not be determined. A review of the airplane's maintenance history revealed that the compressor-turbine disc was rebladed in November 1994, and had accumulated approximately 4,987.7 hours since new. The disc itself had accumulated approximately 7,941.4 hours and 7,170 cycles.

Factual narrative

On August 11, 2006, at 1130 central daylight time, a single-engine Ayres S2R-T34 agricultural airplane, N444HF, was substantially damaged during a forced landing following a reported loss of engine power while maneuvering near Parkdale, Arkansas. The commercial pilot, sole occupant of the airplane, was not injured. The airplane was registered to McGinty Flying Service, of Jones, Louisiana, and was being operated by Wilmot Aero of Parkdale, Arkansas. Visual meteorological conditions prevailed and no flight plan was filed for the local aerial application flight conducted under 14 Code of Federal Regulations Part 137.

A Federal Aviation Administration (FAA) inspector performed an on-scene examination of the airplane. According to the inspector, the pilot reported that the engine suddenly stopped producing power and he executed a forced landing in a cotton field. The airplane sustained structural damage to the right wing and outboard section of the left wing. Examination of the turbine engine revealed a compressor-turbine blade, Part number T-102401-792A, had failed causing extensive damage to the vein ring, segments and small exit duct. This failure also resulted in debris contacting the power-turbine blades, which subsequently damaged all of the power-turbine blades and disc. Additional damage was noted on the exhaust duct and power-turbine shroud. The failed blade was never located and the mode of failure could not be determined.

A review of the airplane's maintenance records revealed that the compressor-turbine disc was last rebladed in November 1994, and had accumulated approximately 4,987.7 hours. The disc itself had accumulated approximately 7,941.4 hours and 7,170 cycles.

The pilot's last FAA second class medical was issued on January 4, 2006. At that time, the pilot reported having accumulated a total of 6,000 flight hours. The pilot did not submit a completed Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2) as of the time this factual report was released.

Weather at the Mid-Delta Regional Airport, near Greenville, Mississippi, at 1053, was reported as wind from 330 degrees at 6 knots, clear skies, temperature 91 degrees Fahrenheit, dewpoint 71 degrees Fahrenheit, and a barometric pressure setting of 29.92 inches of Mercury.

Aircraft

Registration
N444HF
Reported as
Ayres S2R-T34
Category
Airplane
Serial number
T36-191
Airframe hours
8,409.9
Engine
Pratt & Whitney PT6A-36, 750 horsepower, turbo prop
Damage
Substantial damage
Flight
Aerial application · Part 137
Registered owner
McGinty Flying Service Inc
Airworthiness certificate
Special, Restricted (Special)
Last inspection
100 hour · August 1, 2006
Departed
NONE · Parkdale, AR
Airport
None

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
29
Injuries
None
Certificate
Commercial
Airplane ratings
Single-engine land
Medical
Class 2, Without waivers/limitations
Seat
Front
Flight hours
6,000 total

Weather

Conditions
Visual (VMC) · Day
Wind
330° at 6 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
88 °F, dew point 72 °F
Altimeter
29.92 inHg
Observed at
GLH

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.