LAX01LA114

NTSB accident investigation · Air Tractor AT-802 A · Maricopa, AZ · March 10, 2001

Accident · No injuriesLimited investigationFinal report
Date
March 10, 2001, 10:45 local (17:45 UTC)
Place
Maricopa, AZ
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N6059LAir Tractor AT-802 A
Weather
Visual (VMC) · Day
Status
Completed · report November 28, 2001
Report
Approved by Office Director
Parties
FAA MIDO, FAA FSDO
FAA report
20010310003929A
Case key
51897

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

Inadequate selection of landing facilities and improper placement of vehicles near the runway. An additional factor was the use of a runway which resulted in a downwind 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.

OverrunLanding - flare/touchdown
Weather condition - tailwindFactor
Compensation for wind conditions - inadequatePilot in commandFactor
On ground/water collision with objectLanding
Planning/decision - inadequatePilot in commandFactor
Airport facilities,runway overrun area - inadequateCause
Planning/decision - improperGround personnelCause
Object - vehicleCause

Analysis

The orientation of the runway was 340 degrees. The weather at the nearest reporting station indicated that the winds were from 100 degrees at 6 knots. This would have resulted in a 4-knot rear quartering tailwind and a 2-knot crosswind from the right. Using the performance data listed in the airplane's pilot operating handbook, the landing distance was calculated to be 2,109 feet, without using reverse. The Gila River West runway on which the accident occurred was 2,400 feet long. Assuming that the airplane was flown at the reference speed of 73 knots, with no wind, and touched down on the threshold, there would have been only 291 feet remaining on the runway. The tailwind present at the time of the accident would have increased the landing distance required, and thereby reducing the available runway. The presence of an irrigation sump at the end of the runway would have eliminated any margin for error, and made it impossible to overrun the runway safely. The placement of a truck along the side of the runway at the departure end further limits available options in the event of a long landing or overrun. Under the conditions at the time of the accident, there would have been no allowance for error either in pilot technique, or in a real or perceived mechanical malfunction. These factors would force the pilot to make sudden, last minute maneuvers to avoid obstacles at the end of the runway. During an engine inspection, performed by factory personnel, and witnessed by an inspector from the Federal Aviation Administration Southwest Manufacturing District Office (FAA MIDO-41), the engine was operated up to 30 percent of its power range with no anomalies noted. The power was reduced to idle several times and the propeller did not feather. The propeller operated throughout the operating range, including beta, with no defects noted. It was noted that with the power lever in the full aft position, the beta plunger was slightly depressed. This may have been enough to allow the propeller to go slightly past the low pitch stop, toward reverse, when the power lever was pulled back to the idle position. It was observed that rubbing had occurred between the two controls. The FAA inspector and assisting personnel attempted to force the throttle lever to move the propeller control lever aft. The two levers did move aft together, only when the power lever was pulled inboard against the propeller control lever. However, the propeller control lever could not be made to move past the feather detent. If the throttle had been closed, the propeller would move to the low pitch (high rpm) position even with the propeller control pulled aft to the control stop.

Factual narrative

On March 10, 2001, at 1045 hours mountain standard time, an Air Tractor AT-802-A, N6059L, was substantially damaged after striking a vehicle while landing at Gila River West, an agricultural airstrip, Maricopa, Arizona. The commercial pilot, and sole occupant, was not injured. Visual meteorological conditions prevailed for the flight conducted under 14 CFR Part 137. The airplane had originally departed the agricultural strip at 1030, and was returning to Gila River West to reload. No flight plan was filed.

The pilot stated that he was on his 10th landing of the day at this particular agricultural strip when the accident occurred. According to the pilot, he was returning to refill with fertilizer when the propeller feathered in the landing flare. He believed that the resulting loss of drag caused him to float much farther than normal. There was a rectangular irrigation sump in line with the runway at the departure end. To avoid landing in the sump, he attempted to redirect the airplane to a field on the right side of the strip. After diverting to the right side of the landing area, the left wing struck a fertilizer delivery truck, which was parked on the right side of runway, at the departure end. The airplane ground looped and came to rest on the east edge of the irrigation sump.

The orientation of the runway was 340 degrees. The weather at the nearest reporting station indicated that the winds were from 100 degrees at 6 knots. This would have resulted in a 4-knot rear quartering tailwind and a 2-knot crosswind from the right. According to the manufacturer, the maximum demonstrated crosswind component for this airplane is 20 knots. Using the performance data listed in the airplane's pilot operating handbook, the landing distance was calculated as follows. At a reference speed of 73 knots, in a no wind condition, at a pressure altitude of 1,155 feet, an air temperature of 18 degrees Celsius, and a landing weight of 9,250 pounds, the total landing distance over a 50-foot obstacle was 2,109 feet, without using reverse. The Gila River West runway, on which the accident occurred, was 2,400 feet long.

The airplane was transported to the Air Tractor, Inc., production facility in Olney, Texas, and inspected. The engine was operated while still attached to the airframe. An inspector from the Federal Aviation Administration Southwest Manufacturing District Office (MIDO-41) was present for the inspection and operation of the engine.

The engine was operated up to 30 percent of its power range with no anomalies noted. The power was reduced to idle several times and the propeller did not feather. The propeller operated throughout the operating range, including beta, with no defects noted. The inspector noted that the power control rigging was within acceptable limits with the exception of the beta plunger. It was noted that with the power lever in the full aft position, the beta plunger was slightly depressed.

Closer inspection of the power quadrant revealed control interference between the throttle and propeller levers. It was observed that rubbing had occurred between the two controls. The FAA inspector and assisting personnel attempted to force the throttle lever to move the propeller control lever aft. The two levers did move aft together, only when the power lever was pulled inboard against the propeller control lever. However,

Aircraft

Registration
N6059L
Reported as
Air Tractor AT-802 A
Category
Airplane
Serial number
802A-013
Airframe hours
2,520.2
Engine
P&W PT6A-65AG, 1,300 horsepower, turbo prop
Damage
Substantial damage
Flight
Aerial application · Part 137
Operator
Sarita Aerial Contractors Inc, doing business as Sarita Aerial Contractors
Registered owner
Sarita Aerial Contractors Inc.
Airworthiness certificate
Special, Restricted (Special)
Last inspection
Annual · May 31, 2000 · 347.5 hours before
Departed
NONE · Maricopa, AZ
Destination
NONE · Maricopa, AZ
Airport
NONE · Gila River West, runway 35, 2,400 × 120 ft, dirt

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
59
Injuries
None
Certificates
Commercial, Flight instructor
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--w/ waivers/lim
Last flight review
April 25, 2000
Seat
Single
Flight hours
22,000 total · 65 in this make and model · 21,500 as pilot in command · 65 in the last 90 days · 65 in the last 30 days · 10 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
100° at 6 knots
Visibility
10 statute miles
Lowest ceiling
20,000 ft overcast
Temperature
64 °F, dew point 50 °F
Altimeter
30.04 inHg
Observed at
KPHX, 19 nm away

FAA reports on this event · 1

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