Accident Details
Probable Cause and Findings
the pilot misjudged the altitude and ground clearance while performing an unwarranted low altitude flight maneuver.
Aircraft Information
Registered Owner (Current)
Analysis
HISTORY OF FLIGHT
On November 12, 1995, between 1115 and 1200 hours Pacific standard time, a Bell 47D1 helicopter, N78900, collided with the terrain in an open field about 4 miles northwest of the Shafter airport, Shafter, California. The pilot was conducting a visual flight rules personal flight. The helicopter, operated by Lewis Aviation of Shafter, was destroyed by impact and the resulting postimpact fire; about 10 acres of freshly planted roses were destroyed. The certificated commercial pilot and passenger, the pilot's brother and part-time flagger for the operator, sustained fatal injuries. Visual meteorological conditions prevailed. The flight originated from Shafter airport about 0740 hours; the flight departed the aerial application area at an unknown time.
National Transportation Safety Board investigators interviewed the operator and loader at the operator's facility on November 13, 1995. The operator said that the pilot was scheduled to spray a crop of trees on November 12, 1995, sometime between 0800 and 0900 hours. He was not at his facility when the pilot departed on the aerial application flight.
The operator said that the loader returned to the facility about 1115 hours. The loader told him the pilot was returning shortly. When the pilot did not return by 1200 hours, he drove to the field and found the burnt wreckage at 1215 hours.
The loader said that he and the flagger departed the operator's facility at 0800 hours and arrived near the aerial application area (about 1/4 mile southeast of the accident site) at 0815 hours. The loader was driving the loading platform truck and the flagger followed him in a smaller pickup truck. After they arrived at the loading area, the pilot arrived and landed in a hay field next to the parked trucks.
The loader said that he loaded the helicopter with 60 gallons of chemical (about a 12 percent zinc and 88 percent water mixture). The pilot began spraying the trees at 0900 hours and completed a series of aerial application flights until 1050 hours. The helicopter landed on the loading platform and the loader filled the spray tanks with water, between 30 and 40 gallons, for an aerial rinse. After refueling the helicopter, the pilot departed to spray the trees with the water. The loader departed the area at 1100 hours. The flagger was at the loading area when the loader departed.
There were no ground witnesses.
The accident coordinates are: 35 degrees, 32.81 minutes north latitude and 119 degrees, 15.19 minutes west longitude.
CREW INFORMATION
The pilot held a commercial pilot certificate with airplane ratings for single engine land and instruments, and rotorcraft - helicopter ratings. Safety Board investigators did not recover the pilot's flight hours logbook. The flight hours reflected on page 3 of this report were based on the operator's estimate.
The loader, also a certified commercial pilot/flight instructor and crop duster pilot, said he gave the pilot his last biennial flight review (BFR) on June 30, 1994. The BFR was flown in the accident helicopter.
The operator said that he provided the pilot all of his helicopter and aerial application training. The pilot began this training about 18 months before the accident. He estimated that the pilot accrued more than 800 hours in the accident helicopter make and model.
AIRCRAFT INFORMATION
The operator gave Safety Board investigators the helicopter's maintenance records. Examination of records disclosed that the operator performed an annual inspection on the helicopter on October 25, 1995. The helicopter had accrued about 7,640 hours at the time of the inspection. The operator did not maintain an office flight log, but he estimated that at the time of the accident, the helicopter flew about 20 hours since the annual inspection. The maintenance records did not reflect any open maintenance discrepancies which would have affected the helicopter's performance.
The operator installed the "zero time since major overhaul" engine at the time of the annual inspection.
The helicopter was certificated in the restricted category for aerial application and pest control (spraying) purposes. Title 14 CFR 91.313 states:
(a) No person may operate a restricted category civil aircraft-
(1) For other than the special purpose for which it is certificated
(d) No person may be carried on a restricted category civil aircraft unless that person-
(1) Is a flight crewmember (2) Is a flight crewmember trainee (3) Performs an essential function in connection with a special purpose operation for which the aircraft is certificated; or (4) Is necessary to accomplish the work activity directly associated with that special purpose.
The operator told Safety Board investigators that the flagger was not allowed in the helicopter. He said that the pilot was to dispense the water and then return to the airport.
METEOROLOGICAL INFORMATION
The weather data reflected on page 4 of this report was the Bakersfield airport 1148 hours surface weather observation. Bakersfield airport is the closest surface weather observation facility.
The operator told Safety Board investigators that when he arrived at the accident site, clear skies existed, the visibility was greater than 20 miles, and that the surface winds were from the west-northwest between 2 and 5 knots.
FIRE
The operator reported that the fire was extinguished when he arrived at the accident site. The fire damage was contained to the wreckage and the crops beneath the helicopter. There was no evidence of any chemical or water spillage.
The Kern County Fire Department did not respond to the accident site.
WRECKAGE AND IMPACT INFORMATION
The crash site is located in a field of freshly planted roses. The furrows are oriented in an east to west direction. Ground scars and the wreckage examination revealed the left spray boom initially contacted the ground and the fuselage struck the ground in about a 60-degree nose down and about a 30-degree right banking attitude. The initial ground impact crater is about 34 feet northwest of the initial spray boom impact site. A spray boom nozzle was found at the initial spray boom impact site and matched with the fractured surface of the remaining nozzle piece in the boom.
The helicopter came to rest on its left side facing 260 degrees and about 36 feet north of the main impact area. The cockpit area was incinerated by the resulting postimpact fire. A 34-foot ground scar that conformed to the spray boom shape was oriented in a northwesterly direction.
Investigators found a crescent shaped ground impact mark between 20 to 25 feet east-southeast of the main impact crater. Several paint chip pieces which resembled the main rotor blades paint scheme were found near the crater.
Safety Board investigators conducted a detailed wreckage examination on November 14, 1995, at Valley Aircraft Parts, Tulare, California. The parties listed in this report participated in the examination.
COCKPIT EXAMINATION
The right forward side was crushed upward and the heel plates were rolled under the flight deck. The left forward side displayed some upward crushing. The chin bubble was shattered with pieces in the initial impact crater and spread along the ground path to the main wreckage resting point. The right cyclic grip was broken to the right and was found near the left side of the helicopter in the burnt wreckage area; the grip, however, did not display any fire damage. The right rear of the passenger seat (engine firewall) exhibited inboard crushing. The back side of the pilot seat's metal frame tube displayed a symmetrical 12-inch concave mark; the support tubes were broken in numerous places.
CENTER FRAME EXAMINATION
The right side of the forward tube was missing. The right side vertical tube was broken toward the rear and the right lower tube was missing. The left side of the frame was intact, but was bent to the left.
TAILBOOM ASSEMBLY
The tailboom was buckled; the buckling began about 33 inches from the tailboom/center frame attach point. The lower aft cluster weld tubes were broken and bent down about 60 degrees and 41 inches from the rear center frame attach points. The right lower tube was buckled inward.
The forward section of the tail rotor drive shaft was twisted off. The forward male coupling remained inside the dust cover. The rest of the short shaft was not found. The forward section of the drive shaft was twisted to the right and exhibited torsional overload signatures and longitudinal scrape marks. The transmission shaft also displayed torsional twisting signatures.
The tail rotor assembly and the 90-degree gear box separated from their respective attach points. Both tail rotor blades were broken near their respective attach points. The inboard portion of the tail rotor blades remained connected at their respective blade grips; both tail rotor blades separated outboard of the blade grips. One tail rotor blade exhibited a 7-inch concave impact mark. This mark corresponded with a white paint transference mark found on the tail rotor drive casing. The tail rotor blades are painted white with black stripes.
LEFT SPRAY BOOM
The tip end and five other nozzles were broken; the five nozzles were found along the spray boom ground imprint. The tip end nozzle was found at the southeast end of the boom ground imprint.
The boom separated from its skid tube attach point and was bowed upward and rotated rearward about 80 degrees.
The leading edge displayed numerous lateral scrape marks.
RIGHT SPRAY BOOM
The boom exhibited "S" twisting and its outboard section was bent downward. The 4-foot extension was broken and found about 15 feet west of the initial fuselage impact crater. The boom displayed some leading edge lateral scrape marks.
LEFT SKID
The skid was fractured in two places - at the front and rear vertical support tube attach points. The ver...
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# LAX96FA045