NTSB Identification: CEN15LA182
14 CFR Part 91: General Aviation
Accident occurred Thursday, March 26, 2015 in Levelland, TX
Probable Cause Approval Date: 07/23/2015
Aircraft: AIR TRACTOR INC AT 400, registration: N136DB
Injuries: 1 Serious.
NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
The pilot reported that, shortly after takeoff on a postmaintenance test flight, the flight controls felt “stiff.” The pilot flew a traffic pattern and intended to conduct a precautionary landing on the runway. However, after the pilot turned the airplane to the final leg in the traffic pattern, the airplane started to roll left. While attempting to level the wings, the pilot observed the left aileron traveling up and down. During the landing, the airplane bounced twice, rolled left, and then cartwheeled.
The airplane had undergone extensive maintenance throughout the year before the accident, and, during this maintenance, maintenance personnel reinstalled the ailerons. The accident flight was the first flight following this maintenance. A postaccident examination of the airplane revealed that the hardware that attached the long aileron pushrod to the aileron bellcrank was not present, and the hardware was not found at the accident site; therefore, it could not be determined whether new or existing hardware was installed during the recent maintenance. However, given that the flight control malfunction occurred immediately following the extensive maintenance, it is likely that maintenance personnel either did not install the attachment hardware at all or did not install it properly, either of which would have resulted in the loss of airplane control and subsequent impact with terrain.
The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The in-flight separation of the left aileron's attachment hardware at the connection between the long aileron pushrod and the left aileron bellcrank. Contributing to the accident was maintenance personnel’s improper installation of, or failure to install, the left aileron attachment hardware.
On March 26, 2015, about 1455 central daylight time, an Air Tractor Inc., AT-400 airplane, N136DB, was substantially damaged during a precautionary landing on runway 35 at the Levelland Municipal Airport (KLLN), Levelland, Texas. The commercial pilot was seriously injured. Visual meteorological conditions prevailed for the flight, which without a flight plan.. The airplane was registered to and operated by Devil Dusters Inc., under the provisions of 14 Code of Federal Regulations Part 91 as a post maintenance test flight. The local flight was originating at the time of the accident.
According to the pilot, he was asked by HSI Turbine to "test fly" his airplane which they had just rebuilt. During a ground run of the engine an issue with the throttle linkage was found and corrected. The pilot conducted a preflight of the airplane and did not note any issues. After restarting the engine, the pilot went through his preflight checklist including verification that the flight controls were free and correct. The pilot did not discover any discrepancies during the preflight check and the takeoff roll was uneventful.
As the airplane leveled out on the crosswind leg of the traffic pattern, the flight controls felt "stiff." The pilot elected to land the airplane and have the flight controls examined. During the downwind and crosswind legs of the pattern the flight controls continued to feel stiff. After turning to the final leg in the traffic pattern, the airplane started to roll to the left. The pilot attempted to level the wings at which time the flight controls "became loose" and the pilot observed the left aileron "flopping" up and down. The right aileron continued to work correctly.
While trying to land on runway 35, the airplane bounced and rolled to the left. On the second bounce the pilot added power to try and regain control of the airplane. The airplane immediately rolled to the left and the left wing impacted the ground. The airplane cartwheeled and came to rest to the west of runway 35. The empennage, fuselage, and both wings were substantially damaged.
According to the pilot, he had purchased the airplane as a "wreck" in Minnesota. It did not have an engine or propeller and had damage to the right wing and landing gear. He brought the airplane to HSI Turbine during the summer of 2014 to have it repaired. According to the owner of HSI Turbine, the right wing was sent to Air Tractor to be repaired. Several mechanics and mechanic's assistants worked on the airplane and during interviews, they recalled that it was a long project that they worked on sporadically over the winter and spring. All of the mechanics and assistants reported using the maintenance manuals provided by Air Tractor to guide all of their work. All of the mechanics and assistants reported using the existing hardware on the airplane to reinstall the wings and flight controls.
One assistant recalled helping to remount the wings on the airplane and recalled that was in October or November of 2014. Another mechanic recalled installing the ailerons in January of 2015. The maintenance on the airplane was signed off on just prior to the accident flight. Work orders for the airplane, provided by HSI Turbines, indicated that "new hardware" had been used for the installation of the horizontal stabilizer, elevator, rudder, and wings. Specific work on the ailerons was not documented in the work orders provided.
An inspector with the Federal Aviation Administration and an investigator with Air Tractor examined the wreckage of the airplane. Control continuity to the elevator and rudder was confirmed. Separation points were consistent with overload. Control continuity was established to the right aileron control. All of the hardware was installed correctly and separation points were consistent with impact forces and methods used to recover the wreckage from the accident site.
Control continuity was established from the left aileron control, inboard to the long aileron pushrod. The hardware to connect the long aileron pushrod to the aileron bellcrank was not present. The mounting surface on the aileron pushrod was not damaged or elongated, consistent with the hardware not being present prior to the impact sequence. An examination of the remaining wreckage and accident site did not locate the missing hardware.
According to the Air Tractor AT-400 Owner's Manual and Parts Manual, an AN24-19A clevis bolt and an AN364-428 nut should be used to connect the pushrod to the bellcrank. The hardware should be torqued between 30 and 40 inch pounds.
NTSB Identification: CEN15LA182
14 CFR Part 91: General Aviation
Accident occurred Thursday, March 26, 2015 in Levelland, TX
Aircraft: AIR TRACTOR INC AT 400, registration: N136DB
Injuries: 1 Serious.
This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed. NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
On March 26, 2015, about 1455 central daylight time, an Air Tractor Inc. AT-400 airplane, N136DB was substantially damaged during a precautionary landing near Levelland Municipal Airport (KLLN), Levelland, Texas. The commercial pilot was seriously injured. Visual meteorological conditions prevailed for the flight. The post maintenance flight was being conducted under the provisions of 14 Code of Federal Regulations Part 91 without a flight plan. The local flight was originating at the time of the accident.
According to the Federal Aviation Administration inspector who responded to the accident, the airplane had not been operated or flown for 8 or 9 months due to major repair and maintenance. The preflight inspection and ground run-up did not detect any mechanical anomalies. Shortly after takeoff, the pilot felt a binding in the flight controls. The pilot elected to return to the airport and while maneuvering to land on runway 35, noted that the flight controls felt free and the left aileron was "flapping." During the landing the airplane bounced. The pilot added power and the airplane rolled to the right and impacted the ground. The empennage, fuselage, and both wings were substantially damaged.
LEVELLAND — Becky Crockett said her husband was in Levelland getting work done on his small, single-engine plane before it crashed Thursday afternoon.
“He was just taking the plane out to check it out because it had gone in for some work,” said Becky Crockett during a telephone interview from New Mexico. “He said that an aileron (flap on the wing) was loose or had come off and he was trying to put it down as safely as he could but it didn’t go as softly as he would have liked.”
The pilot, who officials identified as 57-year-old Donald R. Crockett, of Artesia, New Mexico, was coherent when he was taken by ambulance to a hospital in Levelland, said Cpl. John Gonzalez with the Texas Department of Public Safety.
Crockett was the sole occupant of the plane, which crashed about 3 p.m., a mile south of Levelland on Highway 385.
The pilot was awaiting more test results from doctors Thursday evening, but Becky said her husband is doing well.
“They don’t know if they’re keeping him or moving him to another hospital for possible cracked vertebrate,” she said. “We’re just waiting to hear from him, what he wants us to do and what he needs us to do.”
Gonzalez confirmed Crockett had previously departed the airport when he noticed something was wrong and tried to land the aircraft at the airport in Hockley County.
“He turned around and tried to come back to land and apparently he was coming in for final approach,” Gonzalez said. “That’s when he came in and landed there and that’s where he crashed.”
An investigation report from DPS revealed the plane fell from the sky onto a field east of Highway 385. The plane skid west and struck a fence before skidding across U.S. Highway 385 to the west.
Pieces of the mangled plane could be seen on both sides of the highway Thursday afternoon.
FAA spokesperson Elizabeth Isham Cory said the plane had bounced off of a runway before sliding into the ditch.
The airplane is registered to Devil Dusters Inc. out of Artesia, New Mexico, according to the FAA. Crockett’s wife said he is president of Devil Dusters Inc.
William J. Fitzgerald, an aviation safety inspector with the FAA, was at the scene of the crash Thursday afternoon taking photos for the National Transportation Safety Board.
Fitzgerald said an NTSB official will be en route to Lubbock Friday to continue investigating the crash.
He said the aircraft Crockett was in is “notoriously rugged,” and pilots are required to wear helmets while flying.
“The pilot did remarkably well surviving that,” Fitzgerald said.
Becky Crockett said her son-in-law was with her husband at the hospital Thursday evening.
“(My husband) was concerned, of course, with what might be the problem but he sounded really good,” Becky said. “We’re appreciating everybody’s prayers.”
Story, video and photo gallery: http://lubbockonline.com
Levelland Police issued the following statement Thursday afternoon:
Today (March 26th, 2015) at 2:58 p.m. the Levelland Police Department received a 911 call in reference to a plane crash just south of the city of Levelland, Tx. near the Levelland Municipal Airport.
We're happy to report that the pilot was attempting to get himself out of the wreckage at the time the officers arrived. The pilot (who's name is being kept until DPS has released it) was taken to the E. R. for injuries but was reported at that time to be doing well.
The road will be closed on South Highway 385 just South East of the RV Park until Texas DPS has opened the roadway.
Story and photo: http://www.everythinglubbock.com
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