20141130022619A

Accident · Destroyed

FAA accident report · Air Tractor AT-502B · Somerton, AZ · November 30, 2014

Date
November 30, 2014 · 01:15 local
Place
Somerton, AZ
Phase of flight
Landing: Approach
Operating rules
Agricultural (Part 137)
Operator
72TG
Damage
Destroyed
Aircraft
N946TR
NTSB investigation
NTSBWPR15LA048
Reported as
Air Tractor AT-502B
Reported engine
Pratt & Whitney Canada PT6A-34AG
People aboard
1
Fatal injuries
1
Other injuries
0
Pilot’s certificate
Commercial pilot
Pilot’s flight hours
10,000 total

From the FAA’s Accident/Incident Data System (AIDS), through its Aviation Safety Information Portal, as reported. The NTSB investigates accidents separately, and its record of an accident is the fuller one. The aircraft is matched to the registry by N-number and event date, checked against the reported make and model; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

What happened

The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.

On 11-30-2014, @ 0115, an Air tractor 502B crashed in an agricultural field, about ¾ miles east of the company airstrip. The manager of the aerial application business believed and other company pilots agreed that the aircraft would have been approaching to land on a heading of 090 degrees at an altitude between 300 and 500 feet AGL. Pilot had completed 10 loads of aerial application and had just dumped his rinse load and was returning to the airstrip to end his night?s work.

The aircraft appeared to have impacted the ground relatively high speed sufficient to bury the engine 6 feet under the ground at its highs point, to collapse fuselage, and to bury the fuselage up to where the rear wing attachments points. The wreckage that separated from the aircraft, turbine fuel and clumps of sod were propelled along the 270 degree direction, opposite the believed direction of flight. The fuselage was in the ground at an angle of nearly 100 degree from horizontal. The tail section was bent over in the 090 degree direction consistent with the nearly 20 degree past vertical impact. Both wings made very pronounced slap marks on the ground with no evidence of rotation. The left wing was more deformed than the wing and the aft fuselage portion above the ground before the tail section was at about a 15 degree angel in with the top pointed north (0 degrees) indicating that the aircraft was nose right about 15 degree consistent with the left wing hitting before the right wing and absorbing more energy.

On propeller blade was found 145 feet south of the accident site and it evidence high power at impact by sheared tip section and torque twisting. Another propeller blade with similar damage was recovered when using a backhoe to extract engine the ground. The propeller hub was found connected to the engine with the dome broken off and one propeller blade attached. All control continuity was confirmed and the engine was cut open and all the turbine blades were ground off consistent with the aircraft making power when it impacted the ground.

Conditions were dark night with the four other company pilots performing aerial application that night describing the conditions as: winds calm from the se at 1-2, with a ?fog inversion? Causing cloud layer to form from 400 - 500 foot AGL down to about 10 feet AGL. The conditions were communicated by radio among the pilots reported, starting about 45 minutes before the accident, as ?patches of cloud moving into the area? And ?it?s kind of eerie out here? And I think it?s coming down.? A company pilot on the ground radioed that ?if the temperature falls a couple more degrees we will have fog forming.?

As the FAA filed it

ON 11-30-2014, @ 0115, AN AIR TRACTOR 502B CRASHED IN AN AGRICULTURAL FIELD, ABOUT ¾ MILES EAST OF THE COMPANY AIRSTRIP. THE MANAGER OF THE AERIAL APPLICATION BUSINESS BELIEVED AND OTHER COMPANY PILOTS AGREED THAT THE AIRCRAFT WOULD HAVE BEEN APPROACHING TO LAND ON A HEADING OF 090 DEGREES AT AN ALTITUDE BETWEEN 300 AND 500 FEET AGL. PILOT HAD COMPLETED 10 LOADS OF AERIAL APPLICATION AND HAD JUST DUMPED HIS RINSE LOAD AND WAS RETURNING TO THE AIRSTRIP TO END HIS NIGHT?S WORK.

THE AIRCRAFT APPEARED TO HAVE IMPACTED THE GROUND RELATIVELY HIGH SPEED SUFFICIENT TO BURY THE ENGINE 6 FEET UNDER THE GROUND AT ITS HIGHS POINT, TO COLLAPSE FUSELAGE, AND TO BURY THE FUSELAGE UP TO WHERE THE REAR WING ATTACHMENTS POINTS. THE WRECKAGE THAT SEPARATED FROM THE AIRCRAFT, TURBINE FUEL AND CLUMPS OF SOD WERE PROPELLED ALONG THE 270 DEGREE DIRECTION, OPPOSITE THE BELIEVED DIRECTION OF FLIGHT. THE FUSELAGE WAS IN THE GROUND AT AN ANGLE OF NEARLY 100 DEGREE FROM HORIZONTAL. THE TAIL SECTION WAS BENT OVER IN THE 090 DEGREE DIRECTION CONSISTENT WITH THE NEARLY 20 DEGREE PAST VERTICAL IMPACT. BOTH WINGS MADE VERY PRONOUNCED SLAP MARKS ON THE GROUND WITH NO EVIDENCE OF ROTATION. THE LEFT WING WAS MORE DEFORMED THAN THE WING AND THE AFT FUSELAGE PORTION ABOVE THE GROUND BEFORE THE TAIL SECTION WAS AT ABOUT A 15 DEGREE ANGEL IN WITH THE TOP POINTED NORTH (0 DEGREES) INDICATING THAT THE AIRCRAFT WAS NOSE RIGHT ABOUT 15 DEGREE CONSISTENT WITH THE LEFT WING HITTING BEFORE THE RIGHT WING AND ABSORBING MORE ENERGY.

ON PROPELLER BLADE WAS FOUND 145 FEET SOUTH OF THE ACCIDENT SITE AND IT EVIDENCE HIGH POWER AT IMPACT BY SHEARED TIP SECTION AND TORQUE TWISTING. ANOTHER PROPELLER BLADE WITH SIMILAR DAMAGE WAS RECOVERED WHEN USING A BACKHOE TO EXTRACT ENGINE THE GROUND. THE PROPELLER HUB WAS FOUND CONNECTED TO THE ENGINE WITH THE DOME BROKEN OFF AND ONE PROPELLER BLADE ATTACHED. ALL CONTROL CONTINUITY WAS CONFIRMED AND THE ENGINE WAS CUT OPEN AND ALL THE TURBINE BLADES WERE GROUND OFF CONSISTENT WITH THE AIRCRAFT MAKING POWER WHEN IT IMPACTED THE GROUND.

CONDITIONS WERE DARK NIGHT WITH THE FOUR OTHER COMPANY PILOTS PERFORMING AERIAL APPLICATION THAT NIGHT DESCRIBING THE CONDITIONS AS: WINDS CALM FROM THE SE AT 1-2, WITH A ?FOG INVERSION? CAUSING CLOUD LAYER TO FORM FROM 400 - 500 FOOT AGL DOWN TO ABOUT 10 FEET AGL. THE CONDITIONS WERE COMMUNICATED BY RADIO AMONG THE PILOTS REPORTED, STARTING ABOUT 45 MINUTES BEFORE THE ACCIDENT, AS ?PATCHES OF CLOUD MOVING INTO THE AREA? AND ?IT?S KIND OF EERIE OUT HERE? AND I THINK IT?S COMING DOWN.? A COMPANY PILOT ON THE GROUND RADIOED THAT ?IF THE TEMPERATURE FALLS A COUPLE MORE DEGREES WE WILL HAVE FOG FORMING.?

NTSB investigation

The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.