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20150326003819A

Accident · Destroyed
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FAA accident report · Air Tractor AT-400 · Levelland, TX · March 26, 2015

FAA Aviation Safety Information Portal

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Date
March 26, 2015 · 14:55 local
Place
Levelland, TX
Phase of flight
Landing: Touchdown
Operating rules
Agricultural (Part 137)
Operator
WBMG
Damage
Destroyed
Aircraft
N136DB
NTSB investigation
NTSBCEN15LA182
Reported as
Air Tractor AT-400
Reported engine
Pratt & Whitney PT6A series
People aboard
1
Fatal injuries
0
Other injuries
1
Pilot’s certificate
Commercial pilot
Pilot’s flight hours
15,792 total178 in this make and model2 in the last 90 days
N136DBRegistration cancelled Dec 11, 2017 · Air Tractor AT-400S/N 400-0504 · Built 1983Airframe modelAir Tractor AT-400Engine modelPratt & Whitney PT6A seriesReciprocating

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.

AT-402, N136DB was being rebuilt; the right wing was sent to the factory for rebuilding and a replacement engine was installed. This was the first flight after completion of the maintenance.

The pilot completed a preflight and a ground run-up (to include a check of the flight controls ? Which were free and clear). On take-off he made a right turn out and noticed that the controls started sticking and then binding. He stayed in the pattern and set-up for a right down-wind and right base for runway 35. As he established final his controls got free, he saw that the left aileron had gotten loose and was flapping. He bounced on the first touchdown and was using full control deflections and right rudder to keep aligned with the runway. The best he could do was hold to the left side of the runway. On the second bounce he added power, but that caused a loss of control and the aircraft nose came up and the aircraft started to roll to the right.

The left main landing gear wheel hit first then the engine broke loose and the aircraft cartwheeled. The pilot pulled in his feet and relied on the 4 pilot safety harness and helmet to protect him.

Aileron control rods were checked at each wing root, both were correct:

? The rod-end bearing for the right aileron was pulled apart; the connecting bolt remained in the flap-drooping fixture along with remnants of the rod-end bearing.

? The rod-end bearing for the left aileron was intact and the bolt hole was filled with dirt. The connecting bolt for the flap-drooping fixture was not in place and does not appear to have been torn loose.

Three of the four aileron linkages were cut with cable cutters when the cockpit was separated from the wing section during the recovery; the 4th linkage was already broken at the threads of the rod-end fitting. These linkages cause the ailerons to droop when the flaps are deployed.

As the FAA filed it

AT-402, N136DB WAS BEING REBUILT; THE RIGHT WING WAS SENT TO THE FACTORY FOR REBUILDING AND A REPLACEMENT ENGINE WAS INSTALLED. THIS WAS THE FIRST FLIGHT AFTER COMPLETION OF THE MAINTENANCE.

THE PILOT COMPLETED A PREFLIGHT AND A GROUND RUN-UP (TO INCLUDE A CHECK OF THE FLIGHT CONTROLS ? WHICH WERE FREE AND CLEAR). ON TAKE-OFF HE MADE A RIGHT TURN OUT AND NOTICED THAT THE CONTROLS STARTED STICKING AND THEN BINDING. HE STAYED IN THE PATTERN AND SET-UP FOR A RIGHT DOWN-WIND AND RIGHT BASE FOR RUNWAY 35. AS HE ESTABLISHED FINAL HIS CONTROLS GOT FREE, HE SAW THAT THE LEFT AILERON HAD GOTTEN LOOSE AND WAS FLAPPING. HE BOUNCED ON THE FIRST TOUCHDOWN AND WAS USING FULL CONTROL DEFLECTIONS AND RIGHT RUDDER TO KEEP ALIGNED WITH THE RUNWAY. THE BEST HE COULD DO WAS HOLD TO THE LEFT SIDE OF THE RUNWAY. ON THE SECOND BOUNCE HE ADDED POWER, BUT THAT CAUSED A LOSS OF CONTROL AND THE AIRCRAFT NOSE CAME UP AND THE AIRCRAFT STARTED TO ROLL TO THE RIGHT.

THE LEFT MAIN LANDING GEAR WHEEL HIT FIRST THEN THE ENGINE BROKE LOOSE AND THE AIRCRAFT CARTWHEELED. THE PILOT PULLED IN HIS FEET AND RELIED ON THE 4 PILOT SAFETY HARNESS AND HELMET TO PROTECT HIM.

AILERON CONTROL RODS WERE CHECKED AT EACH WING ROOT, BOTH WERE CORRECT:

? THE ROD-END BEARING FOR THE RIGHT AILERON WAS PULLED APART; THE CONNECTING BOLT REMAINED IN THE FLAP-DROOPING FIXTURE ALONG WITH REMNANTS OF THE ROD-END BEARING.

? THE ROD-END BEARING FOR THE LEFT AILERON WAS INTACT AND THE BOLT HOLE WAS FILLED WITH DIRT. THE CONNECTING BOLT FOR THE FLAP-DROOPING FIXTURE WAS NOT IN PLACE AND DOES NOT APPEAR TO HAVE BEEN TORN LOOSE.

THREE OF THE FOUR AILERON LINKAGES WERE CUT WITH CABLE CUTTERS WHEN THE COCKPIT WAS SEPARATED FROM THE WING SECTION DURING THE RECOVERY; THE 4TH LINKAGE WAS ALREADY BROKEN AT THE THREADS OF THE ROD-END FITTING. THESE LINKAGES CAUSE THE AILERONS TO DROOP WHEN THE FLAPS ARE DEPLOYED.

NTSB investigation

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

NTSB CEN15LA182Accident · Serious injuriesLimited investigationFinal reportLevelland, TXThe 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…Mar 26, 2015 · Substantial damage

Other reports on N136DB · 1

Matched to the same aircraft by N-number and date.

Incident 20130715013079ILanding: Approach · Whiting, IAPilot was on a test flight to test a suspected problem with the fuel control unit. The pilot was slightly low on final approach to landing and added throttle to correct. The aircraft did not respond to the throttle input and the aircraft landed short of the…Jul 15, 2013 · Minor damage