After being repainted, which included removing and refitting flight controls, a Rayton/Hawker 800XP was to be flown from the paint facility at Peterborough (Ontario Canada) to Buffalo (New York, USA). Before the flight, the flight crew spent several hours inspecting the aircraft. This included operating the flight controls for correct operation and direction of travel, there were no issues with the flight controls.
Elevator Trim System (Source & © Raytheon Aircraft)
Two minor discrepancies and a piece of masking tape were found. These were brought to the attention of the MRO and were rectified. Satisfied that the aircraft was fit for flight the engines were started and the aircraft taxied to the runway. The take-off was uneventful and the aircraft accelerated as expected. However, when accelerating during the initial climb the crew observed they ran out of nose-down trim at 190 knots indicated airspeed. With the speed below 190 knots, the aircraft returned to Peterborough for a safe landing. There was no damage to the aircraft, and the crew (the only occupants) were not injured.
After the aircraft landed it was quarantined, awaiting the Transportation Safety Board of Canada (TSB) investigator. The TSB investigator, with the aid of the MRO Flight Options Quality Assurance Inspector, and mechanics examined the aircraft. Several observations/findings were made;
An access panel to gain access to the elevator trim system was panted over and had not been removed during the removal of the flight controls before painting.
Removal of the panel was required to instal a rigging pin in the elevator control quadrant, as part of the removal procedure of the elevator
Flight controls were not removed per the Maintenance Manual procedures, an alternative procedure was used.
As per the maintenance manual, the elevator rigging was checked;
The elevator was set to neutral with a rigging pin
The elevator trim was set to 35 degrees
In this configuration, the trailing edge of the elevator trim tab should be flush with the elevator trailing edge. It was found that both the left and right trim tab trailing edges were 0.250 inches below the trailing edge of the elevator, giving the aircraft a nose-up trim condition.
With the trim wheel rotated to maximum nose-down trim (against the mechanical stops). When the wheel reached its stop, the trim tab’s trailing edge was still slightly below the elevator’s trailing edge. As such, with full nose-down trim selected, the aircraft was rigged in a nose-up condition.
Rigging pins and incidence boards (A tool used for checking the angle of incidence of an aircraft wing, stabilizer and flight control surfaces) were not used during the maintenance actions on the elevator system.
Maintenance records indicated that the Maintenance Manual procedures were followed, however, the required tooling as per instructions was not used.
The duplicate inspection was not performed as required, only the correct installation of safety locking on the flight controls. The correct assembly and sense of operation of the flight controls were not checked.
Elevator Trim jack (Source; TSB ©; Unknown)
In their report, the TSB concluded that;
The elevator trim tabs were not rigged following the aircraft maintenance manual, resulting in a misrigged condition and a lack of sufficient nose-down trim authority.
Maintenance was not performed following the airworthiness requirements as required by the Canadian Aviation Regulations.
The independent control inspection was not carried out following the standards described in the Canadian Aviation Regulations or Airworthiness Notification, resulting in the misrigged controls being undetected.
Incorrect maintenance release statements were entered in the aircraft documents.
Several safety actions were taken by the TSB, including a notice of suspension for the involved MRO. Full details on the investigation and safety actions taken can be found in the TSB Aviation Investigation Report by clicking on the .pdf file below;
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