15th of April 2018, No Brakes, Blog #699
- V2Aviation
- Apr 13
- 2 min read
A Bombardier CL-600-2B16 (Challenger 605) was parked at Winnipeg-James Armstrong Richardson International Airport (Manitoba, Canada) while Cessna Citation Bravo 550 stopped at the airport for a fuel stop. This as part of a flight from Calgary International Airport (Alberta, Canada) to Bedford/Laurence G. Hanscom Field Airport (Massachusetts, United States). Both aircraft were parked at Apron II where the Cessna would be refuelled.
Approximately 20 minutes after the arrival of the Cessna the fuelling was completed and the crew and passengers boarded the aircraft again after a short break at the FBO. After the flight preparations were completed the engines were started under the guidance of a marshaller. When the aircraft began to taxi the pilot applied left rudder and left brake input to start a left turn towards taxiway C and away from the Bombardier Challenger. The aircraft did not respond to the inputs and did not turn to the left as expected.
As the aircraft accelerated the pilot applied pressure to both brake pedals, again without the expected result. The pilot did not attempt to use the emergency brake system.
Without directional control and functioning brakes, the Cessna's right wing collided with the nose landing gear of the Challenger 605 which was parked opposite the parking position that the Cessna had just left. As a result of the impact the Cessna swung to the right and its nose impacted the right wing of the Challenger 605. The pilot immediately shut the aircraft down and exited the aircraft through the main door. There were no injuries. Both aircraft sustained substantial damage, with the Cessna's right wing leaking fuel. The Transportation Safety Board of Canada investigated the collision. They reported the following findings in their report;
The hydraulic motor and pump failed to operate during laboratory testing. Disassembly of the motor revealed excessive wear of the armature bearings and scarring on both the armature and the stator. The scarring is indicative of the armature making contact with and binding against the stator.
The damage parts of the hydraulic motor and pump (Source and © TSB) The LO BRK PRESS annunciator light would not illuminate when the brake pressure was below 750 psi. Laboratory testing of the power brake low-pressure switch revealed that the switch was in a constant open state. Further analysis revealed internal contamination with hydraulic fluid and damage to the secondary seal. The pressure plate was found jammed in the open position, likely the result of corrosion caused by hydraulic fluid. The open state of the switch prevented the power brake low-pressure light on the annunciator panel from illuminating in a low-brake-pressure situation
The LO BRK PRESS light which failed to operate on the accident aircraft as a result of a faulty press switch (Source & © TSB)
Both aircraft were repaired after the collision and returned to flying. The Air Transportation Safety Investigation Report which served as the source for this blog can be accessed by clicking on the .pdf file below;
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