- In short: An investigation finds the parking handle brake on a Saab 340B aircraft had not been completely seated in the panel when taking off, causing the pilots to experience handling and acceleration issues.
- What's next?: The operator has since briefed its flight crews on the design and function of the parking brake system
The pilot of a plane carrying 25 passengers failed to properly release the parking brake while trying to take-off, a report from the Australian Transport Safety Bureau (ATSB) has found.
The incident happened in November last year when a Pel-Air operated Saab 340B was preparing to leave Flinders Island for Wynyard in north-west Tasmania.
The two pilots made the decision to abandon the take-off after experiencing handling and acceleration issues.
The flight was part of a charter tour and had a cabin attendant as well as 25 passengers.
The ATSB found the parking brake handle had likely not been completely seated in the panel when released by the pilot, resulting in residual pressure remaining in the brake system.
The report said that as the aircraft accelerated, it veered to the left of the runway centre-line and the crew detected a decrease in acceleration.
"The pilots observed significant tyre marks on the runway, a flat-spotted tyre, and that all main landing gear tyres were flat," the report said.
The aircraft had left Melbourne at about 9am and landed an hour later on Flinders Island where the passengers disembarked for a sightseeing trip.
The captain and first officer remained at the airport to conduct post-flight duties and prepare for the next leg to Wynyard at 2:30pm.
When the passengers boarded, the first officer released the parking brake and did a 180-degree turn out of the parking bay, commenting that there was no abnormal handling or power settings required to taxi the aircraft.
The plane taxied slowly to give cabin crew enough time to prepare for take-off.
Take off abandoned at 96 knots
When they started the take-off roll, the report said the first officer noted a crosswind was present and glanced down after setting power to check the torque gauges.
"When the first officer looked up again, they noted that they had drifted over to the left of the runway centre-line, with the airspeed indicating 46 KIAS (Knots Indicated Air Speed)," the report said.
"In response, they applied right rudder and brought the aircraft back onto the centre-line of the runway.
"The aircraft continued to accelerate to around 80 knots when the flight crew noted a reduction in the aircraft's acceleration rate.
"The first officer called failure, the captain called stop and the take-off was rejected. The aircraft reached a maximum airspeed of 96 knots."
After the incident, the pilots inspected the aircraft and found all four main landing gear wheels were deflated and the outboard wheel on the left main landing gear had a flat spot.
Flight crews briefed after incident
An engineering crew from REX Airlines was flown in to further inspect the plane.
The report stated the operator has since made several changes, including sharing a Notice to Aircrew to its pilots with detailed information of the operation of the parking brake, and briefing all relevant flight crew on the design and function of the parking brake system and the importance of completely seating the parking brake handle in the panel.
"This occurrence demonstrates the importance of completing routine tasks in accordance with manufacturer's instructions," ATSB Director Transport Safety Stuart Macleod said.
"The outcome of this event, no passenger injuries and minimal aircraft damage, was a result of the flight crew's effective monitoring of the aircraft's performance and prompt action to reject the take-off when the expected performance was not achieved."
The captain had a total flying time of 4,660 flying hours with 4,461 hours on the SAAB-340 and the first officer had a total flying time of 2,449.5 flying hours with 2,219 hours on the SAAB-340.
During the investigation, the manufacturer, Saab Aircraft Co, was contacted about the brake system.
"They could not identify any other system reason that could contribute to brake application other than the parking brake," the report said.
"They further advised that if the parking brake is released properly and the parking brake valve is serviceable, there is no possibility of both brake systems remaining on."
Saab also said it could not find any other cases of this happening.
