Citation 560X Crash

[Boac]

Indeed - one likes to reach Vr on a runway, though, and not hurtling towards an electricity pylon.....

[TheGreenGoblin]

The Cessna Citation has a lot of previous with respect to overruns it seems, although it is difficult to ascertain if this statistic is the norm across the biz-jet sector, or common to other types as well, or not?

There was an earlier overrun in Antwerp in January year and this earlier textbook "parking brake on" crash highlights the partially on scenario perfectly...

What happened
On 25 September 2015, a Cessna 550 aircraft (Citation Bravo), registered VH-FGK, taxied at Lismore Airport for a private flight to Baryulgil, New South Wales. The flight crew consisted of a captain and copilot, who were the only occupants of the aircraft.

The flight crew did not detect anything abnormal during the taxi and take-off roll, until the captain attempted to rotate the aircraft to the take-off pitch attitude. When the aircraft had achieved the required rotate speed, the captain applied the normal backpressure on the control column to achieve a standard rate of rotation, and the aircraft did not rotate. The captain then applied full backpressure and reported that the controls felt very heavy. Neither the captain nor the copilot detected any change in the aircraft’s pitch attitude or any indication of pitch-up on the attitude direction indicator.

The captain rejected the take-off, applied full braking and reverse thrust, but the aircraft overran the runway. The nose landing gear detached from the aircraft about 50 m beyond the end of the sealed runway, and the aircraft came to rest in long grass and mud. The aircraft sustained substantial damage, and the captain and copilot were uninjured.

What the ATSB found
The aircraft did not accelerate normally as the acceleration was retarded by drag associated with rolling friction. This was indicative of partial brake pressure remaining during the take-off run. The partial brake pressure was possibly due to the parking brake being selected on at the holding point with enough pressure to retard aircraft acceleration during the take-off, but not sufficient to prevent the aircraft reaching rotate speed.

Furthermore, the nose-down moment generated by the partial brake pressure probably prevented the aircraft rotating sufficiently to become airborne, despite normal nose-up elevator deflection.

Heat in the brakes due to partial pressure during the take-off run may have reduced their effectiveness when the captain rejected the take-off, contributing to the runway overrun.

What has been done as a result
The Australian Transport Safety Bureau issued a safety recommendation that Textron Aviation (Cessna) take safety action to address the fact that Citation aircraft do not have an annunciator light to show that the parking brake is engaged and the Cessna 'before take-off' checklist does not include a check to ensure the parking brake is disengaged.

Safety message
For pilots, this incident highlights the importance of attention to the configuration of the aircraft and cockpit settings at all stages of flight, but particularly during take-off. For manufacturers, this incident highlights the importance of systems that bring an irregular or abnormal configuration or cockpit setting to the attention of the crew, especially when that configuration has the potential to adversely affect aircraft performance or control.

https://www.atsb.gov.au/publications/in ... -2015-114/

[Boac]

US Media is reporting an NTSB preliminary which supports the TGG analysis of the crash, saying that the parking brake was found 'SET' in the wreckage. I cannot understand how you can take off with the brake set! We used to say on the Lightning that if you needed reheat to start taxying you either had chocks in or the parking brake set.................

Amazing.

[TheGreenGoblin]

Download the preliminary report here..

The parking brake configuration seems to have been be excluded from the EICAS/ECAM System on the early versions of the 560X. One has to assume that this aircraft did not have a parking brake on warning light, or something simple like that. It seems that the problem is insidious in the sense that if the parking brake is set slightly on and then the toe brakes are used, the additional hydraulic pressure is retained and the braking effect is increased.

[Boac]

Ta for link.

both engines remained at 91% N1

- Why not a bit more?
One of the many puzzles for me is the starboard gear tyre (only) skid marks - cannot be accounted for by crosswind.

[TheGreenGoblin]

Ta for link.

both engines remained at 91% N1

- Why not a bit more?
One of the many puzzles for me is the starboard gear tyre (only) skid marks - cannot be accounted for by crosswind.

I suspect that once the heat in the brakes started to build up, one (or both) of them started to bind, finally causing the starboard brake to lock resulting in the skid mark(s)... (unproven, and TGG theoretical, obviously).