April 10, 200224 yr Commercial Member Fox news is showing it right now - somethign happened and the plane crashed through a fence and onto the street! No one hurt it looks like fortunately, but a pretty amazing scene... Ryan MaziarzFor fastest support, please submit a ticket at http://support.precisionmanuals.com
April 10, 200224 yr I found this online http://www.nbc4.tv/news/1391241/detail.htmlIt looks like the 767 just rolled from it's parking spot near a maint hanger. Note in the picture the second 767 near the top of the picture. See how close they are parked to the fence/freeway. Sounds like someone did "Not" put the chocks under the wheels.Terry
April 10, 200224 yr Well, actually the RW AOM for the 757/767 has all sorts of warnings about the parking brake. Seems we can pull the brake lever on without the brake actually being applied. All the light indicates is the parking brake handle being extended and the related valves are closed.One of those "gotchas"Timothy
April 10, 200224 yr Yeah but when the thing is completely shut down you are not braking at all, are you?Groetjes, http://www.grillsportverein.de/smilies/con...doom/bounce.gifDiederik Krauwer - EHAM
April 11, 200224 yr There you go again making assumptions DK.....the parking brake system will trap fluid that is applying brake pressure and close off the parking brake valve to prevent the pressure trapped in the lines holding the pads from escaping.A brake accumulator in the normal brake system can supply brake pressure when no hydraulic power exists in L/R system. Timothy
April 11, 200224 yr I THINK that you need to step on the brake pedals when setting the parking brake. I'm not positive on this, but maybe the mechanic THOUGHT he stepped hard enough, got off the aircraft, the a breeze or gust started the roll.
April 11, 200224 yr "I THINK that you need to step on the brake pedals when setting the parking brake. I'm not positive on this, but maybe the mechanic THOUGHT he stepped hard enough, got off the aircraft, the a breeze or gust started the roll."I think you'll find that the distance (angle) you have to push the pedals to get the park brake lever and rudder pedals to mechanically latch will provide more than enough pressure to park the brakes properly (assuming there is sufficient hydraulic system pressure available in the first place). For example, full travel of 747-400 brake pedals is 17 degrees. You have to push the pedals through an angle of 15 degrees or more to make the pedals and park brake lever latch properly (this angle is 13.0 to 14.5 degrees on a 767). On a 767, a mere 9 degrees of pedal movement should apply something in the order of 2600psi to the brakes. Irrespective of whether the parking brake was set properly, the AA engineer(s) should have chocked the wheels. Eventually, i.e. over a long period, you will lose pressure in the brake system and the brakes will release. The park brake system on a 767 is designed to hold the brakes for a minimum of 8 hours.The parking brake valve (which keeps pressure on the brakes) needs electric power (dc) to operate. This is provided by the Hot Battery Bus.Cheers.Ian.
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