Boeing 747-8 performs ultimate rejected takeoff
Why Aviation Stack Exchange recommends it
Aviation Stack Exchange answerers point people to it as a real demonstration of rejected-takeoff brake performance, heat, and smoke on a heavy airliner.
Recommended by 1 people across 1 different months, 2015 to 2022.
What it is
Boeing's official footage of the 747-8 Freighter certification test in which the aircraft, at maximum takeoff weight and with fully worn-out brakes, aborts a takeoff at about 200 mph without thrust reversers. It is a short clip showing the brakes absorbing huge energy and the aftermath of the stop.
Cited in 1 Wikipedia article, including Rejected takeoff.
What people said
Recommends Peter Schilling · 2017-07 · Aviation Stack Exchange · on “Why is the use of reverse thrust not considered when calculating accelerate-stop distance on dry runway?”
If your thrust reversers are operational and debris is not a concern, you're right for an in-service rejected takeoff (RTO): There's nothing that prevents the use of reverse thrust on a dry runway for an aborted takeoff. Most in-service RTOs utilize reverse thrust if available (see this video [LINK] for a dry-runway example). However, in order to certify a transport-category airplane, one must show compliance with 14 CFR 25.109, paragraph (f) [LINK] , which precludes the use of thrust reversers on dry runways in calculating the accelerate-stop distance. The demonstration required by paragraph (i), therefore, cannot be conducted with reverse thrust on a dry runway. From a certification standp
Cites mins · 2015-10 · Aviation Stack Exchange · on “What is this orange container labeled "Flight kit wheel"?”
Short answer Corsair [LINK] is a small airline, with a limited number of aircraft, serving airports in remote islands from Paris. For their economical survival their aircraft must keep a high operational ratio. However: The airline may not have a maintenance facility at destination, either a owned facility or an agreement for maintenance services from another company locally based. The facility may not have a satisfactory stock of spare parts for their aircraft or the required tools, and no possibility to obtain them in a very short time, even from their main base. A common solution is to bring parts aboard, in particular MEL [LINK] components. It's a balance between the cost to carry the co
Cites Dave · 2016-12 · Aviation Stack Exchange · on “How often are heavy aircraft brake pads changed?”
The 747-800 uses carbon brakes made by the Goodrich company [LINK] and according to this article [LINK] , The entire industry is leaning towards carbon brakes, Honeywell executives assert. Lufthansa Technik also sees a trend towards carbon brakes, as the mean time between repairs (MTBR) for carbon brakes is 1,500-2,000 cycles, compared with some 1,100 cycles for steel brakes. Also of note, take a look at this video on the testing of the brakes [this video] .
Cites user14897 · 2017-04 · Aviation Stack Exchange · on “How do fire crews handle hot brakes?”
[LINK] ( Airbus [LINK] ) A320 landing gear approach paths. It's important to approach the landing gear from the right angle, because an explosion could throw deadly debris at the firefighters. Cooling According to Airbus [LINK] , water-mist is to be used to cool the brakes. Water, CO2, or foam, are not to be used. All those cause sudden cooling that can lead to wheel cracks or rim burst. Fire If there is fire, then large amounts of water or water-mist is to be used. Foam is to be used if fuel tanks are at risk. [LINK] ( [this video] ) Fire crew attending to 1400°C brakes. Not an emergency, but interesting: [LINK] ( airliners.net [LINK] ) Upon deplaning back in Pyongyang, we noticed the brakes of
Cites Wasserwaage · 2018-01 · Aviation Stack Exchange · on “What are the effects of a rejected takeoff?”
If an airplane is close to V1, the brakes - which have to absorb kinetic energy and dissipate heat - can get hot to the point where the tires automatically deflate, to prevent them from exploding. For a 747 this involves a lot of smoke and glowing brake disks [this video] .
Cites Peter Kämpf · 2022-01 · Aviation Stack Exchange · on “How do airplane wheels differ from automobile wheels and why?”
Let's start with tire pressure. A car tire has somewhere between 2 and 3.5 bars (that's 29 to 51 psi) while airplane tires go up to 24 bars (350 psi) [LINK] . Next, they must withstand extremely heavy loads for a short time. The spinup and impact load of a standard airliner landing would let any car tire burst in the same circumstances. In order to be retractable, and even more when not retractable, airplane tires must be as small as possible. An extreme example is the Tu-144, where each main gear had 8 wheels [LINK] to keep individual tire size down. The tread on an aircraft tire does not have to transmit torque continuously, only during spinup and when braking. It must give good directiona