Comments on: Doh! Grounded http://toolmonger.com/2009/09/30/doh-grounded/ All tools. All the time. Your source for news, information, and reviews of hand tools, power tools, and tools of all kinds. Sun, 21 Mar 2010 18:38:33 +0000 http://wordpress.org/?v=2.6.1 By: Gordon Mott http://toolmonger.com/2009/09/30/doh-grounded/#comment-1034250 Gordon Mott Thu, 01 Oct 2009 03:42:04 +0000 http://toolmonger.com/?p=32368#comment-1034250 Most of those jacks are made by CJC... http://www.columbusjack.com/ Most of those jacks are made by CJC…

http://www.columbusjack.com/

]]> By: Mike47 http://toolmonger.com/2009/09/30/doh-grounded/#comment-1034196 Mike47 Wed, 30 Sep 2009 23:57:04 +0000 http://toolmonger.com/?p=32368#comment-1034196 Air bags are utilized in the event a plane runs off the runway/taxiway system and becomes mired in soft ground that will not allow for point jacking. The objective is usually to raise them enough to get mats or planking or gravel down that will distribute the weight under the gear enough to roll them back onto pavement. Air bags are utilized in the event a plane runs off the runway/taxiway system and becomes mired in soft ground that will not allow for point jacking. The objective is usually to raise them enough to get mats or planking or gravel down that will distribute the weight under the gear enough to roll them back onto pavement.

]]> By: Chris http://toolmonger.com/2009/09/30/doh-grounded/#comment-1034153 Chris Wed, 30 Sep 2009 22:44:54 +0000 http://toolmonger.com/?p=32368#comment-1034153 bajajoaquin is right about the plugs -- they're designed to melt and cause a gradual tire deflation when the brakes severely overheat -- but wrong about the airbags. As Rich M. and paul pointed out, most aircraft (including the 767 shown here) have jack points at various places on the wings, fuselage, and/or landing gear for standard hydraulic jacks (just, well, really BIG ones). I would imagine bursting an aircraft tire would do some serious damage, as the tires are rated to somewhere on the order of 100-200 PSI for normal operation. Bursting one would probably take at least 300 PSI, and I wouldn't think a failure at that pressure would be pretty. Ouch. At least it was a relative non-event. Rejected take-offs have been known to end up off the end of the runway, and that's usually much less benign for all involved. cl bajajoaquin is right about the plugs — they’re designed to melt and cause a gradual tire deflation when the brakes severely overheat — but wrong about the airbags. As Rich M. and paul pointed out, most aircraft (including the 767 shown here) have jack points at various places on the wings, fuselage, and/or landing gear for standard hydraulic jacks (just, well, really BIG ones).

I would imagine bursting an aircraft tire would do some serious damage, as the tires are rated to somewhere on the order of 100-200 PSI for normal operation. Bursting one would probably take at least 300 PSI, and I wouldn’t think a failure at that pressure would be pretty. Ouch.

At least it was a relative non-event. Rejected take-offs have been known to end up off the end of the runway, and that’s usually much less benign for all involved.

cl

]]> By: Toolaremia http://toolmonger.com/2009/09/30/doh-grounded/#comment-1034098 Toolaremia Wed, 30 Sep 2009 21:21:47 +0000 http://toolmonger.com/?p=32368#comment-1034098 This is called a "rejected take off". Commercial passenger planes are designed to come to a safe stop at maximum payload and maxim ground speed without lighting anything on fire for a minimum of something like 5 minutes. They figure fire trucks will be able to get to the plane by then. They test this too. Search youtube for "maximum weight rejected take off". There is at least one of a 767 (I think) performing the test. All the tires go flat, but nothing lights on fire. (Blocked at work else I'd post a link.) This is called a “rejected take off”. Commercial passenger planes are designed to come to a safe stop at maximum payload and maxim ground speed without lighting anything on fire for a minimum of something like 5 minutes. They figure fire trucks will be able to get to the plane by then.

They test this too. Search youtube for “maximum weight rejected take off”. There is at least one of a 767 (I think) performing the test. All the tires go flat, but nothing lights on fire. (Blocked at work else I’d post a link.)

]]> By: David Bryan http://toolmonger.com/2009/09/30/doh-grounded/#comment-1034095 David Bryan Wed, 30 Sep 2009 21:11:33 +0000 http://toolmonger.com/?p=32368#comment-1034095 Jeffrey, glad you made it home all right. Jeffrey, glad you made it home all right.

]]> By: Rich M http://toolmonger.com/2009/09/30/doh-grounded/#comment-1034082 Rich M Wed, 30 Sep 2009 19:58:36 +0000 http://toolmonger.com/?p=32368#comment-1034082 I worked on a BAE111 at Filton Aerodrome with a faulty 'landing gear down' light once. The airframe had clearly labelled 'jack here' points and the whole plane just sat on three tripod stands (one in each wing, one in the tail) while we cycled the gear up and down to find the fault. I worked on a BAE111 at Filton Aerodrome with a faulty ‘landing gear down’ light once. The airframe had clearly labelled ‘jack here’ points and the whole plane just sat on three tripod stands (one in each wing, one in the tail) while we cycled the gear up and down to find the fault.

]]> By: Paul http://toolmonger.com/2009/09/30/doh-grounded/#comment-1034076 Paul Wed, 30 Sep 2009 19:31:28 +0000 http://toolmonger.com/?p=32368#comment-1034076 jack a plane to change the wheels? Hydraulic jack like those used on cars (just bigger). Under the bogey bar (what connects the axles) there will be a jacking dome to accomodate a jack. Most landing gears are designed to be able to get a jack in with all tires flat jack a plane to change the wheels? Hydraulic jack like those used on cars (just bigger). Under the bogey bar (what connects the axles) there will be a jacking dome to accomodate a jack. Most landing gears are designed to be able to get a jack in with all tires flat

]]> By: Chuck http://toolmonger.com/2009/09/30/doh-grounded/#comment-1034021 Chuck Wed, 30 Sep 2009 17:23:11 +0000 http://toolmonger.com/?p=32368#comment-1034021 Rejected take off (RTO) tests are part of the airworthiness certification for all aircraft, sometimes it's quite spectacular, frequently ending in brake fire and total write-off of the tyres and possible the whole bogey. Not only does the aircraft have to stop, but the firefighters have to stand off for 5 minutes before taking action, to simulate a possible real response time. 777 RTO: http://www.youtube.com/watch?v=wXpjBxD0Rhg Aircraft brakes are really quite amazing devices, more fun at: http://www.youtube.com/watch?v=m1dv_y_3EK0&feature=related Rejected take off (RTO) tests are part of the airworthiness certification for all aircraft, sometimes it’s quite spectacular, frequently ending in brake fire and total write-off of the tyres and possible the whole bogey.

Not only does the aircraft have to stop, but the firefighters have to stand off for 5 minutes before taking action, to simulate a possible real response time.

777 RTO: http://www.youtube.com/watch?v=wXpjBxD0Rhg

Aircraft brakes are really quite amazing devices, more fun at: http://www.youtube.com/watch?v=m1dv_y_3EK0&feature=related

]]> By: jeffrey immer http://toolmonger.com/2009/09/30/doh-grounded/#comment-1034019 jeffrey immer Wed, 30 Sep 2009 17:19:14 +0000 http://toolmonger.com/?p=32368#comment-1034019 this was a charted flight by the us military to take us from iraq (via kuwait) to home, this happened in germany. we were told by the mechanic liason that travels on the plane that the tires are only rated to 200 mph and must have failed on that accord. in total i think we had 6-8 flat tires and not enough spares. i did not get to see them jack the plane up it happened after we left (40 hours after it happened a plane came from Atlanta to get us) i was told by other stranded soldiers when they did replace them the guy filling the tires over filled one and it burst and he was severely hurt. this was a charted flight by the us military to take us from iraq (via kuwait) to home, this happened in germany. we were told by the mechanic liason that travels on the plane that the tires are only rated to 200 mph and must have failed on that accord. in total i think we had 6-8 flat tires and not enough spares. i did not get to see them jack the plane up it happened after we left (40 hours after it happened a plane came from Atlanta to get us) i was told by other stranded soldiers when they did replace them the guy filling the tires over filled one and it burst and he was severely hurt.

]]> By: bajajoaquin http://toolmonger.com/2009/09/30/doh-grounded/#comment-1034009 bajajoaquin Wed, 30 Sep 2009 16:25:30 +0000 http://toolmonger.com/?p=32368#comment-1034009 They generally use inflatable bags to lift the plane up. This distributes the weight over a large area of the fuselage, preventing damage. I'd guess that the flat tires came from the plugs in the wheels melting. These plugs are designed to melt and release air in the event that the brakes get hot enough to cause other problems. I.e. it's better to let the air out than have a tire burst. They generally use inflatable bags to lift the plane up. This distributes the weight over a large area of the fuselage, preventing damage.

I’d guess that the flat tires came from the plugs in the wheels melting. These plugs are designed to melt and release air in the event that the brakes get hot enough to cause other problems. I.e. it’s better to let the air out than have a tire burst.

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