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March 9th, 2006, 11:46
| #1 |
| Junior Member  Join Date: Sep 2005 Location: SF Bay Area, Cali
Posts: 287
 |  767 Landing Gear
hey i was always wondering why the angle of the 767 main gears is different fromt the way the 757 and 747 gears are angled. If anyone knows why that would be great. thanks
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March 9th, 2006, 12:08
| #2 |
| Old Skool  Join Date: Oct 2005 Location: ROC
Posts: 2,225
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Its just how the fit into the landing gear bays.
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March 9th, 2006, 12:42
| #3 | |
| Old Skool  Join Date: Sep 2003
Posts: 1,883
| Quote:
There is no reference in any manual of mine that addresses this. I suppose they figure this is not important information for pilots to know. At one point in time, aircraft manuals contained lots and lots of schematics and peripheral information. Not anymore. Now they pretty much just tell you what to do when a light comes on. I remember on the 727 you used to have to use some knowledge to determine if a bleed air leak was on the engine or cabin side of the engine pylon...and then isolate the leak. Newer generation airplanes just turn off the bleed valve and tell you about it. | |
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March 9th, 2006, 12:57
| #4 | |
| Old Skool  Join Date: Mar 2004 Location: the Twin Cities of Minneapolis and St. Paul
Posts: 1,961
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__________________ I'm free of all prejudices. I hate everyone equally. Comm. - ASEL, Instrument 290 TT | |
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March 9th, 2006, 13:00
| #5 |
| Junior Member  Join Date: Nov 2005 Location: Buffalo, NY
Posts: 213
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Similar question for the heavy jet guys... I know that some of the main gear on jets is just "fixed" (doesn't droop-717 for example) when it comes in for landing, but on heavier jets the gear droops down and contacts the runway earlier. This I imagine serves the purpose of spinning the wheels up before all the weight is transferred to the wheels. Now, is it to aid in a smoother touchdown, reduce tire wear, both, or something else?? Thanks
__________________ Patrick |
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March 9th, 2006, 13:28
| #6 | |
| Old Skool Join Date: Sep 2003
Posts: 1,883
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My perception is that the tilt does not provide for a smoother touchdown...but maybe other factors are involved besides the tilt. For example, and not so much so in the 757, but in the 767 when you make a smooth initial touch...it is followed by shuddering and shaking as the nosewheel is lowered to the pavement. I always attributed this to the trucks working level to the pavement. Did not really experience this type of shuddering in non-tilting gear. | |
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March 9th, 2006, 13:48
| #7 |
| Old Skool  Join Date: Nov 2000 Location: Spokane, WA
Posts: 6,545
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My understanding is the tilt is necessary for the gear to fit in the wheel well. The 767 tilts forward, the 757 tilts aft, and that's about all I know or care about. Don't ask me why, that's just what the book says.... |
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March 9th, 2006, 13:58
| #8 |
| Junior Member Join Date: Nov 2005 Location: Buffalo, NY
Posts: 213
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just curious, thanks for the replys
__________________ Patrick |
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March 9th, 2006, 14:43
| #9 |
| Junior Member  Join Date: Feb 2005 Location: KMDT, KATL
Posts: 269
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I was told in 767 school was that it was that way becuase of LGA. You can only have so much weight per square foot. The 767 original landing gear design did not fit the limits for the runway, so they madethe main gear wider. If I remember right they tilted each main out by 17 degrees.
__________________ Larkin A&P, CFI, CFII, MEI Jag fluga flygplan!! |
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March 9th, 2006, 15:59
| #10 |
| Old Skool  Join Date: Sep 2001
Posts: 2,045
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LGA does have some unusual requirements, which led to AA's A300s having a unique wider truck design for the same reason. The 767 was likely just designed that way with some of the U.S. carriers being launch customers. As for smoother touchdown, no, the tilt is just to fit into the well. There are issues with both forward and aft tilt from a design standpoint, as forward tilt can lead to more bogey twist at touchdown with a sideload, but that just requires a stronger structure. The reason bigger airplanes have trucks and not just single tandem sets for MLG is just due to the limits on pavement and also tires and related components. More weight and you add more wheels to distribute it, simple as that. |
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March 9th, 2006, 16:25
| #11 |
| Old Skool Join Date: Sep 2003
Posts: 1,883
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Are we talking LGA as in KLGA? I'm guessing due to the pier construction. If so, interesting that one airport has such an influence on design.
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March 9th, 2006, 16:55
| #12 | |
| Junior Member Join Date: Feb 2005 Location: KMDT, KATL
Posts: 269
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KLGA is the culpret.
__________________ Larkin A&P, CFI, CFII, MEI Jag fluga flygplan!! | |
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March 9th, 2006, 17:08
| #13 |
| Junior Member  Join Date: Mar 2004 Location: COS
Posts: 270
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Wasn't the 727 designed for LGA too? I heard this on the some airplane show..built for United to operate in DEN and LGA..maybe im just making this up though.
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March 9th, 2006, 17:29
| #14 | |
| Old Skool  Join Date: Nov 2003 Location: KPHX, KFFZ, KIWA
Posts: 19,006
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Just a heads up..  | |
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March 9th, 2006, 19:13
| #15 | |
| Junior Member Join Date: Nov 2005 Location: Buffalo, NY
Posts: 213
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 Wow on my part and DUH! Thanks 
__________________ Patrick | |
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March 10th, 2006, 17:24
| #16 |
| Old Skool  Join Date: Dec 2001 Location: Chicago, IL
Posts: 4,833
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Two wheel gear do tilt on some aircraft. For instance, on our EMB-145 we have "trailing link" landing gear, which is an extendable linkage which allows the landing gear to "extend" in a way. This opposed to the B717/MD-80 style gear which is a straight gear assembly. If airliners.net wasn't down at the moment, I would post some pictures of the differences.
__________________ "Anyone can do the job when things are going right. In this business we play for keeps." Ernest K. Gann |
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March 10th, 2006, 17:40
| #17 |
| Old Skool Join Date: Nov 2000 Location: Spokane, WA
Posts: 6,545
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A net's down, too. Funny how flightinfo is down. Wonder if they are gonna combine into the mother of all aviation websites. Airflightinfonet.com Now wouldn't THAT be something.... |
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March 10th, 2006, 18:50
| #18 | |
| Old Skool Join Date: Nov 2003 Location: KPHX, KFFZ, KIWA
Posts: 19,006
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March 10th, 2006, 21:09
| #19 |
| Old Skool Join Date: Dec 2001 Location: Chicago, IL
Posts: 4,833
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Just like the CRJ. Many aircraft have that trailing link type landing gear. Airliners.net is still all messed up. Man, I think if Flightinfo.com and Airliners.net combined you'd see an explosion of rude, know it alls who flame, infest the internet message boards overnight.
__________________ "Anyone can do the job when things are going right. In this business we play for keeps." Ernest K. Gann |
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March 10th, 2006, 23:50
| #20 |
| Old Skool  Join Date: Sep 2003 Location: Left Seat
Posts: 5,718
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FYI, the -200 does have trailing link, the -700 and -900 do not. I haven't done differences yet, but the guys that fly both the 200 and the 700 can tell you how much of a pain it is to land the 700 with the fixed landing gear.
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March 11th, 2006, 00:33
| #21 | |
| Old Skool Join Date: Nov 2003 Location: KPHX, KFFZ, KIWA
Posts: 19,006
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March 11th, 2006, 12:10
| #22 | |
| Old Skool  | Quote:
thanks modern marvels!
__________________ "There needs to be more drinking here on JC. We need more ******* partying!" -Doug Taylor 210TT 20 ME | |
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