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-   -   Position of noswewheel on different era jets (https://www.pprune.org/tech-log/625173-position-noswewheel-different-era-jets.html)

Pelican 2nd Sep 2019 18:50

Position of noswewheel on different era jets
 
Just wondering what the explanation is for jets of a previous era having the nosewheel so far back. The 747, L1011, DC-10, 757, as well as several Soviet designs, all had their nosewheel placed much further back than is usual nowadays (the most notable example of that being the A350). Was it smaller taxiways, did it have to do with CG or weight on nosewheel?

Thanks in advance!

Goldenrivett 3rd Sep 2019 07:30

Probably because we frequently had to do 180 degree turns on the runway to get the full length and needed a short distance between nose and main gear to be able to make the turn.

Also on L1011 and DC10, the rear engine meant the C of G was further aft than on aircraft with wing mounted engines. Therefore the wing was further aft and there appeared to be a longer fuselage forward of the wing. The nose wheel had to be well behind the flight deck to bring the main wheel - nose wheel distance shorter.

stilton 3rd Sep 2019 23:11

Something else to consider


Positioning the nosewheel as far forward as
possible allows the forward cargo compartment to be carried forward unobstructed as much as possible increasing
potential revenue



pattern_is_full 4th Sep 2019 06:55

As Goldenrivett says, at the time those jets were being designed (1960-70s), aircraft were growing faster than the airports they were being asked to operate from (especially with sales starting up to the developing countries). For the most part, wings and tails and noses could overhang the runways, but the wheelbase had to fit into some tight corners and other bits of concrete/asphalt left over from the days of smaller planes.

BTW, you forgot to mention Concorde - its "nose" (hah!) gear is about 19 meters behind the nose tip. https://www.heritageconcorde.com/airframe-dimensions

The Soviets were operating into really remote, small airports in Siberia and such, so in addition to spacing, they needed gear to handle rough surfaces.

And as stilton says, after 40-50 years of airport improvements, today's planes can focus on other considerations. Among others, a nose gear far behind the cockpit requires very careful understanding of the geometry of when to start a turn and keep the gear on the centerline and out of the grass (when the cockpit and pilot viewpoint may be almost over the edge of the next taxiway).

Aircraft manufacturers publish Airport Planning documents that give the gear turning radius, wing clearance radius, heights, weights and gear loads, door sizes and heights, seating arrangements, fuel needs, etc. etc. for each type. Plus a lot of the same info that goes into the operating documents (required runway lengths, climb gradients) - anything an airport manager or her fire and rescue chief might need to know. And of course what operators might need to know in matching aircraft to airports.

https://www.boeing.com/commercial/ai...n_manuals.page

Peter47 6th Sep 2019 14:57

The trident was interesting in having a nosewheel that was off-centre. Any ideas as to why this was and did it cause any problem taxiing?

dixi188 6th Sep 2019 15:23

HS121 Trident nose wheels retracted sideways.

pattern_is_full 6th Sep 2019 15:57


Originally Posted by dixi188 (Post 10563485)
HS121 Trident nose wheels retracted sideways.

Which was itself required due to the Trident employing three nav computers, for triple redundancy and "2:1 voting" in case of failure. The jumbo-sized electronics bay under the cockpit left no room for a fore-and-aft nose-gear bay.

blind pew 6th Sep 2019 18:05

Jumbo sized!
 
Might be for you if you are 4ft 6 but at 35,000 ft kneeling on the external access door whilst hiding from the new girl who was searching for the first officer at the captain's bequest it didn't seem that big.

pattern_is_full 6th Sep 2019 20:13


Originally Posted by blind pew (Post 10563598)
at 35,000 ft kneeling on the external access door whilst hiding ....

Was that the original "blind pew?" ;)

I just meant jumbo for the time...

deja vu 10th Sep 2019 07:03


Originally Posted by blind pew (Post 10563598)
Might be for you if you are 4ft 6 but at 35,000 ft kneeling on the external access door whilst hiding from the new girl who was searching for the first officer at the captain's bequest it didn't seem that big.

Could you imagine the brouhaha if someone pulled a stunt like that in todays PC humourless world. CC would need counselling and untold sick leave.

Spooky 2 10th Sep 2019 16:01


Originally Posted by deja vu (Post 10566235)
Could you imagine the brouhaha if someone pulled a stunt like that in todays PC humourless world. CC would need counselling and untold sick leave.

True and showing some new FA the Golden rivet in the lower 41 on the 707 would surely get you fired as well.

ShyTorque 10th Sep 2019 16:16

Noswewheel?

Let's not forget that some early jets had a tailwewheel.


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