http://www.airliners.net/aviation-forums/tech_ops/read.main/148560/
Username: Lehpron
Posted 2006-03-21 06:49:45 and read 6707 times.
Moreover, how much weight is being supported there? Could I position myself under the nose and pick it up? 
Photo © Christian Eggers
With other aircraft they appear porportional, this looks like it was swapped with a bicycle.
[Edited 2006-03-21 06:50:28]
Username: 2H4
Posted 2006-03-21 07:32:59 and read 6689 times.
I'd say the Metro/Merlin is even less proportional:
2H4
Username: Buzz
Posted 2006-03-21 15:07:18 and read 6575 times.
Hi Lehpron, Buzz here. At work we have a couple 3,000 lb jacks that are small enough to fit between the nosewheel tires and engage the jack pad for tire changes. No, you can't lift up the nose by hand. But there isn't a lot of weight on an empty 737's nosewheel tires either. If there's a significant wind outside (above 25 knot gusts for example) I won't do a nosewheel change because the airplane wants to bounce off the jack.
Remember, the 737-200 NLG wheels were even smaller! I guess as long as you don't do a "wheelbarrow" landing it works fine.
I guess i could look at a tire and see what weight it's rated for - what it'll take as an extreme load and divide that by a factor of 3.
g'day
Username: Jetstar
Posted 2006-03-21 22:27:47 and read 6426 times.
The smallest tire I have ever seen on a jet is on the Dassault Falcon 20.
Photo © Derek Ferguson
On the early Falcon 20’s the nose tires were about 25 percent smaller and wore out real fast, so Dassault came out with a service bulletin to change over to the slightly larger tire and wheel, we used to call them doughnut tires. I believe some modifications had to be done in the nose wheel compartment to accommodate the larger nose wheel assembly. This picture looks like it has the larger nose tire.
Username: Jetlagged
Posted 2006-03-22 08:28:19 and read 6291 times.
As a rule of thumb, the nosegear takes about 10% of the total aircraft weight. No braking action to absorb, landing impact is much less. Just steering sideforces to consider. So it doesn't have to be that big. It's only there to keep the nose off the ground after all 
Username: EssentialPowr
Posted 2006-03-26 07:32:30 and read 5959 times.
Quoting Jetlagged (Reply 4):
No braking action to absorb, landing impact is much less. Just steering sideforces to consider. So it doesn't have to be that big. It's only there to keep the nose off the ground after all
The 727 was offerred, and delivered to several US operators, with nose gear brakes. A lot of those airplanes ended up at NWA and were former Huges Airwest and Eastern airplanes. NWA deactivated the brakes.
To use automotive terms, the 737 nose gear tires are low profile, large diameter. This means they have low sidewalls, which make the tire stiffer laterally, and are still large diameter, which means the speed limit is in the 190 kt range, depending upon the exact spec of the tire for the model, operator, etc.
The Merlin has some redundancy too, as compared to a BE1900, in that it has a dual nose gear. Ed Swearingen was pretty sharp, and the Merlin/Metroliner were pretty advanced thinking for the day.
Username: HAWK21M
Posted 2006-03-27 16:53:25 and read 5869 times.
Quoting Lehpron (Thread starter):
Could I position myself under the nose and pick it up?
With one hand just that you'll need to use a Nose Wheel Jack [Bottle jack].
The B731/2 had much smaller Hubs in their nosewheel compared to their later versions.
regds
MEL
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