Highflyer9790 From United States of America, joined Jul 2005, 1241 posts, RR: 0 Posted (9 years 5 days 2 hours ago) and read 2042 times:
After looking at this rather interesting photo, i am wondering what the two torpedo-like tubes are sticking out above the nose gear. i have seen this on a few other aircraft as well. Also, to how many pounds is that jack rated for?
474218 From United States of America, joined Oct 2005, 6340 posts, RR: 9
Reply 3, posted (9 years 5 days 1 hour ago) and read 2006 times:
They are the nose gear steering actuators. There is a piston in each one and as hydraulic fluid is ported to them the piston either extends or retracts, that is how they move the nose gear left or right.
Sfomb67 From United States of America, joined Dec 2005, 417 posts, RR: 0
Reply 5, posted (9 years 4 days 21 hours ago) and read 1959 times:
Quoting 474218 (Reply 3): that is how they move the nose gear left or right.
To get a little more technical, the main portion of the nose landing gear does not rotate. As you can see, the steering cylinders are mounted where the lower strut piston extends from, or out of, the upper section of the nose gear. The steering cylinders merely turn the lower piston, with the wheels attached. As 474218 stated, fluid is ported to the two steering cylinders (one extends and the other retracts), and as a result, the lower piston rotates and steering is accomplished.
If everything is in equilibrium, and there is no loading or unloading going on, in theory, every millimetre you raise the jack will also lift the entire nose landing gear a millimetre as well. This will then also raise the nose of the aircraft.
The landing gear struts contain pressurised nitrogen which supports the weight of the aircraft. When the nitrogen pressure inside the strut (in psi) multiplied by the area of the inner cylinder (in square inches) equals the weight upon the strut in pounds, the strut will neither extend nor shorten.
JetMech split the back of his pants. He can feel the wind in his hair.
Spruit From United Kingdom, joined Oct 2005, 375 posts, RR: 0
Reply 8, posted (9 years 4 days 15 hours ago) and read 1896 times:
Quoting JetMech (Reply 7): If everything is in equilibrium, and there is no loading or unloading going on, in theory, every millimetre you raise the jack will also lift the entire nose landing gear a millimetre as well. This will then also raise the nose of the aircraft.
Good point, well made, my question seems quite obvious now you've posted this?!