Radicaldude1234
Well-Known Member
Hey guys! Got a little bored last night, did a little reading, and decided to whip up the mechanism on the F-5/T-38.
For those who don't know, the T-38 (and it's F-5 descendant) has really really thin wings. Not quite F-104 thin, but the maximum thickness where the gear mechanism is is just over 5 inches thick. I've always wondered how they fit the mechanism in there...
So I was reading this report: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19800016824.pdf
And ran across this picture:
and this video:
With which I made this drawing:
And created this assembly
Animated
Some observations:
1. The hydraulic actuator that the main gear has would need to be <4 inches to fit into the wing. Assuming the internal piston is 3" in diameter and given that the T-38's utility hydraulic pressure is at 3000psi, that would give over 21000 pounds of force to actuate the gear.
2. The mechanism uses it's braces with over-center locks as a down lock. There is no separate lock to keep the gear from folding.
3. There is a separate up lock that is normally operated by hydraulics. If the hydraulic lock fails to release, as per the T-38 Dash 1 there is a separate handle connected by wire in the cockpit to release the gear. The gear will then lower on its own and can be assisted by the time honored "Rock it to lock it" technique to lock it into place.
Will try to figure out how the nose gear works.
Thoughts?
For those who don't know, the T-38 (and it's F-5 descendant) has really really thin wings. Not quite F-104 thin, but the maximum thickness where the gear mechanism is is just over 5 inches thick. I've always wondered how they fit the mechanism in there...
So I was reading this report: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19800016824.pdf
And ran across this picture:
and this video:
With which I made this drawing:
And created this assembly
Animated
Some observations:
1. The hydraulic actuator that the main gear has would need to be <4 inches to fit into the wing. Assuming the internal piston is 3" in diameter and given that the T-38's utility hydraulic pressure is at 3000psi, that would give over 21000 pounds of force to actuate the gear.
2. The mechanism uses it's braces with over-center locks as a down lock. There is no separate lock to keep the gear from folding.
3. There is a separate up lock that is normally operated by hydraulics. If the hydraulic lock fails to release, as per the T-38 Dash 1 there is a separate handle connected by wire in the cockpit to release the gear. The gear will then lower on its own and can be assisted by the time honored "Rock it to lock it" technique to lock it into place.
Will try to figure out how the nose gear works.
Thoughts?
Last edited by a moderator: