"John?] "
wrote in message
. net...
In article , Kevin Brooks
wrote:

"John?]
"
wrote in message
. net...
In article , Kevin Brooks
wrote:

"John?]
"
wrote in message
. net...
In article , David Windhorst
wrote:

John?] wrote:

much interesting info snipped



Controlled Descent ?

The next question you are probably asking yourself is: "Does
the
pilot
retain control of the helicopter?" The answer is yes. The pilot
will
still have complete control of his descent and his flight
controls.
The
majority of helicopters are designed with a hydraulic pump
mounted
on
the main transmission.

Is this how the anti-torque rotor is driven in the event of
powerplant
failure?

Absolutely.

The tail rotor is powered by a driveshaft which receives output
from
the main transmission. As long as the main rotor and main
transmission
continue to rotate, the tailrotor will do likewise.

On the UH-1 isn't part of that "driveshaft" linkage to the tail
rotor
actually a titanium chain?

Brooks

Nope.

The driveshaft is an actual driveshaft which drives two gearboxes and
the tail rotor.

http://incolor.inebraska.com/iceman/data/tr1.jpg

The titanium chain you have in mind is in the tailrotor control system
as opposed to the drive system and controls the pitch of the tailrotor
blades.

http://incolor.inebraska.com/iceman/data/specs509.jpg

So the breakage of that chain renders the tail rotor of little use?
Honest
question here-- I used to have a chunk of one of those chains; my
brother's
crew chief braved a growing fire and ammo that had started cooking off
to go
snatch the chain from their Dustoff bird after being shot down, and
later
broke it up into pieces for each crewmember as a momento. I just never
knew
the actual role it played in the control of the tail rotor, thinking
instead
it was a drive chain.

Brooks

Bracelets made of tail rotor chain are a popular memento in helicopter
units. If it breaks, the tail rotor continues to function but you no
longer have any control over the pitch in the blades so the aircraft
will yaw and eventually spin left or right as you increase or decrease
collective pitch. Your hole card is the fact that the throttle can be
controlled manually in an emergency and the yaw can be controlled by
increasing or decreasing throttle to keep the nose straight. Hovering
is not possible, so students are taught to execute a low speed running
landing and to control the yaw with throttle. They practice landings
with the pedals fixed both in a nose left and nose right configuration.
The landings can be a little hairy sometimes but like anything else
it's practice, practice, practice.

Ah. Clearer now. Thanks.

Brooks


John