about flying helicopter

[sameer]

while flying helicopter ar a fixed altitude does it is necessary for the pilot to hold his left hand contineously on the collective pitch control or he can lock its position and remove his hand to adjust radio frequency. in a bell helicopter there are two controls one for captain and one for co pilot at a time only one person control the chopper then the other set of control is inactive plz explain this clearly

when low rpm indicator turns on then the pilot must reduce collective pitch why is it so?

[Wally]

while flying helicopter ar a fixed altitude does it is necessary for the pilot to hold his left hand contineously on the collective pitch control or he can lock its position and remove his hand to adjust radio frequency. in a bell helicopter there are two controls one for captain and one for co pilot at a time only one person control the chopper then the other set of control is inactive plz explain this clearly

when low rpm indicator turns on then the pilot must reduce collective pitch why is it so?

 

On short flights, most pilots keep their left hand on the collective. Most helos have "friction" adjusters that allow you to vary how much effort it takes to move a control. Some are as simple as screw with a couple of composition washers and a plate to apply the pressure to. The collective can also be adjusted for counterbalance forces, but this is a maintenance issue and I'm only a pilot. One doesn't want to lock a control in place in flight, in case you need to move it quickly. Friction allows that fine adjustment of force. You make it tight enough that it doesn't move by itself but CAN be moved if you wish. Doing this allows you to use your left hand for radios, if you're seated on the right, or swap stick hands to fly with the left while your right hand works radios.

If two sets of controls are installed, both sets are connected to the same mechanism. Both sets of controls move together and the pilot not flying positions himself so that he's clear of normal control movements.

If the low rpm indicator is activated, it's probably because the engine isn't delivering enough power for the demand. Reducing the collective reduces pitch and power required to make the desired RPM, allowing the engine to accelerate the rotor to the desired speed.