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-   -   Electric tail rotor; an alternative? (https://www.pprune.org/rotorheads/615965-electric-tail-rotor-alternative.html)

chopjock 30th Nov 2018 23:16

Electric tail rotor; an alternative?
 
I think they are all doing it wrong. It would be much simpler if there was an electric motor out on the boom and simply switch it off when not needed...

ShyTorque 30th Nov 2018 23:18

Chopjock, the RAF SAR Wessex which crashed into the lake in Wales with cadet passengers on board had a tail rotor dis-connectable coupling failure.
First of all you complained that a tail rotor drive system is too unreliable but now you want to make it more complicated and therefore by definition less reliable...what sort of logic is that?

Nadar 1st Dec 2018 00:27


Originally Posted by chopjock (Post 10324913)
I think they are all doing it wrong. It would be much simpler if there was an electric motor out on the boom and simply switch it off when not needed...

Everybody relax, the above statement should make it perfectly clear that he's just trolling you.

SASless 1st Dec 2018 01:04

There is a cure for Trolls.

Friends don't let friends troll.

Twist & Shout 1st Dec 2018 05:04

Trolling makes sarcasm look like genius.
Only practiced by the wittless.

dClbydalpha 1st Dec 2018 14:28


Originally Posted by Nadar (Post 10324947)
Everybody relax, the above statement should make it perfectly clear that he's just trolling you.

Seems to me that an electric tail rotor is a rather good idea.

SASless 1st Dec 2018 14:41

Chopjock should show us his design for the Fail Safe Helicopter....one that cannot have any kind of failure.....then explain how to sell them, maintain them, and operate them as he seems to have all the answers.

ShyTorque 1st Dec 2018 14:43


Seems to me that an electric tail rotor is a rather good idea
Only until someone forgets to switch it on, or the motor, the switch or the wiring fails...

dClbydalpha 1st Dec 2018 15:00


Originally Posted by ShyTorque (Post 10325356)
Only until someone forgets to switch it on, or the motor, the switch or the wiring fails...

Same is true of engines, fuel, hydraulics, gearboxes etc. hence the need for safety critical design.

chopjock 1st Dec 2018 15:03


Originally Posted by ShyTorque (Post 10325356)
Only until someone forgets to switch it on, or the motor, the switch or the wiring fails...

You could have it on by default with the ability to switch it off if you want, like when in the cruise or during an un commanded full pedal emergency...

dClbydalpha 1st Dec 2018 15:08


Originally Posted by chopjock (Post 10325370)
You could have it on by default with the ability to switch it off if you want, like when in the cruise or during an un commanded full pedal emergency...

Think a switch is a bit simple, but there would be a number of means of control. Of course the main reason to move to electric is environmental, but it does offer other potential advantages.

jellycopter 1st Dec 2018 16:00

An electric tail rotor could be switched off in the cruise and yaw control achieved by a simple aeroplane style rudder. It would save energy, reduce noise and help significantly with component life. Overall, I think this could be a winner

gevans35 1st Dec 2018 16:38


Originally Posted by dClbydalpha (Post 10325344)
Seems to me that an electric tail rotor is a rather good idea.

I think so too, powered by a generator run off the main engine(s).

Actually, why not the main rotor too? They do it in ships so why not aircraft?

Would take a lot of development though...... Elon Musk?

gevans35 1st Dec 2018 16:47


Originally Posted by chopjock (Post 10325370)
You could have it on by default with the ability to switch it off if you want, like when in the cruise or during an un commanded full pedal emergency...

Almost instantaneous torque.... giro stabilised?

Perhaps start a new thread to discuss?

ShyTorque 1st Dec 2018 16:49


Originally Posted by chopjock (Post 10325370)
You could have it on by default with the ability to switch it off if you want, like when in the cruise or during an un commanded full pedal emergency...

But you would need it on for takeoff and landing, which is where your argument began. Even if you have lost sight of that, I haven't.

chopjock 1st Dec 2018 16:53


Originally Posted by ShyTorque (Post 10325470)
But you would need it on for takeoff and landing, which is where your argument began. Even if you have lost sight of that, I haven't.

Yes of course. I did say simply switch it off when not needed... (Obviously switch it back on again when required). A bit like you do with the gear.

ShyTorque 1st Dec 2018 16:53


Originally Posted by jellycopter (Post 10325431)
An electric tail rotor could be switched off in the cruise and yaw control achieved by a simple aeroplane style rudder. It would save energy, reduce noise and help significantly with component life. Overall, I think this could be a winner

Or, you could have a less complicated design turned by a simple and very reliable mechanical driveshaft and have an aerodynamic tailfin which allows the pitch of the blades to be reduced to near neutral in cruise flight.

But wait, someone already thought of that...

gevans35 1st Dec 2018 17:03


Originally Posted by ShyTorque (Post 10325477)
Or, you could have a less complicated design turned by a simple and very reliable mechanical driveshaft and have an aerodynamic tailfin which allows the pitch of the blades to be reduced to near neutral in cruise flight.

But wait, someone already thought of that...

Or an even simpler design with direct drive electric motors and no gearboxes at all?

ShyTorque 1st Dec 2018 17:10

An electric motor would need to supply a lot of horsepower and it might be just as heavy as a gearbox. The aircraft would also need at least one large generator to supply power to it. Stopping a rotor blade in flight comes with its own set of aerodynamic problems.
But anything is possible, all engineering design is a compromise and let's not forget that most things in engineering have been tried already. There's nothing much simpler than a driveshaft turning a gearbox.

gevans35 1st Dec 2018 17:16

A single turbine generator with battery backup to provide "instantaneous" torque and sufficient reserve to get safely on the ground in the event of generator failure? Would probably be good to have a sprag clutch too.


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