Bell UH-1

[bomber]

that would make for a really slow start up... how long would you say from pressing the start button to 100% rotor speed ?

Could you do us a favour and watch this video of a real start-up (unedited) and explain what's happening at what time up to take-off

https://youtu.be/NRd-yMT_5NE

cheers

Simon

[bell_pilot]

I cant see the video

[bell_pilot]

It appeared on desktop.
Pilot starts engine as below(simplifed)
Press start switch until N1/Ng reaches 40% or 60 secs.
Wait for Ng increasing stop
Increase throtle to Ng 68%-72% (idle)
Some checklist sutff
Increase throttle until Np/N2 reaches 5500 rpm
Some checklist stuff
Full throttle, check N2 is 6600 and Nr %100
Some checklist stuff
Take off.
Enjoy

[bomber]

Confused... Increase throttle to idle 68-72%

At 100% throttle the only way to keep the rpm down is to raise collective.... Doing that will result in take-off.

Isn't throttle adjusted by the auto governor to maintain rpm ?

[bell_pilot]

%100 throttle does not mean to open all gas valve and flow turbines. Governor controls the fuel flow but throttle position determines max allowed fuel flow control of governor.

[bomber]

Ok thanks

[bomber]

I think you're going to love this new turbine/rotor code. It's taken me weeks and more head scratching than I could imagine and has absolutely nothing to do with the UH-1, but everything to do with multi engines helicopters.... but we're in a real good place.

Anyway I have another question... Torque. which one do they refer to...

Rotor torque @ 324rpm
Gearbox torque @ 6600rpm
Engine torque @ 21085rpm

I would have thought rotor myself, but better to ask the question.

Also a number for torque is talked about, but ?I have no idea what units it's in

Simon

[IAHM-COL]

@all
Any update to test or are we on stdby?
IH

PS: Nevermind I read your post just above... duh!

[bomber]

Soon

[bomber]

Ok I'd like to now talk rudder and anti-torque observations.

At full main rotor power I get a certain amount of clockwise torque, so I've set up the tail rotor blade angle to counter this at full left peddle.

So here's the question

When I start the turbine and rotors spinning I have a lowered collective, very little torque generated by the main rotor. If I don't touch the peddles the tail rotor is generating too much anti-torque so to match the low main rotor torque I have to depress the right peddle.... which I'm finding counter intuitive. As I bring the main rotor collective up I slowly apply more left peddle until neutral and then as I apply even more rotor collective depress the left peddle more.

Is this correct ?

Simon