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Re: Bell UH-1
Posted: Fri Mar 05, 2021 12:45 pm
by 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_5NEcheers
Simon
Re: Bell UH-1
Posted: Thu Mar 11, 2021 4:21 pm
by bell_pilot
I cant see the video
Re: Bell UH-1
Posted: Thu Mar 11, 2021 7:03 pm
by 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
Re: Bell UH-1
Posted: Fri Mar 12, 2021 9:22 am
by 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 ?
Re: Bell UH-1
Posted: Fri Mar 12, 2021 11:07 am
by 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.
Re: Bell UH-1
Posted: Fri Mar 12, 2021 11:50 am
by bomber
Ok thanks
Re: Bell UH-1
Posted: Sat Mar 13, 2021 11:20 am
by 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
Re: Bell UH-1
Posted: Sat Mar 13, 2021 5:45 pm
by IAHM-COL
@all
Any update to test or are we on stdby?
IH
PS: Nevermind I read your post just above... duh!
Re: Bell UH-1
Posted: Sat Mar 13, 2021 6:15 pm
by bomber
Soon
Re: Bell UH-1
Posted: Sun Mar 14, 2021 9:18 am
by 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