Bell UH-1

Everything in connection with developing aircraft for FlightGear
bomber
Posts: 1379
Joined: Mon Nov 30, 2015 3:40 pm

Re: Bell UH-1

Postby bomber » Fri Mar 05, 2021 12:45 pm

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
Last edited by bomber on Thu Mar 11, 2021 6:27 pm, edited 2 times in total.
"If anyone ever tells you anything about an aeroplane which is so bloody complicated you can't understand it, take it from me - it's all balls" - R J Mitchell

bell_pilot
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Joined: Sun Feb 07, 2021 2:53 pm

Re: Bell UH-1

Postby bell_pilot » Thu Mar 11, 2021 4:21 pm

I cant see the video
Real Helicopter Pilot 1500+ flight hours
AB206,UH-1H,AH-1W
MSc. Aerospace Engineering

bell_pilot
Posts: 55
Joined: Sun Feb 07, 2021 2:53 pm

Re: Bell UH-1

Postby bell_pilot » Thu Mar 11, 2021 7:03 pm

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
Real Helicopter Pilot 1500+ flight hours
AB206,UH-1H,AH-1W
MSc. Aerospace Engineering

bomber
Posts: 1379
Joined: Mon Nov 30, 2015 3:40 pm

Re: Bell UH-1

Postby bomber » Fri Mar 12, 2021 9:22 am

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 ?
"If anyone ever tells you anything about an aeroplane which is so bloody complicated you can't understand it, take it from me - it's all balls" - R J Mitchell

bell_pilot
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Joined: Sun Feb 07, 2021 2:53 pm

Re: Bell UH-1

Postby bell_pilot » Fri Mar 12, 2021 11:07 am

%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.
Real Helicopter Pilot 1500+ flight hours
AB206,UH-1H,AH-1W
MSc. Aerospace Engineering

bomber
Posts: 1379
Joined: Mon Nov 30, 2015 3:40 pm

Re: Bell UH-1

Postby bomber » Fri Mar 12, 2021 11:50 am

Ok thanks
"If anyone ever tells you anything about an aeroplane which is so bloody complicated you can't understand it, take it from me - it's all balls" - R J Mitchell

bomber
Posts: 1379
Joined: Mon Nov 30, 2015 3:40 pm

Re: Bell UH-1

Postby bomber » Sat Mar 13, 2021 11:20 am

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
"If anyone ever tells you anything about an aeroplane which is so bloody complicated you can't understand it, take it from me - it's all balls" - R J Mitchell

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IAHM-COL
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Re: Bell UH-1

Postby IAHM-COL » Sat Mar 13, 2021 5:45 pm

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

PS: Nevermind I read your post just above... duh!
https://raw.githubusercontent.com/IAHM-COL/gpg-pubkey/master/pubkey.asc

R.M.S.
If we gave everybody in the World free software today, but we failed to teach them about the four freedoms, five years from now, would they still have it?

bomber
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Joined: Mon Nov 30, 2015 3:40 pm

Re: Bell UH-1

Postby bomber » Sat Mar 13, 2021 6:15 pm

Soon
"If anyone ever tells you anything about an aeroplane which is so bloody complicated you can't understand it, take it from me - it's all balls" - R J Mitchell

bomber
Posts: 1379
Joined: Mon Nov 30, 2015 3:40 pm

Re: Bell UH-1

Postby bomber » Sun Mar 14, 2021 9:18 am

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
"If anyone ever tells you anything about an aeroplane which is so bloody complicated you can't understand it, take it from me - it's all balls" - R J Mitchell


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