Bell 205 Throttle Control and Acceleration Torque

[sdsteven]

I'm curious about the throttle control on a Bell 205 because I'm thinking about test flying one soon and possibly purchasing one in the future.

For the startup sequence, after the throttle is rolled back to detent and after the start switch is pressed, when is the throttle bumped up to the idle position? Is it between 0-40% N1 or after 40% (after start switch is released)?

My second question is for the torque. After the warm up sequence and as the throttle is rolled up to 6600 engine RPM, what is the maximum torque that can be applied during engine acceleration?

Thanks.

[oldflyer]

Hi sdsteven, it's been quite some time since I started a huey, but I found a -10 (Army operators manal) here: https://fbacffe2-0588-46d7-a6ff-e2e5a680ab18.filesusr.com/ugd/9f78cd_60998a9ed26b4cbe8a65351e9cc076e9.pdf

It doesn't seem to specify a max torque going up to flight RPM and I don't remember ever having a target number.  It was just a smooth continuous roll on of the throttle, being cognizant of the conditions that may cause the aircraft to shift such as being parked on ice or gravel.

Starting begins on page 8-5

I'm sure someone with much more recent experience can chime in with better info, and the Army -10 is certainly no substitute for the actual aircraft POH, but it might give you a little more insight.

Hope that helps.

 

[Spike]

Your wording is a little confusing to me and to be clear, what I describe will be for a UH-1H….

The throttle is set just below the detent prior to pulling the starter switch. At or just above 40% N1 is when you release the trigger. I have found with some UH-1’s it will start cooler if you hesitate going off on the trigger, like at 42%. Once you go off on the trigger, roll the throttle on into the detent (slight roll on past the detent then back to the detent). I normally just leave it there and consider this position to be “flight idle”.

If you have Dimond J gauges, it may sense a torque spike if you roll the throttle up to aggressively. Therefore, I try to keep the torque below 15% when rolling the throttle on.

[sdsteven]

Spike,

Thank you for your help! Just to be clear, below detent (or engine idle stop) is when the throttle is rolled counterclockwise until it clicks, then released and rolled again until it clicks a second time? I saw a couple videos for a Bell 206 and I'm wondering if it's the same for a 205 or UH-1. Also, do you know if there's a Start Fuel switch on a 205 while starting?

- sdsteven

[SBuzzkill]

This is kinda sketchy dude.  Whoever is letting you test fly should be answering these questions for you.  To me it sounds like you’re trying to figure out how to steal one or something.

[sdsteven]

5 hours ago, SBuzzkill said:

This is kinda sketchy dude.  Whoever is letting you test fly should be answering these questions for you.  To me it sounds like you’re trying to figure out how to steal one or something.

What?! What's wrong with being curious? I want to be somewhat prepared for the test flight because I want to have some primer knowledge before test flying the 205 with my friend. This will also be my first jet powered aircraft so I don't want to be completely clueless either. I just want to show off some knowledge to my friend and act like I know some basics, that's all! Since I couldn't find the answer on the internet, it made me more curious. That would be absolutely stupid to attempt to steal an aircraft under airport security which also requires a key! Just dumb. You really shouldn't just throw baseless accusations out like that, it's wrong.

[SBuzzkill]

It’s not dumb or wrong at all.  This is a sensitive industry when it comes to security.  2 years ago a line tech stole an airliner and looped and rolled it around Puget Sound for an hour.  It all started with him getting familiar with the start procedure.
 

https://en.wikipedia.org/wiki/2018_Horizon_Air_Q400_incident

 

He stole an airliner from a busy, well secured airport.  Assuming you have a plan for stealing the key and accessing the aircraft your last barrier is the start procedure.  Maybe you are a disgruntled employee working for an operator.  Maybe you are who you say you are.  We don’t know, and it raises my eyebrows especially seeing this was your first and only post here.

 

Edited December 30, 2020 by SBuzzkill

[helonorth]

 

I wouldn't worry about how to start a 205. Nobody is going to let you anywhere near the starter until you own it. 

Edited December 30, 2020 by helonorth

[Eric Hunt]

The Allison/RR250 in the B206 is totally different from the Lycoming in the 205. With the 250, you have the throttle at shut-off, crank the engine to 15% N1, then snap the throttle to the idle position - the light-off and acceleration of TOT is a little disturbing to the novice.

 

The Lycoming, in our air force, was started from the idle position. The light-off was gentle, and acceleration gratifying.

 

Some people are worried that a total electrical failure after light-off meant the start and acceleration cannot be stopped, as you need power to activate the solenoid and close the throttle. Hence the "start below the idle stop" procedure.

[sdsteven]

2 hours ago, helonorth said:

 

I wouldn't worry about how to start a 205. Nobody is going to let you anywhere near the starter until you own it. 

Well my buddy knows I've flown a helicopter twice already, so he might let me. Doesn't hurt to ask.

[sdsteven]

4 hours ago, SBuzzkill said:

It’s not dumb or wrong at all.  This is a sensitive industry when it comes to security.  2 years ago a line tech stole an airliner and looped and rolled it around Puget Sound for an hour.  It all started with him getting familiar with the start procedure.
 

https://en.wikipedia.org/wiki/2018_Horizon_Air_Q400_incident

 

He stole an airliner from a busy, well secured airport.  Assuming you have a plan for stealing the key and accessing the aircraft your last barrier is the start procedure.  Maybe you are a disgruntled employee working for an operator.  Maybe you are who you say you are.  We don’t know, and it raises my eyebrows especially seeing this was your first and only post here.

 

I'm not an employee of any air sector. So anyone who is new is suspicious to you? We all have to start somewhere. Seems to me like you want to cause trouble.

[SBuzzkill]

I do indeed want to cause trouble.  I want to make it difficult for you to figure out how to start a Bell 205 without receiving proper instruction.  Your question is not typical of someone “starting somewhere” and you are not asking things that a typical newcomer would ask.  But hey, I’ve said my piece so I’ll leave you alone.

[Eric Hunt]

SDSteven, Don't worry about the negative people on this forum (and there are a lot of them). 

You spoke of 6600 N2 RPM, so it sounds more like a UH-1H, because the B205 used a dial with 100% RPM instead of actual numbers. Probably a better idea, but since 1973 I have had "full throttle, 6600 RPM" imprinted on the brain. 

If it is a Huey, there may be limitations on carrying pax - being a military machine - but a B205 doesn't have that problem. It also has a better tail rotor and (I think) dual hydraulics.

[helonorth]

5 hours ago, sdsteven said:

Well my buddy knows I've flown a helicopter twice already, so he might let me. Doesn't hurt to ask.

Oh, I thought you were inexperienced.

[Spike]

One detent. There is no clockwise/counterclockwise. It’s on or off. Like Eric said, it’s not the 206 so that procedure doesn’t apply. And, it’s not called a “jet” engine. It’s a turbine engine. I suggest you read the flight manual in its entirety before you jump in….

With that, I have no interest in why or what you’re doing. However, time with an instructor is the most appropriate way of going about it. Basically, it sounds like you should rethink your situation and stay within your lane ala; just because you can, doesn't mean you should.....

[Eric Hunt]

...and whatever else happens, leave the switch with the triangle head on it in the AUTO position. Don't even let your mate flip it to Manual, unless he is an experienced instructor on Hueys. Too easy to burn the back out of the engine with ham-fisted Robinson inputs.

[sdsteven]

7 hours ago, SBuzzkill said:

I do indeed want to cause trouble.  I want to make it difficult for you to figure out how to start a Bell 205 without receiving proper instruction.  Your question is not typical of someone “starting somewhere” and you are not asking things that a typical newcomer would ask.  But hey, I’ve said my piece so I’ll leave you alone.

I thought so. I already stated that I will receive instruction from my buddy who owns his 205, so improper instruction is not of concern. Have a nice day.

[sdsteven]

6 hours ago, helonorth said:

Oh, I thought you were inexperienced.

I'm inexperienced when it comes to jet powered helicopters, but I have experience with piston engine helicopters.

[helonorth]

5 hours ago, sdsteven said:

I'm inexperienced when it comes to jet powered helicopters, but I have experience with piston engine helicopters.

You said you had “flown a helicopter twice already” but okay.

[Wally]

11 hours ago, Spike said:

However, time with an instructor is the most appropriate way of going about it. 

Exactly correct and I can't emphasize the point enough. It's easy to learn "wrong" and hard to unlearn "wrong". Especially with as little applicable experience as you apparently have. I appreciate your wanting to learn, but procedures are best taught person to person and hands on the hardware. Unteaching is really, really hard in that scenario. You might think about why you asked experienced people here for information but felt it important to point out-

17 hours ago, sdsteven said:

Well my buddy knows I've flown a helicopter twice already, so he might let me. Doesn't hurt to ask.

Twice? I've got more experience than that crashing (more or less) helicopters. Some of the posters here shade that level of experience by magnitudes.

Systems, limits, structures, dimensions, etc. can be usefully studied before seat time.  If you have access to the aircraft, even better, the book data starts to be knowledge. If you have supervised access, you can have the thingamabob pointed out as part of the system. The very, very best way is a physical examination, first with a pilot and then with a mechanic, with panels open or removed. The two realms of knowledge are different...

Never stop learning, never stop self critiques and accepting criticism. And never, ever skip anything.

[sdsteven]

16 hours ago, Wally said:

Exactly correct and I can't emphasize the point enough. It's easy to learn "wrong" and hard to unlearn "wrong". Especially with as little applicable experience as you apparently have. I appreciate your wanting to learn, but procedures are best taught person to person and hands on the hardware. Unteaching is really, really hard in that scenario. You might think about why you asked experienced people here for information but felt it important to point out-

Twice? I've got more experience than that crashing (more or less) helicopters. Some of the posters here shade that level of experience by magnitudes.

Systems, limits, structures, dimensions, etc. can be usefully studied before seat time.  If you have access to the aircraft, even better, the book data starts to be knowledge. If you have supervised access, you can have the thingamabob pointed out as part of the system. The very, very best way is a physical examination, first with a pilot and then with a mechanic, with panels open or removed. The two realms of knowledge are different...

Never stop learning, never stop self critiques and accepting criticism. And never, ever skip anything.

Thank you for your insight!