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-   -   Bell 222 collective - is it different? (https://www.pprune.org/rotorheads/278648-bell-222-collective-different.html)

Tickle 4th Jun 2007 00:40

Bell 222 collective - is it different?
 
Hello heli pilots,

I am just an enthusiast and I've just seen the Airwolf film again after many years. I've been doing some research and it seems that the unusual collective control as featured in the film actually exists in the real 222. Interior photos are hard to come by but I did see something that resembled it.

Does anyone fly one and how do they find it compared to conventional collectives? It seems rather cumbersome and does it present any unique aspects?

Thanks,

Andrew.

Aesir 4th Jun 2007 01:23

I have a bit over 1000 hrs in the 222 and I absolutely love the collective. I can´t understand why every manufacturer doesn´t use this.

The handle feels natural to your wrist position and the movement is more fwd/back than up/down. Also the switches on the coll control panel are very accessible and easy to use.

The 214ST also has the same coll grip.

Bravo 99 4th Jun 2007 08:42

I fly the B430 ( 222 s) big brother the collective is nice both throttles are twist grip and for throttling up from ground to flight is smooth with both engines torque matched all the way up ( if you do it right) . it looks cumbersome to start with but when you get used to it it is simple and logical the way it is laid out.

let me have your mail address and i will forward to you the cockpit layout.

Sincerely

B99

NorthSeaTiger 4th Jun 2007 11:36

http://www.airliners.net/open.file?i...ext_id=0940099

Robbo Jock 4th Jun 2007 12:00

With the axis of rotation of the throttles being parallel to the axis of rotation of the collective, is there a tendency to roll throttle on/off when moving the collective?

Tickle 4th Jun 2007 12:17

Thanks for posting the very clear picture, Tiger. It doesn't look as big as it did in the show.
I've only once seen a Bell 222 for real here in Australia and I thought it was a Huey going over because of its sound. It was very, very high up and I zoomed right in with a camera, blew it up on the computer and couldn't believe my eyes that it was a 222, right out of my childhood fantasies of flying Airwolf. Hearing its true sound shattered the illusion, never realised it would sound like a Huey with those big two main rotor blades.

Edit: Oh yeah, I wanted to ask. Does the left-side pilot have a dificult time sliding in with that thing mounted at the front of the seat?

chuckolamofola 4th Jun 2007 14:46

The left side has a standard collective stick, which is removable along with the cyclic when flying single pilot.
Chuck

Aesir 4th Jun 2007 17:59


With the axis of rotation of the throttles being parallel to the axis of rotation of the collective, is there a tendency to roll throttle on/off when moving the collective?
No there is absolutely no tendency to do that. The throttles are also perfectly placed and have only about 90-100° of travel if I remember right. They have adjustable friction but there is no concern that they will roll off when moving collective.

It´s very good to have the throttles on the collective in case of emergency particularly as the 222 series are designed as single pilot aircraft and are very good to fly single pilot even IFR.

I´d like to add that the 430 has a very smart "stick shaker" system on the collective which activates when nearing Q 100%.


Fly smart-Fly Bell :ok:

rotorrookie 4th Jun 2007 21:24


No there is absolutely no tendency to do that. The throttles are also perfectly placed and have only about 90-100° of travel if I remember right. They have adjustable friction but there is no concern that they will roll off when moving collective.

It´s very good to have the throttles on the collective in case of emergency particularly as the 222 series are designed as single pilot aircraft and are very good to fly single pilot even IFR.

I´d like to add that the 430 has a very smart "stick shaker" system on the collective which activates when nearing Q 100%.


Fly smart-Fly Bell
I can sence the regrets in Aesir words because his rotors turn in the "wrong" way theses days;)

Robbo Jock 5th Jun 2007 11:48

Thanks Aesir. I assumed there wouldn't, but just thought I'd ask.

NickLappos 5th Jun 2007 20:09

There is a compelling reason for the fore and aft motion of the 222's collective pitch that vastly outweighs the pilot preference - collective bounce.

My guess is that the 2 bladed rotor on the original 222 is of the family that has a significant "bounce mode" where the natural frequency of the collective pitch system (mainly in the rotor head) is very low, and naturally tunes to the pilot's arm/hand frequency. This is quelled on the AH-1G with a friction collet that clamps the collective to the main shaft and forces the servos to fight the friction. The friction strongly damps the collective bounce, but it adds weight, complexity and requires stronger servos than otherwise needed. A big contributer to the collective bounce propensity is the pilot's motions that get amplified by the rotor's natural frequency.

The novel collective pitch lever that has no up/down motion is a wise solution to the pilot end of the problem, IMHO.

chuckolamofola 6th Jun 2007 01:13


My guess is that the 2 bladed rotor on the original 222 is of the family that has a significant "bounce mode" where the natural frequency of the collective pitch system (mainly in the rotor head) is very low, and naturally tunes to the pilot's arm/hand frequency.
Nick,
If that was true then why did Bell use a standard collective installation for the co-pilot's stick's on both the 222/230/430 and 214ST? If it was so problematic, wouldn't the co-pilot suffer from the same issue? I've flown the 222 from the left seat and never had a bounce problem.
BTW, there is a collective collet where the friction is set on the mast.
Chuck

NickLappos 6th Jun 2007 05:24

chuck,
The idea is that the collective improves the situation, not that the aircraft has a bounce problem because of it!

Graviman 7th Jun 2007 11:35

Why not just replace collective friction with a small hydraulic damper? With well designed valves these give almost ideal force/velocity characteristics. The rate could be OEM optimised to damp out any vertical PIO, without any significant servo hindrance (up to reasonable frequency).

The following may be of interest to any OEM control system designers:
http://www.lord.com/tabid/3318/Default.aspx

John Eacott 7th Jun 2007 15:58

The Sycamore had a similar lateral throttle: only 55+ years ago :cool:

Mind you, there was also only one collective, so the left seat needed the throttle to hold onto when it was his turn......

SBoyer 19th Jun 2007 22:40

Some info on the 222/230/430 designs
 
Having been a factory pilot with Bell since the first 222 hit the flight line, I can pass on a little info about the collective and throttles arrangement.

In pre-design in the early 70's the target market was going to be the bizjet community and the set up had the eye appeal that the marketing VP wanted.

Along the same thinking, several of the early prototypes had only a single right side cockpit door, an idea later scrapped when emergency exiting became painfully obvious, but that's another story.

Early prototypes also, in the same vain as several bizjets and turboprops, had T-tails. Unfortunately, because it was very eye appealling, the test flights showed poor stability so the horizontal elevators were chosen instead.

Lastly, the collective design with the throttles at the top of the stick and and the various switches positioned aft toward the middle of the tube allowed us to get by with a built in friction of about 5-6 pounds as opposed to the 10-12 that the 212 and 412 required. Hence it's a lighter feeling touch that pilots prefer and without an excessive amount of weight out on the long arm, the creeping collective and/or bounce could be kept to a minimum.

By the way, the stick shaker in the 430 only works on the pilot's side.

Brilliant Stuff 20th Jun 2007 08:20

Thanks Sboyer for posting on here it is really valuable to have info from the horses mouth so to say. :ok:

NickLappos 20th Jun 2007 11:22

Thanks, SBoyer. I think when you say, "the collective design ...... allowed us to get by with a built in friction of about 5-6 pounds as opposed to the 10-12 that the 212..." this means also that the for and aft movement of the Pilots collective meant that you only needed the friction for the CP collective, and thus could get away with half the "normal" value.

Makes good sense. I always liked the 222 collective.

BTW you guys were the enemy back then, I was the chief pilot and demo pilot on the S76! I recall the emergency exit story we test pilots swapped back then!

toolguy 20th Jun 2007 11:43

222 Collective
 
At FSI Bell 430 school I quickly adapted to the collective and throttle grip position. I did have a problem when switching seats and having to perform emergency throttle control on the CP collective. It seemed that the CP stick was very short and I had a hard time twisting the grip. Anyway, coming from mostly a Sikorsky background, I found the 430 collective easy to use and controls easy to operate.

IHL 21st Jun 2007 02:45

For me the collective was very intuitive and required NO getting use to.

What I really liked about the 222 collective mounted throttles-especially for one converting to a twin for the first time-is the throttle layout: The left engine (#1) is on the left side and the right engine throttle (#2) is on the right side (go figure).

I know it sounds rudimentary but I have seen pilots get it mixed up on the 212 where the left engine throttle is on the bottom and the right is on the top (if I remember correctly).

It’s been 15 years since I’ve flown one [222]; it was a good little IFR platform though it really sucked on power, you didn’t vertical out of anywhere!


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