Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Governor
#11
Picture is the last one in the album, I 'm not sure of the href parameters to include it in the post.


Attached Files Thumbnail(s)
   
Reply
#12
Good idea Hoyt, but it wouldn't be the governor. If the engine is producing full power and the rotor speed is decaying a rotor speed sensor could activate a motor and spring to put a downward pressure on the collective, kind of like the way an autopilot turns the wheel in a conventional aircraft. The pilot could, of course just pull harder on the collective if his/her actual intent is to stall the rotor. Once the rotor speed returned to the correct speed the additional tension would be relaxed. In the case of rotor overspeed the governor will drop the engine power appropriately. But if the pilot is headed down too fast, and that's whats causing the overspeed then, again, a separte system would need to be employed.
Reply
#13
You remind me of a point Ray Prouty made to me once about too much computer control -- the moral of the story is that the pilot must always
be able to override automatic controls -- I think Airbus had software that would not allow control inputs that would overstress the airframe,
however if you're heading toward a cliff at full speed, you'd rather bend the wings than smash into the cliff! (Ironically, I'm currently employed
to write software for the Airbus A400M heavy lift aircraft avionics ).

Countering that, however, is something I learned in servo theory classes (I'm an EE): For military fighters (ground hugging), the computers calculate the optimum path
to go from point A to B. It turned out from the math that if you're flying straight toward a cliff, the optimum path is to dive then climb so you can
be vertical as you approach the cliff, but the pilots freaked out about diving in front of a cliff. I don't know if the software people or the pilots got the last word
on that one, I suspect the software won in this case.

Hoyt Stearns
Scottsdale, Arizona US

http://HoytStearns.com
Reply
#14
Hoyt A. Stearns Jr. - 5/29/2009 3:57 PM

Good thoughts!

Although this is probably not at all practical, I'm thinking the ideal governor would also be able to put pressure on the collective and stick
such that it would lower the collective once full engine power was reached, and if the helicopter was cruising fast, easing back on the collective to
slow it down to the optimum speed. Also if the rotor overspeeds, reduce power and raise the collective a bit. All of this overrideable by the pilot of course.

Hoyt Stearns
Scottsdale, Arizona US
http://HoytStearns.com


Hoyt,

I was avionics on CH53's for 5 years, and what you are asking for would be near to impossible on the Mosquito. First there is little room for the system. Second the processing power (and programming) is very sophisticated. The system would be in the range of $4000-$50,000 depending on the designer/builder.

You are basically asking for AFCS, which performs the quoted actions. I do not think a safe system would be built which would be economical.

These are my opinions only,

James L
Reply
#15
maybe its just me, I kinda like twisting that throttle. Im building a turbine so this is not an issue to me anyway but here is my idea on the two stroke govornor issue. I like the governor idea, dont get me wrong, and on the corporate turbine ships I have flown there is no other way to go, and like someone else said, the R22 has a decent system for a piston helicopter. But something simple that helps a bit that would be alot easier to make than a governor would be a simple friction system. I have most of my piston time in Schweizers, and for any one that has flown a 269/300 series is aware of the simple system this helicopter has. It does not have a govornor, but it is considered "semi correlation". In other words it gets it some where close but you still have to twist it to keep the rpm within limits. Now with the friction system that the Schweizer has, it does enable you to somewhat relax a bit when you have the collective set for a certain flight phase, say cruise flight. By setting a BIT of friction ( not to much you still need to override it if need be! ) you can keep the rpm close and the throttle close. Like I said its not perfect nor does it act as a govornor, I'm well aware of that. But what it does do is do in a smaller way is help ease pilot workload, the same thing a govornor is intended for. I have flown the Schweizer on some long legs and if I was needing a bit of a break, or need to grab a chart, whatever, by using about half collective and throttle friction, I could in that flight phase take my hand off for the short while to do what I needed to do and get back on colective as soon as practicable. I also believe on the ground it would ad alot of saftey. Anyway, just a small simple idea to help ad to the govornor. Ultimatley the govornor is the way to go, but maybe this could be simple small step that won't require the engineering that the govornor will. But like the rest of you guys, if a good dependable govornor gets developed for the 2 strokes, Id have one!!!!!!!
Reply
#16
RSM,

I'm not a chopper pilot per se, but do believe a governor is a good item to have. I do think any pilot should learn to manage the throttle, but after that is mastered a governor for long flight times would be welcomed.

Any other automatic system though is basically unfeasible. Moving the collective or cyclic involves mechanics, and mechanical coupling, which adds weight and complexity. I'm not saying it can't be done, but economics wise, I do not think it is sound.

I am glad Tom took the governor and ran with it. It is, what I consider, a perfect match to the Mosquito.

I hope to see it go to market.

James L
Reply
#17
In response to James L, I never said the govornor wasn't a good idea, its a great idea. What I was explaining very clearly was a friction system would be something simple to work at helping reduce some pilot workload, period. They are two different ideas, and the friction idea does not make a substitute for a govornor, just something that could help get closer in the mean time since we don't yet have a good govornor option for the two stroke. It doesn't correlate or compensate, it just keeps it where you last set your rpm. Very primitive and simple, but it is better than what we have now, thats all I was saying. Just trying to give a PILOTS point of view for some that hadn't thought of a simple alternative.
Reply
#18
It's sounds to me what you guys are really talking about is not a govenor but more precisely a corelation device.
Reply
#19
Not really what I was explaining but ya the 269 series does have a correlation device that is correct but not what I was explaining. I was describing the friction. In talking about the correlation device that may too be another option. But what most seem to want is fully operational govornor. That would be great, but like James L said the complexity of it is just that, complex. I however do think it can be done, how I don't know. I am pilot trying to learn the building side, not a builder trying to learn the pilot side. I do know a governor would be more complicated to make, but with all the great minds here Im sure it can be done. Im up for any option that works, and I was just bringing another simple idea to the table
Reply
#20
Hey Guy's,
Every Mosquito that I have ever flown already has a Friction device on the throttle and also a really good correlator to help maintain your rpm for you. I use them all the time and the friction on the throttle does help reduce the pilot work load. Does someone out there have a Mosquito Helicopter that does not have these features. If you do, you did build your ship according to the approved plans.
Andy
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)