Helicopters without correlators?
 

Hi

Are/were there any helicopters built without a power correlator? What were they like to fly?

The Enstrom 280C for one. Flies beautifully.:ok:

As far as I know Bell 47,so I've been told ,never had the pleasure of flying one but is on my list.
R

@ Chopjock,

Are you talking about corellator or governor? I fly the Enstrom 280FX and it certainly has a correlator. No governor, though...

Yes, the Bell 47 did not have a governor to correlate the pitch-setting with the required engine power-setting.
I took my first helicopter hours at the controls of this historical machine decades ago.

I'm pretty sure the Bell 47 has a correlator. Have a look at the pilot's side of the aircraft, you will see a thin box with a rod going forward to the cabin.

My memory is shot but I am sure this is a correlator box.

Both the Enstrom 28A and the 280 and 280C did not have any throttle correlation. The 28F and the 280FX both have a mechanical throttle correlator.

The Bell 47 does indeed have a correlator, but the Hiller 12E doesn't

phil

Thanks for answers! Will have to try it out someday :)

Next Tuesday it will be exactly 39 years since I first flew a Hiller 12E and, even without a correlator, it was a great machine - 50 hours later I 'progressed' to the Whirlwind 7, which did have a correlator, but wasn't half as much fun.

Are there any machines, other than Lynx, that have correlators from pedals to throttle/collective (governed or otherwise)?

I design, build and fly UAVs. The tail rotor is correlated to the throttle. More left pedal, more throttle, less left pedal less throttle. We also correlate pitch and tail rotor, particularly useful when climbing and descending vertically.

Probably all with FADEC!

To be technically correct every Enstrom prior to the F28F/280F does not have a correlator. It is also the only piston helicopter currently in production that does not have an automatic mixture control, so you can lean the mixture during flight.

Of the 4 hiller 12E's i've flown, all had correlators......none had governors....other than the soloy turbine conversions but thats a different story. As mentioned there is a box linked in to the collective and throttle cable. Locations vary by model but it is generally the size of a paperback book. The two both work towards the same goal but function differently and i think that may confuse some that are not familiar.

Governor senses RPM and adjusts automatically. Usually no manual throttle adjustment necessary.

correlator adjusts throttle based on the position of the collective. It gets the rpm in the ball park but manual throttle "fine tuning" is more or less required.

Interesting activity, Chopjock. I'd like to learn more about this. I'm guessing this is electronic if you account for the TR power-airspeed curve? Which chip/software do you use BTW?

Agreed, RVDT. Talking to some of my colleagues with helicopter control system experience, it gets to the point that mechanical systems get so complicated that you start to wonder whether the FMEAs can account for all the linkages! Of course we all know that software never goes wrong. ;)

Real men do not need correlator's !!!!

Graviman
Yes electronic fly by wire servo system. Adjustment and set up by mark one eyeball.:)

All of the Bell 47's & the one Hiller 12E I've flown had one. Some much better than others...

I learned to fly in an Enstrom F28A. No correlator. It was easy to learn, and I figure if I can learn it anybody can. It became very natural to twist the grip as I pulled or dropped collective, also had to pull in a little more for a left pedal turn and roll a bit out for a right. I do agree there was no automatic mixture control though we always left it rich and stayed low. I have a little time in a Schweizer 300CBi, and that sure looked like a manual mixture control to me. I'll check with one of my buddies and report back if I'm wrong.

-- IFMU

My enstrom 28a/c had a corrolater it was the mark 1 version in consisted a arm and wrist it worked well from memory

The H269 Cbi has a manual mixture control. You can lean off in flight but I never touch it! Its either In or Out!! With Fuel prices the way they are at the moment I have been tempted though!

The Whirlwind Mk10 had an auto system for it's gas turbine engine. This could be disconnected in case of gov failure, or when the bast@@d of an instructor was feeling mean. There was then direct control from throttle on collective to engine. Needed some practice, but quite easy to do quickstops etc.
Most of the Bell 47s I flew had dreadful correlators, and all different - this meant that on some aircraft the throttle had to be opened as the lever was raised - on others, it had to be closed - great fun!

heliboy99,

Can you quote the procedure for leaning from the flight manual?

oldbeefer:
I was told the Bell 47 incorporated an analog randomizer, as opposed to the newer digital, or perhaps even fiber optic randomizers.

I presume if you were to lean fuel mixture in a 269cbi you would need a fuel flow meter and an EGT gauge, like in the Enstrom?

I have one or two hours in 28As. The manual throttle is fine. You can drop the revs down a bit in the cruise to save a bit of fuel- about a gallon/hour is easy - more is possible. You can wind it up to the top of the green if you think you might need a bit of extra oomph for your next manoeuvre. It becomes totally automatic. I bet Dennis K doesn't even notice the manual throttle when he flies his display in a 28A. Correlated Enstroms have their own peculiar quirks - its not a governor. You get used to that too but for me, I prefer manual.:ok: One of my aircraft has a vernier mixture control, EGT, CHT and fuel flow meters, calibrated injectors and runs quite happily at 9 gallons per hour. The other without all the kit runs at 12GPH!

I love watching pax who fly when I do the big pull on the lean knob.:uhoh:

No correlation
 

I fly a '56 Hiller 12C which has a very crude correlator on the pitch and no governor

The Brantly B2-b is also permitted to be leaned in flight as it has a vernier, fuel flow and CHT although it does have a rather decent correlator. :ok:

Shawn
 

Arf Arf ;)

Thank goodness I never had to deal with/ learn from one of those instructors Oldbeefer describes... :ok:

Randomizer is it.

apart from the G2's which were quite good, i don't understand how one can use the two words correlation box and Bell 47 in the same sentence.

especially when one worked for a dude who reckoned that correlation cams, throttle shaft unis and slides were a waste of money and real pilots didn't need 'em as brand new every second day of the week, which always somehow rolled into years. They - cost too much money - or some other flippant excuse.

engineers were judged as being good; if they were an ace on the mystical secret business that went on inside the throttle box, or cam box as we called them at times.

then of course there was the secret 47 business all about the blue nut, that was issued in hushed whispers, just to help out with the power now and then, but could easily account for 45" if not careful.

but now we have this idiot turnout on the Robinson's which on a gusty day sends a 3" surge through the drive system every 2 - 3 seconds. turn it off and things are steady.

Thud and Blunder
 

That is SO unkind! No further chance as I have (finally) retired from flying.

S'alright, OldB - I was only referring to the specific "Bast@@d" ones you mentioned in your post! Had it not been for all the others, I very much doubt I'd still be plugging my way towards helicopter nirvana. Such a shame that the Committee Against Aviation still deem that to happen at age 60 for those of us who don't fly with a Co, eh?

Oh Lordy - I flew the Hiller 12e, Bell47, Whirlwind 3/7/9 and never knew that there was something called a "correlator" in the system. I knew that it/they had an anticipator that probably was the same thing - but was it?

I suspect that correlator is from the land of BP bashing and therefore of little substance.

Am I right or am I older than I think I am..........?

Ready for incoming - glass of rose (insert accent as desired) in hand - sitting in glorious sunshine in idyllic garden in Somerset.:ok: