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Robinson Helicopter Questions


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Heli-o,

I was reading on an other post here and ended up on the FAA web site reading about the original investigation into this bird, this brought up a couple of questions to me.

 

In the intro to the report it stated there was an option for a more conventional cyclic approved.

-Why not use it considering that is one of the first complaints I hear about it. The controls cant add that much weight or complexity as they say (defenders of the bird) it may. Personally the awkward feeling of it has me looking for schools with out it (Robinson). Would feel much safer with controls that my eventual CFI can take over easy when I learn what not to do. :unsure: on accident.

 

Low Rotor inertia

-I was reading the MR blades only weigh around 12lb?? apiece? Couldn't Robinson develop / produce blades with weighted tips? With minimal weight increase you could effectively increase rotating mass and inertia. To me if the hinges could handle the added mass it could be a retrofit as the old blades fall out of service.

 

This covers all the major complaints I've read on this bird, other than these I read nothing but good. It seems they need to do some minor improvements and not just say you need more training and just deal with what is.

Take that back, the mast bump problem but other craft with this type of mast have it too.

 

Thanks in advance,

Dave

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robinson has been using tip weights in thier blades since the 80's. as for blade weight, each blade weighs somewhere in the ball park of 25 lbs.

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Heli-o,

I was reading on an other post here and ended up on the FAA web site reading about the original investigation into this bird, this brought up a couple of questions to me.

 

In the intro to the report it stated there was an option for a more conventional cyclic approved.

-Why not use it considering that is one of the first complaints I hear about it.

There's nothing wrong with the cyclic stick -- it just looks goofy, but it's easy to get used to... I heard that there was a more "normal" center stick STC'd, but have also heard it's no longer available. AFIK, the cyclic has never been implicated in an accident...

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AFIK, the cyclic has never been implicated in an accident...
That's subject to debate - there's no telling how many "instructor's failure to take proper remedial action"- kind of accidents may be attributable to that cyclic design. However, just like many of the design choices made by Mr. Robinson, believers support it staunchly, critics, well, criticise, and students and CFIs just put up with what they feel they must for the next 1,000 hours.

 

As Frank Robinson will be the first to tell you, all design choices and modifications to design on the R22 and R44 are approached in this order-

 

Top priority: reduce the cost of manufacture (as long as it doesn't get heavier or weaker),

#2 make it lighter (as long as it doesn't get more expensive or weaker).

 

From a manufacturing-is-your-business approach, this makes sense (and dollars too).

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  • 2 weeks later...

DMC- Dave...you can't just add weight to the blades to add inertia. That weight requires more power to turn that blade, and more power means a bigger engine, which means a bigger structure to support it and then bigger fuel tanks to get the same range. Oh, did I mention that bigger engines cost more money? Pretty soon your flying a S-58 !

 

The rotor is what it is, low enertia, light, lower cost. Light rotors can recover rotor RPM quicker, but they lose it faster as well. The R22 was known for low rotor RPM problems, but most of those are really related to bad piloting, and the fact that dropping the collective only causes the correlator to reduce the throttle to the engine at a time when you are trying to increase RPM....you have to drop and roll the throttle on together to recover...anyway, the governor takes all the guesswork out of that now.

 

As far as the cyclic. Get over it. Somewhere I heard the T handle vs. conventional cyclic saved about 12 pounds off the bird. I am not a huge R22 fan, even though it is what I fly 90% of the time. The cyclic doesnt bother you until you get about 6'-3" or so.....I'm 6-5 so my knees can get in the way sometimes! Otherwise it feels like the same control as other ships. The R22 is a unique ship to fly, with a unique set of issues to deal with, I would suggest you spend at least some of your early flight time in one.

 

Good flying=-

 

Goldy

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[

quote name='Goldy' date='Jun 30 2006, 23:11 ' post='31157]

DMC- Dave...you can't just add weight to the blades to add inertia. That weight requires more power to turn that blade, and more power means a bigger engine, which means a bigger structure to support it and then bigger fuel tanks to get the same range. Oh, did I mention that bigger engines cost more money? Pretty soon your flying a S-58 !

 

WOW, An S-58, That would be nice! Now I'd just have to win the lotto to pay for fuel! (It would make a great camper) lol

 

The rotor is what it is, low enertia, light, lower cost. Light rotors can recover rotor RPM quicker, but they lose it faster as well. The R22 was known for low rotor RPM problems, but most of those are really related to bad piloting, and the fact that dropping the collective only causes the correlator to reduce the throttle to the engine at a time when you are trying to increase RPM....you have to drop and roll the throttle on together to recover...anyway, the governor takes all the guesswork out of that now
.

 

Thanks for the input, sometimes I over think things and forget the simple probs, but to my thinking that is why you have someone re-check yourself, hence the development of QCs and teams!

 

As far as the cyclic. Get over it. Somewhere I heard the T handle vs. conventional cyclic saved about 12 pounds off the bird. I am not a huge R22 fan, even though it is what I fly 90% of the time. The cyclic doesnt bother you until you get about 6'-3" or so.....I'm 6-5 so my knees can get in the way sometimes! Otherwise it feels like the same control as other ships. The R22 is a unique ship to fly, with a unique set of issues to deal with, I would suggest you spend at least some of your early flight time in one.

 

Good flying=-

 

Goldy

 

I plan on getting Robie training, I just have a small reservation with it as an initial trainer. I feel that the cyclic design adds time to the FIs response. It seems the Robie was designed an inexpensive personal transport and light commercial witch is a roll I see it filling very well, but not well laid out as a trainer. If it works out, I'd like to get my PPL then switch over, by then I believe I'd be well past the initial mistakes that cost. It is just an opinion, no different than the GM vs Ford vs Dodge. (Witch can be very heated)

 

Safe flying to you and thank you,

Dave

 

PS.

I'm 5'7" and I never seem to be able to reach anything!

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I plan on getting Robie training, I just have a small reservation with it as an initial trainer. I feel that the cyclic design adds time to the FIs response. It seems the Robie was designed an inexpensive personal transport and light commercial witch is a roll I see it filling very well, but not well laid out as a trainer.

 

The R-22 is a great personal helicopter, however it makes a terrible initial trainer. It is however inexpensive, which is why 90%+ of flight schools use them.

 

I did my initial training in the 300CB, then moved over to the R-22, and I've taught in both.

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DMC- Dave...you can't just add weight to the blades to add inertia. That weight requires more power to turn that blade, and more power means a bigger engine, which means a bigger structure to support it and then bigger fuel tanks to get the same range. Oh, did I mention that bigger engines cost more money? Pretty soon your flying a S-58 !

Actually, you do just add weight to the blades to add inertia, the closer to the blade tips the better. It does not take more power to turn the blade if there are no aerodynamic profile changes (span, chord, or airfoil section), though it will take longer to come up to speed with the same power input. The structural changes to handle the additional stress are in the blades and the head; nothing from the flapping hinge down would need to change. There would be an increase basic empty weight and a corresponding decrease in useful load.

 

The R22 has slightly over half the main rotor inertia of the 300CBi, yet weighs 78% as much full gross. Ten to fifteen pounds of well-placed additional main rotor structure would have greatly improved it's autorotational characterics. Alas, it's not going to happen at this stage in the product life cycle.

 

Bob

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