So.....

[Fox6]

Fox, Is that the Brantly B2 you mention in your profile? If so can you answer some questions about it?

Cougar, sorry not the Brantley B2. The Aerospatiale AS350-B2 (American Eurocopter now). I've never been in a Brantley. Saw one at HAI and it was a strange looking bird. You don't hear a lot of people training in those for some reason, but they might be great, who knows.

 

[mattpilot]

You don't hear a lot of people training in those for some reason, but they might be great, who knows.

Maybe because it is the most ugliest helicopter in existance?

Looking at the B2, i can see why someone would come up with the theory that "helicopters can fly, because they are so ugly the earth repels them"

 

[Fox6]

Well, I wasn't going to say it....... hopefully there is not too many offended B2 drivers out there., but it is ugly.

 

[cougar6903]

Well, I wasn't going to say it....... hopefully there is not too many offended B2 drivers out there., but it is ugly.

It looks to me like one of the only choppers i'd be able to afford to own one day. They sell for around $50k with good times. Looks like there back in production now. Most of the pilots selling them only have a PPL so I'm assuming there not amazingly hard to fly.

 

[mattpilot]

You can buy a B47 D model for 60k from my school, or a G model for 80K, or a G2 for, i think 100k. No real difference between the D & G model, but the G2 has a bigger engine & an extra seat (but no dual controls).

Or, if you want to go really cheap, buy a Safari kit helicopter - looks just like the B47, but smaller

 

[GVFlyer]

If your "in autorotation", (the way I understand it) then there should be no power therefore no torque applied to the transmission, therefore no spinning. If anything, you would have transmission drag which will actually tend to turn the helicopter the opposite direction as torque. Looking at your flight time and aircraft flown, you may know something I don't. Did you mean that 60 knots in POWERED flight will mainain some semblence of directional control due to the vertical stabilizer (asymmetric in the Astar) taking the load off the tail rotor.
I've never had one myself. Had a friend lose a tail rotor in an OH-6 while in a OGE hover. He said that it was extremely fast and was on the ground before he knew it. He instinctively got the power out though as fast as he could and hit upright before rolling over.

With a tailrotor failure some helicopters will streamline if sufficient airspeed is achieved and some measure of directional control will be maintained. In others this will not occur. I have included a representative Emergency Procedure for a tail rotor failure from the first helicopter -1 I found at my hacienda.



9-19. COMPLETE LOSS OF TAIL ROTOR THRUST.

This situation involves a break in the drive system, such as a severed driveshaft, causing the tail rotor to lose power.


a. Powered flight.


(1) Indications:


(a) Pedal input has no effect on helicopter trim.

(b) Nose of the helicopter turns to the right (left sideslip).

(c) Left roll of fuselage along the longitudinal axis.




NOTE


Degree of roll and sideslip may be varied by varying throttle and/or collective. (At airspeeds below 40 knots, the sideslip may become uncontrollable, and the helicopter will begin to spin on the vertical axis.)


(2) Procedures:


(a) If safe landing area is not immediately available, continue powered flight to suitable landing area at or above minimum rate of descent autorotational airspeed.

(b) When landing area is reached, make an autorotative landing.

(c) Use airspeed above minimum rate of descent airspeed.

(d) If landing area is suitable for run-on landing, touch down above effective translational lift.

(e) If run-on landing is not possible, start to decelerate from about 75feet altitude, so that forward ground speed is at a minimum when the helicopter reaches 1 0 to 20 feet. Execute the touchdown with a rapid collective pull just prior to touchdown in a level attitude with minimum ground speed.



b. Power off. (Autorotation).


(1) Indication. Pedal input has no effect on trim.

(2) Procedures:


(a) Maintain airspeed above minimum rate of descent airspeed.

(b) If run-on landing is possible, complete autorotation with a touchdown airspeed above effective translational lift.

(c) If run-on landing is not possible, start to decelerate from about 75 feet altitude, so that forward ground speed is at a minimum when the helicopter reaches 1 0 to 20 feet; execute the touchdown with a rapid collective pull just prior to touchdown in a level attitude with minimum ground speed.



GV









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[helimech]

First of all, back to Matt's original question.....I've flown both the R22 and Bell 47 and have quite a bit of time in them. They both have their strong points. The Bell 47: Extremely stabil aircraft!! Very forgiving, even with loss of tail rotor thrust (IF!!!!) you have metal blades!!! If not and you have the wood blades, well then you have to be very cautious your last 75 feet down with your airspeed, but it is definately do able, I used to do it all of the time (on purpose and not on purpose). The R22 on the other hand... you have to watch everything a little closer and have to be right on it when you lose anything... engine, runaway governor or tail rotor if at low airspeeds. The only thing i can suggest Matt is to go up with an EXPERIENCED instructor on the R22 and he/she will show you exactly what the aircraft can and can't do... for the commercial checkride in any of the Robby's you have to demonstrate everything!!! Low G pushovers, loss of T/R, engine, electrical system, everything!! They are both fun aircraft to fly. As for the 300, I haven't had very good luck with those! All the ones I ever fly are because they were rolled over and have just come out of maintenance and they always suck after that!!! But try as many as you can!! Just to get your license out of the way, finish up with the Bell and then transition over to the Robinson. One of my customers told me the other day, that they would rather hire somebody with 200 hours in an R22 then somebody who has a 1000hrs flying any type of turbine, because you definately are on your toes when you fly an R22....

 

[mattpilot]

thx helimech - very useful advice!

I'm also glad i got you to post your first post in my thread

 

[GVFlyer]

First of all, back to Matt's original question.....I've flown both the R22 and Bell 47 and have quite a bit of time in them. They both have their strong points. The Bell 47: Extremely stabil aircraft!! Very forgiving, even with loss of tail rotor thrust (IF!!!!) you have metal blades!!! If not and you have the wood blades, well then you have to be very cautious your last 75 feet down with your airspeed, but it is definately do able, I used to do it all of the time (on purpose and not on purpose).

How would you simulate (on purpose) a loss-of-thrust tailrotor failure? Put in full right pedal and hope for the best? And maybe it's just me, but I don't think I'd be flying a helicopter that had me doing tail rotor failure emergency procedures, "all of the time (...not on purpose)."

The R22 on the other hand... you have to watch everything a little closer and have to be right on it when you lose anything... engine, runaway governor or tail rotor if at low airspeeds. The only thing i can suggest Matt is to go up with an EXPERIENCED instructor on the R22 and he/she will show you exactly what the aircraft can and can't do... for the commercial checkride in any of the Robby's you have to demonstrate everything!!! Low G pushovers, loss of T/R, engine, electrical system, everything!! They are both fun aircraft to fly. As for the 300, I haven't had very good luck with those! All the ones I ever fly are because they were rolled over and have just come out of maintenance and they always suck after that!!! But try as many as you can!! Just to get your license out of the way, finish up with the Bell and then transition over to the Robinson. One of my customers told me the other day, that they would rather hire somebody with 200 hours in an R22 then somebody who has a 1000hrs flying any type of turbine, because you definately are on your toes when you fly an R22....

Let me see if I understand you correctly, you are maintaining that the Robinson R22 is somehow better than other helicopters, particularly turbine helicopters, because it is difficult to fly?

GV

 

[Fox6]

t/r failure

How would you simulate (on purpose) a loss-of-thrust tailrotor failure? Put in full right pedal and hope for the best? And maybe it's just me, but I don't think I'd be flying a helicopter that had me doing tail rotor failure emergency procedures, "all of the time (...not on purpose)."


Our company had an instructor that would simulate a tailrotor failure in a hover in a OH-6. Basically by releasing pedal pressure on the left pedal. The recovery was to initiate a hovering auto by rolling the throttle off. He was the only instructor out of five that would do this though. His exprience level was high enough though to get away with it. This is only possible with a collective mounted throttle however. In the BA-B2 Astar, the "fuel flow control" is on the floor and the procedure for tail rotor failure in a hover is to, and I'm paraphrasing this, maintain level and lower the collective until you contact the ground. Hopefully the rate of turn won't be too extreme with that big vertical stablizer on back, but I'll bet it 's still pretty ugly.

 

[HowlinMadMurdoc]

In Tulsa OK - $190/hr


still interested?

Dang, that's a lot for a 47 but nowhere near what WW Helos in East Troy, WI charges for their 47. Last time I checked, WW was getting $275/hr WITHOUT instructor for a 47G3. Yikes.

I remember 47D-1's with wood blades going for $100/hr with instructor. Of course, that was years ago.

HMM

 

[mattpilot]

I remember 47D-1's with wood blades going for $100/hr with instructor. Of course, that was years ago.

HMM

afaik, all 47's have wood blades. Sure hope none of them chip during flight

The 47G4 goes for $210/hr here.

They also had a cheap 206 - only $550/hr. But they sold it a few weeks ago

 

[HowlinMadMurdoc]

afaik, all 47's have wood blades. Sure hope none of them chip during flight

The 47G4 goes for $210/hr here.

They also had a cheap 206 - only $550/hr. But they sold it a few weeks ago

Don't quote me but I believe later 47 models had metal blades (ie G3 and later).

HMM

 

[helimech]

How would you simulate (on purpose) a loss-of-thrust tailrotor failure? Put in full right pedal and hope for the best? And maybe it's just me, but I don't think I'd be flying a helicopter that had me doing tail rotor failure emergency procedures, "all of the time (...not on purpose)."



Let me see if I understand you correctly, you are maintaining that the Robinson R22 is somehow better than other helicopters, particularly turbine helicopters, because it is difficult to fly?

GV

\

To simulate a tail rotor failure, yes you take out the tail rotor and hold it. on most domestic helo's along with some eurocopters, you stick the pedal to the right and hold it. What i was saying about doing it on purpose and not on purpose is that during training you HAVE to simulate loss of tail rotor and also what is called stuck pedal. and i also have lost tail rotor authority completely when i had a t/r driveshaft shear.
Now about the R22, no it is not a better helicopter than most, but you do have to watch everything a little more closely and be right on top of it if you ever lose anything, because it is so squirly. This is why a lot of operators like to see a lot of R22 time, because they know that you can probably recognize emergency's a little faster. No, R22 pilots are not better than other helicopter pilots, everyone that can hover, takeoff, and land a helicopter, without destroying the aircraft or scratching it, in my book is a good helo pilot.

 

[helimech]

afaik, all 47's have wood blades. Sure hope none of them chip during flight

The 47G4 goes for $210/hr here.

They also had a cheap 206 - only $550/hr. But they sold it a few weeks ago

Hey Matt, No, not all 47's have wood blades. The G3 on up and some late model G2's, the Soloy conversion, or any that have the new rotor head without the stibilizer bar, more than likely have metal blades. Wood blades are getting harder and harder to find, so everyone that is getting high time rotor heads will probably have metal blades installed with their new head. That is probably why your 47's are so cheap to purchase, because they haven't had the metal blades installed. I tell all my customers that ever look for a 47, make sure they have the metal blades or you will be spending a ton when it comes time to pull them, the only nice thing about wood blades is that they are not time life, they are on condition, which is a good thing and a bad thing.

 

[mattpilot]

or any that have the new rotor head without the stibilizer bar

Question about that...

whats the purpose of the stabilizer bar? I see that some helo's have it and some don't. Why would a helicopter designer put a bar on one but not on another helicopter?

As i understand it, a stabilizer bar is something Mr. Bell came up with to keep the plane of rotation more horizontal during crosswind operations. Correct? Whats the negative side effect? Only weight? Why don't all helo's have it if it improves stability?

 

[GVFlyer]

Question about that...

whats the purpose of the stabilizer bar? I see that some helo's have it and some don't. Why would a helicopter designer put a bar on one but not on another helicopter?

As i understand it, a stabilizer bar is something Mr. Bell came up with to keep the plane of rotation more horizontal during crosswind operations. Correct? Whats the negative side effect? Only weight? Why don't all helo's have it if it improves stability?

The stabilizer bar and the Bell 47 were developed by Arthur M. Young, a mathematician and philosopher who spent the last half of his life investigating the nature of consciousness.

In the late 1930s, he [size=-1]began a series of experiments with model helicopters that ultimately led to the design of the Bell-47[/size][size=-1] helicopter. After a lot of research Young invented a teetering rotor with a stabilizer bar. The bar had bob weights attached to each end and was directly linked to the rotor blades through the pitch control linkages. The idea was that if the rotor was disturbed in pitch or roll, the gyroscopic inertia of the bar could be used to introduce cyclic pitch into the main rotor system, increasing the effective stability.[/size]

Other manufacturers use other rotor designs to achieve stability.

The other enemy of helicopter design is vibration - a problem that the AH-56 Cheyenne could never solve. During UTTAS development both the Boeing and Sikorsky entrants to become the UH-60 encountered severe rotor vibrations. Although the Boeing was generally a better helicopter and employed more cutting edge technology, Sikorsky solved the problem first through use of a mast extension and was selected to build their version of the Blackhawk.

GV







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