I've got an interesting R22 question...

[budman]

My friend had this question on his CFI checkride but never gave me the answer and none of the CFI's I asked didn't know the answer. Ok here's the question.

Why does the IGE in the Beta and Beta II are different but the OGE is the same at max gross weight and standard day if the Beta II has more power?

 

Can anyone answer this. I really don't wanna give Franky a call at the factory but I just might have to I guess. Happy New Year everyone!!!

[Sparker]

Nice name drop.

 

Don't know....

[JDHelicopterPilot]

My friend had this question on his CFI checkride but never gave me the answer and none of the CFI's I asked didn't know the answer. Ok here's the question.

Why does the IGE in the Beta and Beta II are different but the OGE is the same at max gross weight and standard day if the Beta II has more power?

 

Can anyone answer this. I really don't wanna give Franky a call at the factory but I just might have to I guess. Happy New Year everyone!!!

 

 

I am not sure I understand the question but will give it a shot. As the R-22 helicopter progressed in development, new versions came out with more powerful engines. However, since the helicopter is "derated" the pilots wasn't really able to take advantage of this power increase. It was done to provide for a larger margin of error when working in higher DA's. So instead of always working at the engine at maximum we have a bigger gap there. It will also prolong the engine life.

 

JD

[budman]

I am not sure I understand the question but will give it a shot. As the R-22 helicopter progressed in development, new versions came out with more powerful engines. However, since the helicopter is "derated" the pilots wasn't really able to take advantage of this power increase. It was done to provide for a larger margin of error when working in higher DA's. So instead of always working at the engine at maximum we have a bigger gap there. It will also prolong the engine life.

 

JD

 

Well I looked at the IGE/OGE performance charts and I think on a standard day, max gross weight the Beta is at 7000 PA and the Beta II 9100 PA.(I don't have the POH and can't remember the exact numbers) The OGE for the same condition is 5100 PA for both types. The Beta has a 320 lycoming engine and the Beta II is 360.

[mechanic]

Are you sure you are stating the question correctly?

 

The point of the Beta II features is better High DA performance due to the derated O-360 engine. The main rotor blades are the same pn's, so the engine is the difference in the two. Beta and Beta II's have about the same performance at sea level. The Beta II has better Hot/High perfomance. Remember as DA/temps increases you will loose hp/performance, the larger engine helps offset the loss. I am sure there is a more technical term used to describe this.

 

Also there is approx 10.5 cu in more volume per cyl in the 360 engine for the fuel mixture, than the 320 engine.

 

I am thinking the 320 and 360 share the same carb? I am thinking I read that somewhere. Seems the orig 360 carb idled rough in this application and they switch to the 320's carb to remedy the problem.

[budman]

Are you sure you are stating the question correctly?

 

The point of the Beta II features is better High DA performance due to the derated O-360 engine. The main rotor blades are the same pn's, so the engine is the difference in the two. Beta and Beta II's have about the same performance at sea level. The Beta II has better Hot/High perfomance. Remember as DA/temps increases you will loose hp/performance, the larger engine helps offset the loss. I am sure there is a more technical term used to describe this.

 

I am thinking the 320 and 360 share the same carb? I am thinking I read that somewhere. Seems the orig 360 carb idled rough in this application and they switch to the 320's carb to remedy the problem.

 

I think you're almost there and yes I am stating the question correctly. But why is the OGE the same in both types if the Beta II has more power? I know more power is used for an in-ground effect hover but don't you need even more to hover at 500'? I'm not asking to test you guys on your R22 knowledge. This is for me to know because I don't know the answer. Just in case I get asked this question myself on my CFI checkride.

[mechanic]

Both charts at the top say zero wind. I have a current POH.

 

On the OGE chart the blades are operating in free (open) air.

 

On IGE even though you are at a higher alt you are still in a 2 foot skid clearance hover agl and have a cushion of air under the disc. Then we are back to the Beta II engine is bigger and has better high alt performance.

[lelebebbel]

The point of the Beta II features is better High DA performance due to the derated O-360 engine.

 

And that is what he is asking! The OGE hover ceiling in the POH is the SAME (5100ft on standard day) for Beta I and Beta II, so according to the POH the Beta II does not actually perform better at higher altitude than the Beta I - why?

[budman]

And that is what he is asking! The OGE hover ceiling in the POH is the SAME (5100ft on standard day) for Beta I and Beta II, so according to the POH the Beta II does not actually perform better at higher altitude than the Beta I - why?

 

 

lelebebbel, you are on the same page. That's my question, Why?

[Goldy]

And that is what he is asking! The OGE hover ceiling in the POH is the SAME (5100ft on standard day) for Beta I and Beta II, so according to the POH the Beta II does not actually perform better at higher altitude than the Beta I - why?

 

I wont pull my notes from the RHC safety course, I wont go get my POH, I wont read my Flight Training Guide...but here's two trains of thought off the top of my head.

 

Some limitations and charts listed in the POH, may or may not have ANYTHING to do with actual performance. They are in fact, demonstrated performance. Take the crosswind listed in the R22 POH...what is it..like 13 knots or something. Does that mean you cannot hover in a crosswind greater than that? No, it just means that on that day, someone demonstrated a crosswind hover and the wind was blowing X knots. It has nothing to do with a limitation of the aircraft.

 

Just look at doors off VNE for the R44, its slower than the R22 doors off VNE.

 

As far as OGE hovers, is the transmission or tail rotor rated for more than 124 continuous horsepower in either the R22 B or Beta II ? NO. They both have the same continuous HP rating. So why would the OGE charts be any different?

 

Now IF the Beta is at 5100 Ft it would probably take full throttle to get to 124 HP, whereas the Beta II could put out that same 124 HP with more to spare.

 

And yes, they put on the smaller carb, Frank doesnt want anyone touching the lean control in flight, and the bigger carb runs the engine too rich.

 

Goldy

Edited January 1, 2008 by Goldy

[mechanic]

I am not a CFI, so I had to cheat! I looked in my Prin of Flight book.

 

3 things listed under reduced "air density" limit maximum ops altitude and maneuverability.

Larger angles of blade attack.

Worsening tailrotor drag ratio.

Larger power requirements.

 

I was thinking that blade angle of attack might be at "critical" at 5,100??? With zero wind.

[Goldy]

I am not a CFI, so I had to cheat! I looked in my Prin of Flight book.

 

3 things listed under reduced "air density" limit maximum ops altitude and maneuverability.

Larger angles of blade attack.

Worsening tailrotor drag ratio.

Larger power requirements.

 

I was thinking that blade angle of attack might be at "critical" at 5,100??? With zero wind.

 

But the question is why doesnt the BII with the larger engine have a higher HOGE ? Your point of angle of attack is absolutely true and thats what requires more HP to overcome that added drag. My guess is that 5100 is the absolute limit with the R22B at 124 HP. Any higher than that and the engine cannot produce the 124 HP any more. If the BetaII had a slightly larger transmission rated for 131 continuous and the same weights, then I would expect to see a slightly higher HOGE number. HP is HP and 124 is all you get, regardless of which model R22 you are talking about.

 

Goldy

[Hovergirl]

But the question is why doesnt the BII with the larger engine have a higher HOGE ? Your point of angle of attack is absolutely true and thats what requires more HP to overcome that added drag. My guess is that 5100 is the absolute limit with the R22B at 124 HP. Any higher than that and the engine cannot produce the 124 HP any more. If the BetaII had a slightly larger transmission rated for 131 continuous and the same weights, then I would expect to see a slightly higher HOGE number. HP is HP and 124 is all you get, regardless of which model R22 you are talking about.

 

Goldy

 

OK, so IGE, the limiting factor is engine power, which is different on the two helicopters so the limit is different, but OGE both the Beta and Beta II are limited by other things (transmission, rotors etc.) and those other things are the same on both helicopters, so the limit there is the same. Is that it?

 

HVG

[lelebebbel]

OK, so IGE, the limiting factor is engine power, which is different on the two helicopters so the limit is different, but OGE both the Beta and Beta II are limited by other things (transmission, rotors etc.) and those other things are the same on both helicopters, so the limit there is the same. Is that it?

 

HVG

 

That explanation works for me.

Put it this way, hovering OGE at 5100ft DA takes exactly 124HP, so you can't hover OGE any higher without going over the limit.

 

Hovering IGE takes less than 124HP, so the limitating factor is when the engine runs out of power, which happens at a higher altitude in the Beta II.

 

Good thread!

[skypilot011]

check the wording at the top of both charts "out of ground effec, zero wind, takeoff power or Full Throttle." so , with that said, and your criterium previously stated, both machines at max gross, and standard day and approx. 5100 ft on the chart, The reason the beta II cannot develop more power is because you are at FULL THROTTLE, you have nothing left to give, at full throttle, you may still be able to raise the collective, but you won't get any more power and will be dragging the rotor rpm down (higher pitch in blades, "bad") so you have no more power to gain , getting into low rpm, this is why you train to lower collective and roll on throttle to gain back rpm. Since you have no more throttle, hopefully you can lower the collective, load up your drawers while you watch the rpms slowly recover. Check out the chart for the R22 alpha and hp on page 5-8 and look at the max gross weight lines, there are two of them? why is that? I already know, i just threw that one in for you!!

 

 

check out the bottom of the chart on page 5-10, OGE hover VS. Gross Weight,

Doesn't it sound like a title bout with two contenders ready to duke it out.

 

Thats exactly what you need to know,

[apiaguy]

my 2 cents...

 

Don't agree with any of the previous statements about full power equals 5100 OGE hover.

 

Only thing I can think of is the chart was not required for certification with the 0-360 engine change.... so they just included the original OGE hover chart for the 0-320 as an example of OGE hover power/performance.

 

The 269 (schweizer 300) series helicopters don't have an out of ground effect hover chart included in the POH (except as an additional supplement in the 300C POH) You have to guess for OGE using available power and expected performance in flight.

[Bradley P]

Awesome post!

 

Just my 2 cents.