tail rotor power

[Brien]

What is the % of power a tail rotor at max pedal input takes . Does a
Hughes 269 require the same tailrotor % of power to the 180 hp that a UH-1
of it's 1400hp?

[Dave Jackson]

Brien wrote
> What is the % of power a tail rotor at max pedal input takes . Does a
> Hughes 269 require the same tailrotor % of power to the 180 hp that a UH-1
> of it's 1400hp?

The Americans say 5 - 10%.
The Russians say 10 - 15%
Simon says " Drop the tail rotor and take rotorcraft to the next generation"
:)

[Jim Carriere]

Dave Jackson wrote:

> Brien wrote
>
>>What is the % of power a tail rotor at max pedal input takes . Does a
>>Hughes 269 require the same tailrotor % of power to the 180 hp that a UH-1
>>of it's 1400hp?
>
>
> The Americans say 5 - 10%.
> The Russians say 10 - 15%
> Simon says " Drop the tail rotor and take rotorcraft to the next generation"
> :)

I like your answer.

I'd always heard between 5-15%, approximately of course.

For the most accurate answer to that question, you'd really have to
talk to the engineers at Hughes (make that Boeing-MD nowadays) and
Bell. For a general answer, I'd say yes, they are probably pretty
similar.

Besides it depends in flight regime- the vertical fin makes a
difference hovering in a crosswind, flying at any speed.

[Steve R.]

Hmmm, I don't really know one way or the other but I'd heard that the tail
rotor can take upwards to 25% of available power, depending on the
circumstances.

Getting rid of the tail rotor will improve power efficiency if you're
talking about a twin rotor, counterrotating system (tandom or coaxial) but
even a NOTAR consumes some power to combat torque. Whether or not it's more
efficient than a standard single main rotor / tail rotor helicopter, I have
no idea!

JMO, FWIW! :-)
Fly Safe,
Steve R.


"Jim Carriere" > wrote in message
...
> Dave Jackson wrote:
>
>> Brien wrote
>>
>>>What is the % of power a tail rotor at max pedal input takes . Does a
>>>Hughes 269 require the same tailrotor % of power to the 180 hp that a
>>>UH-1
>>>of it's 1400hp?
>>
>>
>> The Americans say 5 - 10%.
>> The Russians say 10 - 15%
>> Simon says " Drop the tail rotor and take rotorcraft to the next
>> generation"
>> :)
>
> I like your answer.
>
> I'd always heard between 5-15%, approximately of course.
>
> For the most accurate answer to that question, you'd really have to talk
> to the engineers at Hughes (make that Boeing-MD nowadays) and Bell. For a
> general answer, I'd say yes, they are probably pretty similar.
>
> Besides it depends in flight regime- the vertical fin makes a difference
> hovering in a crosswind, flying at any speed.
>

[Jim Burt]

The NOTAR is less efficient in terms of power demand than a conventional
tail rotor, but offers other advantages. The amount of power drawn by the
tail rotor depends on the flight profile. Heavy lift operations require
huge amounts of anti-torque, which contributed to a series of failures of
Bell 42 deg. gearboxes in logging service some years ago (although the
logging operations typically exceeded flight manual limits, so you should
not consider the design defective for its original purpose). The vertical
fin does unload the tail rotor in flight, but makes it less efficient in
some hover regimes, in which "ringtail" and fenestron type systems are more
efficient.

"Steve R." > wrote in message
...
> Hmmm, I don't really know one way or the other but I'd heard that the tail
> rotor can take upwards to 25% of available power, depending on the
> circumstances.
>
> Getting rid of the tail rotor will improve power efficiency if you're
> talking about a twin rotor, counterrotating system (tandom or coaxial) but
> even a NOTAR consumes some power to combat torque. Whether or not it's
> more efficient than a standard single main rotor / tail rotor helicopter,
> I have no idea!
>
> JMO, FWIW! :-)
> Fly Safe,
> Steve R.
>
>
> "Jim Carriere" > wrote in message
> ...
>> Dave Jackson wrote:
>>
>>> Brien wrote
>>>
>>>>What is the % of power a tail rotor at max pedal input takes . Does a
>>>>Hughes 269 require the same tailrotor % of power to the 180 hp that a
>>>>UH-1
>>>>of it's 1400hp?
>>>
>>>
>>> The Americans say 5 - 10%.
>>> The Russians say 10 - 15%
>>> Simon says " Drop the tail rotor and take rotorcraft to the next
>>> generation"
>>> :)
>>
>> I like your answer.
>>
>> I'd always heard between 5-15%, approximately of course.
>>
>> For the most accurate answer to that question, you'd really have to talk
>> to the engineers at Hughes (make that Boeing-MD nowadays) and Bell. For
>> a general answer, I'd say yes, they are probably pretty similar.
>>
>> Besides it depends in flight regime- the vertical fin makes a difference
>> hovering in a crosswind, flying at any speed.
>>
>
>