Anyone flown (or fly) the Huey?

[jessie13]

Is it because of no engine means no torque, so the huey then will want to turn to the left because of rotational friction forces (ie, it will want to spin in the same direction as the main rotor istead of against it. Only guessing.

[Darkhorse30]

Current UH-1H Stuff

Our company has been doing mods on Huey's for some time, at least 20 years. These mods include the P&W PT6C-67D and LHTEC T800 engines. We have tested various weapons including .50 cal Gatling gun, 40mm automatic grenade launcher, and a 30 mm cannon. We also build a Tail Rotor Enhancement Kit (TREK). We sell a vertical fin spar replacement, also. We just sold our Huey without the engine, which was used for a test bed. She was use in a record long distance flight, from Oxnard, CA to Robbins, GA non-stop, non refueled.

Personnally, I have been flying since 67 and in Huey's for some of that time. I have flown the tests as well as TV, movies, and lately for the State of Oklahoma in their marijuana eradication efforts. So I still get 50-100 hours in a standard UH-1H every year.

When I go to an airport, I always get a visitor or two usually a Vietnam vet that has some good or bad experience to talk about. The movie people like them because of that unforgetable blade whop and the Huey profile.

If you are interested, go to our web sight at global helicopter.

[helmet fire]

I recall this warning for an engine failure during a high power climb, not for during a turn. Can you repeat the passage that concerns you, or state the section from which it comes?

The warning I recall related to the UH-1H during sudden lowering of the lever during high power climb outs if suffering an engine failure. This had to do with the massive resultant pitch down change (airflow over rear stabiliser PLUS sudden lack of collective pitch ), the subsequent rapid unloading of the disc into negative g territory followed by the roll coupling causing a bank angle with an unloaded disc. And then mast bump if not corrected properly. Where are you Lu Zuckermann???

[kulttt]

Uh-1 Engine Rpm

I heard americans were flying with 6400 Eng RPM during cruise flight at first, but later they changed it into 6600. any knows why did they change eng rpm into 6600?

[Ascend Charlie]

6600 is the normal operating RPM.

In the cruise, it was found that beeping down to 6400 gave a better fuel consumption, whereas 6600 is optimised for low speed or hover work.

[Oldlae]

Ascend Charlie
On the 205A-1, the civil Huey with a T53-13B Lycoming, 6600 N2 gives 100% Nr. Reducing N2 by beeping to say 98% Nr puts the a/c into a "higher gear" thus producing more fuel economy in the cruise. Bell probably chose 6600 N2 as a convenient setting for 100% to cover all the types of missions that could be expected, and could probably give more lift, though I Could Be Wrong (added to protect my six o'clock).

[kulttt]

uh-1

But I wonder why americans change cruise N2 6400 into N2 6600 in late 1990s?
What happened?
did they find out something?
nevertheless they had been flying with 6400 N2 till 1990s.

[NickLappos]

The rotor speed is determined by the conflicting needs of several systems:

For high speed cruise, especially at high altitude, the rotor is closer to stall, and so must have the max rpm possible. This maximizes the maneuver thrust of the rotor, should it be called for.

At all other times, the rotor has "too much" reserve thrust, and is operating at a point where it has too much speed and too little angle of attack to be at peak efficiency.

This is especially evident at a hover, where the rotor wants to be near peak lift and peak angle of attack for highest efficiency, and it is still useful up to best range speed, where the lower power required makes less fuel burn and more range.

The problem with using lower rpm in a hover is that the tail rotor is also slowed down, so that the max left pedal available is reduced, and even at lower altitudes, at high weights this pedal might be needed. Other than the tail rotor effect, hover generally favors lower rpm.

All this is basic helo aero, the flight manual has the procedures that you must use!

[emergov]

Huey N2 RPM

The Huey does have a roll / pitch couple - we used to demonstrate it in effects of controls. Pull up on the collective - nose goes up and you roll right. Push down, you roll left and the nose goes down. I always thought it was to do with the horizontal stab (g'day Helmet Fire) but have never worked out where the roll comes in. Perhaps it's phase lag?

As for the 64 / 66 question, the reason it was changed to 66 in Australian service was to reduce the risk of pilots losing T/R auth in the hover at high AUW after completing their cruise at 64 (g'day Nick).

There was an issue a while ago with N2 spur gear failure - a NZ operator crashed I believe, among others - where ops at 65 created a resonance which led to failure of the N2 spur gear. This led to loss of the OS governor and torquemeter boost pump, leading to indications of low Tq while the engine accelerated due to sensing low N2. End result - engine failure.

[Darkhorse30]

At high gross weight near Vne, the response to sudden engine failure in a UH-1H is pretty rough. The Nr bleeds off rapidly and along with the pitch and roll problem the danger of mast bumping is increased. The Army found this in a later test, around 1980. I ran into this problem in a test in 2003 and bumped the mast as well as damaged the rubber mast boot. We were testing the UH-1H with the single PT6 engine and were required by the FAA to document the characteristic of what happens when the engine quits at min rpm, high gross weight at Vne in level flight. This would be the worst case cruise condition. Needless to say operating at 6400N2 near Vne is not a good thing unless you are spring loaded to lower the collective rapidly and keep the rotor in a positive loaded condition. We obtained an STC for the engine conversion but limited all flight conditions to 100% N2, 6600rpm, 324 rpm Nr. Trying to save a little on fuel is not worth the risk. I never beep the rpm down in any flight condition.

[arismount]

6400 Rpm

The DAC told us in '78, near the end of instrument training..."Beep it down to 6400, then pull 32 lbs of torque...that'll get you about 30 miles farther down the road on a tank of gas." He was right (thanks Mr. Whitehead). Army doctrine was to set cruise power to hover power (usually around 28 ft.-lbs. torques) and fly at 90 KIAS. But in the field we'd usually always do the 6400/32 thing & fly about 110 KIAS. It did get you more range. The before landing checklist had you check the N2 & beep it back up to 6600.

[kulttt]

UH-1

Thank you very much Darkhorse30,
If you didn't mind could you please send me some documents about army tests concerning mast bumping resulted in increasing cruise N2 RPM to 6600 if you have.
I am goıing to present wing guys about N2 (Why was it increased to 6600? you say because of risk of mast bumping during high altitude high GW in case of eng failure) I need some more detailed information and recommendation about this stuff
thank you very much
email: [email protected]

[daver_777]

Another Huey question

It may have been covered elsewhere in this thread, but i was wondering if anyone could explain, why when you roll the old girl into a left hand turn you get a torque spike of up to 5PSI?.

Cheers

Daver_777

[Arm out the window]

It's the same with any helicopter - if you want to roll towards the retreating blade you have to increase lift on the advancing side and decrease it on the retreating side.
More lift = more drag, and as I understand it, the magnitude of the drag increase on the advancing blade is more than the reduction on the retreating side; more overall drag, more torque required.

[Darkhorse30]

Keep the NR at 100% (324rpm)

kulttt,
I will try to find the report. It is in my archives somewhere. The problem is with the lower NR at high cruise speed, high gross weight, and high density altitude. The collective pitch is high because of these conditions. The rotor rpm decay rate is rapid with a throttle chop/engine failure and keeping the load factor above 0.5g is next to impossible.
I'm on my way to HAI and will not return for several days. I'll look this up when I get back.
DH30

[kulttt]

uh-1

thank you darkhorse30,
I will be waiting for the report.

[topendtorque]

Here you are, another salute to a revered machine and to some of you guys no doubt.

A story about the latest display in the OZ war museum in Canberra.

http://www.abc.net.au/news/stories/2...26/2173063.htm

[Minty Fresh]

Was G-HUEY out and about yesterday?

Sure it was a huey flew over my house (just to the east of Sheffield) late afternoon.

Fantastic site/sound, stood on the drive waiting for it to pass over for a while I heard it coming from so far away.

(one day!!!)

[170']

Hi

Does anyone have the OGE hover charts for both a straight 205A1 and also 205A++

IŽd appreciate a copy if anyone has one...or the numbers for 4500Ž@ ISA 25

Thanks & Blue skies.....170'

[kulttt]

ab-205

hello,
does anyone have ab-205 operator's manual?
thanks