Stealth Helicopter?

[DGthe3]

Originally Posted by 8cd03gro

I thought it was called the YF22/YF23 until the actual LM f22 raptor in 1997.

A name is a name. The advanced tactical fighter program that began in the 80's, which aimed to create a 5th generation air fighter tasked with the role of air dominance, generated 2 competing designs: the YF-22 and the YF-23. The YF-22 was chosen and dropped the Y (which is used only for prototypes) and picked up the name 'Raptor', thus the name F-22 Raptor was born. But by that time, prototypes had already been flying for at least 5 years (perhaps more) and it would take another 8 years to complete everything before the Raptor would be put into service.

[Mr. Wyndham]

Originally Posted by GTAHVIT

Here's a common sense answer.... cus I don't truly know..

But I'm guessing that it has to do with the "direct drive" transmission.

the jet engines that power the the main transmission that turns both the main rotor and the tail rotor are directly connected to the an ouput shaft from the two engines...

My guess is it's that it's more efficient/effective to have the transmission spin at a constant speed, while allowing the engines to respond to the increased or decreased loads caused by the angle of attack of the blades and rotor head... or the work the rotor head is doing...

But to be clear. the engines do spin up under increased load. but the rotor head rpm is relatively constant.

In fact there is a Main Rotor Overspeed indicator that when lit basicaly means that Aircraft is down for maintenance until the rotor can be inspected/serviced...

FWIW.

Good enough for me!

With a constant speed, though - how does the pilot adjust altitude? In a plane, you reduce thrust (engine speed), and the plane drops...obviously choppers are different than planes, but the Black Hawk's operation has me really curious, now.

I'm going to have to look this up...

[DGthe3]

Originally Posted by Dragoneye

Good enough for me!

With a constant speed, though - how does the pilot adjust altitude? In a plane, you reduce thrust (engine speed), and the plane drops...obviously choppers are different than planes, but the Black Hawk's operation has me really curious, now.

I'm going to have to look this up...

You change the pitch of the blades. Increasing the pitch increases the angle of attack for the blades (which are shaped like really narrow wings), giving the rotor more lift. Flatten it out and lift is reduced. A lot of propeller driven aircraft control thrust in a similar manner, by adjusting the propeller pitch rather than by the throttle.

[Zabo]

Originally Posted by DGthe3

You change the pitch of the blades. Increasing the pitch increases the angle of attack for the blades (which are shaped like really narrow wings), giving the rotor more lift. Flatten it out and lift is reduced. A lot of propeller driven aircraft control thrust in a similar manner, by adjusting the propeller pitch rather than by the throttle.

Also done due to air density changes for takeoff. Really important when you've got a STOL situation. In this case it's been said that it could have even been a simple case of air density fubaring the ability of the rotor plane to maintain the lifting force required to keep the helo in the air.

And if that were the case auto-rotation is pointless, dropped like a stone and caught the tail on the wall trying to 'glide' it into the courtyard. I mean you probably can't fit more than two Hawks in there anyway, so if that was the 2nd bird that went in.. someone had to take the 'small car' parking space.

Obviously didn't work.

[Overflow]

I remember reading about this..

The concept is pretty good when you look at the tail that was left..

[CamaroSkooter]

It was an autobot...

[mlee]

Originally Posted by DGthe3

The F22 program is way older than that (or newer ... depending on how you look at it). It began in the mid 80's, prototypes were flying in the early 90's, and it finally went into service a few years ago (2005ish). Originally, they were probably planning on having its replacement ready to go by now.

Dead on... and the JSF or now F-35 Lightning began around 1997.

Originally Posted by 8cd03gro

I thought it was called the YF22/YF23 until the actual LM f22 raptor in 1997.

The YF22 was Lockheed and the 23 was Northrop. Once the flyoff was completed and the 22 won early 90's the Y was dropped and the program began at Edwards AFB Ca. I worked w/ a lot of the Northrop guys that were on the YF23 program and they complained all the time that their 23 was way better than the 22.

Originally Posted by DGthe3

A name is a name. The advanced tactical fighter program that began in the 80's, which aimed to create a 5th generation air fighter tasked with the role of air dominance, generated 2 competing designs: the YF-22 and the YF-23. The YF-22 was chosen and dropped the Y (which is used only for prototypes) and picked up the name 'Raptor', thus the name F-22 Raptor was born. But by that time, prototypes had already been flying for at least 5 years (perhaps more) and it would take another 8 years to complete everything before the Raptor would be put into service.

Dead on again.... When the B-2 went into operational service a lot of us who worked it were offered jobs on the F-22 test program. By that time my wife was pretty much done with living in way out in the middle of the Edwards AFB desert so we went to Langley VA instead.

[ViperTomcat]

Short Answer: It was a modified Blackhawk from the Nightstalkers.

Anything beyond that violates OPSEC. You wont find more information.

[okyankee]

they need whisper mode like they had on blue thunder.

[2ndgenz28]

The rotors only turn so not to tip our hat to the anti grav tech from area 51 they use to fly silent.

[GTAHVIT]

Originally Posted by 2ndgenz28

The rotors only turn so not to tip our hat to the anti grav tech from area 51 they use to fly silent.

Now I have to ban you

[Skill377]

Interesting technology but wonder how much this cost us tax payers! Not to mention they had to blow one up right after the mission!!

[DGthe3]

Originally Posted by Skill377

Interesting technology but wonder how much this cost us tax payers! Not to mention they had to blow one up right after the mission!!

I can think of much bigger ways that the US military wastes money than on a special purpose helicopter. At least they'll get used regularly for the missions they were built for.

And blowing it up wasn't really in the initial plans. Or was it ... ? Afterall, it might be of some benefit for the baddies to know that there is something out there that can deliver a dozen commandos to their doorstep ... and there isn't a thing they can do to stop it. Might also explain why there was still identifiable wreckage left. I mean, a Seal should know what a normal Blackhawk looks like, right? Navy Seals are known for many things ... stupidity and carelessness are not among them.

(awaits a funny looking helicopter to land nearby during the night ... )

[2ndgenz28]

We do need stealth for copters, but im sure its like the stealth bomber.
if your within eyeball range, its not a Hudini ship. [sight or sound]

Id love to see some big advancements in copters though,
we need one as armored as our best tank but as nimble as a bumblebee
[which also by the physics should not be able to fly].

Let them be able to fly in low and slow and take all the small to med arms fire they want to toss as it and not even need to bat and eye. Just sit there n let em use up ammo, then fire a rocket up their..............