[Thaeris]

Yep. I think I was pointing to that sentiment in a way in my initial post. However, I do not think this would be a mere field modification. You can't just put a different set of rotor blades on a helo without changing any of the internal mechanisms and expect everything to work perfectly. Of course, then you might argue that this is the reason for why one of them crashed.

[FreeSpaceFreak]

According to AW&ST, the crash:

was not a mechanical failure or a problem by the pilot that downed the Black Hawk—it was a miscalculation of temperature in and outside the compound. The Black Hawk ran into lift trouble due to a 15F difference inside the courtyard, says Rep. Buck McKeon (R-Calif.). “They couldn’t hold the ­hover.”

Cool stuff though. Stealth choppas...

[redsniper]

So wait, if these guys crashed their helo, how did they get home?

[General Battuta]

So wait, if these guys crashed their helo, how did they get home?

They brought spares man.

[The E]

They redistributed the personnel among the other 3 Helos they brought along.

[Kosh]

According to AW&ST, the crash:

was not a mechanical failure or a problem by the pilot that downed the Black Hawk—it was a miscalculation of temperature in and outside the compound. The Black Hawk ran into lift trouble due to a 15F difference inside the courtyard, says Rep. Buck McKeon (R-Calif.). “They couldn’t hold the ­hover.”

Cool stuff though. Stealth choppas...

Didn't Deus Ex have stealth copters?

[redsniper]

Oh okay, for some reason I was envisioning this lone helo sneaking in with some small team of badasses, who then had to steal a local's car or something to escape.

[headdie]

According to AW&ST, the crash:

was not a mechanical failure or a problem by the pilot that downed the Black Hawk—it was a miscalculation of temperature in and outside the compound. The Black Hawk ran into lift trouble due to a 15F difference inside the courtyard, says Rep. Buck McKeon (R-Calif.). “They couldn’t hold the ­hover.”

Cool stuff though. Stealth choppas...

Didn't Deus Ex have stealth copters?

yep there was a Comanche style design in the first game, though i am not sure if IW's helo was stealthy.  though as a game it is slightly irrelevant to the conversation

[Nuke]

Yep. I think I was pointing to that sentiment in a way in my initial post. However, I do not think this would be a mere field modification. You can't just put a different set of rotor blades on a helo without changing any of the internal mechanisms and expect everything to work perfectly. Of course, then you might argue that this is the reason for why one of them crashed.

then learn how things work on a helicopter (twok reference, lol). the way helicopters work is somewhat elegant. tail rotor is directly geared to the main rotor. very little needs to be done here, though the tail rotor has some gear reduction to get it near where it needs to be to provide adequate thrust. its the pitch of the tail rotor blades that ultimately determine how much thrust the tail rotor puts out. this is what traditionally the antitorque pedals control, though in this case id expect a sophisticated fly by wire system to be somewhere in between. that said the blades dont need to change pitch by much to make the system produce a different level of thrust. so there is probably some calibration required to make it work, but thats hardly as complicated as swapping a rotor (and likely done automatically by the fbw system). that said the tail is usually less complicated than the main rotor, which also has to control yaw and pitch in addition to thrust. still its a matter of calibration.

[Bobboau]

yeah, but I would doubt they brought in a normal black hawk to some base in Afghanistan glues some stealth panels and blades onto it and then went into battle with it. I have a funny feeling that this helicopter was purpose built for it's job. I'm sure 99% of it is a normal black hawk, but I doubt they started with a used one and turned it stealth.

[headdie]

I'm not sure, Give a competent maintenance team a hanger, couple of days, the parts and the instruction manual and it should be doable

[Thaeris]

Nuke, in general I think I'm decently versed in how a helicopter functions (though helicopters were never a great interest of mine). However, the internal systems a helo is designed with are directly related to external components. Any differences in rotor mass, lift characteristics, etc., would have an effect on flight performance if nothing else about the aircraft was changed. It's not impossible that this was a field modification, but it's just highly unlikely. Like others and myself have said, it's assumably just a new variant.

Note that internal changes include software (displays and FBW/SAS, if the aircraft has computer-augmented controls), mechanical elements (as you noted), etc., etc. Given the complexity of modern aircraft, again, a field mod is unlikely.

[Nuclear1]

So wait, if these guys crashed their helo, how did they get home?

They brought spares man.

Must've been hard, they probably needed that other helicopter just to transport their balls.

[headdie]

So wait, if these guys crashed their helo, how did they get home?

They brought spares man.

Must've been hard, they probably needed that other helicopter just to transport their balls.

I belive extracting family mambers was part of the plan and they had to be left behind so all the soldiers could evac

[Nuke]

yeah, but I would doubt they brought in a normal black hawk to some base in Afghanistan glues some stealth panels and blades onto it and then went into battle with it. I have a funny feeling that this helicopter was purpose built for it's job. I'm sure 99% of it is a normal black hawk, but I doubt they started with a used one and turned it stealth.

i was thinking more along the lines of a hanger deck in one of those usmc helo carriers. easier to keep classified things classified that way. this also goes with the whole burrial at sea scenario as well.

[Nuke]

Nuke, in general I think I'm decently versed in how a helicopter functions (though helicopters were never a great interest of mine). However, the internal systems a helo is designed with are directly related to external components. Any differences in rotor mass, lift characteristics, etc., would have an effect on flight performance if nothing else about the aircraft was changed. It's not impossible that this was a field modification, but it's just highly unlikely. Like others and myself have said, it's assumably just a new variant.

Note that internal changes include software (displays and FBW/SAS, if the aircraft has computer-augmented controls), mechanical elements (as you noted), etc., etc. Given the complexity of modern aircraft, again, a field mod is unlikely.

i dont know about that. ive gone through 2 rotor heads and 3 tail assemblies on my rc helo so far. sometimes im supprised with how little ive had to do to get completely different systems to work on the same airframe and the same drive train. point here is that rpm is less important than blade pitch in controlling thrust. not to say that changing the rpm wouldn't have a huge effect, it would. but this tail rotor was likely designed to work at the same rpm as a standard blackhawk tail rotor, so that no changes to the gear ratio with the main rotor would be necessary to achieve the same thrust. the variables are rpm, surface area of the blades, length of the blades (tips go faster if they are on longer blades), number of blades, shape of the blades, etc.

for example the blades are smaller here, but theres 5 of them, instead of 2. the blades likely use a higher efficiency and/or low noise configuration. as a rule of thumb noisy machines tend to be inefficient machines. since so much energy goes into making the noise (of course sometimes you have a system that pumps in extra energy to counter the noise). with reference to airfoils noise means turbulence and turbulence causes drag. it also may compensate for less surface area by varying the pitch of the blades by a larger margin. im merely saying that it is possible to throw actual engineering at the problem and come up with a solution that does not require gutting the chopper and replacing its entire drive train (which probably would include messing with the engine). if that were the case it may have been cheaper to just build a new type of chopper.

[Bobboau]

while possible, I don't think it is likely, they probably told boeing or someone to make 5 of these and they did, it's always easier to make something from scratch than cutting holes and bolting together and stealth tech is finicky about small details, so I doubt they would have started with a built physical helicopter and made it stealthy, though I'm sure it is a relatively minor tweak to the design.

[Nuke]

while possible, I don't think it is likely, they probably told boeing or someone to make 5 of these and they did, it's always easier to make something from scratch than cutting holes and bolting together and stealth tech is finicky about small details, so I doubt they would have started with a built physical helicopter and made it stealthy, though I'm sure it is a relatively minor tweak to the design.

that is nothing the military hasn't done before (huey->cobra). regardless of who's theory is most correct, what is certain is that the details will be classified for a very long time.

[Dilmah G]

According to AW&ST, the crash:

was not a mechanical failure or a problem by the pilot that downed the Black Hawk—it was a miscalculation of temperature in and outside the compound. The Black Hawk ran into lift trouble due to a 15F difference inside the courtyard, says Rep. Buck McKeon (R-Calif.). “They couldn’t hold the ­hover.”

Cool stuff though. Stealth choppas...

I see a different story every time I look at the paper... I think settling with power would be quite a possibility, given the structure of the complexes and the altitude the pilots would've had to keep above them. Either way, I'm glad this bloke was versed enough in it not to call it a 'stall'. That gets me every time I look at it elsewhere.