28 February 2010

Eurocopter designs ultra-quiet rotor blade...

(H/T Gabe in my Google Reader feed)

The distinctive whup-whup sound of the UH-1 Iroquois, or "Huey" as it is better known, can be heard for miles. However, its larger brother, the UH-60 Black Hawk, is much quieter. This is partly due to the design of the Black Hawk's rotor blades; all four blades have tips which are swept back twenty degrees, decreasing the size of the rotor tip vortices and reducing the noise of the aircraft. (Purists can expound upon this for hours, I know).

Engineers at Eurocopter have gone a step further, designing rotor blades which are almost silent, thanks to technologies such as Blue Edge and Blue Pulse--innovations in blade design which minimize the interaction between the rotor blade and the rotor tip vortices.

Listen for yourself:



2 comments:

Paul said...

That's quite a noise reduction -- too bad for the bad guys, I guess.

But here's my question: Back in Vietnam, one of our favorite 2/17 Cav pilots, Capt. "Wild Bill" Mecham, used his rotor blades to cut through the tree branches that had originally caused us to do a ladder extraction. The reason -- the last guy on the ladder had fallen off when a lucky NVA shot severed one of the ropes holding the ladder steps.

When that happened, all the shooting stopped -- Charlie was just as surprised as we were when our man fell. They continued to hold their fire and watch in awe as Capt. Meacham started sawing through the branches. We hopped out, picked up our guy, and got back in the Huey. All of a sudden the NVA remembered that they were supposed to be shooting and started engaging us again. The door gunners took care of that problem in short order.

Meacham sheered off something like 8 feet of rotor blade on each of the rotors but still made it back to Camp Eagle. He received a DSC for this fine bit of carpentry and was told at the same time by the 101st G-3 that if he did it again, he'd be court martialed.

Now, here's the question: what would happen if you tried that with these new "noise reduction" blades?

Bill Taylor said...

I have no answer to your question but having been a Killer Spade in "68 and '69 i had the experience of wiggling tha craft down into a hole to pick up wounded as we delivered the Ammo and that famous one hot a day. As we began to lift off I leaned out the left door and my gunner out the right and began to call out position to the pilot when the first mortar hit the middle of the, ultra-thin LZ. The pilot pulled pitch, I and the gunner crawled back into our seats as tree branches flew flew everywhere. I had my butterfly back in my hands just as we cleared the trees and spotted Charlie dropping the next round into the tube and killed him and three more there. The blades made the screwiest noise I ever heard. We jumped and bumped all the way home but my Baby flew all the way home. The H modles might have been ugly and loud but they flew their hearts out. We had lost just under 18 inches on each blade. And they wonder why they don't want old men to do that job. ;-)

Killer Spade 06...clear on the left!