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The EADS team includes U.S.-based Sikorsky Aircraft Corp., part of United Technologies Corp. and a major player in the large military helicopter market, to provide logistics support.

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Next up for EADS NA is the KC-30 - now that will be interesting!

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BTW - Great article on the aircraft in last weeks issue of Aviation Week dated June 19th - like a Motor Trend test-drive and review; highly reccommended.

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Originally posted by AirKnight:
The UH-72A as it will be called was perhaps not as good as the Bell 412 (too bad the 429 wasn't considered or offered,) but it was just over $1m per copy cheaper and for that aspect, it was the best bang for the buck.

quote:

But aerospace analyst Richard Aboulafia of the Teal Group in Fairfax, Va., said Bell will likely lose to Eurocopter/Sikorsky because its birds cost less -- US$4-million apiece, compared with Bell's US$7-million price. Europter's parent, EADS, is keen to increase its share of U.S. defence spending, and its partner is a unit of U.S. defence giant United Technologies Corp. "I'd say Bell is tied for second" with the others, Mr. Aboulafia said.
--National Post

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Bell spokesman Mike Cox said that company executives were disappointed by the Army's decision, but that they still believe that the Bell 412 "was the best aircraft for the missions the LUH will fly."

The 412 is a larger, more powerful light utility helicopter than the Eurocopter model, but its list price -- roughly $6 million each -- was at least a million dollars per aircraft higher.

quote:

"AgustaWestland, Bell, EADS North America and MD Helicopters each say their twin-engine candidate meets or exceeds the general bid specifications, though the aircraft vary considerably in size, performance, and price.

"While the "L" in LUH stands for "light", there is no clear definition of the range that a "light" helicopter might weigh or cost. Bigger doesn't necessarily mean better when cost is considered. I estimate that base prices of the bid aircraft correlate generally to their MGTOW ratios. Thus, Bell's 412EP would likely be almost twice the cost of the MD902. The AW139 would likely be roughly twice the cost of the EC145.

"The bid aircraft have good reputations and characteristics. But since there is little head-to-head competition among them based on MGTOW and price, Army officials will have to determine the best fit and value to accomplish their listed missions within budget."
--We Fly the UH-145, Rotor & Wing, April 2006

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bring on the KC-30!

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Originally posted by Sgt_Schlappy:

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bring on the KC-30!

AirKnight, put soap in mouth immediately...rinse...repeat!!

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How I Tried to Kill NOTAR

Okay, here's the story:

I was a US Army 1LT, assigned to the Aviation Systems Command (AVSCOM) Applied Technology Laboratory at Ft. Eustis VA in 1979 as an aerospace engineer, working in the Aeromechanics Technical Area doing wind tunnel and performance testing. The Technical Director of AVSCOM HQ in St. Louis had been talking informally with Hughes Helicopter folks about some independent research they were carrying out on a Circulation Control Tail Boom, which would use a Coanda effect to generate sideward force from the rotor downwash in hover. This, combined with a direct jet thruster at the end of the tailboom, would, they thought, provide enough force to replace a tail rotor.

The Tech Director asked Hughes to submit an "unsolicited proposal" for the research, so the Army could decide if we wanted to fund it. That proposal filtered down the ranks to my office, and I and a senior engineer were tasked to evaluate it for technical worthiness. We rejected the proposal, based on our belief that the system would never be as efficient as Hughes claimed. First of all, we thought their projections of thrust available from the circulation control tail boom to be overstated. Second, the projections of thrust available from the jet thruster did not take into account efficiency lost through turning the flow 90 degrees through a set of vanes, from axial to lateral. Third, a smaller, higher velocity flow will always be less efficient in creating a given amount of thrust than a larger, slower one. That's why direct jet vertical lift, like the Harrier, is always so inefficient. Hughes also used as part of their rationale the "success" of the thruster-type antitorque device of the XV-9A (c. 1965). This ignores the fact that the main rotor drive system on the XV-9A was tip jet thrust, using hot air from a set of turbofan engines. Antitorque requirements for this were negligable, needed only to overcome friction! And the final reports on the XV-9A rated the system as marginal! Bottom line, a NOTAR will always be more inefficient than a tail rotor providing the same amount of thrust. Efficiency translates to control power, and ultimately, fuel. Finally, the contractor was proposing that a NOTAR would enhance survivability by removing the tail rotor, ignoring the fact that the entire pressurized tailboom was now vulnerable area. When you shoot a big hole in a pressurized tailboom, you now have TWO jets, and the new one may be pointing in a bad direction.

This last argument, by the way, lingered for years. I once asked the Hughes chief aerodynamicist about it at a lecture, and his answer was that there was enough excess flow available from the fan (IIRC, an Aerospatiale Fenestron with the blades shortened on the prototype) to provide additional air to the NOTAR, forgetting that would make the thrust from the ballistic damage hole higher too. When Boeing Sikorsky and McDonnell-Bell were competing for the LHX (now Comanche) development program, the McDonnell-Bell design had to be modified at the last moment, because the Army survivability analysis considered the whole tailboom to be vulnerable to threat weapons. I was by then in my first year as LHX (Comanche) Test Engineer. McDonnell-Bell countered by lengthening the NOTAR fan drive shaft to move the fan down near the end of the boom - basically creating an inefficient,
internal tail rotor! I should add, in the interest of fairness, that this was not considered a major drawback to the McDonnell-Bell design, and is not the reason they lost the competition.

Anyway, as I started to say, bottom line - NOTAR will always be less efficient and less responsive than a tail rotor for the same amount of thrust. It saves you no weight, offers no performance advantage, and doesn't lower vulnerability. There's only one reason to go with a NOTAR, and that's if you have overriding concerns about backing the tail rotor into the trees (or people!) in confined areas.

Anyway, we wrote up our negative evaluation and sent it up the chain. It got out of the lab (through three levels of engineering review) with complete approval, got up to AVSCOM HQ, and the Tech Director took one look at it, said, "Wrong answer", and sent it back to be redone - with strong hints as to what the right answer should be. It was taken away from my
division and given to another office in the lab. Those folks read the writing on the wall and produced a glowing evaluation of the concept.

The rest is history. Hughes was awarded a $1M (IIRC) contract for development, and an OH-6A as a protoype. They did the work, claimed victory, and tried to sell NOTAR aircraft to everyone. The Army didn't buy it, and I don't think anyone else did either. At one time McDonnell leased a group of NOTAR equipped 500's (MH-6) to the 160th Avn Bn, who kept them for a few months and turned them back in as less capable than the same bird equipped with a tail rotor. I recall some police versions somewhere, anybody know if they're still in use? Boeing sold off that model line a year or so back when they bought McDonnell, and I haven't heard anything about the buyer offering the NOTAR option for sale.

So that's how I tried to get NOTAR aborted before its birth. After 20 years, I still think I was right, and that the lack of NOTAR on anything in production proves it. This, by the way, is just my personal engineering analysis, and does not necessarily reflect the opinions of anyone else who works for the Army (standard disclaimer).

Dan Hollenbaugh
Comanche Test Engineer

quote:

As the NOTAR (No Tail Rotor) helicopter entered a normal descent on downwind for landing, control was lost and the helicopter entered an uncontrollable left spin as it descended to ground impact. A stress corrosion fracture and separation of a fitting in the anti-torque system thruster control cable resulted in a fixed jet thruster nozzle setting and precluded the pilot from controlling the left yawing rotation. RFM (Rotorcraft Flight Manual) procedures provided inadequate information for the pilot to understand the anti-torque system and apply proper corrective action to minimize the effects of the stuck thruster condition. FAA and the manufacturer failed to recognize the implications and significance of a known stress corrosion cracking problem and take appropriate preventative measures in a timely manner. Maintenance diagnostic actions were inadequate to correctly diagnose a yaw control system anomaly reported by the pilot 2 days prior to this flight. The pilot's negative transfer of anti-torque failure procedures from a conventionally designed helicopter precipitated improper pilot control input in response to the fixed jet thruster nozzle condition.