How Many Fuel Stops?
 

Just published:

“Last week, a fascinating experimental helicopter from Sikorsky and Boeing made its longest flight yet: It flew from West Palm Beach, Florida to Nashville, Tennessee—a distance of some 805 miles. The two companies behind the futuristic chopper announced the March 21 flight in a press briefing today, saying it was the first time that this helicopter had traveled out of Florida, where all its previous testing had taken place.”

https://www.popsci.com/technology/si...copter-flight/

Anyone know how many a “couple stops” is for fuel?

Another Defiant Embarrasment
 

While truncated the article still has the pertinent information:

https://aviationweek.com/defense-spa...raa-downselect

This is another PR disaster for Team Defiant. They are proud it took them 7 hours to fly 700 miles between West Palm and Nashville….and they required two hot refueling stops to do it! This is not the speed and range the Army is looking for.

Even More Embarrassing
 

From another article lifted from the SB press release:

So they are proud that it was able to fly 700 nautical miles with only two stops/three loads of fuel and not kill anybody. Kind of like aviation records broken in 1910.

Another quote bragged they never got over 50% torque. Translation: May not have made it if we pulled more than 50% torque. This may give us a clue on how screwed up the drive system is.

No worries. The government money printing presses will keep on pumping out until the project goes the way of the Comanche.

For comparison, from Popular Science Feb. 2012:

“With all its tanks full of fuel, the CV-22 Osprey can go about 2100 miles—farther than the MV-22 and much farther than any helicopter. But it might need to refuel, especially during the return from a mission.”

A quote from an SB executive:

He forgot the old truism;

"Familiarity breeds contempt."

And SB have a lot of dirty laundry with which to fuel this contempt, such as:

Boeing;
- KC-46 tanker fiasco. (How could the company that developed aerial refueling have F'ed this up so badly?)
- Starliner, couldn't get to orbit and designers didn't know it is humid in Florida.
- 737 Max

LM/Sikorsky
- F-35 cost and reliability.
- Freedom class LCS. (So bad the Navy is scrapping the entire series at a 1/4 of their life.)
- CH-148 Cyclone (Years behind schedule and $ billion or so overrun)
- CH-53K (Ditto)
- FLRAA demo program

Bell seems a scrappy little startup by comparison!!

Just don't tell the Army about the V-22's painful development... (although it is technically the Bell-BoeingV-22...)

T&C

Good point. The two prototype V-22's that crashed were Boeing controlled and operated V-22's and could be traced to failures at Boeing. The North Carolina V-22 crash in the early days was due to Boeing leaving dead/bad code in the flight controls which responded badly to pressing the FC reset multiple times. So yes most of the V-22 woes were due to Boeing screw ups.

Relative to FLRAA the concept demo phase did what it was suppose to do which was separate bull**** (fix it in production) and capability. The V-280 flew on time to the original schedule, met or exceeded all of the original program goals, and was kept in service after program completion to do govt pilot evaluations and demo new mission capabilities. On the other side, the SB>1 was three years late and had to beg for an extension to the schedule to accomplish anything, met none of the original program goals and reduced to bragging about flying 700 miles without crashing.

Related to familiarity the last experience the Army had with Bell was the OH-58D which up to its senseless termination had by far the highest mission capability rates in combat operations of any Army helicopter. It would have been #1 for all helicopters except for the Bell UH-1N.

One of the happiest days for Bell Valor engineering was when Boeing announced they were parting way with Bell.

One of the saddest days for Sikorsky Defiant engineering was when Boeing announced they were teaming with Sikorsky.

Wasn't Comanche a joint S/B project? As to LCS, a lot of Naval professionals were unimpressed by it at its debut ... but that's not on topic so I'll not pursue that further.

Defiant at Quad A
 

I’m sorry but I can’t help it. Does this rotor make my aircraft look huge?

[img]blob:https://www.pprune.org/f1486203-89c8-407b-8ea4-001d7259bddd[/img]

Quad A Aftermath
 

Does anyone know what happened to the SB-1? Was it:

- Flown home,
- Trucked home,
- Still there awaiting maintenance, or
- Sent to the museum at Ft. Rucker for temporary display like the Comanche?

-

Now that you mentioned Comanche……er…..Invictus. What’s that adage? : “ Imitation is the sincerest form of flattery “ , or something like that. Curious that Invictus started out as , like a 100% look alike copy of Comanche, but then they dropped the canted ducted fan TR for a standard TR. Had they done a ducted fan before and didn’t like it?? Kind of a shame. Back in the day, when we were flying the prototype S-76 Fantail at the Paris Airshow, Nick L gave a ride in the Fantail to the Eurocopter Chief Test Pilot, and during the return flight from Le Bourget to the Paris Heliport at Issy les Moulineaux, Nick flew it at 80 KIAS in a right echelon off the UH-60 that I was flying with video camera/photographer , and on cue Nick kicked the fan around so he was now in formation, but going backwards at 80, and then after a few minutes of that, kicked it around the rest of the way to resume going down the heli-route at 80 with the nose in the correct direction again.. Nick told me later that when he did that, his French companion said the word ( phonetically here ) “ form-ee-dahl-bluh “. SA has the video somewhere.
( But we knew what he meant: Nick and I had a couple of years of high school french ).

John

The government spent around $7 billion on the Comanche before it was cancelled. Bell probably assumed something from that program could be salvaged and the original 360 proposal included the ducted tail fan to meet anticipated RCS requirements. Once it was recognized that low RCS was incompatible with the pusher ABC configuration, the final requirements for RCS on the selected prototypes were relaxed to allow the Raider to compete. With that requirement no longer a constraint Bell wisely reverted to a conventional tail rotor to save cost, save weight, improve reliability, and reduce program risk while still meeting the final program requirements.

I failed to note another capability of the Comanche ducted fan: it was capable of sideward flight to 100 kts ( paced) . Pretty high bar for low speed directional control. So with all those savings reasons for the conventional tail rotor, does it have performance equal to the Comanche?

My understanding is that the current thinking is RAH-66 was over-specified and/or over-capable in terms of maneuvering capabilities, particularly in yaw and that ADS-33 requirements are getting tailored for a better balance of capability, control sensitivity, and weight/etc. Comanche always struggled with weight and the Army is attempting to shove a similar airframe with more weaponry and a little higher speed under the same ~40’ rotor. Giving up un-necessary yaw performance to reduce the weight/complexity of the yaw control system is reasonable. Of course, it’s also required for an ABC style aircraft with integrated prop to even be competitive. Yaw power isn’t a strength of a coaxial design with a lot of mass (prop, gearbox, and oh so very large horizontal stabilizer) at the end of the tail cone.

So neither aircraft will match Comanche’s impressive yaw control power and this is by design and with concurrence of USG customer, that’s pretty clear at this point.

Didn't the Comanche not have a rotating gun turret because of the ability to literally point the nose at the target whenever it needs to?

From an article at the time of the cancellation of the Comanche in 2004:

That works out to $120 million apiece in 2004 dollars! Additionally, as mentioned previously, it was grossly overweight and could not do all of the missions without significant redesign. About the only place they could have cut the required weight was to scrap the ducted fan and revert to a conventional tail rotor. I am sure somewhere at Sikorsky there is a sketch of such a change.

No, Comanche had a conventional turreted cannon that did have the unique feature of being able to swivel towards the tail for stowage in a reduced RCS configuration. So it could fly 100 knots backwards and shoot in all directions for some reason (fall out capability due to other requirements, lol).

My Two Cents, and at the risk of being controversial: the core problem with Comanche (weight wise) was that the original LHX concept was departed from and the Army insisted on a two pilot cockpit, not a single pilot aircraft. But there ya go, that is a part of requirements being established and the US Army's mind set. Not sure if Invictus will run into this as well before all is said and done.

By the way, what the Comanche program produced was a remarkable machine (IIRC, LRIP had in fact commenced when the Army pulled the plug). The Sultan's observation on the price point bears considering - similar issues arose with F-35. I am of the opinion that the "Apache Mafia" in the US Army is what finally killed it, but opinions are like navels ...
:p
I remember being in a room with Togo West (then Secretary of the Army) and a bunch of career Army types. The Secretary threw out this idea (mid 90's, Clinton Administration years, as money kept getting milked out of various DoD budgets) - does the Army really need Comanche? Well, long after he was replaced by someone else, Comanche was still moving forward, one milestone at a time.

V-22 Osprey ran into similar push back over the years at various points, but it made its way through all that in the end.