Video: Defiant - 247 knot helicopter

[patrickrio]

 

[TFF]

I saw the unveiling of the proof of concept test aircraft at the big helicopter trade show years ago. It was a two seater. Sikorsky had bought Schweitzer Helicopters/ Hughes to use as a prototype shop for the project. On tear down day, they were taking it apart and I got guts pictures. They split the tail, blade mounts, good stuff all in my little camera. Unluckily in the airport parking lot my boss said he would take care of my stuff while I went in to check on the plane. Cab driver did a bait and switch and hid it and kept it with my new laptop. Grrrrr still.

 

[cblink.007]

Call me biased, being an Osprey guy, but knowing several people within the co-ax development program, a huge concern is vibration management due to its incredibly stiff rotor system design. Without being able to flap and feather as much as it needs to bleed off energy from the aerodynamic forces it encounters, all those forces need to go somewhere. The bird has an active vibration suppression system onboard to deal with it, and if it fails, and you happen to be above 160 KTAS, it could be a bad day. Don't get me wrong; it very likely has a place on the battlefield and even in the civilian sphere of operations, just not in the long-range, high-speed assault support mission set.

 

[TarDevil]

The bird has an active vibration suppression system onboard to deal with it, and if it fails, and you happen to be above 160 KTAS, it could be a bad day.

Which describes a lot of newer (last 30 years, maybe more) military hardware.

 

[cblink.007]

Which describes a lot of newer (last 30 years, maybe more) military hardware.

So true. Our friends over in F-35B land can attest to that...when they actually get up off the ground to go fly. I am not 100% privy to specifics on the SB-1 vibration issues, but yeah, it's a big time no-go structural limit exceedance if its AVSS goes down while at high speed. We have an AVSS in our bird, but it is more or less a pilot/crew comfort device; we can put the TCL to the firewall all day with a disabled AVSS. Half the time, we shut it off if we are bounding between VTOL and Airplane modes frequently.

 

[TFF]

My understanding is the blades are all fly by wire. I figured the Osprey is more airplane that can hover and the Sikorsky is more helicopter that will go fast. The US always wants to buy one to do all. I see them as different. Is the Sikorsky considered powered lift or a helicopter?

 

[D Hillberg]

Not much faster then a Chinook

 

[TFF]

I think where it wins in speed is range; the rotor is just lift in higher speed ranges. Rotor does not make it go fast just the rear fan. Wherever the changeover range is I don’t know, but probably around 80 kts it stops acting less like a helicopter. I know the computer has the retreating blade go flat. There is always an advancing blade on each side. That also makes almost no downwash for an advancing blade to deal with.

 

[cblink.007]

My understanding is the blades are all fly by wire. I figured the Osprey is more airplane that can hover and the Sikorsky is more helicopter that will go fast. The US always wants to buy one to do all. I see them as different. Is the Sikorsky considered powered lift or a helicopter?

The SB-1 is a fly by wire helicopter.

 

[TFF]

I would think the Osprey would win any heavy lift contest. Being Sikorsky, they have to build a big helicopter. To me it would be a better Apache or Cobra replacement. It is scalable to build different sizes. But I bet a smaller one would fly upside down without drama.

Being a helicopter it means minimum transition form another, at least in paper. Powered lift probably takes some getting use to the rules to play with. Being able to have one rotor in settling with power and maybe inducing it

Now when it comes to personal ownership, I can’t afford an out of annual for thirty years helicopter. I would hate to have to pay for Osprey or X2 technology aircraft day to day. I have been disappointed that there is no Augusta 609 in my yard. Even a crashed one; at least that means there are some out there in the wild.

 

[cblink.007]

We can lift 12,500 without much trouble; I've 2-point slung a Humvee at 200 knots!! During my transition training, flying a tiltrotor took some getting used to; pushing for power instead of pulling (what we nickname "helicopter dyslexia"), but strangely enough, transitioning for VTOL to APLN mode was not as tricky as going from APLN back to VTOL. That said, if I got you in the simulator, you'll be able to figure it out quick! In either case, the proprotors, at 38' diameter, have a pretty high disk loading, so one cannot truly "sling it around" the way you can with a more traditional helicopter, such as an H-60 (great bird in its own right).

IMHO, the 609 is a bad tiltrotor design; it ripped itself apart in flight, killing a mentor of mine. There was a funky structural mode in the vertical stabilizer that turned into a yawing mode resulting in the proprotors flapping enough to strike the wing. It has a more simplified swashplate control system than what we have in the Osprey that was unable to compensate for yaw mode feathering & flapping. The 609 does not have the three-axis swashplate controls that we do. I can presume this was done in an effort to reduce the cost of the aircraft...

I had a chance to check out the X2 some years ago. Those blades were stiff enough to to chin-ups off the tips! I'd like to try a co-ax bird some time (even a Kamov), and I wish I could have tried out the V-280 prototype before we retired it.

 

[David L. Downey]

back when we were doing the early development of the XV15/V22, the project and customer partners always assured us skeptics that all service pilots for the V22 woudl be cherrys. no conversion fixed wing or rotary wing pilots would be allowed to fly it. Why? exactly what cblink said. muscle memory is very bad for something that uses customized control inputs for its multile flight regimes. And then of course, when the 609 came along, we were told that they were changing the controls concept but I never learned what was different.

 

[TFF]

Sorry you lost someone. I did not know the 609 did not have all the features of the V22. I figured it would have been better being smaller. Sounds like a pretty big problem that they keep trying to live with.

 

[Aviacs]

Sikorsky is kind of a bad taste in the mouth around here.
Schweizer was an old line family business, the brothers/founders were regular members of the community, as were their involved 2nd & 3rd generation. Many of our EAA chapter members worked there, one was an engineer on the X2. Another was the plant acceptance officer for the government, etc. A few were even old Piper technical employees from down in Loch Haven.

Sikorsky bought the plant, also set up a Blackhawk completion center at the other end of the airport. The Warplane Museum was broke and not paying their lease on their purpose built building, but Sikorsky was in a position to take it over as corporate facilities if the county forced museum off the airport.

A few years later, having eliminated a potential large competitor for government work, Sikorsky shut everything down and moved away.

I did get a lot of nice machine tooling at the auction.
It's disappointing not to fly in the pattern with the B17 (several of our members were captain or 1st officer), PBY, or B25 some late afternoons. Or watch various experimental prototypes, including the X2 zooming overhead. And then hear about development at the next EAA meeting.

 

[BBerson]

Why is Lockheed Martin also involved? Must be infinite bureaucracy and cost. Future Vertical Lift: DEFIANT X™

 

[Toobuilder]

LM bought Sikorsky a few years ago.

 

[cblink.007]

Sorry you lost someone. I did not know the 609 did not have all the features of the V22. I figured it would have been better being smaller. Sounds like a pretty big problem that they keep trying to live with.

There is a reason why Bell washed their hands of that thing years ago...

 

[cblink.007]

muscle memory is very bad for something that uses customized control inputs for its multile flight regimes

I wouldn't call it customized inputs for the different regimes. It's just a matter of pushing for power as opposed to pulling the way some of us prior helicopter guys did. Believe it or not, it became a non issue after a small amount of practice; alot of us had a ton of fixed wing time prior to rotary wing and tilt-rotor as well.

My understanding is that the 609 has a collective in it, opposed to the "Thrust Control Lever" that we have in the Osprey.

 

[TFF]

I have been in the demo sim cockpit of the 609. It has a collective. More speed with blades forward is pulling more collective. Blade tilt on the collective. Seems intuitive for regular helicopter or airplane background. The TCL is always forward for more? So in helicopter mode it’s backwards from a normal helicopter which probably takes a bunch of wrist slapping in the beginning for a helicopter pilot. Either by themselves or by the teacher. Someone can’t be nonchalant to transition into one.

 

[cblink.007]

The TCL is always forward for more?

Correct. Push for Pitch/Power, regardless of configuration. Also, flaperons are AFCS controlled, so no need to work those (unless called for in select EP's).

Like I said, some of us had some "helicopter dyslexia" going on at first...some more than others. But, it self solves within 4-5 hours after first touching the simulator. Mine was cured before the first actual flight.

All this said, I recently flew a model 505 Jet Ranger X out at Fort Worth; last time flying a "real" helicopter was 2018. Pulling for pitch for the first time in a while; no issues. Jockeying a tail rotor? Different story...