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Subject: Highly Autonomous Excalibur UCAV to take flight in 2009
DarthAmerica    6/2/2009 5:51:53 PM
Excalibur Excalibur is a purpose-built armed, tactical UAV. Excalibur fills a gap between current weaponized UAVs and manned strike platforms that provide tactical air support. To enable the attack role, Excalibur will be compatible with Hellfire, APKWS, Viper Strike and other small, precision-guided munitions recently developed by the Department of Defense. Excalibur will use a turbine-electric hybrid propulsion system to give the aircraft VTOL capability while allowing optimization of the turbine engine for horizontal flight. The aircraft's advanced flight control system operates with a high level of autonomy. The aircraft is not remotely piloted, therefore operators are able to focus on mission planning, finding, and engaging targets instead of flying the aircraft. Excalibur combines VTOL launch and recovery, high-speed flight (in excess of 400 knots), and low speed loiter (100 knots) into one aircraft. Excalibur can operate in a STOL or STOVL mode for increased mission durations or payloads. Aurora is under contract to the Army's Aviation Applied Technology Directorate to design a 700 pounds Excalibur technology demonstrator aircraft, will have it's first vertical takeoff and landing (VTOL) flight test planned for summer of 2009
 
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DarthAmerica       6/4/2009 3:36:24 PM

The interesting thing is that the video says it "is not remotely piloted, allowing operators to focus on mission planning, finding, and designating targets", by which they must mean it has a really simple navigation interface where you basically point and click on a map.  That in itself is a pretty interesting advance, particularly for an armed UAV.

Its a severely limited architecture and stupid architecture relying on forward observer and tele-operator joint positive control through a click and cue menue driven setup. Limited..
 
I've directed several air support missions that run with similar setup. I've been directly told by Iraqis, friendly IPs and captured that this was a huge fear they had when encountering us. Whenever they saw the monitor or antenna they knew that any nearby ground, air or indirect fire support assets were in some cases seconds away from being on top of them. The only real difference here is the integration of a UA into the system which we desperately requested and sometimes got. The difference is that the UA was not organic.


I don't think its inabilitiy to fire while hovering is really a valid criticism -- we don't bash the Predator because it can't fire in a hover, do we?  The VTOL feature is to allow it to operate from totally unprepared surfaces and confined quarters.  Once it's in flight it can apparently dash at over 400kts and loiter as low as 100kts, which are good speeds for the kind of mission it is intended for.

The hover configuration is a three point FAIL and an unnecessary to mission engineering complication. JATO aloft and parachute or net recover. KISS!.

 As are Main Rotor, Tail Rotor and Engines with todays common battlefield manned CAS/ISR.


The whole inverted thing does look pretty awkward, but it is an interesting approach to fixed-wing VTOL.  According to the manufacturer, the reason for the inverted landing and takeoff is that this way the wings protect the weapons payload from dust and debris thrown up by the aircraft's thrust.  That isn't really obvious from the cgi video so I'm guessing the full scale version will have its weapons mounted on the wings instead of on those little stubs on the fuselage.


Again another FAIL point that the idiots who designed this thing did not think through.

That's pretty harsh but everyone is entitled to their opinion I suppose.

Neat stuff in any case.

"NEAT" stuff is not what gets it done, Phaid. Sound engineering does.


After test and validation you might be able to make this statement and support it but for now this is more opinion which of course is you right.


-DA 
 
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FJV    I know it's easy to look "smart" by bashing someone else's design, but:   6/4/2009 3:48:56 PM
Just compare this design to a helicopter based UAV:
 
- If one of the three hover engines fail the UAV at the very least be unusable at the worst it will crash.
  (In an emergency situation that central engine might theoretically function as a hover engine)
- On a helicopter based UAV should the engine fail you can land it using autorotation.
  If you wanna get fancy you can use dual engines. (Now 2 engines have to fail and you can still use autorotation)
  Or you can spend more rescources on the single engine making sure it does not fail compared to having to spread
  out rescources on 4 engines
 
- In the 3D rendered video the 2 ducted fans on the wings retract into the wings, it's the only
  place where they could have gone.
      - Note that on the 3D simulation the ducted fans are fixed.
      - Note that on the prototype mock up model parts of the ducted fan stick out above and below the wings.
        This makes extra actuators necesary or at least some mechanism to retract these.
        (Maybe extending the wing covering (sleeve) over the ducted fan is an option (less weight to move)
         also gives you a longer wing for the same weight)
   If one of the actuators rectracting + mechanism the ducted fan fails, then:
     - It can only hover (ducted fan stuck in extended position)
     - It has to land conventionally (ducted fan stuck in retracted position)
     - It becomes unstable (ducted fan stuck somewhere halfway)
- On a helicopter based UAV you have the actuators + mechanism in the main rotor for a coaxial
  design or in the main and tail rotor. Should these fail the UAV crashes.
  The thing is though that the number of actuators is less and that means that again you can either:
     - Spend more resources on a better quality actuator to make sure it doesn't fail.
     - Spend rescources on redundend actuators so that when one fails another can take over.
 
There is the main engine in the middle, If that engine fails the UAV cannot do it's mission, even worse if the actuator rotating that engine fails the UAV cannot do it's mission.
There is also an extra actuator needed to make the UAV rotate about it's z-axis at the beginning of the video. 

A lot extra stuff that you need more that can fail when compared to a "simple" UAV based on a coaxial helicopter design IMHO.
 
PS
Next time maybe discuss a smart desing and why it's smart maybe?
 

 
 

 
 
 
 
 
 
 
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DarthAmerica       6/4/2009 3:58:02 PM
FJV,

We also have to consider the design requirement. Speed has in the past been an issue with ISR UA that have been adapted to be capable of lethal response. 400kts is a lot to ask of a rotor winged platform. The ducted fans allow for useful VTOL performance, better durability/survivability, low speed loiter, fuel economy, smaller storage and logistics footprint and good dash performance. All desirable for a FWD deployed high endurance UA. It's certainly a unique approach and I think any criticism should be based against requirements and certainly the actual ability of the platform to demonstrate it can meet those requirements.

-DA 
 
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Herald12345    FJV covered a lot of it, but I will slam thois in your face, poster.    6/4/2009 10:15:51 PM




The interesting thing is that the video says it "is not remotely piloted, allowing operators to focus on mission planning, finding, and designating targets", by which they must mean it has a really simple navigation interface where you basically point and click on a map.  That in itself is a pretty interesting advance, particularly for an armed UAV.


Its a severely limited architecture and stupid architecture relying on forward observer and tele-operator joint positive control through a click and cue menue driven setup. Limited..



 

I've directed several air support missions that run with similar setup. I've been directly told by Iraqis, friendly IPs and captured that this was a huge fear they had when encountering us. Whenever they saw the monitor or antenna they knew that any nearby ground, air or indirect fire support assets were in some cases seconds away from being on top of them. The only real difference here is the integration of a UA into the system which we desperately requested and sometimes got. The difference is that the UA was not organic.





I don't think its inabilitiy to fire while hovering is really a valid criticism -- we don't bash the Predator because it can't fire in a hover, do we?  The VTOL feature is to allow it to operate from totally unprepared surfaces and confined quarters.  Once it's in flight it can apparently dash at over 400kts and loiter as low as 100kts, which are good speeds for the kind of mission it is intended for.




The hover configuration is a three point FAIL and an unnecessary to mission engineering complication. JATO aloft and parachute or net recover. KISS!.



 As are Main Rotor, Tail Rotor and Engines with todays common battlefield manned CAS/ISR.






The whole inverted thing does look pretty awkward, but it is an interesting approach to fixed-wing VTOL.  According to the manufacturer, the reason for the inverted landing and takeoff is that this way the wings protect the weapons payload from dust and debris thrown up by the aircraft's thrust.  That isn't really obvious from the cgi video so I'm guessing the full scale version will have its weapons mounted on the wings instead of on those little stubs on the fuselage.






Again another FAIL point that the idiots who designed this thing did not think through.




That's pretty harsh but everyone is entitled to their opinion I suppose.





Neat stuff in any case.



"NEAT" stuff is not what gets it done, Phaid. Sound engineering does.








After test and validation you might be able to make this statement and support it but for now this is more opinion which of course is you right.







-DA 




















Something like it, has been tried before and didn't work for OBVIOUS reasons.
 
 
Don't tell me about aviation engineering and "opinions", poster, and don't compare that piece of CRAP engineering you cited with Igor Sikorsky's eggbeater design that he spent a decade getting RIGHT.
 
Herald

 
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WarNerd       6/5/2009 4:19:10 AM

I don't think its inabilitiy to fire while hovering is really a valid criticism -- we don't bash the Predator because it can't fire in a hover, do we?  The VTOL feature is to allow it to operate from totally unprepared surfaces and confined quarters.  Once it's in flight it can apparently dash at over 400kts and loiter as low as 100kts, which are good speeds for the kind of mission it is intended for.
 
 The Predator is not a VTOL, so the question would not apply.

The hover configuration is a three point FAIL and an unnecessary to mission engineering complication. JATO aloft and parachute or net recover. KISS!.
 The main engine pivots to.  I suspect that the fans provide a limited amount of lift and are mainly to provide pitch, yaw, and roll in a hover.  If so, then 2 of them may have to fail to make the craft uncontrollable if the system can compensate correctly.
 
Catapult or JATO launch are simpler, but this vehicle may be too large for a truck mounted ramp.  And the need to produce and haul JATO units would limit the operations tempo.
 
As for parachute recovery, would it work to recover a this vehicle with a full weapons load in a moderate wind or higher?  Parachute recovery may limits when  the vehicle can operate, needs more turnaround time, and increases the likelihood of damage on landing.
 
Net recovery for a vehicle this big would be a maintenance nightmare because of the stresses it places on the airframe.

VTOL operation makes sense if you want the vehicle to operate at a high tempo near the front lines.
 

I guess the real question is what roles is this craft supposed to fulfill?
 
If it is a Predator alternative then the VTOL feature is unnecessary.
If it is a alternative for the A-10 the payload looks light and it needs a gun.
If it is alternative to the Apache then it needs to be able to fire from a hover or 'pop-up'.
 
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DarthAmerica       6/5/2009 5:54:35 AM

Something like it, has been tried before and didn't work for OBVIOUS reasons.


Invalid comparison.

Don't tell me about aviation engineering and "opinions", poster, and don't compare that piece of CRAP engineering you cited with Igor Sikorsky's eggbeater design that he spent a decade getting RIGHT.

 
Herald


Again, as others have told you NULL CONTENT. Needless vitriol and arrogant in the extreme. But whatever, you have zero credibility based on the nature of your post and because you demonstrated a complete inability to be objective when confronted by real subject matter experts with the inappropriate missile for merchants suggestion there is no reason to believe you will behave any differently here POSTER. So you may go back to being ignored so long as you continue to behave immaturely. When you are ready to actually debate something get back to us.

-DA

P.S. Thanks for calling me a Truck Driver. I qualified on 4 new platforms after shedding my Abrams and where I come from A LOT of good people I know, some of whom are KIA/WIA, are driving trucks into harms way right now on your behalf so you might want to consider that. It's time for you to let this obsessive BS you have with me go. You're too arrogant to realize it but it's REALLY making you look bad. We all know you wont care about any of this since you consistently disrespect the Mods and other members who have asked you to tone down the personal attacks, hostility and rudeness so carry on until you get booted again. 


 

 
 
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Herald12345    Technical SARCASM.   6/5/2009 9:09:12 AM



Something like it, has been tried before and didn't work for OBVIOUS reasons.







Invalid comparison.
 
Valid comparison. The thrust fans to control X-plane tilt  on it didn't work right either.
 
 



Don't tell me about aviation engineering and "opinions", poster, and don't compare that piece of CRAP engineering you cited with Igor Sikorsky's eggbeater design that he spent a decade getting RIGHT.



 

Herald






Again, as others have told you NULL CONTENT. Needless vitriol and arrogant in the extreme. But whatever, you have zero credibility based on the nature of your post and because you demonstrated a complete inability to be objective when confronted by real subject matter experts with the inappropriate missile for merchants suggestion there is no reason to believe you will behave any differently here POSTER. So you may go back to being ignored so long as you continue to behave immaturely. When you are ready to actually debate something get back to us.
Incompetent answer. Here's why
 
 
 
 
 

Note third insert picture of the air flow. ALL three fans have to provide thrust to keep the cockeyed device in level flight even during forward thrust as the stupid thing is nose heavy and has no Y plane stabilizer. Nose fan fails, it falls. Left fan fails it rotates, left out of plane off its two thrust lines and falls. Right fan fails, it rotates right out of plane of its tow thrust lines and falls. ANY rotation out of the X plane where it loses wing lift or topples off its jet engine and it falls. Not to mention ballast and trim issues, side drift, point issues, yaw and pitch, sideslip control, etc. etc. etc. etc. You have no idea of what I discuss do you?
      

P.S. Thanks for calling me a Truck Driver. I qualified on 4 new platforms after shedding my Abrams and where I come from A LOT of good people I know, some of whom are KIA/WIA, are driving trucks into harms way right now on your behalf so you might want to consider that. It's time for you to let this obsessive BS you have with me go. You're too arrogant to realize it but it's REALLY making you look bad. We all know you wont care about any of this since you consistently disrespect the Mods and other members who have asked you to tone down the personal attacks, hostility and rudeness so carry on until you get booted again.
 
Its time for you to understand that I could care less about what GROUND VEHICLE you drive and who you know when it comes to your assertions and claims. Unless you are a subject expert in aviation (and you ain't), your opinions as to why this piece of junk is a good idea are meritless. The fact that you compared this bodged up piece of engineering to a helicopter just shows you have no clue as to why it is nothing like a helicopter and why the most famous piece of junk to which it can be compared is the Avro air car.
 
Herald
 






 



 
 
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Herald12345    Technical SARCASM.   6/5/2009 9:37:44 AM




I don't think its inabilitiy to fire while hovering is really a valid criticism -- we don't bash the Predator because it can't fire in a hover, do we?  The VTOL feature is to allow it to operate from totally unprepared surfaces and confined quarters.  Once it's in flight it can apparently dash at over 400kts and loiter as low as 100kts, which are good speeds for the kind of mission it is intended for.


 

 The Predator is not a VTOL, so the question would not apply.



The hover configuration is a three point FAIL and an unnecessary to mission engineering complication. JATO aloft and parachute or net recover. KISS!.


 The main engine pivots to.  I suspect that the fans provide a limited amount of lift and are mainly to provide pitch, yaw, and roll in a hover.  If so, then 2 of them may have to fail to make the craft uncontrollable if the system can compensate correctly.

It only needs one fan to fail even partially to rotate out of plane and crash. Three fans=three fails. The Harrier has one fail point, the jet engine.It uses NOZZLES. The British are NOT stupid. KISS.   

Catapult or JATO launch are simpler, but this vehicle may be too large for a truck mounted ramp.  And the need to produce and haul JATO units would limit the operations tempo.
 
Maybe, but you can get a fairly large UAV into the air with a gunpowder powered zero length launcher. The Navy and Air Force hurled whole planes (Sabres for example) much larger than this piece of junk into the air off a rail launch catapult of less than twenty  feet for more than eighty years! . .


As for parachute recovery, would it work to recover a this vehicle with a full weapons load in a moderate wind or higher?  Parachute recovery may limit when  the vehicle can operate, needs more turnaround time, and increases the likelihood of damage on landing.

Its a suggestion. I don't see why a farm pasture and SKID body wouldn't work with a conventional. Wht doi we want bring back of live ordnance here again? Are we going to have bomb specialists travelling with the bird that we will be able to depliy iut from mointaintops? (One of the "NEAT" odeas that shpws me that these incompetwents at Aurora have NOT thpought this crazy odea through to completion) Who is going to safe the HELLFIRE at the battalion level again? 

Net recovery for a vehicle this big would be a maintenance nightmare because of the stresses it places on the airframe.

Lift body and skid lander. BUILD IT TOUGH

VTOL operation makes sense if you want the vehicle to operate at a high tempo near the front lines.

Then make it a coax helo like this.

Cypher II....

I guess the real question is what roles is this craft supposed to fulfill?
 The USMC know what they are doing..
 
If it is a Predator alternative then the VTOL feature is unnecessary.
Absolutely. KISS.
If it is a alternative for the A-10 the payload looks light and it needs a gun.
True.
If it is alternative to the Apache then it needs to be able to fire from a hover or 'pop-up'.
Which is what Cypher can and will do. But note even Cypher has design troubles and issues?
 
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reefdiver       6/5/2009 9:37:45 AM
Back to the aircraft. Its going to be test flown in the next couple of months (almost 2 years behind schedule).
They've apprently done lots of wind tunnel and CFD software analysis of this thing and the Army has invested in it.
VTOL and 400knots. Sounds like something worth having.  One capable of carrying a person is planned. (Personally, I want a 2 person manned version although I might want to still carry my parachute).
 
Will it fly?  I'd bet on it with today's technology. Will it meet all its technical and mission specs and be adopted by the Army is the better question.  At least we'll know if it will fly in the next couple of months. 
 
 
 
 
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reefdiver       6/5/2009 9:38:52 AM
Whoops - that was "apparently" ...fingers are faster than the brain.
 
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