Canadair/General Dynamics CL-84 Projects

[hesham]

Hi,


may be the early CL-84 drawing,please note the cockpit shape.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19720007351_1972007351.pdf

 

[Apophenia]

Hesham, the earlier incarnations of the CL-84 had somewhat snubbier noses and PT6 engines rather than Lycoming T53s. See:

http://www.flightglobal.com/pdfarchive/view/1963/1963%20-%200278.html?search=Canadair%20CL-84

 

[Stargazer]

Hesham, the earlier incarnations of the CL-84 had somewhat snubbier noses and PT6 engines rather than Lycoming T53s.

Here is another example taken from RAF Flying Review, February 1963:

 

[fightingirish]

An Update at SDASM Flickr Archives showing drawings of CL-84 ASW, AEW Gunship & USMC variant proposals.

Link: http://www.flickr.com/search/?q=CL-84&w=49487266@N07&ss=2&s=rec


Sorry folks,
no time to attach some resized pictures. :-[
Maybe good members like Stargazer or hesham will find the time to do so...

 

[Stargazer]

Maybe good members like Stargazer or hesham will find the time to do so...

Sure. But I'm not finding time... I'm MAKING time. Usually means getting less sleep in the process... :-\

 

[Stargazer]

Also:

 

[Antonio]

Star,

Gorgeous! many thanks for that treasure.

Antonio

 

[Jemiba]

Thanks Stéphane for accepting a sleepless night ! Looking at those pictures, I think,
it was worth it, especially the A2A-Version is interesting and ne w to me. Would mean,
that the CL-84 would have been fitted with an Air-to-Air radar. What was the minimal
radar suit to enable an aircraft to use Sparrows ?

 

[Abraham Gubler]

Thanks Stéphane for accepting a sleepless night !

x2

Would mean,that the CL-84 would have been fitted with an Air-to-Air radar. What was the minimal radar suit to enable an aircraft to use Sparrows ?

The USN did a bit of thinking in the 1970s of A2A helicopters including Sparrows on a Seasprite. Apparantly to shoot down incoming missiles. The CL-84 would have no problems carrying a fighter type radar with continuous wave (CW) illumination capability. Radar dishes as small as 24” diameter and as large as 48” (F-4B Phantom had a 32” diameter dish) were used to guide Sparrows.

Interesting that one of the naval CL-84 pictures shows a wing fold method of rotating the wing to vertical and folding forward the part of the wing outboard of the engines. The counter rotating props are spun to line up lengthways. The LTV XC-142 wing fold method was to rotate the wings to vertical and then fold the entire wing aft requiring a pivot in the cross power gearing.

 

[Grey Havoc]

The USN did a bit of thinking in the 1970s of A2A helicopters including Sparrows on a Seasprite. Apparantly to shoot down incoming missiles. The CL-84 would have no problems carrying a fighter type radar with continuous wave (CW) illumination capability. Radar dishes as small as 24” diameter and as large as 48” (F-4B Phantom had a 32” diameter dish) were used to guide Sparrows.

There were plans to for an anti-ASM variant of a new build (lightweight) version of the Seasprite referred to as the SEALITE. Mission was referred to as CMD (Cruise Missile Defense). It was to be able to mount one or two AIM-7Es, along with a dedicated ECM/ESM suite, apparently.


EDIT: SPF topic on the SEALITE: http://www.secretprojects.co.uk/forum/index.php/topic,489.0.html

(h/t hesham)

 

[Grey Havoc]

On another note, the missiles being carried in one of the new pictures seem to be the 'original', i.e. ASW version of the Harpoon.

 

[elmayerle]

One combination I've always wondered about would be a tilt-wing with wingtip engines and prop-rotors. You wouldn't tilt the nacelle, but the whole wing. I could see this reducing loading in vertical modes and definitely simplifying the wiring and plumbing to the engine nacelles.

 

[Archibald]

Apparantly to shoot down incoming missiles

You mean, huge Soviet antiship missiles such as the AS-6 Kingfish ? (of Red Storm rising fame : )

Imagine the kind of aces that would have made: five A2A victories... flying an Helicopter against cruise missiles.

 

[Stargazer]

One combination I've always wondered about would be a tilt-wing with wingtip engines and prop-rotors. You wouldn't tilt the nacelle, but the whole wing. I could see this reducing loading in vertical modes and definitely simplifying the wiring and plumbing to the engine nacelles.

Isn't this exactly what the XC-142A was about, or am I misunderstanding your point?

 

[elmayerle]

One combination I've always wondered about would be a tilt-wing with wingtip engines and prop-rotors. You wouldn't tilt the nacelle, but the whole wing. I could see this reducing loading in vertical modes and definitely simplifying the wiring and plumbing to the engine nacelles.

Isn't this exactly what the XC-142A was about, or am I misunderstanding your point?

No, the XC-142 still had propellers mounted on the wing. If you want a quick description of what I was suggesting, think of a V-22 where the entire wing, not the nacelles, tilts. Those big prop-rotors are rather more efficient in hover that a number of smaller propellers.

 

[Tailspin Turtle]

No, the XC-142 still had propellers mounted on the wing. If you want a quick description of what I was suggesting, think of a V-22 where the entire wing, not the nacelles, tilts. Those big prop-rotors are rather more efficient in hover that a number of smaller propellers.

The reason that configuration hasn't been demonstrated is that a tiltwing requires relatively high disc-loading propellers located along the wing to keep it from stalling in partial wing-borne flight. As a result, one of the tiltwing's shortcomings is an inability to make a low-power, steep descent because of wing stall. The relatively low disc loading tiltrotor, since it doesn't accelerate the air going through the rotor disc as much, can't keep the tilted wing from stalling over an even larger portion of the flight envelope. The tiltrotor pays a penalty relative to the downloading on the wing and doesn't have as high a top speed as the tiltwing. However, the lower disc loading of the tiltrotor offsets the download penalty relative to the tiltwing's hover performance so it is still more efficient in a hover. Roughly speaking, the tiltwing is a turboprop airplane that can hover, albeit not as efficiently as a tiltrotor and with some limitations on handling qualities. The tiltrotor is not as good an airplane as the tiltwing but closer to the helicopter in its hover capability. So far, the tradeoff of cruise speed and hover performance and handling qualities has favored the operational use of the tiltrotor. However, a case can be made that the tiltwing is more appropriate for a civil passenger-carrying application since only a brief hover would be required and it would be operating from hard surfaces.

 

[AeroFranz]

That's a very good description of the tradeoffs between the two configurations. I would expand and add that the so-called "inbound transition" (converting from cruise mode to hover) is the biggest problem for tiltwings, because you are powering down (props are not accelerating the flow as much over the wing) and you are descending (higher angle of attack). As mentioned by TT, if forced into excessively high angle of attack, the result is stall over portions of the wing, thus drag and increased power requirement.
That puts a limit to the flight envelope, which can be more or less acceptable from an operations point of view. It's good to point out that ALL VTOL machines have flight envelope limitations, some more than others. In the case of tilt wings, there are ways to improve the handling qualities and broaden the envelope. For example, tests with the VZ-2 and wind tunnel tests have shown that four props, giving more uniform flow over the entire wing, were better than two. Also, leading edge devices like slats or krugers could delay separation to higher alphas.

 

[elmayerle]

thank you both for the information.

 

[cluttonfred]

Ditto, a very helpful comparison of the two systems which helps to explain why, for examples, the Marines would be most interested in the tiltrotor configuration for assault operations. Another point to consider is that the smaller props of tiltwing allow it to operate as a conventional aircraft when the VTOL or even STOL function is not necessary.

I have always liked the Canadair CL-84 and especially the LTV XC-142 and thought that a less ambitious cousin, giving up the hover to create a super-STOL aircraft with a variable incidence wing blown by multiple props, would have made a fantastic all-around assault transport, a cargo and passenger plane for bush use or a commuter airliner able to operate out of short strips close to the city.

 

[AeroFranz]

Such thing was given consideration. Canadair studied a tiltwing regional airliner, we have it somewhere else on the forum. The studies were pretty far along, Flight international even has a cutaway of it. Sorry, i can't remember the designation!

 

[hesham]

Hi,


here is advanced designs developed from CL-84.

http://www.dtic.mil/dtic/tr/fulltext/u2/761972.pdf

 

[hesham]

Hi,


the CL-84 Sea Control Ship.

http://www.dtic.mil/dtic/tr/fulltext/u2/761972.pdf

 

[Pioneer]

Found this video interesting in regards to the proposed CH-84-1D attack variant & CH-84A AAFSS proposal!!

View: https://youtu.be/sv4vKser4Ck


Regards
Pioneer

 

[VTOLicious]

Thx for posting Pioneer!

It is really impressive how smooth and fast it transitions to forward flight after the reverse flight at around 04:00.

BR Michael

 

[Abraham Gubler]

Found this video interesting in regards to the proposed CH-84-1D attack variant & CH-84A AAFSS proposal!!

Thanks for posting. Very interesting video. The CL-84 showed itself to be a very stable and responsive gun platform from the hover and pass. Also very interesting to see it hover rearwards and then drop the wings and power forward.

 

[kagemusha]

A great document about the CL-84.

There's also a paragraph describing the McDonnell Model 175.

And details on the General Dynamics proposal for the OVX study, too.

http://documents.techno-science.ca/documents/CASM-Aircrafthistories-CanadairCL-84VSTOLhistory.pdf

 

[hesham]

Brilliant and great report,many thanks to you Kagemusha,

tomorrow,I will divide it into a pictures.

 

[AeroFranz]

Fantastic! this made my day! ;D ;D ;D
Many thanks, Kagemusha!

 

[Apophenia]

Fantastic! this made my day! ;D ;D ;D
Many thanks, Kagemusha!

Mine too ... thanks!

 

[Michel Van]

Big THX, kagemusha

 

[Avimimus]

Such thing was given consideration. Canadair studied a tiltwing regional airliner, we have it somewhere else on the forum. The studies were pretty far along, Flight international even has a cutaway of it. Sorry, i can't remember the designation!

Two other places on the forum actually!

[NOTE: these two topics were merged and now appear here: https://www.secretprojects.co.uk/forum/index.php/topic,30472.0 — Mod.]

 

[VTOLicious]

A great document about the CL-84.

There's also a paragraph describing the McDonnell Model 175.

And details on the General Dynamics proposal for the OVX study, too.

http://documents.techno-science.ca/documents/CASM-Aircrafthistories-CanadairCL-84VSTOLhistory.pdf

Wow, excellent stuff! Thx for sharing kagemusha!

 

[hesham]

From that great report.

[NOTE: All previously attached images can now be found in a separate topic devoted to all pre-Dynavert Canadair VTOL projects — Mod.]

https://www.secretprojects.co.uk/threads/canadairs-vtol-projects-before-the-cl-84.709/

 

[hesham]

And;

[NOTE: All previously attached images can now be found in a separate topic devoted to all pre-Dynavert Canadair VTOL projects — Mod.]

https://www.secretprojects.co.uk/threads/canadairs-vtol-projects-before-the-cl-84.709/

 

[hesham]

And;

 

[hesham]

And;

[NOTE: All previously attached images can now be found in a separate topic devoted to all pre-Dynavert Canadair VTOL projects — Mod.]
https://www.secretprojects.co.uk/forum/index.php/topic,30469.0/all.html

 

[hesham]

And;

 

[hesham]

And;

 

[hesham]

Finally;

 

[Archibald]

An AWACS CL-84, now that's interesting ! Better, performance-wise, than a Sea King. Good for the RN.