Canadair CL-45 ASW Helicopter Project

[hesham]

Hi,

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


[NOTE: all attached images removed and replaced by better quality, properly labeled versions, see further below — Mod.]

 

[Pioneer]

Interesting hesham, haven't heard of this project before.
Thanks

Regards
Pioneer

 

[hesham]

Thank you my dear Pioneer.

 

[Stargazer]

CL-45 VTOL

In June 1954, a proposal and design requirements study for a new Air-Sea Warfare (ASW) helicopter was issued by the Assistant Chief of Naval Staff (Air) Royal Canadian Navy (RCN). Canadair Limited, along with the specialized assistance of the moderately experienced Hiller Helicopter Company of Palo Alto, California, were co-sponsored on this specific RCN project study.

During November and December 1954, Canadair sent a small delegation of their Preliminary Design engineering personnel to Hiller to assist in the conceptual design of the proposed single-rotored CL-45 A.S.W. helicopter. With power supplied by three General Electric T-58 GE2 engines, this helicopter, with a 19.5 m (64.0 ft) diameter two-bladed main rotor, was to have a gross weight of 7,711 kg (17,000 lbs). It was to have an overall length (main rotor tip to tail rotor tip) of 23.4 m (76.7 ft) and an overhead clearance of 5.2 m (17.0 ft). Nominally, a crew of four would man the helicopter during typical flight operations.

Along with the intended search and attack mission roles for the stated A.S.W. helicopter, other tasks included those of personnel or ambulance transport, rescue operations, cargo transport, and training. Droppable weapons would be carried internally on three stations below the main cabin. From ship and shore stations it could also be utilized as a crew trainer. Alighting gear configurations had a fixed 4.4 m (14.3 ft) wide 4-wheel arrangement as basic with flotation bags or skids available as alternates. For stowage aboard ships, the twin-bladed tail rotor section would be folded upwards and forward to rest atop the rear fuselage section, then the main rotor would be folded aft, being stowed inline with the main fuselage. Stowed dimensions were limited to 12.8 m (42.0 ft) long by 15.2 m (15.0 ft) wide.

The RCN had formed its first anti-submarine warfare squadron in July 1955, equipping it with the latest version of the Sikorsky HO4S helicopter. A year later, ASW helicopter operations with the HO4S from small warships was investigated and RCN service standardization with this type remained until the advent of the much larger Sikorsky CHSS-2 Sea King in 1962.


Photo captions:
1. A small, articulated model of the “Canadair CL-45 A.S.W.” helicopter, seen here in February 1955, depicts its normal flight.
2. Note the personnel access hatch location on the starboard side and the two small windows for crewmembers seated at separate workstations located immediately behind the bulkhead of the fully glazed cockpit.


NOTE: this write-up is taken directly from a PDF document, previously shared by forum members Kagemusha and hesham in the CL-84 topic and here, and entitled:
DESIGN AND DEVELOPMENT HISTORY OF THE CANADAIR CL-84 V/STOL TILT-WING AIRCRAFT (written by Bill Upton, Canada Aviation Museum Research Volunteer, and published by the Canada Aviation Museum).
http://documents.techno-science.ca/documents/CASM-Aircrafthistories-CanadairCL-84VSTOLhistory.pdf

All other pre-Dynavert VTOL projects by Canadair are now covered in a separate topic (also made up of excerpts from the same document):
https://www.secretprojects.co.uk/forum/index.php/topic,30469.0/all.html

 

[Hood]

Nice work formatting all these projects Skyblazer.

One small aside/question regarding the CL-45 ASW helicopter. I have seen references to the RCN conducting light helicopter trials with a Hiller helicopter around 1954/55 aboard HMCS Labrador.
I wonder if this was linked to this programme? Does anyone know which Hiller model was used for the trials?

 

[CJGibson]

The CL-45 does have a rather Hilleresque main rotor.

Chris

 

[Pioneer]

Wow thanks Skyblazer, I've never heard of the CL-45 ASW helo program, and the pictures and drawing you've provided has gained my attentiin!


Regards
Pioneer

 

[hesham]

From, Canadair The First 50 Years.

 

[riggerrob]

Dear Hood,
"Meanwhile, small deck - a 6,500 ton icebreaker cannot really be called a small ship ... In 1955 HMCS Labrador embarked two Bell HTLs and the next year the ship's flight was augmented by a Piaseki HUP. The operation of these aircraft ... throughout Canada's Arctic... flight trials of an HO4S-3 from a platform built over the aft end of HMCS Buckingham, a Perstonian class frigate. Flight trials commenced in 1956 ..."
from Captain Rolfe G. Monteith's book: "Certified Serviceable, from Swordfish to Sea King" (1995, CNATH Book Project, Canada).

I worked on the flight decks of HMCS Athabaskan and HMCS Iroquois hauling down Sea King helicopters with the Beartrap system.

 

[ILikeTanks]

They already have the CX-131 multirole tiltrotor under development, which is a faster and longer-ranged alternative to helicopters for ASW.

 

[hesham]

View attachment 706023They already have the CX-131 multirole tiltrotor under development, which is a faster and longer-ranged alternative to helicopters for ASW.View attachment 706022

By that time (Year 1954),they didn't have yet CL-84 ?!.

 

[Apophenia]

By that time (Year 1954),they didn't have yet CL-84 ?!.

Quite right, that RCN ASW contest was about a decade earlier.

The concept of using sonar-equipped helicopters instead of a DDE screen was only 2 years past experimental installations in 1954 (the purpose-designed Sikorsky HSS-1 Seabat wouldn't enter USN service for another year). Canada was asking for ASW helicopters because the former Chief of Naval Staff, VAdm Harold TM Grant, had told the Cabinet Defence Committee in 1948 that the future RCN's main role within NATO would be ASW.

The 1954 requirement sprang out of a Naval Staff committee formed the previous year. Its conclusion was that helicopters held great promise in ASW hunter-killer roles but that available airframe types "were unsuited to the rigours of ASW at sea". The result was a recommendation for form an ASW squadron on six Piasecki Retriever helicopters ... which was rejected. [1]

Instead, the RCN held out for a more capable helicopter. That came in 1955 in the form of the Sikorsky HO4S-3 Sea Horse fitted with US AN/AQS-4 dipping sonar. Doubtless, had the decision come a year later, the candidate would have been the USN's Seabat. But the HO4S-3 did have the advantage of commonality with the in-service HO4S-2 rescue choppers. Beginning their active ASW role embarked aboard HMCS Magnificent (CVL 21) in April 1956, the HO4S-3s had almost a decade of service in by the time that the prototype CL-84 had flown.

______________________________

[1] That may have been fortunately, a handful of HUP-3s were bought for use aboard the Arctic Patrol Vessel, HMCS Labrador and they had their issues. One of these helicopters would eventually land-on - 662 operating off the flight deck of HMCS Assiniboine in August 1963.