Avro Canada CF-105 History by Keith Clifford
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The Avro Canada CF-105 Arrow or more commonly the Avro Arrow was a twin engine, supersonic
interceptor of Canadian design.  It was the most advanced interceptor of it's day.  Had it gone 
into production it is likely that variants of it would be still flying today.  The Arrow 
represented the best of Canadian aviation technology in the 1950's.  It boasted many innovations
in aircraft design that are common place today.  These included one of the first fly-by-wire 
control systems.  A decision was made very early in the program that the first aircrfat would be 
pre-production prototypes built with production jigs and tools.  This was in opposition to the
standard practice of hand built prototypes.  This was done with a view to drastically shortening 
the time required to bring the aircraft into service.  

The CF-105 started out as a private Avro study in anticipation of a request by the Royal Canadian 
Air Force to find a replacement for the Avro Canada CF-100.  This was started in 1952.  A series 
of configurations was considered but the two final designs were high wing delta aircraft.  One was 
single engined while the eventual choice was a twin engined design.  Given the harsh conditions 
and remote locations over which the aircraft would have to operate, the safety of two engines made 
considerable sense.  The aircraft was intended to be an all Canadian design.  Both airframe 
and engines were to be of local production.  The engine eventually designated to power the Arrow
was the Orenda Iroquois.  Orenda Engines was a subsiduary of Hawker Siddeley who also owned Avro
Canada.  Development work continued in secret up to shortly before the roll out of the first 
prototype in October 1957.  

The Arrow was to be produced in a series of different Marks.  The Arrow Mk 1 was a pre production
series of five aircraft.  As the Iroquois engine was not yet reday for flight, the Mk 1's were
powered by the Pratt and Whitney J-75.  This engine later went on in service which such aircraft
as the Republic F-105 and Convair F-106.  The sixth aircraft was the first Mk 2 and also the first 
aircraft to feature the Iroquois engine.  Preparations were well in hand and it was only a few 
days before the first flight of the Mk 2 when the project was cancelled in February 1959.
Had Avro had the chance, 37 aircraft could have been completed with the materials on hand.  
This included the first aircraft destined for squadron service.  As such the Arrow never had a
chance to demonstrate its full potential with the Iroquois engine.  The Arrow Mk 2A likely would
have been the version to enter RCAF service.  It would have had increased range over the Mark 2.
The CF-105 Mk 3 was in the planning stage.  It would have featured variable geometry intakes, 
revised aircraft skins and the capability of operating at Mach 2.5 at 65,000 feet.  

The Arrow was a spectacular aircraft.  It was designed to operate at 60,000 feet at speeds in 
excess of Mach 2.   The original RCAF requirements called for performance in the range of Mach 1.5 at 
50,000 feet in a 2G turn without any loss of altitude.  This was easily met by the J-75 powered 
Mark 1 aircraft. What the eventual Iroquois powered Mk 2's and 3's would have achieved 
is open to speculation.  Combat radius was designed to be 500 to 650 miles.  Provision was made
for a 500 gallon drop tank mounted on the aircraft centerline.

It was planned to use a Canadian designed fire control system called ASTRA in conjunction with the 
Sparrow missile as the main armament.  The Arrow had a quick change weapons bay which could be 
configured to accept other missiles such as the Falcon.  The bay was sixteen feet in length.
The Arrow mission was planned on being "automatic" from shortly after take off to just prior to 
landing.  The mission would be integrated with the NORAD SAGE system.  The aircraft would be directed 
from the ground to interception and the subsequent release of weapons.  (A similar but
less advanced system was used by the F-101 Voodoo.)  The Arrow would then be directed back to its
base.

The Arrow fell victim of escalating costs and the mistaken belief that a manned bomber threat would 
evaporate in favour of the ICBM.  There were delays and heavy costs in the ASTRA development program.  
By the time of cancellation in February 1959 it was estimated that the
production examples of the aircraft would cost $9 M Cdn.  The Canadian government of the time
chose instead to obtain two SAM sites with 56 CIM-10B Bomarc missiles. It later became apparent
that the aging CF-100 interceptors would have to be replaced as the manned bomber threat didn't go away.  
Sixty-six F-101B Voodoos were obtained from the US.  These aircraft had a lesser 
performance than the Arrow.  Given the expenditures incurred with the Voodoo and the Bomarc, the
Arrow program, it was argued, could have been completed with the same funds.

Despite all this, the Arrow was a remarkable achievement for a country like Canada.  Many of the
Avro Canada design team later went on to achieve distinction in such areas as the American space program 
and the Anglo/French Concorde SST program.


References:  Avro Arrow; The Story of the Avro Arrow from its Evolution to its Extinction
	     Richard Organ, Ron Page, Don Watson and Len Wilkinson
	     The Boston Mills Press  1980

	     Aviation In Canada
	     Larry Milberry
	     McGraw-Hill Ryerson Ltd  1979  

      
