DESIGN AND EARLY
HISTORY
Even
before the prototype CF-100 had flown, the Canadian Air Force began to make
plans for its replacement. The CF 100 had been designed as a two place, twin
engine, day and night, all weather, long range interceptor to meet Canada's
requirements for defense of the north during the cold war.
A swept wing version, the
CF-103 was found to be obsolete before it left the drawing board. In 1953, the
RCAF issued specifications calling for the following....
The fighter must be a two
seater, capable of
operating from a 6000 foot runway, have a range of 600 nautical miles, and
a speed of Mach 1.5. It was also to have been able to carry an advanced missile
and fire-control system, necessitating a large internal weapons bay. It was
to be able to pull 2 G's at 50,000 feet without any loss in speed or altitude. These
were extremely advanced requirements for the day
As with the CF-100 in it's day, no
other aircraft in the world was found to be capable of this performance, so the
decision was made to design and produce the aircraft in Canada.
GENERAL DESCRIPTION
In July, 1953, AVRO AIRCRAFT,
Canada, got the go-ahead to begin design on a two seat, twin engined fighter/ interceptor
based on these requirements. A high delta wing configuration was chosen, both
for good high-speed flight characteristics, and to give easy access to the
weapons bay and power plants. A large amount of room for fuel storage would
be possible in such a wing, although it could also be made very thin for low
drag. This same thinness would be a disadvantage as well....the
undercarriage would have to be extremely slim to fit inside. (the brakes used
had not been designed for the weight of such an aircraft, so these, reaching
white hot heat, coupled with the tiny tires used, were a source of many blowouts
and other taxiing problems). A four degree anhedral was incorporated.....it had
no appreciable effect on aerodynamics, but it kept the undercarriage length
manageable.
ENGINES
Originally, Rolls Royce
RB106 engines were to be used. By 1954, these became unavailable so AVRO
switched to Curtiss Wright J-67's. These, too, were discontinued, so the choice
became Pratt and Whitney J75's. This was an interim measure, as the ultimate power plant
was to be the extremely advanced PS-13 IROQUOIS engine then
under development at ORENDA, a division of AVRO.
COMPUTER CONTROLS
The technical difficulties to
be overcome in developing such an advanced aircraft were enormous. Almost every
aspect of it's design broke new ground. It's control system was
computerized....what we now call "Fly by wire". Instead of a
mechanical link between the pilot's controls and the control surfaces, there was
a complex system of sensors to detect the pilot's input, and servos and
hydraulic jacks to deliver the required movement to the control surfaces at the
correct time. In the event of failure of either engine under power, the computer
could instantly compensate....so quickly that the pilot wouldn't notice a change
in the handling....this in direct contrast to the severe yaw which is normal in
such a situation. The handling parameters could be readily changed via software.
Ultimately, it was planned, the aircraft would be able to
virtually fly itself on missions, as it was thought that interception at supersonic speeds would be
too fast for the reflexes of any human pilot. Missions would also be
controllable from the ground via a new telemetry system.
AERODYNAMICS
A huge amount of aerodynamic
testing had to be carried out as well....no one had ever had to contend with the
speeds expected before. The best aircraft of the day could only exceed Mach 1
under good conditions...i.e.......in a dive. The Arrow was conceived to be equally
comfortable operating routinely on either side of the sound barrier. Heating and
weakening of the structure due to air friction had to be taken into account, so
an extremely powerful air conditioning system was needed. Extensive use
was made of titanium and other exotic substances. The air intakes came in
for special attention....airflow here for supersonic flight is especially
critical. Various wind tunnel facilities were utilized, both in Canada and the
U.S. Much supersonic proving was done at the N.A.C.A. facility in Langley, West
Virginia, as nothing similar was available in Canada. A lot of theoretical work
on the so-called "area rule" was carried out. (It was found that a
fuselage which is shaped like a Coke bottle creates far less drag at supersonic
speeds, and, therefore is far more efficient regarding power requirements.)
WEAPONS SYSTEM
Another important innovation
was the fully enclosed, retractable weapons bay on the bottom of the fuselage.
This space ( 3 feet by eight feet by eighteen feet) was larger than the bomb
bay of a B-29 bomber. A variety of armament packs could be used, or the space
could hold extra fuel or bombs, as required. This was a much neater and
efficient method than hanging everything under the wings, which is STILL done
on many of today's fighter jets.
Two weapons systems were being
considered. AVRO favoured a fire control system from HUGHES AIRCRAFT as they
had successfully dealt with this company on earlier projects. The Canadian
military, on the other hand, was for an extremely advanced, but undeveloped
missile system called ASTRA 1. Theoretically, this would have been a
"do-everything" system...but the contractors working on it were
inexperienced, and the costs of getting it up to speed showed every sign of
becoming enormous. In 1956, AVRO again formally requested that an advanced
Hughes system be used, but due to the fact that ASTRA was heavily classified,
couldn't mount proper arguments. AVRO didn't push the issue enough,
perhaps....the RCAF was, after all, the employer upon whom their entire
existence depended! Ultimately, control of costs WAS passed over to the
military. The ensuing huge cost overruns from endless re-designs and changes
that had to be made to the entire aircraft were therefore beyond AVRO's
control. (And, unfortunately, this did indeed become a major factor in the
demise of the whole project)
PROPOSED PRODUCTION
METHODS
Also radical on the Arrow
project was the fact that all aircraft would be built directly from production
tooling...there would be no prototypes as such. This meant that all of the
myriad systems would have to be extensively tested before being approved for
tooling. This would mean enormous cost savings and less time to get the
aircraft into actual service.
ROLLOUT AND FLIGHT
TESTING
The
first official roll-out of the Arrow was on October 4, 1957 before
approximately 12,000 people. An unveiling speech was made by the Honorable
George R Pearkes V.C, Minister of National Defense.
Here is a significant excerpt: "Much
has been said of late about the coming missile age and there have been
suggestions from well intentioned people that the era of the manned aeroplane
is over and that we should not be wasting our time and energy producing an
aircraft of the performance, complexity and cost of the AVRO ARROW. They
suggest that we should put our faith in missiles and launch straight into the
era of push button war. I do not feel that the missile and the manned aircraft
have, as yet, reached the point where they should be considered as
competitive.
They will, in fact,
become complimentary. Each can do things which the other cannot do, and for
some years to come both will be required in the inventory of any nation
seeking to maintain an adequate "deterrent" to war. However, the
aircraft has this one great advantage over the missile. It can bring the judgment
of a man into the battle and closer to the target where human judgment,
combined with the technology of the aircraft, will provide the most
sophisticated and effective defense that human ingenuity can devise.
These words
are rather significant, in light of the Military's later total reversal on
this issue...and the fact that they later had to reverse their reversal!
FIRST FLIGHT
Engine run-ups began in December,1957 and
ground taxi tests were began in January, 1958. Finally....on March 25, 1958,
the aircraft and the weather were both ready. Jan Zurakowski, AVRO's chief
experimental pilot climbed into Arrow number RL25201 and took off at
9:51 am, followed by two chase planes, an F-86 Sabre and a CF-100. The
aircraft performed almost perfectly and was put through some mild maneuvers
The total flight time was 35 minutes.
TEST FLIGHTS
By April 3, the Arrow had been taken to an
easy Mach 1.1 at 40,000 feet. On Friday, April 18 a speed of Mach 1.52
was reached at 49,000 feet while still climbing. These early tests were
conducted over the Hamilton- Toronto area of southern Ontario and complaints
were received from within a hundred mile radius of windows being rattled from
sonic booms. As a result future tests were switched to over Northern Ontario.
Flight testing continued. In August, the
second Arrow became airborne. On Sunday September 14, Zurakowski flew Arrow
202 to Mach 1.86 at 50,000 feet, the highest speed he would reach in his
career.
......to be continued at
a later date
