|Here are the
four men who co-ordinated the efforts of all phases
of Engineering which went into creating the Arrow.
From left: R. N. Lindley, Chief Engineer; J. C. Floyd,
Vice-President Engineering; Guest Hake, Arrow Project
Designer; and Jim Chamberlin, Chief of Technical
|was received in October of that year.
NAE found the C104/2 design had many desirable features
but considered the proposed aircraft too heavy. It
recommended that further studies be made on this configuration.
In addition, changes were made at this time to the
RCAF requirements for the all-weather fighter concept.
These primarily called for an increase in the aircraft's
"Go-Ahead" . . .
The C104 proposal was, as a result, redesigned,
and the new configuration was established as the
C105. To meet the aerodynamic requirements the
new proposal maintained the delta planform and
was twin-engined, but its weight was reduced while
the overall size was kept as small as possible.
Avro submitted the C105 proposal to the RCAF in
In less than one month the "Go-Ahead" was
received from the government authorizing a design study of the C105 to meet the
First step in the design study was to adapt the new
concept to Rolls Royce RB106 engines which were then in an advanced stage of
development. From that point things progressed rapidly and the first tests of
the wind tunnel development program were run in September 1953, only two months
after the "gun was fired".
To date, Arrow wind tunnel models have been tested from
low speed to twice the speed of sound. Facilities used included
| NAE (Ottawa) for low and high speed
testing, Cornell Aeronautical Laboratories (Buffalo)
for transonic tests, NACA (Langley Field, Virginia)
for supersonic tests, and NACA Lewis Laboratory (Cleveland)
for air intake tests. Seventeen models, ranging from
1/80th to 1/6th scale were used at one or the other
of these facilities, to obtain necessary structural
and aerodynamic data.
Wind tunnel limitations caused Avro engineers to explore
further techniques for obtaining important aerodynamic data. These consisted
mainly of a lengthy program of firing large scale free-flight models, with rocket-propelled
boosters to supersonic speeds to simulating flight of the full scale aircraft
at altitude. The models were instrumented to measure performance and stability
and to transmit the information back to a ground station.
Eleven free-flight models were fired between
December, 1954 and January, 1957-nine at the CARDE range at Point Petre, Ontario,
and two at the NACA range in Virginia. All rocket launchings and booster separations
were successful and the firing program was completed satisfactorily. In nearly
every test, complete performance records were obtained.
During 1954, when preliminary design was completed,
the RCAF adopted the CF-105 designation for the aircraft. Initial proposals,
design studies and tests which led to establishing the basic configuration of
the CF-105, resulted mainly
fuel tanks are a feature of the Arrow. Extensive
checking of the entire fuel system is continually
going on in this specially-built test facility. Prevention
of leakage is imperative.
AVRO NEWS 3
|Structure of a free-flight
model is tested at key points, with strain gauges
to measure deflection. When ready for flight, models
were heavily instrumented to transmit data to engineers.
|Mock-up of the cockpit
was mounted on a truck at actual height and taxiing
attitude of the Arrow in order to check pilot visibility
under actual daylight and night operating conditions.
|from the efforts of the Preliminary Design
Office, under the direction of Jim Chamberlin, who
is now Chief of Technical Design.
Later in 1954, powerplant problems arose which
required major changes in the proposed program. The Rolls Royce RB 106 engines
which were incorporated in the design, would not be available in time for the
CF-105, and were replaced by two Curtiss-Wright J67 engines. Then, in early 1955,
the U.S. Air Force disclosed that the J67 also would be too late to meet the
Avro schedule. At this point, the program now in effect was laid on-the installation
of Pratt & Whitney J75s as an interim measure, and Orenda PS13s (Iroquois)
when they become available. Although the Iroquois development was well advanced,
and its specifications more than met Avro's requirements, the combination of
an untried engine and an untried airframe was considered not practical on an
aircraft development flight test program.
A great deal of theoretical work on the application
of the "Area Rule" was carried out on the CF-105 project. This is essentially
a method of refining the fuselage shape to give the so-called "Coke-Bottle" effect
for the purpose of reducing supersonic drag of the aircraft.
Both the RAF and USAF were kept constantly informed
of the progress of the Canadian project, and contributed significant encouragement
by their concurrence in the soundness of the concept.
From the time the basic configuration was established,
to the end of 1956, up to 460 engineers, technicians and drafts men worked on
the design and development of the CF-105 structure and systems. Under the general
direction and guidance of Bob Lindley, Chief Engineer, and the co-ordinating
efforts of Guest Hake, Project Designer, a multitude of problems in each of the
|fields of engineering were resolved.
An engineering mock-up of the complete aircraft was
built to provide a three dimensional check on installation clearances and general
accessibility. Construction was mainly of wood with some metal formers. At first,
a rough mock-up of the J67 was installed to check clearances around the engines.
However, the later decision to install J75s required numerous changes to the
engine bay structure. RCAF evaluation of the mock-up took place in February last
year, and included assessment of a metal mock-up of the armament pack under consideration
at that time.
To demonstrate pilot visibility while taxiing
and cockpit lighting techniques, a special mock-up of the front cockpit was mounted
on a truck to simulate the actual height and attitude of the cockpit during ground
manoeuvering. This mock-up was later modified to include the radar nose and the
trials were repeated.
Early in 1956 work got under way to change the engine
bay section of the mock-up to accommodate the Iroquois engine and to iron out
primary installation problems. Associated ground handling equipment was also
built at that time.
Later in the year, conversion of the remainder of the
engineering mock-up from CF-105 Mk 1 to CF-105 Mk 2 configuration began. Timing
of the rebuild was based on the need to obtain RCAF evaluation results in time
to incorporate any necessary changes in the Mk 2 engineering release. A number
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