number of different kinds of missile armament can
be carried in the large armament bay. The missiles
are housed in a removable pack below the fuselage,
attached at four points, and re-arming is very fast,
the pack being lifted into place by a mobile rig
which also serves as a transport dolly (Fig. 12).
FIGURE 12. Weapon pack.
the early phases of preliminary design, we decided
that a great deal of data could be accumulated from
free flight model firing, especially on dynamic stability
and control, and also that free flight models would
give a better means of establishing the aircraft
drag than wind tunnel models, since the effect of
the data boom on the relatively low Reynolds numbers
of the wind tunnel tests, and the difficulty of making
an accurate strain gauge drag balance, free from
the interaction of other components, made it difticult
to establish the drag by tunnel tests.
We estimated that 1/8th scale models, fired to the correct Mach number
at low altitude would give approximately full scale Reynolds numbers, due to
the higher air density closer to sea level.
The first model was fired in December 1954 to evaluate the techniques
for launch, separation, telemetering, and tracking (Fig. 13). Four crude models
had been made with an approximate representation of the CF-105 configuration
to check general problems
associated with firing. These were followed by seven considerably more sophisticated
and representative models, having up to 16 channels of telemetry. Of the last
seven models, three were drag models, two lateral stability models, and two longitudinal
The models were all launched from a zero length launcher, and boosted
to a Mach number of 1.7 by a JATO booster, having 50,000 lb. of thrust for a
period of three seconds.
The telemetry package radioed back to a ground recording station,
position, pressures, acceleration data and so on.
Separation was achieved by means of drag; the greater drag to weight
ratio of the boosters when power is exhausted, slows the booster more rapidly
than model, and the two separate.
FIGURE 13. Free flight model launching
Most of the firings were done at the Canadian Armament Research and
Development Establishment at Picton, on the shores of Lake Ontario, which has
a range telemetry ground station. Our own telemetry mobile trailer receiver was
also used as a check.
Additional range instrumentation consisted of kine-theodolites taking
pictures at five frames a second, complete with azimuth and elevation scales.
All the shutters of the cameras were synchronised. Doppler veloci-meter radar
was utilised to obtain correct velocity information, with an 8 ft. diameter transmitting
and receiving dish.
There was also a tracking radar, operating 600 pulses per second on "S" band.Quick-look
data was obtained from a plotting board.
Two models were fired at the N.A.C.A. Range Wallops Island. One of
these models had the fuselage, contoured for what we called, " super" area
ruling, to ascertain what decrease in supersonic drag might expected as we optimised
the shape to achieve
minimum drag at a given speed. The gains were shown to be quite small.
For the lateral stability models, lateral accelerations were excited
by means of a yaw impulse system mounted in the nose of the model in the form
of a motor-driven Geneva cross mechanism, containing five cartridges of 10 lb.
second impulse, and firing alternately port and starboard, through a hole in
each side of the nose at intervals of 1 1/2 seconds.
On the longitudinal stability models, the elevators were actuated
by a mechanism contained completely inside the model using a hydraulic oil-air
In all, these tests were remarkably successful, the three drag models
provided the data to evaluate supersonic airframe drag and also served as a qualitative
assessment of the CF-105 dynamic stability. We had no aborted firings, even on
the crude models, and the reliability of the telemetry transmission was over
95 per cent. On one occasion, for instance, a model fired over Lake Ontario hit
the water after the test and then skipped out again over the surface, and continued
to send back information to a group of surprised technicians at " point
ACQUISION AND HANDLING
an aircraft of the complexity of the Arrow, an extremely
large number of individual readings of several hundred
parameters are necessary during a test flight, if
reliable dynamic characteristics of both aircraft
and systems are to be obtained.
With the possible data points per flight running into several million,
it is obvious that manual handling of this data would be impractical. The only
way that such a mass of data can be handled quickly is by means of an automatic
This data handling system requires that the information be presented
in an electrical form, and magnetic tape is used to store the large masses of
It was felt that " in flight " monitoring would be necessary
during the Arrow flight testing to enable the maximum data to be obtained from
each flight, and to monitor against possible troubles in flight. The means of
accomplishing this was already present in the company in the form of a mobile
telemetry unit which had been initially constructed for the free flight model
The Arrow data acquisition and handling system is composed of an
airborne multi-channel recorder system, an airborne radio telemetry link, a mobile
telemetry receiving station, and a mobile data reduction unit capable of reducing
data obtained by either airborne system (Fig. 14).
FIGURE 14. Data acquisitison system.
the large armament bay required on the Arrow, in
the form of a removable self-contained unit, it has
been relatively easy to
house all of our telemetry transmitting instrumentation
and oscillographs, and so on, in the weapon pack
For visual monitoring of flight conditions a special "operations" room
was prepared, containing recording oscillographs giving instantaneous visual
records of data in analogue form during actual flight. Personnel in this room
are in radio contact with the pilot by means of the conventional radio links,
so that instructions and comments may be exchanged at any time during the flight.
15. Instrument pack.
the first series of flights, we were plagued with
a number of minor problems, mainly due to the literally
thousands of wires and connections running to the
instrument pack. A central " patch board " has
since been included to allow any circuit changes
to be made at one location.