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Arrow Pilots: Jack Woodman

Jack Woodman:
Flying the Arrow.



continued from page 3,

   The aircraft systems (the fuel system, hydraulic system, electrical system, pneumatic system, etc.) were all relatively conventional except, perhaps, for the landing gear and the flying controls system.

   The tricycle landing gear consisted of a forward retracting nose gear with dual wheels, and main gear with two­wheeled bogies, which retracted in­board and forward into the wing.

   Cockpit control was by means of a lever in the shape of a wheel, located on the left-hand forward panel, and it was operated by a simple up or down motion.

   Emergency lowering of the landing gear was by a 5,000-psi nitrogen bottle, which, when activated, released the door and gear uplocks, and the gear then fell in a normal manner by gravity, aided by air loads.

   The problem with the CF-105 landing gear was one of stowage. Because of the high, thin wing the gear was relatively long. In order to stow the gear, it had to be shortened and twisted as it retracted. On June 11, on the 11 th flight of the first airplane, the gear failed to extend completely, even though cockpit indicators showed it down and locked. The landing was made with the left main gear cocked approximately 30° to one side. In other words, it had not fully untwisted. The landing roll was about 4,000 ft., and, of course, with the port leg twisted it pulled the aircraft to one side. As the aircraft left the runway and came in contact with soft ground, the undercarriage snapped. The aircraft came to rest on its right gear and left wingtip.

   Because of the excellent photographic coverage, the cause of the accident was quickly determined. Avro had the airplane flying again approximately four months later, and flight procedure from that time was to have a chase-plane check gear extension prior to landing. Zurakowski was the pilot, and I know that if he had only had some indication of a problem, the accident would never have occurred.

   The CF-105 flying control system was a fully powered, irreversible, artificial feel control system. There were three modes of operation: a normal mode, an automatic mode, and an emergency mode. The automatic mode was not installed in the early aircraft.

   Two independent hydraulic systems provided the muscle, each with two engine driven pumps. The supply was 4,000 psi. Also, a ram air turbine was to have been installed on later aircraft for use in the event of a two-engine flameout.

   In the normal mode, a damping system provided stability augmentation for all three axes, and co-ordinated rudder movement with movement of the ailerons and elevators. Artificial feel was provided by an electrical system in such a way that stick force required was made to feel proportional to the amount of g's pulled. Stick force per g was constant, irrespective of speed or altitude.

   When the pilot exerted a -force on the control column to move the elevators, a force transducer on the control column transmitted electrical signals to a series of servos, which converted the electrical signals into mechanical movement by means of hydraulic pressure. The electrical output at the transducer was directly proportional to the force exerted at the grip. The control column would move as the force was exerted, as with a conventional flying control system, but it was not moved directly by the pilot. Movement of the control column followed the positioning of the elevators. The response of the system was instantaneous, and it therefore appeared as if the control column were moved by the pilot.

   In the emergency mode, the force transducer was taken out of the loop. The control column was linked by cable directly to the hydraulic actuators, which controlled the elevators. Artificial feel was provided by a spring-loaded assembly along with a bob-weight, which induced loads on the control col­umn and made control column move­ment progressively heavy as g's were applied.

   Operation of the ailerons and the rudder by means of electrical signals, or by cables, was very similar to operation of the elevators. Components in the systems differed slightly, but from the pilot's point of view, the systems operated in a similar manner. The damping system was duplicated in yaw, however, as this was the critical axis and of major importance to the safety of the airplane in the high-speed range. The airplane in the lateral-directional axis was naturally unstable. It was de­signed that way, by necessity, to meet performance guarantees specified by the RCAF.

   The flying control system was anything but developed at the time the program was cancelled, and if I remember correctly, it had No. 1 priority in the flight test program. The airplane, at certain speeds and altitudes, flew as well as any airplane I've ever flown; at other points control was very sensitive and the airplane difficult to fly accurately. However, I know it was just a matter of optimizing the controls, the damping system, and the feel throughout the complete flight envelope. And it would have been accomplished.

   I know the control system sounds sophisticated and perhaps overly complicated, and maybe it was for its time. But the Arrow flight control system was very similar to the systems being used now in today's most advanced aircraft. If the automatic mode had been installed, we would have had what is known today as Control Wheel Steering (CWS), i.e., flying the airplane through an autopilot. The Arrow control system was the same as a "fly-by-wire" system except for the mechanical linkage provided in the emergency mode.

   I can't help but feel that if Avro had been permitted to develop the Arrow, both Avro and Canada would have been recognized as leaders in the field of high-performance airplanes.


   The cockpit was generally comfortable and well arranged. It was a bit small, and with a pressure suit some of the controls and switches on the side consoles were difficult to see or operate. There was only 2 or 3 ins. of clearance between the canopy and the pilot's helmet, and I remember hitting the canopy with my helmet on several occasions with normal head movement and look-around.

   Entry and exit to the cockpit was by means of a vertical ladder, nine or 10 steps high, hooked over the engine intake ramp. From the ladder, you stepped to the top of the engine intake, over the canopy, and down into the cockpit. This was a little awkward. Also, I think it would have been a source of trouble in squadron servjce, with people stepping on the side railing and air-conditioning ducts with dirty or snow-covered boots. Generally, however, I think the cockpit was quite comfortable.

   The parachute harness and the seat harness were combined, and strapping in was relatively simple. Leg restraints were used to pull and hold pilots' legs back against the front of the seat pan during emergency ejection.

   A Martin-Baker C.5 automatic ejection seat was used, which provided an escape envelope from ground level up.

   The Arrow had a V-shaped wind­shield and vision splitter. This is not, in my opinion, the best kind of windshield to fly behind, but it was obviously satisfactory, and Avro did a good job with forward visibility.

Flight test program

   The flight test program was scheduled as an eight-phase program. Basically, the first series of tests were to evaluate the general handling qualities of the aircraft, to evaluate the flying control system and damping system, to check instrumentation and telemetry techniques, and to check safety under adverse conditions.

   The initial series of flights entailed pre-production testing and development, using the first five aircraft with the J.75 engines. This was the Arrow Mk. I.

   The Arrow Mk. II started with the 6th airplane, with production Orenda engines. Phases I through III were to have involved contractor testing and development, and phases IV through Vlll were slated for Air Force testing and evaluation.

   Obviously, only a portion of the initial Phase I pre-production testing was accomplished; however, some significant milestones were reached:

First two flights were familiarization flights.

On the third flight, the aircraft flew supersonically (M 1.1-M 1.2).

On the seventh flight, the aircraft flew to Mach 1.5 (1,000 mph) at 50,000 ft.

Maximum speed attained was Mach 1.97-1.98.

Four pilots were checked out. According to my records, the five aircraft flew 64 flights for a total of 68 hours and 45 minutes.



Scott McArthur.




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