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Avro Newsletter:Roll Out of the Avro Arrow

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Rollout, Pg10



Avro's Computer Capacity was greatly increased with the addition, this year, of the IBM 704 electronic data processing machine shown above. Latest and most powerful digital computer available to industry, Avro's 704 is the only one outside the U.S.

From Concept To Completion
In Record Four Years

(Continued from Page 3, Col. 4)

ground support equipment mock-ups were also built for design appraisal. The CF-105 was officially designated the Avro Arrow in early 1957, and the two versions of the aircraft were designated Arrow 1 and Arrow 2.
     Aerodynamically, the Arrow was entertaining a new realm of science. Performance, stability and control problems were difficult to evaluate, and data had to be obtained to establish air loads on the wing, fin, canopy and control surfaces. In this respect, wind tunnel results proved and supplemented theories in over- coming some of these problems. Im- provements in longitudinal stability, buffet characteristics, subsonic drag and directional stability for example were a direct result of wind tunnel testing.

Computer Capacity
Analog computing equipment was installed to accelerate the solution of dynamic and stress problems. The company also obtained a new electronic digital computer of great speed and capacity to accommodate its accelerated research and development program in supersonic aircraft. This was the IBM 704 electronic data processing machine the latest and most powerful digital computer designed for scientific applications, now available to industry. The giant computer is equivalent in calculating and problem solving power to 3000 tireless, perfectly organized and trained engineers. A staff of thirty mathematicians, technicians and operators is involved at the present time in feeding problems to the 704, analyzing results, and keeping the machine in operation. Avro's 704 is the only one installed outside the United States.

     The Arrow structure is designed to provide a high wing, delta planform, all metal aircraft. Although the air loads had been determined by the Aerodynamics Department, it was impossible to know at that time what effect manoeuvrability would have on the structure. For this reason a large number of stressing cases had to be investigated. Supersonic aircraft are virtually flying pressure vessels, and the problem was further complicated by the need to keep weight to a minimum. Supersonic aircraft also involve problems which previously could be ignored. Two such problems which required extensive investigation by the Stress Department were structure weakening caused by heat and sound.
     In simple terms the heat problem is caused by friction between the air and the aircraft skin. Temperatures attained while flying at supersonic speeds are high enough to weaken structure-the higher the speed, the more the heat, bigger the problem.
     There are two main types of detrimental sound-jet engine and aero dynamic. These can cause skin panels to fracture and rivets to loosen, again weakening structure. Sonic structural tests are being car- ried out constantly, and will con tinue, until they have run Ion enough to indicate satisfactory pane life.
     Proper ground support equipment plays an important role in the operational effectiveness of any modern military aircraft. Since most existing equipment could not be used for Arrow servicing requirements it was essential to ensure adequate main- tenance facilities were available.

Ground Handling
A joint Avro-RCAF Maintenance Engineering Group was formed, and to date has designed some 200 pieces of equipment. Problems to be overcome in this field were as great in their own way as those in the aircraft itself. This is self-evident when one realizes for example that the engine starter truck is a jeep- mounted gas turbine, and the power- and-air-conditioning truck m u s t maintain

a constant air flow at 55°F to the weapons, electronic and other sensitive equipment, under all ground temperature conditions. Arrow development presented some problems that were not even dreamed of when the CF-100 was designed. At supersonic speeds, for instance, air loads on the control surfaces are extremely high, and the pilot must be provided with considerable amplification of his physical strength. In fact, control mechanisms are installed on the Arrow wliieh are sufficiently powerful to lift the equivalent of six elephants standing on the elevators.

Modern military aircraft require elaborate electrical and electronic systems. In the Arrow there are some eleven miles of wiring and enough vacuum tubes to equip about two hundred television sets except for picture tubes.
     Tremendous power is needed to fly an aircraft at supersonic speeds, and the Arrow uses about twice as much power as that required to drive the Queen Mary. To develop this power, the engines consume fuel at the rate of more than a quarter of a ton per minute. Much of this power is dissipated in air friction at these very high speeds, and air friction raises the aircraft temperature to such a degree that the air conditioning required to protect the crew and the vital equipment is sufficient to produce 23 tons of ice a day.
     The complex structural requirements, and the desire to keep construction as simple as possible made extensive research necessary in this field. A vast amount of development has been done in the field of metal- to-metal bonding which ehninates much of the time-consuming and difficult processes of conventional riveting and fastening. In order that metal bonding can be used successfully, it must be sufficiently strong, reasonably easy to use, and must have sufficient heat resistance to be unaffected at temperateres experienced by an aircraft flying at supersonic speeds.

Static testing of wing structure being conducted by the Structural Test department. Dial test indicators are being used, along with strain gauges, to measure deflection.






Production Prototype
While bonding of aluminum alloys imposed no great problem, considerable experimental work was required with magnesium alloys. A process has been developed by Avro metallurgists which has proven very satisfactory under tests, and is used in many parts of the aircraft.
     Until recently, high-performance aircraft were not committed to production until after flight testing of one or more prototypes. Normally quite a number of changes are necessary before the aircraft can go into production. The Arrow program is unusual in Canada in that even the first flying model has been built on production tooling. This time-saving approach made it essential to prove the basic soundness of the structural and system concepts by exhaustive testing prior to the actual build of the aircraft. This procedure subjects nearly all components to test
















equivalent to the most severe and varied conditions expected.
     All the aircraft systems, too, must undergo the most rigorous tests to ensure the high safety standard and efficient component operation demanded of the Arrow.
     The fuel system for instance, has been set up in every detail on an elaborate test rig which simulates its operation and allows it to be tested in any position that the aircraft may assume. Fuel system test program includes investigations of the pressure system, refueling and de-fueling, simulated flight sequences and emergency operation,

Stress Analysis
The difficult task of analyzing the structure of the Arrow imposed many unique problems on the stress engineers. The complexity of the Arrow's structure demanded the use of the most advanced analysis methods and techniques available.
     A novel technique used in the stress analysis program involved the use of plastic models. These models had to be constructed with great care so that the structure would have the required degree of similarity to the actual aircraft. They were then placed in test rigs which were capable of producing loads on the models comparable to the predicted flight loads. After intensive testing, the deflections and stresses which were produced showed that the methods being used for analytical studies were valid.

Ancilary Equipment
The hundreds of items of mechanical, hydraulic, electrical and electronic equipment in the Arrow are all required to operate in a severe high temperature, high-altitude environment with the utmost reliability. Equipment which would perform under these conditions simply did not exist when the Arrow design got under way. It was therefore necessary for Avro to specify the special performance necessary for each one of these devices to do its job, and to assess the proposals of equipment manufacturers throughout the continent to determine their capability to develop the items. Avro then maintained close engineering contact with all these sources while the units which had to meet the Arrow's stringent requirements were being designed, built, tested and delivered.

     In modern military terms, an aircraft like the Arrow becomes the central component of a "Weapon System". Besides the basic aircraft, this Weapon System must include a complete, compatible air and ground environment, starting with the support and maintenance equipment at RCAF bases, through the ground radar and communication facilities, up to and including the airborne electronic system and weapons. All this is essential for a supersonic interceptor to perform its specified task.
     As the Arrow program progressed, it soon became evident that no existing combination of electronic equipment met the RCAF's operational requirements and the Arrow's environmental needs. After evaluating several proposals, the RCAF selected RCA as the electronic system contractor, with the task of developing this most essential component of the Arrow weapon system.
     RCA and RCA's associate contractor, Minneapolis-Honeywell, along with their Canadian affiliates, plunged into the task of creating the advanced specialized electronic system for automatic flight, weapon fire control, communication and navigation which has been designated the "Astra I" system.

What Next?
 To date, approximately 17,000 different dawings have been released for the Arrow 1 and Engineering has formed a liaison team, which is on call twenty-four bours a day, to ensure that any drawing geery or problem which may arise is immediately dealt with.
     It is now four years since the design started. This is considered better than average for the time required to design and build present day high performance aircraft.
     The Arrow is a fighter aircraft, yet its armament bay is as large as the bomb bay of some World War II bombers and the power of its two Iroquois engines is almost sufficient to lift the aircraft vertically off the ground!
     With the Arrow 1 engineering complete, the Engineering Division is looking toward future development of the aircraft; It. is a flexable, versatile, aircraft and with development it can have a greatly extended future. The present Arrow is on the threshold of the heat barrier, popularly called the Thermal Thicket, and studies are now under way as to how to adapt the aircraft for even higher speeds

Pilots' view from the cockpit of the Arrow shows excellent visibility despite slight nose-up attitude while taxiing. Photo was taken from mobile cockpit mock-up.

Test Pilots Aid Program

(Continued from Page 9, Col. 4)
by General Joseph Caldara, of the Office of the Director of Flight Safety, U.S.A.F., following an official visit to the plant, ater which he stated that the Arrow's cockpit layout is the best he had seen.
     Members of Avro's Experimental Test Pilot staff have, as part of their preparations for preliminary flight tests of the Arrow, spent some time at the Convair test facility at Palmdale, California. There they have flown experimental and production version of the F-12 single-engine, delta-wing interceptor now being
produced for the U.S. Air Force. Now that the Arrow is completed and is unveiled for the first time, it will be moved from the production bays to the flight test hangar in preparation for its initial flight. The test pilots experience a strong feeling of pride in the achievement of the Engineering and Manufacturing divisions, and of anticipation for the opportunity to launch the Arrow on its flight program. They are eager to commence that portion of the development which is implied by the professional title: Experimental Test Pilot.

Page 1:
Cover Art Work.
Page 2:
Tribute, Proposal To Product, All-Weather Interceptor, Delta Planform.
Page 3:
Go-Ahead, Aerodynamics Tests, Powerplant Changes, Pilot Visibility.
Page 4:
Precision Keynotes All Arrow Tooling, Drawn Full Scale, Travelling Cutter
Page 5:
First Production Arrow Sets Low Manhour Record, From Paper to Hardware.
Page 6 and 7:
Centerfold Art Work.
Page 8:
Quality Control Gains New Inspection Skills, Interchangeability, Inspection Innovations, Pioneering.
Page 9:
Selling New Designs Requires Specialists, Need Test Pilots Aid At Early Design Stage, Set Out Details, Training Aids, Cockpit Layout.
Page 10:
Concept To Completion..., Computer Capacity, Ground Handling, Electronics, Production Prototype, Stress Analysis.....
Page 11:
Low Manhour Record, Sound Control, Outside Suppliers, Coast to Coast, Efficient Handling, New Methods, Bottlenecks, Impact, Quality Control......
Page 12:
Advertising, Tribute, DDP Helpful Partner, Subcontractors, Flight Test Program. Precision Keynotes, Selling New Design

Scott McArthur.




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