First Flight of the Avro Arrow
Better than projected...By Randall Whitcomb
ENGINE RUNS WERE CONDUCTED on the pre-production Arrow Mk. 1 on 18 January 1958. Also in January 1958, taxi trials at speeds of up to 100 knots were done. Drag chute deployment proved unreliable so some modifications were introduced. On these tests Zura found that idle thrust from the de-rated J-75s was sufficient to maintain a taxi speed of between 25 and 50 knots. Heat-sensitive paint was applied to the engine bays to observe temperature characteristics during these runs. During these taxi-trials the brakes were found to be inadequate under emergency conditions and new units were developed. The nose-gear door was found to have the potential to cause crosswind-landing weather-cocking (making the nose move sideways in the direction of any crosswind) and was modified to close after gear extension.
this period the weapons pack was ground tested by conducting
repeated extensions and retractions to test the doors
and missile struts. With the Falcon missiles, extension,
door closure and firing were designed to be accomplished
in less than one second. "Quite a trick," as
Jim Floyd stated in 2001, a trick apparently accomplished
during tests. Dummy-missile firings into sandbags were
conducted in an effort to determine the wear characteristics
of the launch rails.
For three weeks in February RL-201 was on jack-stands in the flight-test hangar undergoing intensive flight-control system checks. These were the "last chance" checks to convince Zurakowski that the radical, computer controlled, synthetic flight control system would actually work "as advertised." The flight-control development rig, already described, that had been developed into a simulator was not quite right on the simulator side. Other works have mentioned that Zurakowski and Potocki had quite low survival times in the simulator-in the order of seconds in the dynamically unstable regions under simulation. Zura elected to fly the jet anyway, believing it "looked right" and having faith in the engineers and designers. Obviously he wanted to make very sure that the actual prototype's systems were working perfectly, under every flight performance regime they could simulate in the hangar while attached to the computers. (This anecdote came from a letter from Am Floyd to Dobson, responding to a rumour Dobson had heard, that the Arrow had flown in February 1958!)
On 25 March 1958, the bird was ready to fly. RL-201 had been scheduled to fly on the previous Saturday but an all-too-common (to sophisticated aircraft) hydraulic leak had scrubbed the mission. Once it was ready, the plant loudspeakers blared an invitation for nonessential personnel to leave their posts and witness the making of history. The plant emptied in seconds! Zura's diminutive form marched smartly around the big delta while he conducted the preflight inspection. He then climbed the ladder, completed his strap-in and helmet connections and began the cockpit check. Long seconds later the switches were flicked, throttles adjusted and the big J-75s began their slow moan, ignitors snapping, as the engines spooled-up to light-off rpm. After a brief roar they quickly settled down to idle revs. Zura scanned the instruments for rpm, exhaust gas temperatures, hydraulic pressures and other signs of life, while working the stick and rudder and watching for correct movement of the control surfaces. "RL-201, taxi 3-2!" was the characteristically crisp request for taxi clearance.
As a signal of his approval two small flight-booted feet on the brakes relented to the insistence and Zura's body was snapped to attention by the force of 25,000 lbs of jet propulsion. Eyes flicked from airspeed to rapidly blurring runway centerline as he pushed the throttle past the detents and into full afterburner. Two tightly spaced slaps in the back acknowledged their cooperation. At 100 knots indicated air speed (IAS) the stick was progressively pulled backwards. The nose began to rise as control authority increased. At 120 knots the nose-wheel left the tarmac. By 170 knots the main gear legs had completely extended and then wheels left terra firma ... the Arrow was aloft!
There was no time for pondering the moment however as the Arrow was now thundering hungrily for both more altitude and speed! As the airspeed zoomed upwards and the runway disappeared under the nose, a gloved hand, probably a bit too slowly, backed off the throttles and selected "gear-up". Having the confidence to select gear retraction on a first flight was and is still somewhat unusual.
Once RL-201 was airborne, the then state-of-the-art Orenda-powered fighters closed in to check for proper gear retraction and to have a general look-over of the aircraft. Externally, all appeared as it should despite Zura's cockpit indication of incomplete nose-gear door closure (this annoying yet minor glitch would rear its head on subsequent occasions). The throttles were nudged forward slightly to give an airspeed of 250 knots. At 11,000 feet a general handling assessment was conducted with the fly-by-wire system in emergency mode. A half-hour of flight time passed and the aircraft was returned to the landing circuit. A faster than projected approach was made for the sake of safety with the aircraft touching down smartly at 160 knots. The drag-chute streamed "as advertised" and the aircraft came to taxi speed less than halfway down the runway. Zura only required light braking to slow to taxi speed well within the hardtop available. On the way back to the shacks Zura was heard to exuberantly shout over the radio: "Wonderful stuff!"
Once the Arrow had stopped, the engines spiralled down and Zura climbed out. He was immediately accosted by a jubilant horde. Zurakowski was instantly hoisted shoulder-high and paraded around the tarmac! The first flight snag sheet was framed since it revealed only the failure of two tiny microswitches in the nose gear bay! Zura's comments included the statement that the aircraft behaved "within expectations," with his one gripe being the lack of a clock by which to check the time! Perhaps this is an indication of how time fails to progress in a linear fashion when flying something out of this world!
Statistically, speaking, the second flight of the Arrow, less than a week late & roughly doubled the performance of the first flight. Speeds up to 400 knots were demonstrated at altitudes up to 30,000 feet. The aircraft was turned at past 60 degrees of bank at 2.5 G. Again the nose-wheel door microswitches malfunctioned and did not indicate full closure. Two short days later the Arrow spread its supersonic wings and broke Mach 1.1 at 40,000 feet before throttling back. On its third flight the Arrow had, for all intents and purposes, met the top performance of the F-102 without even breaking a sweat. On the return flypast from this record-breaking flight Zura began something that would become his trademark during Arrow testing. "Zorching" over the runway at modest speed he pulled the nose up... higher.. still higher.. then impossibly high to the vertical with full afterburner thrust ripping attentive eardrums. The gleaming delta pulled up into a vertical climb and almost disappeared from sight. This manoeuvre became a symbol of the confidence of the company and pilot in the performance and potential of their products. It was certainly an analogy of what they expected the project's future to bring not only to Avro but also the Canadian people, and perhaps the people of the Free World. On the fall of 1958 the British magazine Aviation Studies stated that "Canada owes it to the free world to put into production the Arrow aircraft, the most advanced interceptor in the Western world.' The Iroquois-engined Mk. 2 would have been able to accelerate while climbing vertically and carrying a useful load. The developed Iroquois promised this performance at dose to gross takeoff weight.
Most of the remaining development flying of the Arrow was devoted to exploring the various flight regimes of the aircraft in an effort to obtain data with which to refine the fly-by-wire and artificial stability programming and to validate the mechanical design. Stability tests, stress, temperature effects and other variables were quantified and assessed against projections. They found no "show-stopper" design deficiencies, unlike the CF-105's competitors.
© RL Whitcomb 2006
ONLINE STORE FEATURED ITEM:
|| HOME | STORE | NEW INFO | CONTACT US | ABOUT US ||
© C© Copyright AvroArrow.Org, 2009. Materials may be freely copied and distributed subject to the inclusion of the copyright notice, and credit must be given to AvroArrow.Org. The site is intended for historical and informational purposes. This site contains links to other Internet sites. These links are not endorsements of any products or services in such sites, and no information in such sites has been endorsed or approved by this site.