CANADA AVIATION AND SPACE MUSEUM

BOEING MODEL 720B PRATT & WHITNEY CANADA FLYING EXPERIMENTAL TEST BED

REGISTRATION C-FETB

Introduction The practical era of jet-age passenger transport aircraft officially dawned when the British de Havilland Company D.H.106 Comet made its premiere flight to great acclaim from the Hatfield, Hertfordshire aerodrome in England on 27 July 1949. Catering to British and mid to long-range routes to European, Middle Eastern and overseas destinations, the Comet series of airliners carried their passengers aloft in luxurious opulence for more than twenty years. Military and test derivatives followed suit and these continued flying for many decades, including two Comets for the Royal Canadian Air Force (RCAF). Just 14 days later, across the vast Atlantic Ocean, in the small town of Malton, Ontario, Canada, a new aviation company called Avro Canada successfully accomplished the same task with much less fanfare and accolades. Avro sent its small, medium-range, turbo-jet transport, called the C-102 Jetliner, aloft for its first flight, inaugurating the dreamed potential for such a unique travel experience for the public on the North American continent. United States Air Force personnel found the aircraft favourable when they tried it out on flights at Wright Field, Ohio in March 1951. However, this Canadian dream didn’t last for long. The modestly successful Comet-series didn’t shine as brightly as its popular name when a series of tragic, fatal accidents to production civil aircraft nearly snuffed out its very existence. Following design rectification’s, the Royal Air Force continued to employ Comets in versatile roles, such as modifying the design into the Nimrod. Success of the sole C-102 Jetliner was hampered, then denied, by lacklustre marketing efforts and, as is all-too-often in Canada, a long-time pernicious lack of interest, knowledge and funding by the government for nearly all new things with any kind of aviation moniker attached to it. It wasn’t for another, long five years before a new smoky and thunderous roaring of powerful jet engines on a revolutionary jet transport sounded again, this time coming from the ever-imaginative and growing product lineage emerging from the famed Boeing Airplane Company of Seattle, Washington. On 15 July 1954, the first example of a soon-to-be very long line of jet engine powered passenger, cargo, and military transport derivatives, factually called the Boeing Model 367-80, known simply as “Dash 80”, flew. The model lineage from the premiere “Dash 80” aircraft to the last of the modern-era versions of this Boeing transport-series is long and varied. One of those ‘varied’ examples is a specific Boeing 720B (Serial Number 177) that spent many years earning a living hauling paying passengers across the skies under numerous commercial banners. Later, it was chosen and heavily modified as a dedicated inflight test platform for short-term testing of many experimental and production jet engines by Pratt & Whitney Canada (P&WC). This last surviving example of the Boeing Model 720B series ended its engine-testing career then retired to the renowned CASM collection for an honourable static public display in Trenton. Cover Photo Caption: The Boeing 720B Flying Experimental Engine Test Bed (C-FETB) “Red” of P&WC takes off on 29 September 2009, from the Saint-Hubert airport, east of Montreal, with a nose-mounted PT6 turboprop engine to test in flight. (via Mario Mattarelli)

Boeing Model 367-80 “Dash-80”, Model 707-Series Prototype The post-war period was a unique time in aviation when nearly all aircraft manufacturers were kept very busy trying to come up with new, or revolutionary and experimental designs to offer potential military and commercial customers. Interestingly, in 1946, one of these new revolutionary and experimental designs came from the talented engineering mindset at the Douglas Aircraft Company in Santa Monica, California. This aircraft, designated as the XB-43, was powered by two General Electric J35 turbojet engines and was to potentially take over some tasks of the Boeing B-29 Superfortress bomber. This medium-attack bomber historically became the first jet-powered bomber to fly in the United States, but it was ultimately destined to never go into production as better ideas were on other manufacturers drafting boards. Using a pugilistic frame of reference of the time, in one corner was Boeing, principally the builder of multi-engine jet-powered bombers for the US military like the B-47 Stratojet and later B-52 Stratofortress. As well, Boeing produced piston-powered transports like the military C-97 and KC-97 aerial refueling tanker, and the Model 377 Stratocruiser commercial transport. In the opposite corner was the rival, Douglas, that produced so many piston-powered airliners like the DC-3 and its successors; the DC-4, DC–6 and DC-7 types for the civil market, and C-54, C-124 and C-133 cargo and personnel transports for the US military. In June 1955, Douglas announced its intention to develop a lengthy and spacious new turbojet-powered airliner, designated as the DC-8, to supercede the older DC-7. Now, the fight was on. To help in the push for potential sales, the “Dash 80” interior was modified reflecting a combination of a passenger (seat rows on the right side), and cargo space (along the left) configured interior to satisfy the proponents of each. In the US Tactical Air Command (TAC) and the Strategic Air Command (SAC) direct aerial refueling support for the fleets of fast fighter aircraft types and the high-flying B-47 and B-52 jet bombers consisted of only the relatively slow piston-engined aircraft like the KC-97 tanker with its Boeing-developed flight refueling boom. There was a lot of “make do” and tense moments where flight crews of the two aircraft were forced to constantly adjust their handling of the fast (jet) and slow (prop) aircraft boom-joined combinations to avoid accidents. The later addition of General Electric J47 turbojets slung in pods at the wingtips of the KC-97s only marginally helped. This was never an ideal compromise. What was truly needed was a jet-powered transport, tanker, and passenger combination all-in-one design, however both Boeing and the military were both seriously hurting for funds. This design attempt was to be a big gamble. Again, the “Dash-80” was reconfigured, this time incorporating a retractable dummy refueling boom under the rear fuselage, and performed rendezvous and simulated inflight refueling to prove the concept sound. During the service trials of Boeing’s civil Stratocruiser, feasibility studies of a proposed Model 367 Pratt & Whitney J57 jet-powered version towards use as a possible passenger airliner began in earnest. The proposed addition of swept wings and tail, derived from the successful B-47 strategic bomber, to the design, would go a long way towards enhancing its performance. In 1955, after losing a commercial aircraft order to the Douglas Aircraft produced DC-8 airliner, that had a longer fuselage to accommodate more fare-paying passengers, Boeing started a production line of its own civil aircraft model, the 707-120. By the final bell, years later, Douglas merged with McDonnell; then Boeing took over its long time rival. The Model 367-80 Lineage It all began as the Model 367-80 with “Boeing 707” emblazoned upon the tail as the 707 prototype. Next came the official Model 707 civil airliner version that sold in great numbers around the world. The Model 717 became the military’s C-135, KC-135, EC-135, VC-137 et al series. The Model 720 series was a new design, basically, at first glance, seeming to be just a stubbier and lighter, short to medium-range version of the basic Boeing Model 707 commercial aircraft.

Surrounded by workers, VIPs and press personnel, the yellow and chocolate-coloured Model 367-80, Boeing 707 prototype (N70700), is being officially rolled out from Boeing’s Renton, Washington plant on 15 May 1954. (Bill Upton Collection) Canadian and American Flying Engine Test Beds (FETB) In the 1950s and 1960s, some large multi-engined aircraft were modified and employed as experimental flying engine test beds. Ground-based static test runs of engines only produced a baseline set of results regarding engine operation and thrust when performed in a contractor’s dedicated test facility. Dynamic tests of an engine mounted on an aircraft while flying would produce a more definitive set of interactive measurements with the test aircraft, which would still have its original installed engines available and operating for standard onboard instruments and in case of an emergency or other potential mishap. Avro (Victory Aircraft) Lancaster Mk X

The Lancaster Orenda test bed FM 209. (CASM Collection) The premiere flying engine test bed in Canada was a modified Canadian-made Lancaster Mk X, RCAF FM 209, loaned in 1950 to Avro Canada. It was utilized to test the new Orenda jet engines destined for the definitive versions of the Avro CF-100 Canuck (Mk 2 to Mk 5) interceptors and Canadair CL-13 (F-86) Sabre (Mk 5 & Mk 6) fighters for the RCAF. Two of these powerful jet engines were tested on the Lancaster’s outer engine pylons, supplemented by the operation of the original Rolls-Royce Merlin engines at their original inboard mountings working the aircraft’s basic monitoring systems.

Avro Canada CF-100 Mk 5 Canuck

CF-100 Mk 5 serial 100760 engine test bed. (Bill Upton Collection) United Aircraft of Canada Limited had arranged for the long-term loan of a surplus RCAF Avro Canada CF-100 Mk 5 interceptor in 1967 towards use as a flying test bed for the JT15D turbofan engine, to be used principally on the Cessna Citation business jet. The test engine was mounted in a nacelle slung on the fuselage beneath the cockpit of the former Canadian military aircraft. Due to the engine’s low placement with minimal ground clearance, a retractable intake cover prevented possible foreign object damage (FOD) from debris during runup and taxiing of the aircraft along the tarmac and runway. Beech Model 18 Expeditor

The former RCAF Beech Expeditor HB 109. (via CASM Collection) The piston-powered P&WC Beech Model 18 Expeditor, initially on loan from the military, required a completely new nose structural section manufactured to permit the installation of the new P&WC PT6 turboprop engine and cowling. At first the aircraft still bore the original RCAF serial number HB 109, then, when “civilianized” at P&WC, it assumed the Canadian experimental registration CF-ZWY-X. Gates Learjet 36 In November 1981, a prototype of the Gates Learjet small business jet (Serial No. 36-001) that was being used as the all-round test aircraft for other Learjet models was acquired by P&WC and received the Canadian civilian registration C-GBRW. It formerly bore the US registration N26GL. On the starboard side of the aircraft was its standard TFE731 jet engine. On the port side was the test P&WC JT15D small turbofan jet engine installed within its much noticeably larger nacelle.

Vickers Viscount

P&WC Viscount and nose mounted test engine. (Bill Upton Photo) This particularly special Series 757 Viscount, civil registered C-FTID-X, had been acquired by P&WC following its retirement from airliner service with Air Canada in 1972. Once the aircraft arrived at the sprawling P&WC facilities at Saint-Hubert, the former Air Canada livery was duly removed and replaced with a new house white and blue paint scheme overall. The forward part of the nose section bulkhead had been heavily modified to permit the structural installation of any of the P&W PT6A, PT7, PW100 and PW120 engines to be test flown. By the mid-1980s, having accumulated a number of pressurization/depressurization cycles on the critically fatigued airframe, ‘TID ended its test career and was retired to the Ēcole nationale d’aérotechnique also at Saint-Hubert. In 2011, what was remaining of the fuselage was relocated to the Collège Montmorency in Laval, Quebec, for use in fire fighting training. Canadair CL-52

Canadair CL-52 with Orenda PS-13 engine. (Bill Upton Collection) Under contract to Orenda Engines Ltd., Canadair Limited in Montreal produced the CL-52 Flying Test Bed in early 1956. This was a much modified Boeing TB-47B Stratojet bomber (USAF serial 51-2059), on extended loan to the RCAF (then re-serialed as X059), on which to flight-test the new Orenda PS-13 Iroquois turbojet engine. With the TB-47’s bomb bay crammed full with recording instrumentation, the powerful Iroquois engine was mounted in a special nacelle affixed to the starboard side of the aft fuselage for testing by the all-Orenda flight crew. This large engine had been slated to power the production version of the Avro Canada CF-105 Arrow interceptor destined for the RCAF. The Canadian Government, on 20 February 1959, summarily canceled the combination Avro Arrow aircraft / Orenda Iroquois engine. The TB-47B was then retired back to the United States, de-converted, then broken up and scrapped.

Boeing NB-52E

NB-52E with GE engine on inboard pylon. (Bill Upton Collection) Two modified USAF Boeing NB-52E Stratofortress bombers were contracted out to engine manufacturers General Electric and Pratt & Whitney to test the latest in high by-pass turbofan engines to be used on the new generation of jumbo / wide-bodied passenger and military transports. General Electric used NB-52E USAF serial number 57-0119 to test the CF6-50 engine for the Douglas DC-10 airliner in March 1970 and the TF39 powerplant for the heavyweight Lockheed C-5A Galaxy military transport. Pratt & Whitney employed aircraft serial 56-0636 in June 1968 to test the JT9D designed for the Boeing 747 Jumbo Jet. Boeing Model 367-80

At the AMARC, the “Boeing 707”, N70700, is seen preserved on “Celebrity Row” on 17 January 1990. Then, stripped of its preservative coverings, it is being prepared on 6 April 1990 for the long flight back to Boeing at Seattle. (Bill Upton Photos) In April 1961, a single Pratt & Whitney JT8D jet engine destined for the proposed Boeing B-727 tri-jet airliner was mounted on the aft port side of the fuselage above the window line, behind the wing’s trailing edge. An extended bent up and rearward exhaust pipe directed the hot engine gas above and outboard from the horizontal tailplane and movable control surfaces. Following its lengthy test career, N70700 was retired to the Aerospace Maintenance and Regeneration Center (AMARC) in 1976 for the Smithsonian Institute. The AMARC is an expansive storage facility at Davis-Monthan AFB, near Tucson, Arizona. The “Dash 80” was parked next to other distinguished kin on AMARC’s “Celebrity Row”. Here, one example of every type of aircraft stored at the AMARC was selected for the prestigious place of honour there, to be lined up side-by-side on “Celebrity Row” at the entry to the famed desert storage facility. In April 1990, the slightly weathered “Dash 80” was removed to a nearby ramp where it was basically refurbished in preparation to be able to fly it back to its original Seattle, Washington home for additional restorative work to become the star attraction at Boeing’s 75th anniversary celebrations. Following a lengthy restoration process and repainting as it had been seen in at its rollout, it was finally flown to Washington D.C. to later become a permanent static display exhibit of the Smithsonian National Air & Space Museum.

Boeing Model 707-321 and Model 747-121

The General Electric Boeing B-707 (N707GE) and B-747 (N747GE) engine test beds are seen on the ramp next to the GE facilities at Mojave Airport in 1997 and 1993 respectively. The B-707 has “X” and “Experimental” in red within the red/white/blue side cheat stripes ahead of the wing, and has a big “GE” logo on each side of the tail fin. (Bill Upton Photos) The ramp areas at Mojave Airport with the backdrop of the Tehachapi Mountains, and in proximity to famed Edwards Air Force Base, is a Mecca for numerous military and civilian aviation research / test establishments and aircraft enthusiasts alike. About a third of the way down the tenant flight line is the General Electric Aircraft Engine Business Group with two of the largest test aircraft on-site – the Boeing B-707-321 and B-747-121 engine test bed aircraft. The ‘707 had been dedicated towards testing of the GE / Snecma (CFM International) CFM56-series of engines. The ‘747 was used similarly to test the GE CF6 engine and then mounted the large diameter GE90 turbofan for the new Boeing 777 on its pylon at the No. 2 (port inboard) engine position in 1993. By 1997, this B-747 was taking over the tasks of the aging and hard to maintain B-707 that was eventually retired from use once the B-747 became available. Boeing Model 720-023B (720B) “Blue”

The two big P&W flying engine test bed aircraft - nicknamed “Red” and “Blue” by their crews – are seen – each configured with a PW307 turbofan engine installed on their respective fuselage-side pylons during an unusual close inflight formation of such very large aircraft. This first (and last) time in history event occurred on 21 June 2004. The bare metal panel atop each aircraft acts as a heatsink for the many instrumentation racks centered within the fuselage. (via Mario Mattarelli)

The American-based operational P&W engine test bed aircraft was painted in an overall dark blue with a red vertical fin, nose radome and wingtips. It incorporated a specific small test engine pylon mounted on the aft port side of the fuselage. Known informally as “Blue”, it was originally based at the engine manufacturer’s plant in East Hartford, Connecticut, later transferred to operate from new support facilities at the former USAF Strategic Air Command military air base located in Plattsburgh, New York. This aircraft had been registered in 1995 with Pratt & Whitney Canada Leasing as C-FWXI and was flown out west to spend some time at Mojave Airport, California. It was taken over by the US-based Pratt & Whitney Engine Services in January 1999 where it became formally US civil registered as N720PW.

Beginning in February 2000, engine test bed B-720, N720PW, was initially utilized for a series of development flight tests of the new P&W PW6000 turbofan engine that was destined for the proposed Airbus Industrie A318 100-passenger commercial airliner. A special pylon designed for the PW6000 replaced the initial unit used for one of the aircraft's original P&W JT3D powerplants. Another smaller airfoil-shaped engine pylon was also attached to the aft port side of the fuselage of N720PW for additional small engine testing capabilities. Following its somewhat short career with P&W, “Blue”, this American-based Boeing Model 720B engine test bed aircraft, was decommissioned and scrapped in mid-2008. Boeing Models 747SP-B5 and 747SP-J6

This stubby Boeing B-747SP-B5 engine test bed aircraft, bearing the civil registration C-GTFF, seen in the new-era P&WC livery, is parked on the far west Mirabel tarmac near its home hangar on a hot and hazy day in mid-June 2013, and then, banking away inflight. Note the interesting placement for a test engine and its unique pylon assembly. (Bill Upton Photos) The latest, and by far, largest Canadian multi-engine flying experimental test beds are the two Mirabel Airport-based Pratt & Whitney Canada’s B-747SP (“SP” for Special Performance, not Shorter Plane) wide-body aircraft bearing the Canadian civil registrations C-GTFF (“GTF” for the Geared Turbofan) and C-FPAW (“PAW” for Pratt and Whitney). Both of the big ‘747s can be readily housed side-by-side within the secure confines of the P&WC Plant 15 hangar at Mirabel. These aircraft are also utilized as a personnel and parts shuttle between the Mirabel, Quebec and the East Hartford, Connecticut Pratt & Whitney facilities. To help visually differentiate between the two aircraft, C-GTFF has a distinctive airfoil-shaped pylon, for mounting the test engine and nacelle, located immediately behind the flightdeck on the reinforced starboard upper cabin of the aircraft, where a long window line used to be. These aircraft were chosen to perform the preliminary flight tests of the new Pratt & Whitney PurePower PW1524G Geared Turbofan (GTF) engine slated initially for installation on the new generation of the Bombardier regional airliner variants originally designated as the BRJ-X, later to be renamed as the CSeries jetliner.

P&W “PurePower Engines” B-747SP, C-FPAW with test engine on the No. 2 pylon at Mirabel on a hot and hazy day in mid-July 2015. (Bill Upton Photo)

The Museum’s Aircraft Boeing Model 720-023B (720B) “Red” On 28 October 1960, a shiny, new, run-of-the-mill Boeing 720-023B airliner, with the Boeing Model 707 type sequential Line Number 177, was rolled out from the extensive Boeing Airplane Company plant in Seattle, Washington without any pomp and ceremony. The Boeing construction number assigned to this recent addition of a long line of the Boeing-made fleet of aircraft was 18024. This nondescript plane was just one of many, lost in the crowd of large four-engine airplane types, originally destined for the simple daily grind of ferrying people, pets and cargo from one place to another around the globe, over and over. As the queue of new aircraft being delivered to waiting customers was moving along, number 177 had its first flight on 14 January 1961 bearing the US civilian registration N7538A. In short order, it started its service life when it was delivered to American Airlines on 3 February and was titled as their “Flagship Idaho”. Bearing the name “Astrojet” on the nose above the pointed tip of the cheat line, N7538A served its first owner well, being operated without undue circumstance until August 1971 when it was withdrawn from service due to the availability of newer aircraft for that airline’s rapidly growing fleet. Following the out-with-the-old and in-with-the-new methodology, this not quite so old-ish and yet retired Boeing 720 was then put into temporary storage at an “old planes home” type facility somewhere near Tulsa, Oklahoma.

Boeing 720 s/n 177 is on its final approach to land in its distinctive American Airlines livery then is seen later in its new Middle East Airlines – Air Liban colours and markings at an airport. (via National Air Force Museum of Canada - NAFMC) On 25 September 1971, a reprieve from the bane of possible long-term storage was bestowed upon this ex-American Airlines airplane when it was sold to Middle East Airlines (MEA) Air Liban, the largest airline in the region. It was duly refurbished, re-painted, re-marked, and re-registered as OD-AFQ. In the new livery it was re-delivered to its new owners on 30 September. This aircraft, as well as most of the MEA fleet, was forced to stay away from its main base in Beirut, Lebanon, when Israel invaded Lebanon in June 1982. To help avoid the strife, ‘AFQ was to be based principally at Orly Airport, located near Paris, France, flying passengers for Air France and Air Inter, both French airlines. This air service continued until 1985 when the aircraft was finally withdrawn from airline service and parked / stored on the tarmac at Beirut Airport. During this storage period in the conflict area it was reported that the aircraft may have received a few stray bullet hits that imparted some damage to the skin of the large hard-to-miss fuselage. In the fall of 1985, MEA, not wanting to invest large sums of money and time upon a well-worn passenger aircraft with an upcoming major inspection and requiring a structural overhaul, decided to sell OD-AFQ to a little known British company, named Aviatek. At this same time, on the other side of the Atlantic, Pratt and Whitney Canada (P&WC) was starting to search around for a new flying platform to add to its varied aircraft test fleet, towards dynamically flight testing their new and future aircraft engine designs. In December 1985, P&WC’s quest for a new engine test bed aircraft ended with their purchase of old ‘AFQ.

On 1 April 1985, the OD-AFQ registered airplane arrived in the UK and was extensively overhauled at Stansted Airport, Essex by Aviation Traders Engineering. During this work period the aircraft was partially converted for use by P&WC along with acquiring a striking new overall red and white paint scheme. Some of the initial exterior structural modifications to the aircraft to prepare it for its new test role included a new airfoil-shaped pylon mounted to a hard point on the right-hand side of the forward fuselage for the testing of small turbofan engines. To permit testing of large turbofan engines, like the International Aero Engines (IAE) V2500, the aircraft’s number three engine pylon was modified to accept such engines in place of its original P&W JT3D-1 turbofan. This was the initial formal rationale behind acquiring this large test bed aircraft. For this latter requirement, the right wing’s external skins and internal wing box structure were strengthened to accommodate the higher loads that could be imparted due to the mass and thrust of such engines that were to be evaluated. Only one test engine at a time could be accommodated and tested on this aircraft at this early point in the refurbishment process. To remain somewhat self-sufficient in case of the necessity of off-site testing from small airports and remote basing areas, an auxiliary power unit (APU) was installed for the aircraft’s internal power requirements and an integral Airstair unit provided access to the cabin for the crew and other personnel. When it had been formally delivered to Pratt & Whitney while overseas, it was assigned the new Canadian civil registration of C-FETB (“FETB” as in Flying Experimental Test Bed) on 10 January 1986. Following a three-hour formal acceptance flight that had been successfully performed on 9 October, the enormous red and white test bed departed Stansted Airport on 12 October 1986 with a full P&WC crew aboard bound non-stop for its new base of operations at Saint-Hubert Airport, in Quebec, Canada.

Looking just like a regular, run-of-the-mill Boeing B-720, Pratt & Whitney Canada’s newest acquisition, as C-FETB, has yet to undergo the distinctive modifications to turn it into a test aircraft. Here it is seen arriving in Canada resplendent in its new red and white paint scheme after its long flight from Stansted Airport in England in October 1986. (via Mario Mattarelli) As yet, there was no hangar large enough at the airport to completely house the new big bird. That would come a short time later. In the interim, a small hangar was made available. With the aircraft towed into it nose first, the vertical tail fin was removed and the still exposed remainder of the fuselage was covered over with a large tent. Two days later the P&WC employees at Saint-Hubert were assembled outdoors, front and center, for an exciting low altitude demonstration flight of their new, big, and noisy airplane around the small airport and environs. However, the local residents of the area weren’t quite so enthused!

Once established at its new location, there was still much preparation and refurbishment work to be completed to the exterior and interior of C-FETB to prepare it for formal flight test operations. The tasks included principally the installation of numerous test and instrumentation recording racks, test engine operational controls and engineering personnel’s monitoring stations along the interior centerline of the long fuselage. Major structural modifications to the nose bulkhead to accommodate the installation of varied turboprop engines and their nacelles for tests were completed. A new, aerodynamically profiled and elongated nose radome was also provided for when there was no nose-mounted test engine installed. Due to these specific nose structure modifications, the aircraft’s weather radar was relocated, mounted centered upon the fuselage above the cockpit’s window line. Also, the static / pitot tubes were transferred from the nose to the top, leading edge of the vertical fin. With all of these airframe renovations and modifications completed, the reworked aircraft made its first fully configured flight from the Saint-Hubert base of operations on 27 January 1988. With the aircraft now ready for work on new home soil, its owners and crews would thereafter refer to it internally as FTB1 (Flying Test Bed 1). The later acquisition by P&W of B-720B N720PW “Blue” in the United States was similarly to be known as FTB2.

To commence the formal operational service of C-FETB, the new IAE V2500 turbofan engine, destined for use initially on the Airbus A-320, was installed onto its dedicated right inner wing pylon and first tested inflight on 7 May 1988. This was the first time that P&W had flown another engine for test other than one of their own. This flight test programme was successfully completed with approximately 50 hours of testing performed. Thus began a long series of varied new types of engine flight evaluations.

C-FETB is seen with a nose-mounted PW150 turboprop engine during operational testing. Two relocated pitot tubes on forward top portion of the vertical fin were apparently scavenged from USAF Convair F-106 fighters. (via Mario Mattarelli) Next in the series flown was a version of the new PW100 family of turboprop engines designed and proposed for the small regional, commuter and business aircraft markets like the twin engined DHC-8, the ATR42, and Embraer Brasilia. The Canadair CL-215T and the later Bombardier CL-415 amphibian aircraft were powered by the PWC123AF. The PW115 variant was first formally tested on 27 February 1982 installed on the extended nose nacelle of the P&WC Viscount. After this venerable Viscount had been retired, additional testing of the PW100 series engines continued during November 1988 utilizing a similarly modified elongated nose test installation on the replacement test bed aircraft, the Boeing 720B.

A unique topside view of the big Boeing B-720B testbed with a PW500 engine mounted for testing on the fuselage side pylon. It also displays the mid-fuselage heatsink to good advantage in this 1989 air-to-air photo shoot. (via Mario Mattarelli) The PW305 turbofan engine aimed for the burgeoning small to medium-sized corporate / executive jet market successfully completed its first flight aboard ‘ETB in a dedicated nacelle on the starboard wing pylon on 1 May 1989. Another test flight of this engine was performed with the B-720 that same day due to the powerplant having met or exceeded all expectations. Other turbofan engines like the JT15D, the PW500 and PW600-series, destined for other types of emerging business jets from manufacturers around the world were all performance tested, having first flown aboard the Boeing Test Bed from 1983 to 2002. On 29 September 2010, C-FETB made its final official working flight to test a version of the world-famous P&WC PT6 turboprop engine. ‘FETB landed at 1914 hours at Saint-Hubert, then was officially taken out of service the next day. To add to its deserved claim of fame, this historically significant test bed aircraft was the last airworthy and operational Boeing Model 720 in the world. C-FETB had proved invaluable towards validating engine electronic controls’ software and various performance parameters for almost all of the small turboprop and turbofan engines designed and produced by Pratt & Whitney Canada.

However, age and fatigue had eventually caught up to the large, well-utilized test bed. With its inability to accommodate the large diameter new P&W turbofans then under development, all of these factors spurred the decision to acquire the larger, younger, reliable, and support-friendly B-747SP aircraft to continue along the path towards future inflight P&W engine test evaluations in North America. During its more than two decades of reliable service (1985 – 2010), C-FETB had made some 2,444 flights with 688 individual engines installed for specific flight test missions. Some of the engine-types and their associated series tested on ‘ETB have included the: · IAE V2500 turbofan May 1988 · P&WC PW100 turboprop November 1988 · P&WC PW300 turbofan May 1989 · P&WC JT15D turbofan May 1993 · P&WC PW500 turbofan April 1994 · P&WC PT6 turboprop October 1996 · P&WC PW600 turbofan October 2002

Over Quebec’s famed northern Laurention’s wintery landscape, C-FETB, with the nose engine mount faired over with its radome, is seen carrying the PW308 turbofan engine on the fuselage-side pylon during a test flight. (via Mario Mattarelli)

A nice operational shot of ‘ETB, although rare to see it fitted with two test engines at the same time. In this case a PW100 turboprop operating on the nose and a PW500 turbofan mounted on the forward fuselage-side pylon. (via Mario Mattarelli)

“Saving the P&WC 720B” Flight Engineer Mario Mattarelli, with P&WC Flight Test Operations, was actually the initial driving force behind saving the endangered Pratt & Whitney Canada B-720B, C-FETB, from the scrap heap following its distinguished career. This is his recitation of the events as they transpired:

Saving the PWC 720B almost did not happen as it was slated to be cut up on several occasions if I did not find a suitable home for it. I originally contacted the Ottawa museum, but they did not seem to be interested. I never did get a formal letter back from them but I did hear from other sources that they were not in a position to take on an aircraft of that size. Several other museums, mostly in the US, showed interest especially the organizations in Florida and Kansas who were interested in the historical aspect as the last surviving Boeing 720B in the world. I wanted to keep the aircraft in Canada so I was most pleased when Paul Cabot of the Toronto Air & Space Museum was interested in using it as a PWC display and training aid. They were quite serious about taking delivery. I remember figuring out weight limitations for their asphalt, however an agreement could not be reached with Bombardier, the main tenants of the ramp. In a last ditch effort, due to ongoing pressure from my manager to, “…get rid of this thing one way or another.” I contacted Chris Colton to see if they would be interested and pitched it as a quasi CC-137 display. Of course they jumped on it right away and the rest is history. As it turns out the aircraft is actually owned by the Canada Aviation and Space Museum but on loan to the Trenton Air Force Museum. Funny how things worked out.

In January 2012, a proposal was put forth by the Canada Aviation and Space Museum (CASM) in Rockcliffe, Ontario towards acquiring this historically significant aircraft from Pratt & Whitney Canada for its world famous aircraft collection. Notably, unlike most other aviation museums, this interesting collection includes numerous aircraft exhibits reflecting principally the prototype, the first produced, last produced, the sole produced, the only remaining, and a few aviation record-breaking types. This particular Boeing 720B readily fit into the mold of this unique collection, if not into any of the buildings. With the formal approval of the proposal, the sole and last remaining operational B-720B, the unique (Canadian) engine test bed known at P&WC as FTB1 and “Red”, was officially donated and handed over to the CASM in May 2012. Due to the lack of capabilities to handle and store the big aircraft at the Ottawa museum’s Rockcliffe aerodrome location, C-FETB was deemed to be on loan from the CASM to the National Air Force Museum of Canada (NAFMC) at Trenton, Ontario, for a public outdoor static display. On 9 May, the pristine aircraft made its, and the world’s, final flight ever of a Boeing 720. Prior to this last flight, most of the Boeing’s test engine(s) operational controls, instrumentation and recording equipment at the test engineers’ stations in the long cabin were duly removed by P&WC for potential use on other projects and due to some proprietary issues. It left its south shore-based Saint-Hubert home for the final time and performed a series of ceremonial low flybys and wing tipping salutes there, as well as over the north shore-based Mirabel Airport-based P&WC facilities just a few short flight-minutes later.

Employees and press watch C-FETP taxi away from Saint-Hubert and is cleared for take-off on RWY 24R at 1418. (rwings)

C-FETB enters the aviation history books clearing the runway on its last take-off as viewed from the control tower. (rwings)

Knowing that the final flight was going to be historic, the flight crew also decided to make it a most memorable one by performing two low-level passes at its former home at a height of 100 feet “officially”. Fuel was not going to be a problem. As seen in these photos of each runway pass, the reader can be the judge on the actual altitude attained. (Both via rwings)

Not long after the Montreal-area flyby salutes, C-FETB flew over its new owner at the CASM’s historical Rockcliffe aerodrome enroute for a planned final touchdown on the long, paved runway at CFB Trenton. The aircraft’s destination and course was set towards its final landing and expected arrival ceremony at CFB Trenton and later static public display at the co-located NAFMC following its nearly 25-minute final flight.

With its four P&WC engines belching dark smoke and the landing lights on, C-FETB makes a high-speed arrival fly-by pass over the environs of CFB Trenton prior to touchdown, taxi in and the ensuing official arrival ceremonies. (NAFMC) Upon arrival and last stop on the expansive No. 8 Wing tarmac at Trenton, LCol Dave Alexander, the 8 Wing Chief of Staff and acting Wing Commander for the occasion, formally welcomed the aircraft and the dedicated five-man P&WC flight crew for this truly historic occasion in the annals of many Canadian aviation achievements. For the last crew of C-FETB, their own personal and the aircraft’s official Log Books were duly filled in and annotated with this final flight event of the big red Boeing that they had dedicated so many flight hours to.

This is pristine P&WC B-720B, C-FETB, as her flight crew taxis past the large hangars on the big 8 Wing ramp following the short farewell-and-‘adieu’ flight with an uneventful final landing at 1630 hours at CFB Trenton on 9 May 2012. (via NAFMC)

The big airplane is shutdown and parked front and center on the ramp at 1634 hours for the formal arrival ceremony. Then the five-man P&WC flight crew disembarked and posed for the requisite formal Photo Op for the final time with their formally retired charge. (L-R) – Sylvain Beauvais (QA), Capt. Steve Krochenski (Pilot this flight), Capt. Barkley Bates (Co-Pilot this flight), Marc Kirner (Flight Operations), and Mario Mattarelli (Flight Engineer). (Photos via Barb Neri, NAFMC). This new huge aircraft required quite a sizeable area for proper display by the newly renamed National Air Force Museum of Canada, formerly known as the Royal Canadian Air Force Memorial Museum. A short, yet distinctive line of such large aircraft, such as a Lockheed CC-130 Hercules, CAF serial 130313, and a Canadair CP-107 Argus, RCAF serial 10732 were arranged alongside the museum’s outdoor display area facing the perimeter fence bordering RCAF Road. C-FETB deservedly joined this line. Starting off the formal arrival and hand-over proceedings following the final shutdown of the B-720’s four turbojet engines, the P&WC Director of Flight Operations, Marc Kirner officially handed over C-FETB to the CASM. In turn, the NAFMC Board Chair, Bob Burke accepted the big one-of-a-kind aircraft on behalf of the museum along with NAFMC Curator Chris Colton. Representing the CASM was Director General Stephen Quick, anxiously waiting to examine the CASM’s newest, and largest, jet-propelled acquisition.

To move the big Boeing into position from the hard tarmac of the RCAF Base to the soft turf area next to the museum complex, some unique aircraft moving resources were applied. In the sequential series of photographs below taken by the museum staff during the relocation, on 2 October 2012, can be seen the pieces of moving machinery required for this effort. Long, large diameter steel cables attached two heavy-duty bulldozers to the rear of the main gear bogies for the initial stage of the carefully coordinated move. Towing the aircraft rearwards from the tarmac to the soft, grassy field area, the machines’ tracks and the aircraft’s wheels made huge, long muddy ruts. Once maneuvered to proximity of the proposed display location, a large aircraft tug, pushing on the front gear, aligned the B-720 into its final resting-place.

Seen here on 24 June 2015, still resplendent in its original red and white overall paint scheme, C-FETB is chocked on the “big aircraft” display line at the NAFMC facing RCAF Road. In line next to it are the Hercules and Argus. (Bill Upton Photo) Exterior and Interior Aircraft Details (24 June 2015) Unlike the standard passenger and freight-carrying B-720 variants, this modified aircraft’s fuselage was crammed full of instrumentation racks, arranged lengthwise and centered, where the various recording and test instrumentation units were mounted within reconfigurable numbered consoles. Each console station had chairs for the test engineers monitoring the instrumentation for the particular engine(s) being tested at the time. The main passageway is on the starboard side; a narrow catwalk is along the port side.

Without the re-profiled and extended nose radome, this is a basic plan view of the interior instrumentation station console layouts and the test personnel seating arrangements aboard the P&WC B-720B, C-FETB. (Modified drawing by Bill Upton)

Atop the center portion of the main fuselage of ‘FETB can be seen the 6m (20 foot) long, large metal electronic load bank (oftentimes referred to as a heatsink) panel array. This was used to simulate loading of accessory components normally attached to the test or the new production engines being evaluated. At the forward edge of the metal sheets array is a wind blast deflector. (Bill Upton Photo)

Due to some localized corrosion and structural fatigue accrued during this aircraft’s long service and test career, many of the main cabin window surrounds are seen with reinforcing doubler plates installed around the exterior of the affected window/fuselage areas. Some of the instrumentation consoles can be seen through a few of these, now less than crystal clear, windows. (Bill Upton Photo)

Note the heavily reinforced nose and forward fuselage structure for the principal test engine mountings. The airfoil-shaped protrusion on the side of the fuselage covers the attachment systems for testing small turbojet engines. (Bill Upton Photo)

This Boeing B-720B’s test aircraft’s weather radar assembly had to be moved from its original nose installation to its aerodynamically new and pylon-mounted location just above the cockpit. To help keep harmful solar rays from heat-damaging the aircraft’s interior and furnishings during prolonged exposure while displayed outdoors, thin aluminium foil packs were produced and specifically fitted to the interior side of all of the individual cockpit windows. (Bill Upton Photos)

The principal flight crew positions in the tight confines of the cockpit of C-FETB. The Flight Engineer’s station is seen nearest at right. This cockpit’s analogue instrument arrangement was fairly typical for the aircraft designed and built during the 1950s and 1960 eras. You will not find a head-up display or digital flight control system here. (Bill Upton Photos)

The aircraft’s Flight Engineer station in ‘FETB is located on RHS of the cockpit, immediately behind the co-pilot. P&WC Flight Engineer Mario Mattarelli left permanent indentations in this swiveling (for take-off and landing) sheepskin-covered seat. Below, there are two additional jump seats on the LHS of the cockpit for any other crewmembers. Normally the jumpseat behind the pilot’s position was removed to add some breathing room in the crowded cockpit. (Bill Upton Photos)

The respective views over instrument panel coaming and the elongated faired nose of the aircraft as seen by the pilot and co-pilot through the cockpit’s forward windscreens. Above the window frames are simple handholds. (Bill Upton Photos)

The portable integral Airstairs unit stored just aft of the main entry door. (Bill Upton Photo)

In the main cabin, the forward most engineering workstation is identified as the PW100/PW150 Station. (Bill Upton Photos)

The next engineering monitoring station, immediately aft of the PW100/PW150, is the PW300 Station. (Bill Upton Photos)

These engineering test consoles, numbered from 15 to 26, are aligned down the centerline of the cabin. The aircraft’s Galley is at left. The ceiling’s overall red tint is due to reflections from the wings through the windows. (Bill Upton Photo)

Below is the furthest aft grouping of the aircraft’s Engineering Stations with the individual engineering test consoles left untitled, simply being numbered from 45 to 55. The designated F.M. Recording Station arrangement included the engineering test consoles numbered from 45 to 49. Note on this page and the previous page that most of the Engineering Stations’ racks are devoid of instrumentation and equipment.

Views looking forward & aft on the F.M. Recording Station arrangement seen at the rear of the aircraft. (Bill Upton Photos)

This is the forward view of the central portion of the Aft Stations. (Bill Upton Photo)

These are the forward and inboard view of the aft group of the Engineering Stations numbered 30 to 36. (Bill Upton Photos)

In these views looking forward from the rear to the front of the long cabin, there is a very narrow catwalk that runs along the port side of the aircraft, and the main walkway and station access route is along the starboard side. (Bill Upton Photos)

This view, from the aft bulkhead, shows the placement of the Engineering Stations within the fuselage. (Bill Upton Photo)

Works Consulted: Books: Floyd, Jim The Avro Canada C102 Jetliner, Boston Mills Press, 1986 Francillon, René J. McDonnell Douglas Aircraft since 1920: Volume 1, Naval

Institute Press, 1988 Hurturk, Kivanc N. Individual Aircraft History of the Boeing 707, BUCHair (USA)

Inc., 1998 Lake, Jon Boeing B-52 Stratofortress: Part 2, International Air Power

Review, Volume 9, AIRtime Publishing, Summer 2003 Lloyd, Alwin T. B-52 Stratofortress, D&S Vol. 27, Airlife Publishing, 1988 Markman, Steve and Holder, Bill One-Of-A-Kind Research Aircraft, Schiffer Publishing, 1995 Pither, Tony The Boeing 707, 720 and C-135, Air Britain (Historians), 1998 Sullivan, Kenneth H. and Milberry, Larry Power, The Pratt & Whitney Canada Story, CANAV Books, 1988 Periodicals: Aviation News 31 October – 13 November 1986, Page 571 Aviation News 7-20 June 1981, Page 80 P&WC NEWS May 1983 Correspondence from Mario Mattarelli, P&WC Flight Test Engineer. PT6 Nation News Brief portions of some historic text have been excerpted from a written acquisition presentation from 2014 on the Boeing Model 720-023B Engine Test Bed of P&WC by Mr. Rénald Fortier, CASM Curator. Acknowledgements and Thanks: Chris Colton (NAFMC), Rénald Fortier, Barb Neri (Public Relations NAFMC), Stephen Quick, Don MacNeil, Mario Mattarelli, Robert St.-Pierre (“rwings”).

2015