Despite what constituted the regional jet revolution during the 1990s with low-capacity, twin-engine designs from Canadair, Embraer, and Dornier, the concept had its origins some two and a half decades earlier in France, Russia, and Germany.
Market studies, particularly in the latter country, had been conducted during the 1960s and, with passenger acceptance of pure-jet speed and comfort, as evidenced by the then-emerging proliferation of short-range, low-capacity twin-jets, such as the Sud-Aviation SE.210 Caravelle, the British Aircraft Corporation BAC-111, the McDonnell-Douglas DC-9, the Boeing 737, the Dassault-Breguet Mercure 100, and the Fokker F.28 Fellowship, the need for an even smaller, 40-passenger aircraft, with a range as short as 50 and as long as 1,000 statute miles, arose. Hitherto the domain of turboprop and piston regional types, this segment represented the final frontier for this powerplant.
Although Fokker’s own F.28 Fellowship accommodated as few as 65 in its original, short-fuselage F.28-1000 version and bridged the gap between propeller commuter aircraft and the larger twin-jets, it was still too large for particularly thin, low-demand routes. Average passenger capacity requirement on such sectors, as exemplified by the high-wing, twin-turboprop Shorts 330, was 30.
This was no coincidence. Designing a regional-ranged and -capacity jetliner and designing an economical, profit-generating one were almost inherent contradictions, especially with the then-current state-of-the-art powerplant technology. There was no equal sign between high-speed and low operating costs.
The smaller cabin, the lower was the number of passengers to cover these costs through their fares.
But the actual engineering of such an aircraft, in and of itself, was no technological feat, since the existing twins in their initial variants, including the 80-passenger SE.210-I/IA/III, the 89-passenger BAC-111-200, and the 90-passenger DC-9-10, could have been easily scaled down with shortened fuselages. The latter two, in fact, had proposed 60-seat versions, respectively designated BAC-107 and DC-9-5. But both would have been too heavy and too overpowered for profitability and therefore would not have satisfied the requirements of a true “regional jet.”
What was ideally needed was the speed of these twins and the capacity of the Shorts 330 that would be cost-effective on very short sectors. In essence, the design would need to be a DC-3 jet replacement.
The turboprop engine, which combined the turbine’s core with propellers turned by reduction gear, equally powered DC-3 replacements in the form of the quad-engine Vickers Viscount, which attained impressive sales of 444; the Fokker F.27 Friendship, which seated between 44 and 60 in its several versions; and the Handley Page Herald. The latter two were high-wing, twin-engine designs. But a pure-jet aircraft with a capacity approximating these propeller airliners only remained an elusive concept.
Suitable powerplants for one were just as limited. Of the eight low- to medium-capacity twin- and tri-jets that had preceded it, four–the 727, the DC-9, the 737, and the Mercure 100–were powered by the Pratt and Whitney JT8D engine, three–the HS.21 Trident, the BAC-111, and the F.28–were powered by the Rolls Royce Spey, and one, the Caravelle, was powered both by the Rolls Royce Avon in its initial, short-fuselage variants and the JT8D in its later, stretched-fuselage ones. None of these engines was suitable for a 40-passenger design.
Although this obstacle remained to be resolved, questions of whether such pure-jet speed could be exploited on commuter and regional routes, where their flight profiles entailed almost as much time in climb and descent as in cruise.
But on that horizon was development of what may become the engineless bush plane’s powerplant, not in turboprop form, but in pure-turbine one. Both Bristol Siddeley in the UK and SNECMA Société Nationale d’Etude et de Construction de Moteurs d’Aviation in France were designing small, low bypass ratio engines, the latter, the M 45 F, for a military fighter, which, in the event, would never proceed into production. Nevertheless, its core, with modification, had civil application.
The proposed bush type, which had subsequently been redesignated VFW-614, seemed a prime candidate for it, provided it was subjected to its own modifications that retained its rugged, low operating cost characteristics, but mated them with pure-turbine technology that would considerably increase its speed and performance.
The VFW-614 bush plane, in the meantime, continued to evolve, as features requested by potential operators were incorporated into it. Unlike any of the other preceding short-range, low-capacity twin-jets-with the exception, perhaps, of the Tupolev Tu-124 and Tu-134 in Russia-it would offer a fuselage only wide enough for four-abreast coach seating, with a single, central aisle, and its present length and round passenger windows bore a strong resemblance to a shortened F.28-1000.
The hinged mechanism that allowed the nose section to swing to the right was installed on the forward, starboard side, behind the cockpit, facilitating the straight-in loading of large freight items. But the aircraft’s convertible nature was intended to increase its versatility by accepting all-cargo, all-passenger, and mixture loads, internally separated by a moveable divider. In the latter case, boarding was achieved with a ventral, extendible air stair, a feature incorporated in some of the other preceding twin-jets.
VFW defined its mission by stating that its design “shall carry out successfully the challenging task of developing dependable and profitable operation in the service of the many airlines expecting just that from a jet aircraft. The VFW-614 is destined to develop new markets so far not accessible to operators and to increase passenger volume in established markets where outdated equipment is setting narrow limits of expansion.”
In 1966, the Federal German government provided 80 percent of the program’s financial backing, earmarked for its design and development phase. Two years later, in July, it expanded that to the construction of three prototypes and two static airframes. Still two years later, it gave full production go-ahead permission.
VFW defined its aircraft as “the definite answer to the short-haul challenge.” That that project was a challenge was an understatement. In addition to its design, engineering, and unique configuration, it also had to change and convince operators that the traditional turboprop market could become a pure-jet one. This shift had hardly been a new one.
The solution to this dilemma, VFW believed, lay in the optimum powerplant, that at the time, was the M 45 H with its 2.85-to-1 bypass ratio, which was significantly higher than the comparable 1-to-1 ratio of the Pratt and Whitney JT8D engine that powered most of the tri- and twin-jets. By generating almost triple the amount of thrust with air that bypassed the core, or hot section, the VFW-614’s powerplant would reduce the higher fuel consumption traditionally associated with pure-jet engines, along with their noise and operating costs, in essence, making the type possible.
Predating this bypass ratio by at least a decade, the M 45 H become the first commercial turbofan to appear, the likes of which would ultimately power the later twin-jets such as the McDonnell-Douglas MD-80, the Boeing 737 next generation, the Airbus A320, and the Fokker F.100. Despite its advancement, VFW nevertheless faced the formable task of convincing carriers that its technology package was the right move for the regional market.
Poised behind the slightly ajar hangar doors with a tow bar attached to its nose gear, the prototype of Germany’s first pure-jet airliner, designated G1 and registered D-BABA, awaited roll out on April 5, 1971, its almost mirror-reflective fuselage sporting its “VFW-614” type number emblazoned on either side and its manufacturer, “VFW-Fokker,” on either side of its vertical fin. The word “Experimental” was also written below the aft, left, almost triangular cockpit window ahead of the passenger door, and the names and insignias of the carriers that had ordered or optioned the aircraft were stenciled below the passenger windows.
Before the nose probe-fitted jetliner was towed out of the hangar, a brief introductory speech was made to the hundreds who had gathered for the momentous occasion.
“Today, the VFW-614-for years our number one goal-leaves the factories in Bremen as scheduled in order to be subjected to an extensive ground and flight test program. It is a moment which is as significant to us as aircraft manufacturers as a launch is to a ship builder. This roll out completes the first phase of a development program which was initiated by VFW many years ago and had for a long time been plagued by unsolved financial problems and which had finally achieved its go-ahead in August 1968 after economic and partnership requirements had been fulfilled.”
As the hangar doors were opened, permitting sunlight to flood into the aircraft’s womb, it was towed outside, giving it birth. Test pilots Leif Nielsen and Hans Bardill subsequently subjected it to steering and braking trials.
The regional jet initially appeared as a smaller version of the F.28-1000 with its two engines mounted on either side, perhaps because the observer was unaccustomed to their unexpected above-wing pylon location. A second glance, however, confirmed their actual installation point, but just as quickly may have led him to believe that he was viewing the airplane upside down.
The VFW-614 featured a 66.1-foot-long, 9.5-foot-diameter circular cross section fuselage constructed of high-strength aluminum alloys and utilizing advanced metal bonding techniques to simultaneously reduce weight and yield optimum fatigue resistance during daily high-frequency pressurization cycles characteristic of regional airline operations. The fail-safe structure, containing the pressurized cockpit and passenger cabin, rendered a 67.6-foot overall aircraft length.
The low-set wings, spanning 70.6 feet, offering a 688.89-square-foot area, 15 degrees of sweepback, and three degrees of dihedral, were comprised of a continuous two-spar torsion box divided into a center, fuselage-integral section and two outer ones. Each wing was equipped with two ground spoiler panels, which extended upon main wheel ground contact and spin-up; two flight spoilers, located on the outboard side of the engines; manually-operated Flettner-type bonded duralumin ailerons with a honeycomb trim tab on the left of the two; and hydraulically actuated, single-slotted, uninterrupted, trailing edge Fowler flaps that had a 124.86-square-foot area and covered three-fourths of the span.
Fuel was stored in the two outer wing vented integral tanks, each of which was comprised of a main tank, a supply tank, and a vent compartment and collectively had a 1,383-Imperial, or 1,663-US, gallon capacity. The engines, fuel-fed by two booster pumps, could utilize either tank.
A single-point pressure fueling system, whose control panel was equipped with a valve position and fuel quantity indicators, provided ten-minute, rapid turn-around refueling capability. Capacitive probes, measuring each tank’s quantity, indicated its readings both on the single-point refueling station instrument panel and in the cockpit. A gravity refueling system was also located on top of each wing at the tip.
The wings, designed both for high-speed cruise to reduce block times and increase daily utilization and low-speed approaches to reduce deceleration runs and tire and brake wear, incorporated low wing loadings of 59.5 pounds per square foot, high-lift coefficient, and effective trailing edge flap design that provided extension to the 40-degree position.
The all-metal, swept, variable-incidence tailplane, mounted with dihedral, featured a 29-foot, 6.25-inch span which gave it a 140.70-square-foot area and sported both a 52.96-square-foot elevator and a control tab. Powered by an electric motor, the horizontal stabilizer trim equally operated off of a manual reversion system.
The two Rolls Royce/SNECMA two-spool, 7,511 thrust-pound M.45-H-01 turbofans, with bypass and pressure ratios, respectively, of 2.85:1 and 18:1, were mounted on above-wing pylons which were located behind the aft wing spar. The unique configuration avoided vulnerability to foreign object ingestion, which facilitated operation from semi-prepared fields without requiring vortex dissipator or gravel reflector installations, increased payload configuration flexibility, reduced landing gear strut length requirements, (which themselves reduced structure weight and improved ground accessibility for passenger boarding and baggage loading), eliminated the need to divide flaps into sections, reduced the aircraft’s noise footprint, and avoided the aerodynamic problems, such as deep-stall associated with aft-engine-mounted, t-tail designs, like those of the HS.121 Trident and the BAC-111. VFW’s solution also facilitated future aircraft stretchability and hence capacity increases.
Because the wing served as a noise shield, which enabled crews to use full power during takeoff from airports where noise abatement procedures were ordinarily implemented, the VFW-614 was able to depart an area more rapidly, reducing the time the noise footprint was heard and consequently reducing block times.
Lower approach speeds, which also produced lower noise levels, resulted in shorter landing runs, precluding the need for higher-weight, complicated, noise-generating thrust reversers.
In flight, noise was diminished by the fact that almost three times the amount of thrust as that of lower bypass ratio turbofans was created by the cooler, slower-velocity air that avoided passage through the engine’s hot, central core.
The powerplant itself, comprised of a seven-stage high pressure compressor driven by an air-cooled, single-stage turbine; a five-stage medium-pressure compressor, circular combustion chambers with vaporizing burners, and a fan which was devoid of inlet guide vanes, was characterized by shorter length, reduced weight, lower cost, and reduced vulnerability to icing. Its modular construction, decreasing maintenance costs and aircraft down time, enabled the fan, the high- and low-pressure turbine, and the combustion chamber to be separately removed. A complete engine change could otherwise be accomplished in under two hours by three mechanics.
Internal temperatures varied between 1,926 degrees Fahrenheit during takeoff and 1,737 degrees at a 21,000-foot cruise altitude at Mach 0.65.
Engines could either be started with a ground starting unit, the auxiliary power unit (APU), or by cross feeding bleed air from one of the two already running ones.
Hot, compressed bleed air also served to deice intakes.
Unlike the lower bypass ratio engines of the first-generation of quad jets, such as the Boeing 707-320B and the Douglas DC-8-50, which were often only operating at their peaks twice per day on long-range sectors, the M.45-H-01 turbofans were specifically designed for the high daily frequencies characteristic of regional jet operations, whose short sectors sometimes numbered between eight and twelve, offered high takeoff and cruise thrust, but low fuel consumption, weight, noise, and smoke emissions.
The VFW-614 rested on a tricycle, twin-wheeled undercarriage of Dowty Rotol design, which employed B. F. Goodrich tires and Messier antiskid units, and was rated for more than 60,000 landings. The nose gear, which was steerable through 140 degrees and used 26 X 8.7-size tires with a 57-psi pressure, retracted forward into the fuselage-provisioned wheel bay and was covered with two aerodynamic doors. The main gear, which used a 34 x 12-12 tire size and whose pressure was 65 psi, was equipped with a high energy Goodrich dissipation brake system for close-interval landings and retracted laterally into center wing box, uncovered wheel wells, the stored wheels themselves forming an aerodynamic seal by following the fuselage contour in order to decrease weight and simplicity. The Boeing 737 featured a similar configuration.
Entrance was provided by a forward, left, six-foot, 10.75-inch by two-foot, 5.5-inch curved, downward-opening, electrically operated passenger door, which contained an integral, lighted, seven-step air stair that was stored in the inverted position after door closure.
A 3.10 by three-foot, 7.25-inch main deck cargo door was positioned on the forward, right side and a 5.25 by 4.0-foot galley servicing door was located on the aft, right side. Two overwing emergency exits facilitated rapid egress.
The VFW-614 was standardly operated by a two-person cockpit crew. A third, folding observer’s seat, used for test flying and crew training, was installed behind the center console.
Vision was through two forward, curved, oblong-shaped windshield panels, two square side panes, and two almost triangular-shaped ones, and all facilitated the reduction of slipstream noise to minimize pilot fatigue. Only the first pair of the two side windows were openable.
The main control panel, duplicated for the captain and first officer positions, contained the primary flight instruments, while the single center one featured the engine instruments. The master warning panel was located above the windshield. The left, side panel, next to the captain, contained the nose wheel steering tiller for ground taxiing. The two control wheels featured autopilot disconnect buttons and the electrically operated stabilizer trim. Adjustable rudder pedals and toe brakes were installed ahead of and below either pilot.
The center console contained the engine throttles and trailing edge flap extension levers.
Standardly equipped for Category I landings, but optionally convertible to Category II or III operations with additional instrument installation, the aircraft featured two VHF compasses, two very high frequency omni directional instrument landing systems (ILS), one automatic direction finder (ADF), two compass systems, one autopilot/flight director, distance measuring equipment (DME), one ATC transponder, weather radar, a flight data recorder, and a cockpit voice recorder. A DECCA navigation system, a high frequency communication system, a DECCA type 72 Doppler navigation system, a radio altimeter, and a Category II or III autopilot with a flight altitude reference system could be optionally selected.
The VFW-614 was equipped with a 3,000-psi main and emergency hydraulic system that used flame-resistant Skydrol 500B fluid, the former of which operated off of two engine-driven axial piston pumps, and powered the nose wheel steering, the undercarriage, the wheel brakes, the flight and ground spoilers, and the trialing edge flaps, and the latter of which powered the nose gear doors, the emergency and parking brakes, the flaps, and the flight and ground spoilers during takeoff. The wheel brakes operated off of both.
The 36.9-foot-long, 6.5-foot-high, 8.9-foot-wide passenger cabin, with a 248.75 square foot floor area and a 1,748 cubic foot volume, was standardly configurated with 40 single-class seats in a four-abreast, two-two, arrangement that entailed eleven rows and were separated by a 16-inch central aisle. Itself separated from the cockpit by a bulkhead, to which a flight attendant jumpseat was attached on the port side, it was partially hidden from the air stair by means of a half-divider.
Of the eleven seat pairs installed on the left side, the first was positioned 23 inches from this partition and the remainder were separated from each other by a 32- to 33-inch pitch, with the exception of the fifth and sixth ones, whose overwing emergency exit alignment featured additional separation in the event of evacuation needs. Because of the slightly curving fuselage wall, the eleventh pair was set slightly into the aisle.
The starboard seat pairs, which entailed only nine rows, began with an installation 24 inches behind the forward cargo compartment wall and aligned with the emergency exits at their fourth and fifth rows.
The first configuration, intended for convertible operations and therefore facilitating the installation of only five seat rows on the right side, necessitated the extension of the compartment wall to the overwing emergency exits, while the last configuration, targeted at high-density services, required a reduced seat pitch, of from 31 to 32 inches.
The aft service area was formed by the port lavatory and the starboard, single-unit galley, the latter of which was comprised of a sink, food and storage compartments, and counter space. Because of the aircraft’s intended regional sector nature, it was adequate for beverages and cold snacks or meals.
Reflecting the wide-look interiors introduced by the widebody airliners of the 1970s, the cabin featured a flat ceiling; enclosed overhead storage compartments with upward-opening, spring-loaded doors; seat row coincident passenger service units (PSUs) with reading lights, fresh air vents, flight attendant call buttons, and oxygen mask plug valves; molded sidewalls devoid of pull-down window shades; and reclineable, slimline seats provisioned with pull-down tray tables, material literature pockets, and ashtrays.
Divider design, overhead storage compartment door color, and seat covering pattern varied according to customer choice. One carrier, for instance, selected a modern, circular, collage resembling pattern with upholstery varying between yellow-gold and a light green. Another chose an orange motif with a geometric v-shaped fabric pattern.
The four-abreast seating, generous headroom, considerable seat pitch, galley, lavatory, and low interior noise combined to produce a passenger experience whose comfort had never before been associated with commuter or reginal flying on sectors whose block times varied between 30 and 90 minutes.
Baggage, cargo, and mail were carried in two underfloor holds, both of which were accessed by 33.8 by 30.5-inch, downward-opening doors, but their volume varied-from 62.8 cubic feet in the forward one to 51.2 cubic feet in the aft one.
With a 44-passenger configuration, the two holds accommodated 12 pounds per cubic foot if the baggage weight was calculated as 31 pounds per passenger. This increased to 58 pounds in the 40-passenger configuration and to 89 pounds in the 36-passenger one.
The VFW-614’s empty delivery, empty operating, maximum payload, and maximum takeoff weights were, respectively, 24,250 pounds, 26,900 pounds, 35,500 pounds, and 41,000 pounds. The aircraft’s high thrust-to-weight ratio, optimally designed airfoil, high lift coefficient flaps, and high floatation tires facilitated takeoff runways on strips as short as 3,890 feet or 2,870 feet with 14 degrees of trailing edge flap-performance, in fact, comparable to turboprop-powered airplanes.
Its high thrust-to-weight ratio equally ensured climbs to its 25,000-foot service ceiling in as little as 13 minutes. It was certified for one engine-out ascents from 8,000-foot airfields with temperatures as high as 20.5 degrees Celsius.
Its integral design philosophy of reducing block times by means of superior performance, especially at lower altitudes, fostered high daily, successive-sector utilization, consisting of 3,400-fpm climbs and cruise speed increases with distance-that is, to 235 knots on a 200-statute mile segment, 325 knots on a 600-mile one, and 397 knots on all others, its maximum speed. This performance resulted in a 20-minute block time reduction over that of turboprop airliners on average 125-mile routes.
Range varied between 415 statute miles with a 40-passenger, 8,200-pound payload to 1,030 miles with a 20-passenger, 4,100-pound one.
Because its maximum landing weight of 41,000 pounds was the same as its takeoff one, the aircraft required no enroute fuel burn off, enabling operators to fly initial sectors as short as their route systems merited. Its high lift coefficient Fowler flaps, low wing loading, rugged undercarriage, and effective brakes facilitated slow approach speed, short-filed landings. Required runway length varied from 3,000 feet at a 26,000-pound weight to 3,760 feet at a 41,000-pound one. Both were conducted with 40 degrees of flaps, which reduced the stalling speed to 88 knots.
Collectively, these features enabled the VFW-614 to combine a turboprop regional airliner’s passenger capacity and short-field performance with a longer-range jet’s speed and comfort.
FLIGHT TEST PROGRAM
The first VFW-614 flight, scheduled for the morning of July 14, 1971 and stipulate upon at least a 3,000-foot ceiling, was delayed until 12:30 p.m., shortly before which the light rain and the intermittent wind squalls subsided and the sun managed to filter through the cloud breaks.
The prototype, emerging from Hangar 20 amid the television, radio, and newspaper reporters, taxied to the runway, making a 180-degree turn on its threshold and spooling up its above-wing-mounted turbofans after receipt of takeoff clearance at 12:56. Releasing its brakes and accelerating down the strip, it rotated, almost like a seesaw, on its fulcrum-serving main wheels and surrendered to flight after a mere 500-meter sprint.
Generating sufficient lift with its swept back wings and 15 degrees of trailing edge flaps, it peeled itself off of German soil, marking the first flight of the western world’s first regional jet and the first flight of a German-designed transport aircraft after a 34-year gap.
Quickly followed into the air by a Hawker Siddeley HS.125 chase plane, the VFW-614 initially demonstrated its flying and handling characteristics at no more than a 280-kph speed so that its single-slotted Fowler flaps and undercarriage could remain in their extended positions. Even lower-speed handling characteristics, with the flaps deflected to their full, 40-degree position, were subsequently tested.
After some 22 airborne minutes, the twin-jet made a 360-degree circuit. Heading east toward Neuenlander Field, it reduced its velocity with the aid of its speedbrakes and once again re-extended its flaps to their full deflection, initiating a sharply downward, but controlled approach profile. Passing over the outer marker and then the runway’s threshold, the regional jet was trimmed into a shallower descent angle, elevator-flaring over the ground with a coincident power reduction, effortlessly brushing the concrete with its main wheels, bowing onto it with its nose wheel, and deploying its spoilers to interrupt the lift generated by its wings.
Deceleration, facilitated by toe brake applications and the release of a drag chute, was easily achieved.
The nose-probe fitted aircraft, taxiing toward the cheering crowd after a flawless, 31-minute maiden flight, shut down its engines and extended its forward, left, airstair-provisioned door, enabling Chief Test Pilot Leif Nielsen to emerge and proclaim, “Das Ding fliegt. Wir hatten keine Probleme.” “The thing flies. We had no problems.”
Elaborating, he said that the aircraft was very easy to handle, similar to a Cessna 172, with simple, forgiving characteristics-the very ones most suited to commuter airlines and the types of routes and conditions to which it would be subjected.
But the flight test program did not continue in this flawless manner. Instead, the first of three prototypes crashed, taking the life of one of its three crew members with it.
Based upon this evidence, the Luftfahrt Bundesamt determined that the probable cause of the accident was the flutter of the elevator servo-tabs. Their limited degree of travel had prohibited the elevators from being deflected into the neutral position, resulting in the severe aircraft shake just before the dive. Based upon these findings, it was also concluded that the test pilots had exhausted all possible corrective actions and measures, and, based upon cockpit instrument readings, sensations, and aircraft flying and handling characteristics, made the correct decision to leave. With proper modifications, it was concluded, the VFW-614 was a sound design.
The VFW-614 received its German type certification on August 23, 1974 and the first production aircraft first flew on April 28 of the following year and was ultimately operated by Air Alsace of France, Cimber Air of Denmark, and TAT Touraine Air Transport of France, along with the Lufwaffe.
Left without further orders for commercial versions of the regional jet, the German government withdrew financial support for the program and production ceased on October 31, 1977 with only 16 aircraft having been produced, along with three prototypes. Three other aircraft flew, but were never delivered, and four incomplete airframes were broken up before completion. VFW ultimately repurchased the operational aircraft in order to eliminate the cost of supporting a minuscule, in-service fleet.
Although the type was commercially operated for three more years, it ended up qualifying as the second worst-selling European commercial airliner after the Dassault-Breguet Mercure 100, whose dozen produced even included the two prototypes.
Germany had certainly made a valiant attempt, through the Vereinigte Flugtechnische Werke, to produce its first post-war commercial design, its first pure-jet one, and its first reginal jet one, with a novel configuration, at a time when technology was not quite right and ripe for an economical one, as evidenced by the lack of such aircraft elsewhere, with the exception of those in Russia, where airline economics and profitability were low in concern.
Although the VFW-614 program was plagued by financial problems, engine manufacturer bankruptcy, design flaw, and life-losing prototype accident, the aircraft itself ultimately triumphed by being certified, ordered, and commercially operated. But it was hardly successful, begging the question why. Was the culprit the design itself or the regional jet concept it attempted to establish?
Air Alsace, Cimber Air, and TAT all eventually withdrew the type from service, stepping up to larger equipment, such as the F.28 Fellowship for higher-demand routes or down to turboprops for lower density ones, which enabled them to attain profitability without surcharge-type fares or consistently high load factors. In this respect, the VFW-614 was, in a way, the Concorde of the first regional jet era. Unique in the market, it provided the speed, comfort, and performance that passengers enjoyed, but that speed could not always be exploited on sectors where a high percentage of them were spent in climb and descent and not the profitability that its operators required. In exchange for its advantages were higher operating costs. Inflation and the 1973-1974 fuel shortage further impacted airline operation with the type, since these factors escalated its operating costs and the ensuring recession reduced travel demand.
The Rolls Royce M-45H-01 turbofan also proved costlier to maintain than envisioned, especially since it was subjected to high-frequency, short-range frequencies, which resulted in peak output with every takeoff.
Most commuter and regional airlines could ill-afford to purchase and then operate a regional jet in its class, whose only measurable benefit was a slight decrease in block times. Cimber Air, for example, replaced its VFW-614s with turboprop ATR-42-300s, which offered almost identical capacity. Its, along with Air Alsace’s and TAT’s operation of it, based upon then-current and deteriorating economic conditions, indicated that the market for which it had been designed either did not exist or required a design of greatly improved economics to render its operation profitable, leaving carriers with the choice of employing the existing types, such as the smaller, turboprops in the form of the Shorts 330 or the larger, pure-jets, such as the F.28 or the BAC-111.
That VFW was a virtually unknown commercial aircraft manufacturer that did not enjoy worldwide recognition or had not established an existing customer base, further impacted the type’s success.
In the end, the VFW-614 had attempted to penetrate the final pure-jet frontier, but all of these factors failed to create, tame, and fill it.