Peter Henley/BOURNEMOUTH HURN
Flying a 35-year-old Handley Page Dart Herald was markedly different from Flight International's usual flight tests of aircraft closer to the leading edge of technology. It was, however, a fascinating experience piloting one of the last operational examples of this first generation turboprop regional airliner.
Returning to an aircraft of that era after flying the world's latest types underlines the enormous strides that have been made since the Herald was designed in the 1950s. It was also a reminder of the excellent service that the rugged, relatively simple, aircraft of that era have given their operators. Good maintenance and corrosion protection have kept aircraft like the Herald safe and reliable. Their owners have liked their low capital costs, although this always has to be balanced against relatively high maintenance costs.
Like its contemporaries the Fokker F27 and Hawker Siddeley (HS) 748, the Herald was conceived as a replacement for the Douglas DC-3. Much design work and some flight trials had been completed by Miles Aircraft at Woodley airfield near Reading, UK, on its Marathon short-haul airliner when the company was liquidated in 1948 and was bought by Handley Page to become Handley Page (Reading).
The Marathon concept clearly influenced Handley Page's initial thinking, including its four piston engines (600kW (800hp) Alvis Leonides Major radials) and triple tail fins (mainly to provide directional control to counter an engine failure on take-off). Sir Frederick Handley Page was reputedly impressed by the F27's single fin configuration and wanted the Herald to be of similar design.
The first production version, the four Leonides-engined HPR3 Herald, had a large single fin that became a characteristic feature of the aircraft. The first HPR3 flew in August 1955, three months before the twin Rolls-Royce Dart turboprop-powered F27. Two four-engined Herald prototypes were flown, but it soon became clear that potential customers demanded turboprops rather than piston engines, and the aircraft was reconfigured as the twin-engined HPR7 Dart Herald, equipped with two 1,570kW Dart 527 turboprops.
The first Dart-powered Herald was created by converting a Leonides-powered prototype, and was flown on 11 March, 1958. In all, 48 Dart Heralds were delivered from three Handley Page plants - Woodley, Radlett and Cricklewood - before production ceased in 1968. Two years later, mounting losses closed Handley Page down.
By the end of 1998, just one example of the Herald remained in regular operation worldwide: G-BEYF (serial 175) - a 35-year-old Super Dart Herald freighter operated by Bournemouth-based Channel Express. Yankee Foxtrot, a Dart 532-9-powered Series 400, is due to be withdrawn by the second quarter of 1999 when the aircraft would have to undergo an expensive major maintenance check.
Our Herald was first flown in January 1964, and its original operator was the Royal Malaysian Air Force. In 1977, it was acquired by British Air Ferries, was registered G-BEYF and operated in the passenger role until acquired by Elan Air in 1984 when it became a freighter. Since 1988, it has been owned by the Dart Group and operated by Channel Express.
By December 1998, Yankee Foxtrot had accumulated 27,100h and 25,500 landings, spending its time regularly flying between Bournemouth and Guernsey carrying newspapers and mixed freight, up to a maximum of 5t. It is available for miscellaneous charters and recently flew car parts between Southampton and Germany.
Being loaded on the ramp early on a dull, damp winter's morning, the Herald certainly did not look out of place among F27s and HS748s. Closer up its age becomes more obvious, however. To describe it as dated is not to denigrate it. It is old-fashioned, but it is part of the UK aircraft industry's heritage and that it is still working for a living is a result of both its enduring and endearing qualities.
The Herald has pleasant handling characteristics, but its concept and systems are significantly different from the latest generation of comparable aircraft, so much so that pilots have to approach flying it in a much different way from its modern counterparts.
The high wing allows the fuselage to sit comfortably close to the ground when the aircraft is parked, which makes loading through the rear port side cargo door easy. Unlike some modern high-wing aircraft such as the ATR family, that have fairings on the underside of the fuselage to house the main undercarriage, the Herald's main wheels retract forward into the aft part of the long, slim engine nacelles, like the F27. The result is long, slender undercarriage legs with a robust geometric down lock. The wheels and legs rotate forwards to retract and are enclosed by the long, narrow wheel bay doors.
Ingenuity of design was needed to accommodate both the undercarriage and the engine jet pipe in the nacelles. The engine mounting point on the wing, the position of which was first determined by the earlier plan to fit four piston engines, was too close to the fuselage for propeller tip clearance with the Dart's larger diameter propeller. To solve this, Handley Page moved the engines 762mm (30in) further outboard and routed the jet pipe alongside the undercarriage bay on the outboard side of the nacelle, while putting the oil cooler and air-conditioner intercooler on the inboard side of the undercarriage, resulting in the distinctive, asymmetric nacelle.
The Channel Express aircrew for the return flight from Bournemouth to Guernsey was captain David Lloyd and first officer James Hallam, who view the Herald with affection and have enjoyed flying it. On the return, non-revenue, sector to Bournemouth, I was invited to fly the aircraft from the right-hand seat. Lloyd occupied the left hand seat as that was the only position from which the nose wheel steering was useable.
Crew entry to the aircraft is gained by using a small step ladder, and after mounting the two steps from the cabin to the cockpit, entering the seat is still a minor challenge. There is little room between the seat and the centre control console and the roof has many panel corners and switches on which to hit your head. The seats are of contemporary, welded tubular frame construction with adjustment for recline and height, but not for travel fore and aft. There is a four-point harness with a shoulder strap lock operated by a small lever beside the seat cushion.
The rudder pedals are adjustable for reach via a floor-mounted wheel, best operated by a foot. The result is tolerably comfortable for relatively short flights. The cockpit overall is cramped, however, and there is no room to stow flight bags or documents and no notepad holders. It verges on the claustrophobic compared with that of its contemporary, the HS748.
The field of view is adequate, but the area of glass is noticeably smaller than in a modern aircraft. There is an openable window on each side and the windscreen in front of each pilot is electrically anti-iced. The centre windscreen panel relies on a warm air duct for de-icing and, subsequently, in slight icing conditions, suffers a build up of rain ice.
The control columns rise from the cockpit floor outboard of each seat and then turn inboard through 90° to carry the control wheel in front of each pilot. The large control yoke is at chest height rather than the more usual waist height of modern control wheels. The outboard grip of each wheel has a communications switch at its top. There is little clearance between the outboard grip and the hot air duct to the side windows with the control at ailerons neutral. Rotating the wheel through 60° results in the grip fouling the flexible glare shield.
The layout of the cockpit is very period. There are large, centrally placed analogue engine instruments arranged in two vertical columns. Each pilot faces a set of flying instruments comprising an artificial horizon, airspeed indicator, turn and slip, rate of climb and descent indicator, a compass rose, an altimeter and a zero reader. The centre console houses the two power levers, two high-pressure (HP) fuel cocks, the low pitch stop lever, large manual trim wheels and the parking brake lever.
The science of ergonomics clearly played little part in the rest of the cockpit layout. The manual controllers for the pressurisation spill valves, to be operated after take-off and before landing by the first officer, are on a side panel behind his right elbow. The pressurisation controller (for rate of climb and descent) is beside his right arm and his communications mode selector is just forward of that. None of these can be seen by the captain from his seat.
Engine starting is laborious compared with a modern aircraft. There is no auxiliary power unit, so a ground power unit powered the bus bars for the electric starter motors. The starter panel above the first officer's windscreen would be difficult for the captain to reach. Once engine rotation has been initiated by pressing the starter button until it holds in, fuel can be fed carefully to the engine by cautiously opening the relevant HP cock while monitoring the turbine gas temperature (TGT) on the large gauge.
Once the HP cock has been opened, further fuel is allowed to the engine as it accelerates via the fuel datum switch (on the rear of the centre console) while again monitoring TGT until the fuel datum setting for the day (dependent on temperature and pressure altitude) is achieved on the fuel datum gauge. This process will be remembered by all pilots who have flown any Dart-powered aircraft. It is a technique that demands a modicum of skill to ensure that the engine accelerates smoothly without overheating the turbines. It is an example of many instances where the pilot of a Herald feels that he is contributing to the way his machine behaves rather than being a mere monitor of an automatic, computer-controlled process.
Taxiing the Herald is also something of a black art. The wheel brakes are reasonably smooth and progressive but the nose wheel steering, controlled by a spade grip attached to the top of the captain's control wheel, is distinctly quaint. The Dart engines and their large four bladed propellers are also slow to accelerate, causing a tendency to apply a lot of power to move off, only to have to reduce power again to maintain an equable taxiing gait. Once again the pilot feels he is exercising some skill if he taxies the Herald smoothly. The twin main wheels and twin nose wheels transmit noticeable thump from joins in the taxiway paving and centreline lights. The overwhelming sensation in a taxiing Herald is one of noise. The characteristic scream of the Darts is very audible inside; the propellers rumble and roar as they change speed and pitch and the cabin air conditioning is capable of producing hurricane levels of wind and noise.
On departure from Guernsey the all-up weight was 14,560kg (32,000lb), including 1,822 litres (480USgal) of fuel. Guernsey's elevation is about 330ft (100m), runway 08 was in use and there was a stiff crosswind from the north. Flap was set at 5í and the reference speeds were V1 /Vr 89kt (165km/h) and V2 93kt. The Dart's power can be enhanced with water methanol injection (wet power) for take-off at high weight, high ambient temperature or high field elevation. On this occasion the conditions were such that it was not necessary to use water methanol; dry power was sufficient.
The Channel Express operating procedures required the non-operating pilot to apply the power. The Herald's acceleration was fairly modest, but the rudder became effective at about 60kt and the aircraft was surprisingly light to rotate. Once airborne, retraction of the undercarriage resulted in little pitch change, some noise and a discernible thump from the nose wheels as they nestled into their bay. Retracting the flap from 5° at 600ft above the ground caused a slight pitch change which was easily trimmed. The aircraft settled comfortably into the climb at 120kt; the rate of climb passing 6,000ft was 900ft/min (4.5m/s). Flying the instrument departure procedure was a pleasure so far as handling the aircraft was concerned, the flying controls being well harmonised and the control forces lighter than expected.
The workload for managing the manual setting of the compass heading, the radio magnetic indicator (RMI) course and the zero-reader attitude and heading crossbars is infinitely higher than that needed to follow the demand information on a modern flight instrument system programmed for the instrument departure before leaving the ramp. The zero-reader provides only raw demand information in the form of an attitude indicator for climb (or descent) and a vertical bar to indicate any deviation from the chosen heading. To maintain an RMI radial in a crosswind, the drift has to be guessed so as to arrive at a likely heading to compensate for drift. The heading and attitude indicators then have to be selected using a zero reader controller on the centre instrument panel. Dexterity and frequent revisions are the order of the day. A Herald pilot could pride himself in his ability to co-ordinate an instrument procedure as he went, but in terms of workload and situational awareness the process was far less satisfactory than a modern flight instrument system.
The transit from Guernsey to Bournemouth was made at a cruising speed of 190kt and an altitude of 9,000ft, with the two Darts jointly consuming some 900kg of fuel per hour. The Herald seems to have excellent static stability - but not at the cost of handling qualities. The unswept high wing with notable dihedral, relatively long fuselage and large vertical tail all appear to contribute to the natural stability.
The mechanically operated primary controls with servo tabs endow the aeroplane with pleasant control responses and modest forces. It is easy to trim and was inclined then to fly almost hands-off in smooth air conditions. The aircraft's pneumatically operated autopilot was not used on this short flight primarily because the Herald was enjoyable to fly. Steep turns were a pleasure, while the roll acceleration and rate of roll from 45° of bank in one direction to 45¼ in the other were surprisingly good for an aeroplane of this size and era.
With undercarriage down and 30° of flap, the speed was reduced to 100kt. Roll control remained good and speed could easily be maintained with power. Accelerating from 100kt and retracting the flap and undercarriage was straightforward and the aircraft easy to rim during speed and configuration changes.
These qualities made the manually flown radar vectored and then instrument landing system approach to runway 26 at Hurn enjoyable and left room for unravelling the intricacies of using a zero-reader for an instrument approach. Extending the flap to 5¼ and lowering the undercarriage before reaching the glideslope causes little trim change. But the final selection of 30¼ (full) flap late in the approach caused a pronounced tendency to balloon and had to be countered with an appreciable amount of re-trimming. Standard operating procedures demand the use of full flap for all landings in the Herald, including crosswind conditions - because, I was told, there is a great risk of hitting the tail on the runway in the landing attitude with 5° or 0° flap.
Touching down in the Herald was straightforward but the main undercarriage legs were noticeably less compliant than most of the modern trailing link types. Once on the runway the low pitch stop lever has to be withdrawn to release the propeller blades to the ground operating regime. Failure to do so is courting disaster because opening the power levers again with the pitch stops still limiting the blades to the flight fine position schedules fuel into the engines which are unable to accelerate sufficiently promptly. Burning out the engine turbines is the inevitable consequence, and the pitch controller is amusingly dubbed the "P45 lever" by Channel crews suggesting its miss-use could warrant immediate dismissal.
Overall, a Herald pilot gets his job satisfaction not through his mastery of computerised aircraft systems, but through becoming an integral part of the aircraft and its working. Through his skill at manipulating the systems and his knowledge of his aeroplane's quirks and peculiarities he can make a discernible contribution to the way it behaves and performs.
The Herald is probably nicer than the F27 and HS748 to handle, but it must have suffered commercially through the period of dithering before the decision to fit Dart engines - a vital loss of time when its peers were winning orders. Its cramped cockpit compared to that of the 748 and poor range and performance compared with the F27 also must have limited its appeal.
Despite its age the Herald maintains its pilot appeal. While it will be sad when it is no longer possible to see this old British airliner plying its trade, on economic grounds it is impossible to argue with the type's impending retirement.
| Dimensions | |
| Length | 23.01m |
| Wingspan | 28.88m |
| Height | 7.34m |
| Weights | |
| Maximum take-off | 19,500kg |
| Maximum landing | 17,915kg |
| Maximum payload | 5,300kg |
| Performance | |
| Maximum range | 2,830km |
| Maximum cruise speed | 239kt |
| Powerplant | 2 x R-R Dart 532-9 turboprops |
CHANNEL VISION
Channel Express began its flying activities in 1978, when it launched operations as Express Air Services (EAS) with two secondhand Herald freighters carrying flowers between the Channel Islands and the UK mainland. Twenty years on and the Bournemouth-based airline has expanded its cargo charter business to include 16 freighters with a capacities ranging between 6t and 45t, as it prepares to phase out its last of 14 Heralds.
In 1983 EAS was renamed Channel Express when ex-Marlboro aerobatic flying team founder Philip Meeson bought the operation. In 1988 Channel's parent, now called the Dart Group, was listed on the stock exchange.
The flower flights, which lent Channel both its name and its logo, now represent a tiny portion of the group's air freight business. "We still carry the flowers, but now on our climate controlled trucks," says the airline's managing director Ian Doubtfire, referring to the vehicles operated by Dart's integrated haulage division.
Expansion was undertaken in 1989, when the first of four Lockheed L188 Electras was introduced, each one providing Channel with three times times the cargo capacity of the Herald (15t). In the early 1990s, the Fokker F27 was selected to replace the Herald, which although from the same era as its UK rival, is faster, quieter and more efficient, offering greater range and up to 1.8t more payload.
In 1996 Channel was again at the forefront of UK freight strategy, with its decision to acquire 45t Airbus A300B4 freighters. Three A300Fs now flying.
Source: Flight International
