Update – BAe 1000

The 125 has come a long way since the prototype de Havilland 125 first flew in August 1962 thanks to an ongoing development programme. With de Havilland now nationalised as part of the Hawker Siddeley group, early aircraft first delivered in 1964 were called the HS. 125 Series 1 and were powered by two thirsty and noisy Bristol-Siddeley (now Rolls-Royce) Viper turbojets each producing 3,000lb thrust. Maximum weight of the Series 1 was 20,000lb (9,072kg), high speed cruise was just under 500mph (804km/h) and maximum range at a long-range cruise of 420mph (676km/h) was 1,320mls (2,124km) with VFR reserves.

By comparison, the 125-800 is powered by two fuel efficient and quiet Garrett-AiResearch TFE731 turbofans of 4,3001b thrust each, has a maximum weight of 27,400lb (12,428kg), cruises at between 461 and 525mph (742-845km/h) and can travel a maximum of 3,450mls (5,5552km), the latter figure representing a more than two and a half times increase over the original, on less than 30% more fuel.

Increases in general efficiency and a knack of keeping the aircraft modern in appearance and function have marked the 125’s development over the years – a bit more speed here, a bit more cruising altitude there, continual styling, cockpit and interior upgrades, a slightly longer fuselage, a revised wing – and so on. Through all this the 125 has remained basically a six/eight passenger aircraft (in typical corporate configuration) although high density seating has been offered. The standard of interior design and fittings has always been of the highest order.

A major change came in 1977 with the Series 700 and the installation of Garrett turbofans in place of the previous Vipers. With that came an instant increase in range of 50% over its immediate predecessor and a great reduction in noise.

The newest version of the 125 is also the most radically changed. Marketed as simply the “British Aerospace 1000”, compared to the 800 it is a slightly stretched and longer range development of that aircraft with different and more powerful engines and increased fuel capacity.

The differences are greater than just those, however, as the 1000 is aimed at a very different market as indicated by the fact that both it and the 800 will be produced side by side. With a VFR range of 4,185mls (6,734km), the 1000 is not too far short of the capabilities of the larger and more expensive ‘heavy’ corporate jets such as the Gulfstream, Challenger and Falcon 900.

British Aerospace has identified a market for the 1000 in which operators of the bigger jets will trade down to a smaller aircraft offering genuine intercontinental range against the harshest seasonal winds and those who want to trade up from a similar sized or smaller jet to something which offers the range capabilities of the larger aircraft without their cost.

For example, the 1000 is capable of comfortably flying nonstop from London to New York, from London to Sydney with only two en route stops or from Los Angeles to Sydney against the prevailing wind with two stops. According to a market survey conducted by BAe, the average passenger load on a long-range business is mere threeor four, half the100O’s typical accommodation and considerably less than the normal layout in the larger aircraft.

The 1000 differs from the 800 is several key areas. Firstly, the powerplants are new generation Pratt & Whitney Canada PW305s offering 5,200lb thrust each and the latest in technology including ‘fly-by-wire’ Full Authority Digital Engine Control (FADEC), an automatic power reserve which automatically increases power on the live engine, if a failure should occur at takeoff, and specific fuel consumption 20% better than the already fuel efficient Garretts on the 125-800.

This fuel efficiency in combination with a 13% increase in fuel capacity gives the 1000 its very long range. The extra fuel is housed in a larger rear ventral tank and a new forward tank in the characteristic and now enlarged wing/fuselage fairing. The bottom line for 1000 operators is that in terms of range, the new aircraft will do at its maximum cruise speed what the 800 is capable of at its long-range cruising speed, some 40-50mph (64-80km/h) slower. Conversely, the 1000 will travel more than 700mls (1,126km) further than the 800 at long-range cruise power.

Externally, the 1000’s fuselage is 33 inches (0. 84m) longer than the 800’s, almost all of which is translated into extra cabin space. This stretch has allowed the addition of one extra cabin window per side (now seven in all) and, in combination with the enlarged wing/fuselage fairing, provides the new model with its main appearance change. Internally, the fuselage has been strengthened to meet the Joint Airworthiness Regulations (JARs) for flight above 41,000ft. The 1000 retains the longer span wing introduced on the 125-800, albeit in slightly stronger form and, despite an increase in maximum takeoff weight from 27,4001b (12,429kg)to 31,000lb (14,061kg), will better the 800’s takeoff field performance by 7 to 15% (depending on the conditions) thanks to a better power to weight ratio. Landing field performance is maintained by virtue of standard Rohr ‘target’ type thrust reversers and the 125’s familiar lift dump system whereby the selection of airbrakes on landing opens them to their fullest extent and drops the flaps to 75°.

The 125 series has always used manually operated primary flight controls and trim surfaces actuated by a series of cables and rods, a tried and true system, which is continued in the 1000. At the other end of the technology scale is the standard advanced Honeywell SPZ-8000 avionics system, in which all elements are fully integrated into a complete digital avionics package. Standard instrumentation includes a five tube EFIS (Electronic Flight Instrumentation System) panel, a dual Primus II radio system, dual FMS (Flight Management System), dual Laseref Ill inertial reference systems providing attitude, heading and position parameters, dual automatic flight control systems, a global positioning system, Primus 870 weather radar and all the other advanced avionics associated with the modern longrange aircraft.

The 125’s large cabin has long been one of its major selling points, its 5ft 9in (1. 75m) headroom providing ‘stand up’ height for a large proportion of the population and needing only a slight stoop for most others. An aeroplane which has an endurance of up to nine hours needs to be comfortable and the 1000 provides the largest cabin of any of the mid-sized business jets. Several standard layouts are offered: five swivelling individual chairs and a three seat couch, eight individual seats in ‘double club’ arrangement or six individual seats and a three seat couch, four individual seats and a three seat couch plus a large refreshment entertainment centre complete with television.

In corporate layouts, a full width toilet with wash basin is provided at the rear of the cabin with a baggage compartment (accessible from both the cabin and from outside for loading) behind that, while the entrance vestibule at the front of the cabin has a comprehensive galley and wardrobe/storage space. Other possible layouts include a 15 passenger high density arrangement (with no toilet or rear baggage area), a two stretcher air ambulance interior and special interiors for flight inspection, search and rescue, training and other roles.

The first flight of the BAe 1000 was scheduled to take place in the “first few weeks” of 1990, but at the time of writing an industrial dispute affecting several British Aerospace factories (including Chester, where the 125 is built) had delayed that slightly. Nevertheless, that first flight should have taken place by the time these words are read, or shortly afterwards. The plan is to deliver the first aircraft in the first quarter of 1991 With combined production of the 1000 and the 800 reaching 50 per annum by 1992. Of these, about 30 will be the new model.

The BAe 1000 is the most capable version yet of a highly successful design which, through constant development and astute assessment of the market, has remained the standard by which others in its category are judged. Its combination of solid, conservative airframe design and the latest technology in avionics and powerplants should prove to be another winner for British Aerospace.