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INCREASES in air traffic of all kinds and in particular, large aircraft accommodating 400 passengers or more, have brought ground handling problems at airports to the forefront of design considerations. Adequate apron space must be provided for these aircraft to manoeuvre, for the many vehicles and additional equipment necessary for passenger, baggage and freight loading and unloading, for servicing requirements that must be undertaken on the apron and for other vital needs such as control and security. Nowadays of course, airbridges are used for passengers whenever possible and an effort has been made to reduce the number of vehicles, etc, on the apron at the same time with their associated conventional exhaust fumes.

MAINTAINING older aircraft to conform to a continuing standard of structural airworthiness has become a major part of any civil or military operator's activities. Emphasised by recent events, achievement of this level of maintenance has become more rigorous as knowledge of the behaviour of aircraft structures has progressed. Many of the issues involved were discussed at a recent Royal Aeronautical Society conference where operators, manufacturers and regulatory bodies made their views known.

MORE power is continuously being demanded from aero‐engines and a leading feature of the Rolls‐Royce RB 211 series of turbofans is the progressive development of this unit from its original design rated at 42,000 lb thrust to the Trent which in its fully developed form, will be able to deliver 95,000 lb thrust. The RB 211 initially powered the short range TriStar and the latest model has already been ordered for the MD‐11 and Airbus A330 and is being considered for the so‐called MD‐12X and the Boeing 777.

IN March Air France becomes the first airline to take delivery of an Airbus A320. Two more will follow in April and a fourth in September with all of the 25 ordered gradually replacing the earlier Boeing 727's over the next few years. British Airways will also receive its first A320 during March and others will be delivered during the year.

FOR its 1992 Technical Presentation the Guild of Air Pilots and Air Navigators considered flight deck developments for the 21st century and gave indications of trends now being realised and portents for the future. From NASA assumptions for the next generation cockpit and aircraft's physical, fiscal and operating environment were stated, based on the concept that the design has its genesis in the environment in which it must be productive and efficient.

EMPHASIS on aspects of rotary wing design and operation and comments on many of the contributory factors were contained in the recommendations of the Helicopter Airworthiness Review Panel (HARP) Report issued by the CAA in 1984. A great deal of data had been consulted and since the report further studies have amplified the findings and indicated the directions in which development is necessary.

Currently undergoing NASA flight testing is the Grumman X‐29 forward swept wing (FSW) demonstrator aircraft which was built under a contract sponsored by the Defence Advanced Research Projects Agency (DARPA) and funded through the Air Force. The FSW aircraft first took to the air in December, 1984 and after four flights with the manufacturer was handed over to NASA for a verification programme involving all the benefits of this design. Advanced technology features which will be demonstrated are the forward swept wing for improved aerodynamic efficiency and good control at high angles of attack; tailored composite wing structure that resists the tendency towards structural divergence inherent in this configuration; thin supercritical aerofoil for improved transonic performance at high lift coefficients; variable camber trailing edge to reduce drag at all lift coefficients and avoid supersonic drag associated with aerofoil camber; canard longitudinal control for efficient trimming of variable camber pitching moments and favourable canard‐wing interactions; highly relaxed static stability for very low trim drag at all Mach numbers; and a digital fly‐by‐wire flight control system.

MANY significant characteristics of the development of aero engine design together with likely trends for the future were addressed at a recent Seminar sponsored by the Institution of Mechanical Engineers and the Royal Aeronautical Society. Environmental effects play an important part together with advanced technology features and the requirement that an operator would always like to see high reliability and trouble‐free maintainability.

PRECISE and carefree handling and control are the qualities to be achieved in future helicopter designs and a great deal of study has been devoted to ways of achieving them. Recent conferences and reports of work undertaken on behalf of the civil and military authorities have produced evolving techniques and in some cases revolutionary ones in the ever‐more demanding environment of safe and more efficient rotary‐wing operations. It has been emphasised recently that the time is ripe for radical new approaches in the search for a reduction in the number of accidents and incidents caused by pilot error.

THE achievement of higher thrust‐to‐weight ratios and the realisation of thrust vectoring and reversing engine nozzles were among subjects highlighted at Le Bourget. Prominent among the former was the Pratt & Whitney F100‐PW‐229 engine which is a growth version of the F100 rated at 29,000 lb thrust and providing up to 35% more power than its predecessor, the −220. It is scheduled to replace existing engines in F‐15 and F‐16 aircraft without modification and without increasing the size of the inlet. Flight testing of the new engine began in 1988 and production is scheduled for later this year. Much of the technology incorporated represents adaptation or refinement of that derived from previous F‐100 models and an 8:1 thrust‐to‐weight ratio is achieved. The airflow is increased by reducing the size of the fan hub while retaining the same overall dimensions. A new compressor is incorporated which still retains capacity for futher growth, there is an improved durability combustor and the LP turbine is designed to match the increased power requirements of the higher airflow fan.