When I accepted the invitation, to speak at this meeting on “Some Outstanding Developments and Activities” it was presumed that in preparing this paper, it would be possible for me to make a selective use of information presented at our IVth International Agricultural Aviation Congress held in August 1969 in Canada. Unfortunately this is not possible. Therefore, I am unable to pass on to you a comprehensive summary of the interesting technical details of various congress papers. So, I have to take the risk, when addressing you, of spoiling my reputation.

These reservations being made, I would like to give you some facts regarding the IVth International Agricultural Aviation Congress of August 1969. The registered participation was 259 (35% of this number from the host country). It was therefore sufficiently international, although the participation from Asia and Africa was very small indeed.

The spraying of crops using light aircraft or helicopters poses a number of problems or hazards to the agricultural aviation industry. The toxicity hazard to humans and to neighbouring crops, due to drift, have already been considered in detail in previous symposia and much information is available on this subject. Another hazard which has not received much prominence, possibly due to the lack of incidents, or the reporting of them, and which is associated with the handling of flammable liquids is that of a fire or explosion risk. This is particularly true for spraying operations; incidents arising from aeroplane or helicopter crashes are rather obvious and these are not considered in this paper. The paper attempts to describe hazardous conditions and what steps can be taken to minimise fire and explosion risks.

In this paper an attempt is made to outline the hazards which can arise, with particular reference to light aircraft, due to static electricity. Accidents, some of which are described in detail later, can and do happen, yet the precautions which should be taken to reduce the dangers are very easy to carry out. These precautions are detailed in the final section of this paper and it cannot be over emphasised that the habitual use of these simple techniques could well prevent a fire from being started with the resultant loss of an aircraft and the possibility of injury or death from such a fire.

As there is apparently no expert in the world on “De-icing Runways from the Air”—and certainly not the author— the best start is to relate something of the difficulties of de-icing runways, the chemicals used and the rival methods of spreading them, and to leave it to the operators of agricultural aircraft to decide whether and how agricultural aviation can do a useful job in freeing runways from the menace of ice.

Clearly for the safety of landings and take-offs, runways should be kept clear of anything which reduces the coefficient of friction, whether this reduction is the result of plain wet, snow, ice or slush. It is the objective of the British Airports Authority in common with other airports, to remove precipitation so that one, to use the Canadian expression, “gets down to the black top”—even though one's runway is near-white concrete. When ice forms on an untreated runway, it is liable to key itself to the irregularities of the surface and become difficult to move. Therefore a good plan is to have deposited one's chemicals, when there is precipitation, before the temperature falls to freezing point or else early on in the fall before freezing is too firmly established. However, on occasions, precipitation, as everyone knows, occurs without being forecast or the temperature falls unexpectedly.

Agricultural flying is a highly competitive business in which the rate for the job appears to be continually dropping as more and more operators enter the field. In this environment, every piece of extra equipment must earn its keep either in terms of improved efficiency or improved safety and, as a result, the adoption of such things as modern navigational systems has lagged behind that in general aviation practice.

What then can a suitable electronic navigation system offer the agricultural flyer? First and foremost, immediate knowledge of his present position and secondly a clear indication of track made good. These two characteristics translate very quickly into a reduction in non-effective flying time both en route and while spraying, together with a marked improvement in application quality and control, to say nothing of reduced pilot fatigue and improvement in safety; features with appeal to operator, pilot and farmer alike.