Table of Contents
Flying agricultural aeroplanes and helicopters is particularly dangerous work requiring the highest qualifications. To carry out agro flights, flying crews and those servicing this equipment must possess high aviation qualifications as well as physical and mental aptitude.
Maintaining best range speed on one engine I was descending and unfortunately full of fears that the other one, the working one, would not shut down too… not to over-pitch the rotor, to hit the chosen point precisely at minimum speed… there is no other place to land… — Kazimierz Witek*
The work of an agro pilot is unlike work in any other branch of aviation. It consists of repetitive flights over crops, constant concentration to maintain a steady, low flight altitude and avoid terrain obstacles. Agricultural aircraft have no autopilots and the pilot flies manually only, additionally operating the agro equipment. It is essential to meet agrotechnical deadlines linked to the pest’s development stage or crop growth stage. Flights then often last from early morning hours until dusk. The air around the aircraft is permeated with toxic chemicals that are harmful to health.
Cockpits have no air conditioning, and flights are often conducted in temperatures reaching 50 degrees Celsius. Working airstrips are usually situated near the crops and the crew is left to its own resources. A high degree of responsibility for the quality of work and the serviceability of flying equipment and agro apparatus is required. During work abroad, Polish crews lived in primitive conditions without contact with their families, sometimes for several months. Knowledge of foreign languages was also necessary for communicating with contractors, and during ferry flights, knowledge of communication procedures was needed for contact with air traffic services.
Agricultural aviation is a branch of aviation in which aeroplanes and helicopters are used for work in agriculture, forestry and other sectors of the economy. Aircraft and helicopters designed for this purpose and equipped with appropriate apparatus are used for these tasks.
Above all, the aeroplane plays an unrivalled role in the fight against pests and various parasites of crops and fruit trees. — Jadwiga Pitulanka*
Agricultural aviation owes its development to the capabilities of the aeroplane, which allow for rapid treatment of large crop areas, particularly in situations where appropriate ground equipment is unavailable or its use is impossible, e.g. on boggy, waterlogged terrain or where access roads are lacking. The aeroplane allows threats to crops to be combated in their initial phase and when pest infestations affect large areas. During aerial treatment, neither crops nor soil are damaged. The use of manpower and ground equipment is limited. In agriculture, aeroplanes and helicopters are used for tasks such as: combating pests and plant diseases, destroying weeds, fertilising and supplementary feeding of crops, and seed sowing. Among these, tasks such as combating mosquito plagues, migratory locusts, cotton pests and plants clogging water reservoirs are practically only feasible by aircraft.
In forestry, aeroplanes are used primarily for combating pests feeding in tree canopies and for forest fire protection. Aeroplanes and helicopters are employed here for patrolling large forest areas, rapid transport of firefighting teams particularly to incipient fires, and for dropping water and fire retardants onto the blaze. Aero-hydro-seeding is also performed by aircraft. A mixture of seeds and fertilisers is dropped onto mining spoil heaps or areas of extensive earthworks for the reclamation of these sites. The use of aviation can be limited by meteorological conditions such as fog, strong winds causing chemical drift, high air temperatures causing evaporation of liquid chemical solutions, terrain features (slopes and elevations), and terrain obstacles – power lines, trees, buildings.
The work cycle consists of the following elements: operations at the working airstrip – refuelling with fuel and chemicals, taxiing and take-off to transit altitude, transit to the work zone, working flight over the crop repeated until the chemical tank is emptied or the field is completed. Successive flights are offset by the working width; turns after each working pass are made at an altitude of 50 m.
The cycle of each agrotechnical flight is the time counted from the moment of the initial movement of the aircraft (at the point of loading it with chemicals or mineral fertilisers) to the moment of stopping at the same loading point after returning from the working flight. — J. Krężałek*
Their duration is approximately 1 minute, followed by a return to the working airstrip or transit to the next field. The working flight pattern is analogous for fertilising and spraying, differing only in flight altitude. Guidance onto the next working run was until recently accomplished with the help of so-called flagmen, who held a board on the flight line and moved it by the working width for each successive pass.
Nowadays guidance is carried out using GPS. The pilot enters field data, the location of terrain obstacles, wind strength and direction into the onboard computer and flies while observing the recommendations on the indicator screen. From GPS memory, the entire work cycle can be replayed after the flight.
Firefighting of forest fires using aeroplanes and helicopters forms part of the firefighting operations of ground services. During the fire season, aeroplanes or helicopters are grouped at field bases located near major forest complexes.
Professional firefighters appreciate the participation of aeroplanes in fighting forest fires. Their great advantage is independence from terrain conditions. […] Furthermore, they can transport considerable quantities of fire retardants. — Jerzy Popow*
From there, patrol and firefighting flights are conducted to detect fires and mount rapid drops on incipient blazes. During firefighting flights, the following are performed: isolating drops made ahead of and alongside the fire front to impede its spread; direct drops onto the fire; mopping-up drops to prevent secondary ignitions. Drops are made from a flight parallel to the fire line at an altitude of 15–20 m. Runs are usually made by a group of at least 3 aircraft one after another. For the drops, water with additions of foam and wetting agents is used as fire retardant. The pilot can adjust the proportions of additives during flight according to need. The following types of drops are used: water bombs – characterised by high impact force, used for direct drops.
The water covers an area of approximately 50×15 m; trailing – used for creating isolation strips 10–15 m wide on open terrain; foam drops – characterised by a longer settling time, used mainly for creating isolation strips on tree canopies or soil cover. Aircraft tanks are filled with water at the airstrip from ground tanks. Large firefighting flying boats can fill their tanks during a scoop run on large open water bodies. Unlike aeroplanes, helicopters perform better when extinguishing incipient fires and during operations over limited areas where high drop precision is required. They can also transport firefighting teams, particularly in difficult-to-access terrain. Helicopters use a water bucket suspended on a cable, which can be filled while hovering from natural open water bodies.
