With specialized learning and experience gained during his career in the IAF, Navin Rattan elaborates on the challenges faced by the high altitude aviators and the space faring community
India is on the threshold of crossing the realms of deep outer space with its Mars Mission. We have come of age as a true aerospace power. While unmanned spacecraft dominate the current Indian scenario, the time is not far when we will venture with a manned mission. Human physiology is not adaptable and compatible to the physical dimensions of high altitude / space.
Spacecraft and even aircraft are designed to support human physiology in space. There are extremes of physical, physiological and psychological factors of the troposphere and stratosphere as well as Space that have to be overcome for man to sustain himself. It is in this context that the medical discipline of Aerospace Medicine has emerged in the early fifties and continues to grow and expand as Human’s quest for reaching outer space.
As a person ascends beyond 10000 feet the fall in oxygen pressure, consequent to fall in atmospheric pressure, is such that there is requirement for either supplemental oxygen or cabin pressurization. In India there are extreme high altitudes which require military helicopters/ transport and fighter aircraft to operate at very high altitude, quite unprecedented, in the world. The challenges of retrofitting helicopter oxygen systems is enormous and has been overcome by the Indian Aerospace Medicine community in terms of capacity of oxygen carried, fitment of these systems, delivery at optimum levels and pressures to ensure physiological normalcy and at the same time to conserve oxygen. Rapid induction of troops and fighter as well as transport aircraft into extreme Indian high altitude is another challenge which has been overcome by High Altitude Acclimatization Protocols which includes using small doses of a very useful acclimatization drug, even during flying, to ensure flying fitness of aircrew within 48 hours against the seven days required earlier.
Design and ergonomics of fighter cockpits is the domain of the Human Engineer, which requires intricate knowledge of adequate reaches and forces, optimization and design of controls surfaces, lighting systems including escape systems which are compatible with the human body’s acceleration/ deceleration tolerances and crash dynamics. As fighter aircraft become more agile the need for adequate G protection to realize the aircraft’s optimum combat potential is essential. Design and development of Flying Clothing appropriate to our aircraft and climatic conditions requires knowledge of sizing parameters of Indian male and female pilot population, selection and use of appropriate materials and dynamic protection from the rapidly changing physiology as aircrew fly higher and higher.
Enhancement of combat potential like use of night vision glasses in aviation requires expert aviation ophthalmologist’s and physicist’s help. High cockpit workloads, fast processing of complex multifocal inputs of modern aircraft and their weapon systems requires multifaceted training to improve attention, concentration, scanning techniques and superb eye to hand coordination. Every factor contributing to a safe flight has a failure rate. Aviation medicine aims to keep this rate in the involved humans equal to or below a specified risk level. This standard of risk is also applied to airframe, avionics and systems associated with flights Human factors in aviation merits a great amount of investment by the organization with support from aerospace medicine.
Spatial disorientation is experienced by all aircrew at one time or another and is another area which requires aviation medicine experts for its prevention. Night flying, Carrier
AVIATION OR AEROSPACE MEDICINE IS A SUB DISCIPLINE OF OCCUPATIONAL MEDICINE INVOLVING A COMPLEX INTERPLAY OF CLINICAL MEDICINE, PHYSIOLOGY, ENGINEERING, PHYSICS AND PSYCHOLOGY WHICH ADDRESSES THE CHALLENGES OF PUTTING HUMANS INTO THE “UNNATURAL ENVIRONMENT” OF AVIATION AND SPACE.
operations, Combat Search And Rescue , High altitude and Jungle Search and Rescue are other specific areas where aerospace medicine plays a significant role. The aircrew themselves need to be selected, trained and developed into capable fighting machines sustaining themselves in hostile environments and for long durations during combat operations especially, intense short
term battles. In such cases optimization of human performance, prevention of fatigue in aircrew as well as ground and support crew is critical.
Pharmacological support will need to be resorted to ensure intense round the clock operations in modern warfare. Such protocols are now in place. Aircrew, like the rest of the populace , are equally susceptible to illness and disease. However, when compared to the rest of the general public , the prevalence illness and disease is about one tenth of the general population. This is due to pre-selection, health monitoring and emphasis on fitness. Nevertheless, it is of great concern when we lose a trained and experienced aviator to common ailments especially the omnipresent lifestyle diseases so prevalent today. A number of medical publications focused on aircrew health, monitoring and what to do when aircrew fall sick are in place in India and are revised regularly to keep pace with both emerging diseases and emerging technology. It is in this context that “Aeromedical Certification” of all civil
aircrew is in the purview of aviation medicine to ensure that all aircrew are mentally and physically fit to safely fly commercial aircraft. Aircraft accident investigation including aviation toxicology is another area where expertise of aviation medicine specialists is available. Aviation medicine also looks at a subset of occupational health hazards which links to aviation like aviation noise induced hearing loss and its mitigation in the airfield environment, high workload and stress of Air Traffic Control operators, stress and fatigue in technical staff supporting flight operations.
Leaving the domain of the earth’s atmosphere and entering outer space provides the greatest challenge to the human being. Selection and training of astronauts is a huge task. The spacecraft itself is built to support life and human physiology. However microgravity cannot yet be simulated and sustained exposure to microgravity adversely impacts musculoskeletal, neurosensory and cardiovascular health of astronauts. Maintaining their health and fitness is imperative for any space mission to succeed. Space motion sickness, psychological problems related to space flight, reentry accelerative stress, life support during extra vehicular activity including protection from radiation injury are some of the other problems which need to be addressed.
In essence Aviation or Aerospace medicine is a sub discipline of Occupational medicine involving a complex interplay of clinical medicine, physiology, engineering, physics and psychology which addresses the challenges of putting humans into the “unnatural environment” of aviation and space.
The author, Air Vice Marshal Navin Rattan, AVSM , VSM is a former Assistant Chief of Air Staff (Medical) and is qualified in both Aerospace Medicine and Internal Medicine. He has pioneered many facets of the modern flying clothing effort and operational aerospace medicine of the IAF. He is also the author of the two latest editions of Medical Standards and Examination for all IAF personnel.