Aerospace Medicine is essentially a branch of occupational medicine. Unlike traditional medical disciplines where a patient in a normal environment experiences abnormal diseases and pathology, occupational medicine often provides medical services to patients of normal health and physiology in an abnormal environment. There are a variety of industries in which workers in good health are exposed to abnormal environmental stressors due to their occupations. Some of these groups include factory workers, firefighters, miners, auto mechanics, professional divers, and aircrew. Like other branches of occupational medicine, aircrew are exposed to hazards not commonly experienced by the normal lay person. Due to the physical composition of gases and extreme cold at altitude, excessive vibration and acoustic energy produced from aircraft, increased gravitational forces experienced in flight, rapid changes of ambient pressure, and the man-machine interface; aircrew are at risk for unique illnesses and medical syndromes that the aerospace physician needs to fully understand. Some of the consequences of the above exposures results in medical conditions such as hypoxia, hypothermia & frostbite, sensorineural hearing loss, G-induced loss of consciousness, decompression illness, trapped gases in the sinuses & inner ears, circadian rhythm disturbances, and spatial disorientation. Astronauts experience even more extreme environments and as such have a longer catalogue of physiologic implications. This list goes on.
Educating, diagnosing, and appropriately treating unique medical conditions caused by the aerospace environment are only one aspect of the daily activities of the military flight surgeon or civilian aviation medical examiner. An additional critical responsibility of the aerospace medicine professional is to ensure fitness for flying duties by pilots, astronauts, other aircrew, and air traffic controllers. In this way, flight medicine doctors play a critical role in maintaining general safety of flight.
In order to become a pilot, one must be medically cleared by completing a flying class physical exam. As expected the medical standards differ depending on the type of pilot or aircrew position that is pursued. In general, aeromedical standards in the military are much stricter than those of their civilian counterparts. This is due to the conservative nature of the military, but more importantly due to the fact that military pilots may be flying high performance aircrafts and be tasked to fly highly tactical missions, all while evading anti-aircraft weapons systems. For these reasons, it is imperative that one’s general health not be an obstacle to mission success.
CIVILIAN AEROMEDICAL STANDARDS
In order to become a civilian pilot in the United States, one must have a medical certification from an FAA-certified Aviation Medical Examiner (AME). The FAA states that “Aviation Medical Examiners are a key element in the medical certification process, ensuring that airmen meet the medical standards prescribed in the Federal Aviation Regulations, and are medically fit to perform safety-related duties. AMEs play a vital role in the FAA Office of Aerospace Medicine’s goal to promote aviation safety through excellence in aeromedical certification of airmen.” The Federal Aviation Association provides information on how to became an AME on their website.
The FAA places pilots into three general categories:
1. First-Class Airline Transport Pilot
2. Second-Class Commercial Pilot
3. Third-Class Private Pilot
The medical standards differ slightly based on one’s category with the First-Class qualifications being most stringent. A brief synopsis of the FAA’s medical standards can be found on the FAA website.
MILITARY AEROMEDICAL STANDARDS
In the United States military, aeromedical standards are much stricter. Clearly, a pilot operating the F-22 Raptor needs to meet different criteria for aeromedical fitness than the general civilian aviator. The three branches of the military (Army, Navy & Air Force), each have their own unique medical standards as it applies to the special duty status, the types of aircraft they operate, and their tolerance to accept risk. In addition to flight doctors, the Navy also employs dive medical officers.
Although each branch has a slightly different approach (each unique approach will be detailed in later articles), the basic concept is that candidates for pilot training or other special duty receive a flying class physical by a flight surgeon, who then completes the paperwork and submits the application to the appropriate approval authority. If a candidate does not meet a specific medical standard, an aeromedical waiver can be requested. The DoD never lowers a medical standard, but will instead waive a standard when the demand for a particular career field has a high enough demand to outpace medically fit applicants. Once an applicant is medically cleared for aviation duties (or dive duties), they undergo continuous monitoring in the form of annual flying preventive health physical exams with their flight surgeon. If a disqualifying medical condition were to develop the aviator would need be taken off of flying status until an aeromedical waiver is requested and granted.
MEDICATIONS IN AIRCREW
There are also many temporary medical conditions and prescribed medications that are incompatible with continued flying duties. It is the job of the flight surgeon to identify medical conditions and medications with known side effects that could diminish one’s ability to operate an aircraft or perform other aviation-related jobs. For example, an air traffic controller taking a narcotic pain medication after a routine excision of wisdom teeth should be formally taken down from active controlling duties until the sedating medication has been discontinued and appropriate time has passed to allow full excretion from the controller’s body. Prescription medications are not the only concerning substances. Illegal substance obviously must be monitored for usage, but more commonly dietary supplements or performance enhancements are being utilized with potential for either medication interaction or adverse effects. An entire post on dietary supplements for aircrew can be found here.
Both in the civilian and military aviation, safety of flight is ultimately tied to the flight doctor’s ability to vigorously apply aeromedical standards to ensure that pilots, navigators, air traffic controllers, and a variety of other aviation professionals are FIT TO FLY!