Aerospace and Operational Physiology

Aerospace and Operational Physiologists are experts in human factors and physiological threats related to the military operations and physiological elements. Since World War II, Naval Aerospace and Operational Physiologists have used the principles of physics, biology, and engineering to support Navy and Marine Corps operations by providing:

Research, development, test and evaluation (RDT&E)

The antecedents of modern aerospace physiology reach back as far as the late 1700s, a time

of early balloon flights. It was during this period that the term "balloon sickness" first appeared

in recognition of the fact that changes occur in persons during ascent in altitude. The problem

was highlighted with the death of two French balloonists in an ascent to 28,000 feet in 1875.

The fortunate survival of the third crewmember provided much information concerning human

reaction to high altitude and stimulated the French physiologist, Paul Bert, into a systematic

research program dealing with the effects of low pressure and oxygen deficit on humans. These

studies resulted in the publication, in 1878, of Bert's famous text LaPression Barometrique, a

comprehensive document dealing with pressure effects. For his contribution, Bert is often

referred to as "the grandfather of aviation medicine" (Adams, 1940).

 

Recognition of the Problem

 

Powered flight for man began on 17 December 1903. Only six years later, in 1909, LT

George C. Sweet became the first naval officer to fly. For practical purposes, naval aviation

began at that time. On 14 November 1910, a Curtiss pilot, Eugene Ely, flew a four-cylinder

Curtiss biplane from a wooden platform built on the deck of the USS Birmingham, thus laying

the basis for modern carrier aviation.

Although naval aviation had scarcely begun, the medical profession quickly recognized the

hazards of this new profession and the unusual demands placed on participants. On 8 October

1912, the Navy Bureau of Medicine and Surgery issued the first set of physical requirements for

naval candidates for aviation duty. Following this auspicious beginning, however, progress in

aviation medicine in the Navy slowed. In 1919, the U.S. Army established a Research

Laboratory and School for Flight Surgeons at Mitchell Field on Long Island. In 1.921, the first

Navy medical officers were sent for training at this facility , later known as the Army School of

Aviation Medicine. This represents the first formal training of Navy personnel to deal with the

medical and physiological problems of aviation.

 

The primary role of naval aviation in World War I was antisubmarine warfare. In fact, naval

aviation was used more extensively for this purpose than generally is realized. Thirty attacks

were executed against enemy submarines, with at least ten being considered partially successful

(Naval Aviation News, 1968). However, although naval aviation grew during World War I, the

nature of the activity involved principally low level, low speed flight. Aviation crewmen

operated, for the most part, in an environment producing minimal stress, with one major

exception the inherent danger of emergency ditching. For this reason, the World War I period

is not marked by rapid advances in aviation medicine and physiology . The work that was done

tended to focus on selection rather than training considerations. Physical fitness was stressed in

an attempt to identify aviation candidates most likely to succeed in this new and unusual

approach to warfare.

 

Problems relating to the physiology of flight were given greater consideration at the close of

World War I as the altitude capability of aircraft increased. At this time, aircraft were available

that could attain an altitude of 25,000 feet (Williams & Barr, 1946), although flight at the

higher altitudes was seldom attempted. As the difficulties of flight at higher altitudes became

more apparent in the 1920s, increasing consideration was given to the use of supplemental

oxygen. In 1927, a letter from the Chief of the Bureau of Aeronautics indicated that the 2,000

oxygen tanks purchased by the Navy in 1922, probably for welding purposes, could be used for

aviation. At this time, such tanks supplied oxygen to the aviator through a pipestem hooked

over his lip. In general, although the use of oxygen was authorized, it was not required and not

necessarily recommended. However, the advantages of oxygen use soon became more apparent.

In 1929, a memorandum endorsement from the Director of Fleet Training to the Chief of Naval

Operations stated that "it is apparent that the use of oxygen at altitudes of 15,000 to 16,000

feet is not necessary for safety but is extremely desirable in that the physical and mental

capability of the pilot is increased. Above these altitudes, the necessity for oxygen increases and

the factor of safety to personnel enters."

The simple inconvenience of using oxygen delivered through a pipestem weighed against its

use. The delivery tube caused Up irritation and made it difficult to hold and use a

microphone. The answer to these problems came with a prototype oxygen mask developed in

1937 by LT J. H. Korb, MC, USN, and LT A. B. Vosseller, USN. This system consisted of a

modified painter's mask, a soda lime canister, bellows, oxygen tank, and valve controls for

inhalation and exhalation flow. These components formed a rebreathing apparatus in which

oxygen from a pressure tank was fed into bellows until the bellows were two-thirds full. Oxygen

then was passed to the pilot and from there into a canister which removed carbon dioxide

and water before returning the oxygen to the bellows. When the bellows supply was depleted

to only one-third full, additional oxygen was let in from the storage tank. With this system,

and later refined versions, use of oxygen became more practical, and extended flights above

15,000 feet became more routine. Lengthy flight at high altitude, however, placed the pilot

in a much more hostile operating environment. Courage was no longer sufficient. The pilot

had to understand the effects of loss of oxygen, prolonged exposure to intense cold, reduced

pressure, and the many other characteristics and hazards of high altitude operations. The

operational readiness of naval air forces was coming to depend, in part, on the training and

indoctrination given aviators concerning the physiological stresses of aviation. The stage now

was set for the formalized training programs which were developed under the urgency of

World War H.

 

World War II

 

Although World War II did not begin for the United States until 7 December 1941, the

preparations and actual warfare occurring in Europe and the Far East for several years prioi

to this had made it obvious that such a cataclysmic event was certainly possible and perhaps

even likely. Around 1933, the Navy began a gradual program of updating and expanding its

forces. Naval aviation in this period was characterized by increasing numbers of aircraft and

greater specialization, with aircraft being developed specifically for patrol, scouting,

dive-bombing, and torpedo missions (Cagle, 1969). In 1940, Congress enacted Public Law

671 which eliminated peacetime restrictions and revolutionized traditional procedures for

procurement of military equipment (Howeth, 1963). Under the provisions of this act, the

Navy air arm was able to achieve tremendous increases in aircraft and material in the

following several years.

 

As naval activities grew, the training establishment also expanded. In February 1940, a

recommendation was made by the Medical Research Section of the Bureau of Aeronautics

that facilities be procured to provide oxygen indoctrination for all flying personnel (Williams

& Barr, 1946). It was recommended also that instruction be given, by means of lectures and training films, on the physiological and psychological effects of "anoxia" 1 and on the use of

oxygen equipment, and that practical demonstrations be given to small groups in low

pressure chambers where the effects of anoxia could be experienced and observed and where

the beneficial effects of oxygen could be demonstrated. The Bureau of Aeronautics approved,

in July 1940, the installation of four low pressure chambers to be located at Naval Air

Stations in Pensacola, Florida; Corpus Christi, Texas; Miami, Florida; and Jacksonville,

Fl orida. These chambers, the first of which began operating at Pensacola in June 1941, were designed to accommodate 14 airmen simultaneously.

Routine oxygen indoctrination was begun for the first -time in the Navy in July 1941.

Training at Pensacola initially was given to cadets, officer student pilots, enlisted student

pilots, and Royal Air Force and Royal Navy personnel. In lesser numbers, officers and men

from the Free Gunnery School at Pensacola were trained (Pollard, 1961). As the size of the

naval air forces increased in 1941, the early altitude training facilities became overloaded and

plans for more chambers were developed. Six eight-place low pressure chambers were

procured in late 1941 for installation at other air stations. In late 1942 and early 1943, two

new low pressure chambers became operational at Pensacola to handle the increased volume.

Gemmill reported in 1942 that by that time 2,521 students had gone through the low

pressure chamber training program at Pensacola.

 

The low pressure chamber facilities, known as Altitude Training Units, soon began to operate under a systematic program for instruction. The first formal syllabus of training was developed and placed in operation at Pensacola in August 1941.

As aviation physiology training increased in intensity again during the late 1940s and early

1950s, it also expanded in scope, dealing with new topics and new aviation equipment. The new

equipment included improved oxygen systems developed to meet jet needs. The automatic

positive pressure diluter demand oxygen regulator and the pressure compensated oxygen mask

were introduced in 1946. These items represented a marked advance over oxygen equipment

previously used. This new equipment allowed aviators to fly military aircraft at altitudes as high

as 43,000 feet. In 1949, oxygen badout equipment was developed to provide oxygen for

emergency use in aircraft egress at altitudes up to 50,000 feet. Sufficient oxygen was supplied

to allow a free fall descent of 2 Vi minutes, during which time the aviator could descend to

15,000 feet from maximum altitude. Also in 1949, the Type A-13A oxygen mask was adopted

for general use by the military services. In 1952, the development of liquid oxygen converters

was successfully accomplished and liquid oxygen supplies began to be installed in jet aircraft.

With each advance in oxygen systems technology, aviation physiology training was expanded to

include lectures and demonstrations dealing with the new equipment.

 

Almost simultaneously with the introduction of the first Navy jet aircraft came a new

method of aircraft emergency egress, the ejection seat. In 1949, the F-9F Panther jet offered the

ejection seat as standard equipment.

Navy Aerospace Physiology Tech must first a Hospital Corpsman.

HM 8409 training starts with Naval Survival Training Institute (NSTI) onboard Naval Air Station Pensacola in Pensacola, Florida.  Students are trained to be Aerospace Physiology and Water Survival Instructors and safety observers. Instruction includes aeromedical aspects of flight, in-flight visual problems, spatial disorientation, low pressure chamber systems and operations, emergency egress systems, personal and flight/survival equipment, laser safety, night vision devices, medical intelligence and water survival techniques.

Air Force Aerospace Physiology tech

·       Thorough understanding of aerospace and closely related subjects

·       Completion of appropriate aerospace-related courses

·       Clear voice without speech impediments

·       Ability to perform aerospace and operational physiology duties both alone and as a team

·       Completion of 7.5 weeks of Basic Military Training as well as Airmen’s Week

Must be between the ages of 17 and 39

 

Navy and Air Force Medical Service Corps Officers:

·       Be a U.S. citizen currently practicing in the United States

·       Master’s or doctoral degree in physiology (cardiovascular, pulmonary, neuro, exercise or occupational). Applicants with related degrees (biology, biomedical engineering, kinesiology, zoology or other biological sciences) will be considered if appropriate physiology and anatomy courses are completed

·       Complete courses in organic chemistry, an additional chemistry course (e.g. biochemistry or inorganic chemistry), physics, college mathematics, statistics, anatomy, and physiology. The following courses are highly recommended: biochemistry, biomechanics, comparative anatomy, histology, microbiology, and calculus

·       GPA of 3.0 or higher on a 4.0 scale in each degree earned

·       Complete an interview with two aerospace physiologists

·       Be in excellent physical condition (with the ability to swim) and physically qualified for flight in accordance with the Manual of the Medical Department Article 15-90

·       Be willing to serve a minimum of three years of Active Duty after completion of training (including the internship)

·       Be between the ages of 18 and 41

·       Be in good physical condition and pass a full medical examination

* Applicants with significant military aviation experience who have completed a bachelor's degree in a biological science will be considered.

You may also be expected to meet certain preferred requirements:

·       Experience as an instructor or teacher is desirable

·       Strong personal endorsements in areas of initiative, teamwork and leadership

·       Military or general aviation experience

·       Public speaking experience

Strong interest in military aviation

When an emergency happens at 35,000 feet, it’s crucial that the aircrew is familiar with the emergency procedures and equipment to ensure safety and survival.  HM 8409’s train in the basic knowledge and skills as a technical assistant to the Naval Aerospace Physiologist and Aeromedical Safety Officer.  They provide Aviators, Aircrews, perspective flight personnel, as well as joint service personnel the skills needed to handle in-flight emergencies, ground and water survival.