Heat In The Aviation Environment Flashcards
*What is the primary heat stress problem in an aircraft?
Solar radiant heat
What is the process in which solar radiant energy penetrates plexiglass exteriors and transmits energy to the interior of aircraft, which then cannot escape? At what altitude range is this an issue?
Greenhouse effect.
0 to 10000 ft.
What is kinetic heat in flight? What can reduce it?
When the aircraft structure is heated by friction between its surface and the air, and by compression at the aircrafts front. Cockpit insulation and air ductwork reduce its effects.
Comfortable temperature and humidity limits in the cockpit
68 to 72 degrees.
25 to 50 percent relative humidity.
In general, one extra pound of load =_____ pounds in structural support and fuel.
9 pounds
The body maintains heat balance with several mechanisms. What are they?
Radiation
Conduction
Convection
Evaporation
What is radiation?
Transfer of heat by radiant energy such as IR. Rate of HT depends on objects relative temperatures
Conduction
Transfer of heat through contact. Proximity dictates heat transfer.
What is convection?
Transfer of heat through a liquid or gas medium from one object to another.
What is evaporation heat loss?
Heat is lost to water on the body surface which then evaporates.
Radiation, conduction, and convection become ______ effective as temperature increases.
Less.
At 95 degrees or more, what type of heat loss accounts for most heat loss?
Evaporation heat loss.
Factors that affect evaporation process…
Protective clothing
Availability of drinking water
Relative humidity above 50 percent
Temperature above 82F
What factor most limits evaporation heat loss?
Relative humidity
Name issues that predispose soldiers to heat injury.
Sleep loss Increased exertion Heat exposure Poor fitness Illness Medications Alcohol Prior history Skin conditions Age
