Atmospheric pressure, more commonly known as air pressure, has been a key factor in the advancement of aviation science and flight physiology. The general rule of thumb is that air pressure decreases as an aircraft gains altitude. This decrease in air pressure affects both the pilot and aerodynamic performance of the aircraft. The pilot has to depend on the aircraft’s designs to make sure that the feeling of air pressure is the same as being on the ground. As a result, pilots must be trained to the effects of flying at high altitudes and on flight physiology.
In order to understand the effects of atmospheric pressure on flight physiology, we must consider its implications on human body as well. The lower the air pressure, the lower the oxygen level which can cause dizziness, fatigue, or even unconsciousness if left untreated. Conversely, high air pressure can cause difficulty in breathing, and lead to hypertension or hypoxia which can have serious health risks. Understanding the effects of atmospheric pressure and flight physiology is essential to ensuring the safety of all pilots.
Key Takeaways
1. Atmosphere pressure has a significant effect on the aerodynamic performance of an aircraft. This, in turn, has an effect on the overall efficiency of the flight operation.
2. Pilots also need to be aware of the pressure changes in the atmosphere that they will encounter when flying. They should take these into account when making important decisions when operating their aircraft.
3. Aircraft instruments measure parameters such as airspeed, altitude and pressure, and provide the pilot with important information to monitor aircraft performance and react to unexpected changes in the atmosphere.
4. Flying at high altitudes increases the effects of hypoxia, a dangerous lack of oxygen that can significantly affect physical and mental performance. Pilots can combat this by using supplemental oxygen during the flight.
5. To ensure safety and optimize performance, pilots must be aware of the different weather conditions and adjust their flying techniques accordingly.
What Impact Does Atmospheric Pressure Have on Flight Physiology?
Pressure and Height
Atmospheric pressure is the pressure exerted by the weight of the air in the atmosphere of the Earth. This so-called “barometric pressure” is usually expressed in pounds per square inch (psi) or millibars. The higher the altitude, the less pressure there is in the atmosphere. The lower the altitude, the higher the atmospheric pressure. As aircraft ascend along their flight paths, their altitude increases, and therefore the atmospheric pressure is reduced.
Pressurized Atmospheres in Aircraft
Since human physiology is dependent upon normal barometric pressure, aircraft cabins are pressurized to provide a comfortable atmosphere for passengers. During normal flight, cabin pressure is maintained at around 8,000 feet with a high pressure differential (around 13.9 psi or 0.95 atm). This range of altitude and cabin pressure helps to ensure optimal levels of oxygen and pressure in the aircraft cabin. In the event of cabin depressurization, the oxygen masks which are located in the overhead compartments deploy and supply supplemental oxygen to the customers.
Decompression Sickness
Decompression sickness, also known as “the bends,” is a condition caused by rapid depressurization or exposure to high pressure environments. When an individual is exposed to a low pressured atmosphere, the nitrogen in the body may form bubbles that can cause pain, paralysis, or worse. To avoid decompression sickness, pilots and passengers should ascend gradually to reduce the rates of depressurization and allow the body to gradually adjust to the changing atmospheric pressure.
Pressure and Temperature
Atmospheric pressure and temperature are closely related. As the air pressure increases, the temperature decreases, and vice-versa. This would explain why the cabin temperature often increases when the aircraft descends. Since the change of pressure at higher altitudes is more gradual, the temperature difference between the cabin and the outside air is much less pronounced.
Pressure-Sensitive Instruments
Flight instruments are extremely sensitive to pressure changes, and can be adversely affected by changes in air pressure. Aircraft instruments are calibrated to read accurately at 30.00 inches of mercury or 1013.2 millibars (mbar). Minor pressure changes can cause incorrect readings on the aircraft altimeter and airspeed indicators. Pilots must be able to adjust the altimeter and airspeed indicators to accommodate the changing atmospheric pressure.
How to Reduce the Effects of Atmospheric Pressure on Flight Physiology
- Climb and descend gradually to reduce rates of depressurization to avoid decompression sickness.
- Adjust the aircraft instruments according to the atmospheric pressure to ensure accurate readings.
- Carry supplemental oxygen on board at all times in case of any cabin depressurizations.
- Monitor cabin pressure every 10,000 feet to ensure it remains within the optimal range of 8,000 feet.
- Adjust the cabin temperature according to the altitude and barometric pressure.
What is Atmospheric Pressure?
Atmospheric pressure is the pressure exerted on the earth’s surface by the weight of the air. It can be measured in different units such as inches of mercury, millibars, and atmospheres. Pressure increases with altitude, so as a plane reaches higher altitudes the pressure decreases.
How Does Atmospheric Pressure Affect Flight Physiology?
Atmospheric pressure affects flight physiology in many ways. Pressure affects the plane cabin, which is important to the passenger’s comfort. Poorly managed pressure can cause passengers to experience pain in their ears, headaches, and other physiological issues. Pressure also affects avionics systems, airfoil performance, engine performance, cooling airflow, and aircraft control.
What Are The Effects of Low Atmospheric Pressure on Humans?
The effects of low atmospheric pressure on humans can be extreme. As the plane ascends, the passengers may experience the symptoms of altitude sickness. This includes dizziness, lightheadedness, rapid breathing, shortness of breath, and nausea. At higher altitudes, the problem can be exacerbated as the person’s cognitive abilities become impaired due to the lack of oxygen.
Why Is It Important To Control Cabin Pressure During Flight?
It is important to control cabin pressure during flight in order to maintain the comfort of the passengers and to ensure the safety of the plane and its occupants. Uncontrolled pressure can lead to serious physiological issues for passengers and can cause the aircraft to be difficult to operate.
What Are The Risks of High Cabin Pressure?
High cabin pressure can cause a variety of problems. It can cause problems with engine performance, avionics, airfoil performance, cooling airflow, aircraft control, as well as cause passenger discomfort. High pressure can also reduce the amount of oxygen available to the passengers, which can lead to hypoxia.
What Safety Measures Are In Place to Control Atmospheric Pressure?
Aircraft are equipped with safety systems to help control the pressure in the cabin. These include the pressurization system, which is responsible for controlling the cabin pressure and maintaining an appropriate pressure throughout the flight. There are also backup systems in place that are designed to take over in the event of a failure of the primary pressurization system.
How Is Low Pressure Monitored in the Cockpit?
Low pressure is monitored in the cockpit through the use of altimeters. Altimeters measure the aircraft’s altitude and provide an indication of the atmospheric pressure outside the aircraft. This information is then used to help the pilot control the cabin pressure and ensure the safety of the passengers.
How Can Passengers Help to Avoid Altitude Sickness?
The best way for passengers to avoid altitude sickness is to stay hydrated and breathe deeply. It is also important for passengers to eat lightly and take frequent breaks to rest. Additionally, passengers can use over the counter medications that can help reduce the symptoms of altitude sickness such as dizziness and headaches.
Why Is It Important to Increase Cabin Pressure Gradually?
It is important to increase cabin pressure gradually in order to reduce the risk of passengers experiencing physiological discomfort. Rapid changes in pressure can cause the passengers to feel dizzy and experience ear pain or even nausea.
What Are The Risks of Flying in Unpressurised Cabins?
The risks of flying in unpressurised cabins are serious. Unpressurised cabins can cause passengers to experience hypoxia, which is a lack of oxygen. Hypoxia can cause nausea, confusion, loss of consciousness, and even death if not managed properly.
Final Thought
Atmospheric pressure and flight physiology are interconnected and it is important for pilots, aircraft operators, and passengers to understand the risks associated with different pressure levels. Safety systems are in place to help control atmospheric pressure but passengers and crew should be aware of the symptoms of altitude sickness and have the knowledge to help prevent it. Cabin pressure should never be increased rapidly as that can cause discomfort for passengers and effect aircraft performance.
By understanding the basics of atmospheric pressure, passengers and crew can ensure their safety and comfort during air travel. Awareness of the physiological effects of changes in cabin pressure can help reduce the risks of altitude sickness and ensure the plane operates safely and efficiently.
