Significant Impact of Pressurized Cabin in Aviation Development
Significant Impact of Pressurized Cabin in Aviation Development
In aviation history, airplanes, for example, the DC-3 and the Boeing 247, denoted significant developments and improvements in airplane design, but they had a significant shortcoming. They could not hover beyond 10,000 feet, for the reason that passengers or crew became dizzy and even lost consciousness due to the decreased oxygen levels at higher altitudes (“History of Aviation – First Flights,” 2020). In the 1930s, aviation scholars and scientists found that air travel at high altitudes above the weather would play a critical role in passengers’ comfort, higher speed, and more extended range. The aircrafts wanted to fly higher, to get above the turbulence and stormy weather typical at lower altitudes. Airsickness was problematic for many commercial airline passengers and a hindrance to the growth of the industry.
The advancement was made at Boeing with the Stratoliner, which was presented in 1940. It was the first airplane to be pressurized, meaning that air was pumped into the airplane as it acquired height to keep an atmosphere in the interior of the cabin the same as the atmosphere that happens innately at lower elevations (“History of Aviation – First Flights,” 2020). With its controlled air compressor, the 33-seat Stratoliner could fly to a height of 20,000 feet and attain speeds of 200 miles per hour. Aircraft cabin pressurization is a recognized way of safeguarding the passengers and the crew against the hypoxia effects. The comfort of the passengers is also a factor to consider. Typically, the best comfort is attained at rates of the fly of 1500 feet per minute (Dumas et al., 2014).
Background of Pressurized Cabin
Commercial and military airplanes first started carrying out experiments with higher height air travel by way of encircled, oxygen-supplemented cockpits in 1920 with the LUSAC-11. George Lepère designed this fighter airplane in France, but it was constructed in the US for experiments and would establish several altitude records. The aircraft also encouraged and motivated airplane constructors to advance upon the cockpit concept resistant to altitude (Cabin & Courtney, 2020). In 1921, Glenn Curtiss was assigned to construct 4000, improved British Airco DH.9A aircraft to be used in the war, which, when created in the United States, would be branded as Ninak. There were only nine aircraft that were made before the war stopped, and the assignment was terminated, but one of those aircraft gave way for the construction of XC-35, which created definitive history.
That aircraft was improved and advanced to comprise a pressurized enclosed cockpit and would be taken on the world’s first pressurized flight of high altitudes, which was navigated by test pilot Lt. Harris (Cabin & Courtney, 2020). In 1937, the United States was able to create the Lockheed XC-35 that contained a cockpit, passenger cabin, and crew area that were all pressurized.
In 1935, the United States Army Air Corps reached out to Lockheed Aircraft Corporation to ask for an experimental airplane that can extend flights more than sixty minutes above 25000, with a flight endurance of ten hours. Two structure engineers, Major Greene and Younger, were tasked to be in charge of creating a pressurized cabin. They started constructing a pressurized cabin by involving their teams to modify the Electra (Cabin & Courtney, 2020). The aircraft was built-in with a rounded cross-section fuselage that could endure an atmospheric pressure of up to 10 per square inch; small windows designed not blow out when dealing with differentials in high-pressure, and two turbo supercharged engines with 550 horsepower each.
The cabin’s pressurization system designed and constructed by the two engineers gave the path for the technique most of the airplanes are still using today. Pressurization of the passengers’ cabin was done by means of air redirected from the engine’s turbocharger, which was then forced via compressor outlets, regulated physically or by hand in the aircraft by the onboard engineer. All this granted the occupants a cabin altitude of about 12000 feet, which was exceptional and marvelous but was not that comfy.
After these massive adjustments and reformations, the Electra was renovated into the XC-35. After the aircraft’s testing, it was presented to Wright Field in Ohio, where it performed its first flight. In 1937, Army Corps pilots flew the XC-35, demonstrating and displaying its many remarkable capabilities to military officials and reporters alike (Cabin & Courtney, 2020). In this flight, the pilots did not use any oxygen suits or masks, and they reached the highest velocity of 350 miles per hour. The aircraft, XC-35 fulfilled and surpassed each expectation, which was projected; for this reason, it made the Army Air Corps to earn the Collier Trophy, an annual aviation award managed and governed by the US National Aeronautic Association.
The award gave the Army Air Corps more confidence and permitted the XC-35 to be used as the executive transport of the assistant secretary of war at the time (Cabin & Courtney, 2020). Later on, pressurized airplanes took part in the commercial aviation field when Pan Am Airways expanded its fleet by buying two Stratoliners (Boeing 307). This made the Stratoliner be the first pressurized commercial transport.
Challenges and Barriers Confronting Pressurized Cabin
Cabin depressurization refers to the incapability of the airplane’s pressurization system, maintaining or keeping its pressure schedule design. It can be brought about by the system’s breakdown, by an inadvertent crew action, by the structural damage of the aircraft, or by a deliberate crew intervention. Cabin depressurization is a possibly life-threatening urgent situation in an airplane flying at the typical traveling height for most jet passenger airplanes (Dumas et al., 2014).
Decompression is typically categorized as gradual, rapid, or explosive based on the time spacing over which the pressure in the cabin is lost. Decompression is considered explosive when the lungs cannot decompress the fast variation in pressure in the cabin. It usually happens more frequently in small volume pressurized airplanes like military jets than in the biggerpressurized airplane and can cause lung harm to airplane passengers and crew. In contrast, rapid decompression occurs when there is a cabin pressure change, but the cabin can decompress slower than the lungs. In rapid depressurization, the risk of lungs harm or destruction is meaningfully decreased. Slow or gradual depressurization usually is harmful and unsafe only when it is undetected at an early stage. The warning systems do not always show or signal a slow decompression until its effects have become significant and these warnings have been continuously figured out incorrectly.
These decompressions, either explosive or rapid, could result from structural damage with possible catastrophic outcomes; though, such nature incidents are infrequent (“Loss of Cabin Pressurization,” 2020). During depressurization, there are two groups of instant dangers, physical and physiological hazards. Physical hazards, for instance, noise, distraction, debris, cooling, and misting, are well-recognized, but there is a low danger of mechanical injury in most decompressions. Hazards considered physiological include hypothermia, gas expansion, decompression sickness, hypoxia, and damaged human performance.
Depending on the airplane’s altitude when depressurization occurs, loss of pressurization can quickly result in the occupants’ breakdown except if they obtain supplemental oxygen. In the incident of failure in pressurization, the flight crew must put on oxygen equipment immediately. In the event of a deliberate depressurization, the crew should be on oxygen before the depressurization begins. In depressurization, which cannot be controlled, the crew will want to go down without delay to a height at which they and the passengers can take breaths with no supplemental oxygen (Sukhov & Timofeev, 2019).
The Lasting Impact of Pressurized Cabin on Aviation in Today’s World
It is pressurization of the cabin, along with heating and air conditioning, that make it possible for the high altitude passenger jet airplane of today to fly over the weather conditions and storms, where passengers could be seriously harmed or killed by subzero coldness and the thin air within a short time if they were not protected. Cabin pressurization is essential because of the nuances between low and high-altitude air density. Air is less dense at high altitudes than low altitudes. At ground level, the air pressure is a little over 14 pounds per square inch. When an airplane reaches its typical cruising altitude, usually about 30000-40000 feet, the air pressure may be just four to five per square inch (“A Brief History of Airplanes and Aviation Safety,” 2020).
The low air pressure associated with high altitude flights can restrict passengers from receiving adequate oxygen unless the cabin is pressurized. Low air pressure means the air is less dense. Therefore, it contains less oxygen. If airplanes did not pressurize their cabins, it could lead to insufficient oxygen and related medical problems like hypoxia. Planes need pressurized cabins to ensure passengers and crew members receive an adequate amount of oxygen in the air they breathe.
The good news is that modern-day airplanes are designed with redundancy measures in case of pressurization failure. If an airplane’s cabin loses its pressure, oxygen masks will automatically drop down in front of passengers. Passengers can place one of these oxygen masks over their faces to obtain a sufficient amount of oxygen until the airplane descends and lands.
