where the height h above sea level is expressed in meters. If the pressure is given in millimeters of mercury (mmHg), the barometric formula is written in the form: P(h)=760exp(−0.00012h)[mmHg]. P(h)=29.92exp(−0.0000366h)[inHg].

8000 ft cabin altitude= FL080. 080/100=0.8… so pressure at Cabin Alt 8000 is about 1/2*0.8^2 -5*0.8+14.7, which is . 32 -4 +14.7=11.02 (versus 10.9 actual). So the PSID is just 11.02-4.2, or about 6.78.

Highest mountain on Earth?

• Mount Everest’s peak is the highest altitude above mean sea level at 29,029 feet [8,848 meters].
• Mount Chimborazo’s peak is the furthest point on Earth from Earth’s center.
• Mauna Kea is the tallest mountain from base to peak at more than 33,500 feet [10,210 meters].

The regulations2,3 stipulate that the maximum cabin altitude should not exceed 8000 feet during normal operations, and, in fact, at usual cruising altitude the cabin altitude rarely exceeds 6000 or 7000 feet in a modern jet airliner.

The cabin altitude warning horn will sound when the cabin altitude exceeds 10,000ft. It is an intermittent horn which sounds like the take-off config warning horn. It can be inhibited by pressing the ALT HORN CUTOUT button.

The Cabin Altitude of a pressurised aircraft is normally maintained at and altitude of 8,000 ft or less as a compromise between the physiological needs of the crew and passengers and the structural limitations of the aircraft. At 8,000 ft the use of supplemental oxygen is not required.

The CA alert system is designed to warn the crew if cabin altitude has not been set at 8,000ft. The alert is activated at 10,000ft in case the system fails or the crew have, for example, turned off the pressurisation before take-off to gain more engine power, but then forgotten to reset it.

Cabins are pressurized to create a safe and comfortable environment for pilots, crew and passengers. Most commercial airplanes fly at around 30,000 to 40,000 feet above sea level. At high altitudes such as this, the air is thinner than it is on the ground.

12,500 feet

18,000 feet

Boeing research shows that takeoff and landing are statistically more dangerous than any other part of a flight. 49% of all fatal accidents happen during the final descent and landing phases of the average flight, while 14% of all fatal accidents happen during takeoff and initial climb.

Death in a high-impact plane crash is usually pretty quick and painless.

A middle seat at the back of a plane was found to be the safest, with a 28 per cent mortality rate – compared to the worst, an aisle seat in the middle of the cabin, which has a mortality rate of 44 per cent.

160 to 180 MPH

The biggest reason for this altitude lies with fuel efficiency. The thin air creates less drag on the aircraft, which means the plane can use less fuel in order to maintain speed. Less wind resistance, more power, less effort, so to speak. Spending less on fuel is also great for airlines, for obvious reasons.

Before each and every flight, one of the pilots will conduct a preflight check to evaluate whether the aircraft is airworthy and fit to fly. This is done before every flight. Every.

The Lockheed SR-71 Blackbird is the fastest jet aircraft in the world, reaching speeds of Mach 3.3–that’s more than 3,500 kph (2,100 mph) and almost four times as fast as the average cruising speed of a commercial airliner.

How fast do commercial passenger jets fly? A typical commercial passenger jet cruises at a speed of about 400 – 500 knots which is around 460 – 575 mph. Generally speaking, the higher the aircraft flies, the faster it can travel.

Top 10 fastest passenger airplanes in the world

MacCready Gossamer Albatross