How does the consumption of fuel effect the altitude of an airliner?

Question

Does the pilot have to constantly adjust alitude as the plane consumes fuel and becomes lighter?

Answer 1

not at all!!! controller gives him an altitude and he keeps it...  you cant start going anywhere as you want to...

Answer 2

Airliners will consume less fuel at higher altitudes.

However, with a nearly full fuel load, the airliners need to start cruising at a lower altitude because the plane doesn't have enough power to climb higher.

As the fuel burns off, the plane climbs higher to take advantage of the lower fuel burn.

Answer 3

Usually an Airliner will file a Flight Plan to cruise at a Flight level for best ground speed and best econmy fuel burn. The aircraft's fuel flow is automatically controlled to perform at best economy fuel burn or best power fuel burn. As we know the higher the airplane flies the less dense the Air becomes, which in turn demands less fuel flow. Also as the altitude is increased the aircrafts speed through the air (True Airspeed, TAS) is increased. This makes it possible for jets to easily cruise at high altitudes at about 84% of the speed of sound.

Answer 4

OBT, when a long-haul flight takes off, it is not uncommon for the aircraft to be too heavy to reach its optimum altitude. When the aircraft burns off some of its fuel, the aircraft asks for, and usually gets, a higher altitude from ATC. This is pre-planned by a computer which makes up flight plans. Large aircraft carry large amounts of fuel, which weigh a lot. Hundreds of thousands of pounds!

A Boeing 747-400 can fly a long way, and can carry over 57,000 gallons of fuel. United Airlines flight 895 leaves Chicago's O'Hare airport and flies non-stop to Hong Kong, a distance of 7800 miles. It will take this flight a while to get to its optimum altitude.

Once the crew gets to its altitude, the auto-pilot keeps the aircraft at its assigned, programed altitude, as the auto-pilot is much better at this than is a human. When the crew wants to change altitude, they usually just change the auto-pilot's directed altitude.

Regards,

Dan

Answer 5

As we burn fuel we beg to climb. And aviator, not so regarding increased speed with altitude. Most airliners reach the point where Vmo and Mmo are equal at approximately 28,000 feet give or take. Since we fly a Mach number above that, indicated airspeed and therefor true airspeed will decrease with further climb. In other words, the fastest a jet airliner can go is reached at 28,000 feet. Any lower or any higher will net a slower TAS for a given mach number.