The practical ceiling of the aircraft ( Eng. Service ceiling ) - the maximum height of the real application of the aircraft, helicopter [1] ; the highest altitude at which, when flying at a constant horizontal speed , there is still an excess of thrust ( power ) sufficient to perform the lift at a certain vertical speed [2] . This vertical speed is usually defined as 0.5 m / s [3] (or 100 feet per minute [4] for reciprocating and 500 feet per minute for foreign turbojet aircraft).
The practical ceiling indicator serves as an important characteristic when comparing aircraft of different types, as well as in controlling the quality of mass production of aircraft [2] .
The practical ceiling is several hundred meters smaller than the theoretical ceiling [3] .
As a rule, flights at maximum distances are carried out at altitudes close to the practical ceiling. At the same time, during a flight, due to a decrease in the mass of the aircraft (flight weight), the kilometer fuel consumption decreases in proportion to the flight weight, and the practical ceiling increases. That is, due to the consumption of part of the fuel, you can adjust the flight altitude , which ultimately leads to an increase in the practical ceiling [5] .
Airplanes of our time when flying at high speed have such a large supply of kinetic energy that they can gain altitude with it, while if the flight passes near the practical ceiling, then, by using the kinetic energy reserve and maintaining controllability, the aircraft can rise to a height exceeding its theoretical ceiling, even if there is no excess thrust [3] .
On the practical ceiling, due to the low air density , the flight of the aircraft is carried out at large angles of attack and the margin for increasing the angle of attack to the maximum angle of attack is small, therefore, maneuvering the slide on the practical ceiling will be performed with a very large radius of curvature of the trajectory , and this , in turn, will lead to a slow climb and the path will begin to bend down due to a lack of lift [3] .
See also
- Theoretical ceiling
- Dynamic ceiling
- Battle ceiling
Literature
- Practical ceiling // Military Encyclopedic Dictionary / prev. ch. ed. in 63 commission Ogarkov V.N .. - M .: Military Publishing, 1984. - 863 p.
- Practical Ceiling / Aviation: Encyclopedia. - M .: Big Russian Encyclopedia. Editor-in-chief G.P. Svishchev, 1994.
- Pripadchev A. D. On the issue of determining operational characteristics in the process of passenger transportation // Scientific Herald of the Moscow State Technical University of Civil Aviation. - 2010. - No. 160 . - S. 69-72 .
Notes
- ↑ Wind Farm, 1984 , p. 582.
- ↑ 1 2 Papadchev, 2010 .
- ↑ 1 2 3 4 Aircraft ceiling - Theme № 5. Aircraft lifting - Practical aerodynamics // Aircraft club "Golden eagle"
- ↑ Climb Performance Archived June 25, 2015. , page 10-7 / FAA “Pilot's Handbook of Aeronautical Knowledge” (FAA-H-8083-25A)
- ↑ Typical flight profiles Archived copy of March 4, 2016 at Wayback Machine - Horizontal flight // Training materials, SMU USATU