Сборник технических текстов для домашнего чтения по английскому языку. Морозова М.А. - 19 стр.

UptoLike

ВУЗ: 

УлГТУ | Ульяновск

Составители: 

Рубрика: 

titude and at a speed which is just below the start of the transonic drag rise. The drag
(and thus the thrust required to maintain constant Mach number) will change as the
weight of the airplane changes. The angle of attack (and thus the drag) of an airplane
will become slightly lower as fuel is used since the airplane is becoming lighter and
less lift is required to hold it up.
Climbs and descents are accomplished by using power setting respectively
higher or lower than that required for level flight. When an airplane is in level flight,
just reducing the power begins descent. Instead of pulling back on the stick to main-
tain altitude as the airspeed slows, the pilot keeps the stick neutral or pushes it for-
ward slightly to establish a descent. Gravity will provide the force lost by the reduc-
tion in power. Likewise, increased power results in a climb.
Airspeed can be controlled in a climb or descent without changing the throttle
setting. By pulling back on the stick and increasing the climb rate or by decreasing
the descent rate, the airspeed can be decreased. Likewise, lowering the nose by push-
ing forward on the stick will effectively increase the airspeed. In most climbs and de-
scents, this is the way airspeed is maintained. A constant throttle setting is used and
the pilot changes pitch in small increments to control airspeed.
If the pilot were to fly a climb such that the airplane was at the best-climb
speed as it passed through each altitude, it would be achieving the best possible rate
of climb for the entire climb. This is known as the "best-climb schedule" and is iden-
tified by the dotted line.
Flying the best-climb schedule will allow the airplane to reach any desired alti-
tude in the minimum amount of time. This is a very important parameter for an inter-
ceptor attempting to engage an incoming enemy aircraft. For an aircraft that is
equipped with an afterburner, two best climb schedules are determined; one for a
Maximum Power climb (afterburner operating) and one for a Military Power climb
(engine at maximum RPM but afterburner not operating). The Max Power climb will
result in the shortest time but will use a lot of fuel and thus will be more useful if the
enemy aircraft is quite close. The Mil. Power climb will take longer but will allow the
interceptor to cruise some distance away from home base to make the intercept.
For cargo or passenger aircraft the power setting for best climb is usually the
maximum continuous power allowed for the engines. By flying the best-climb sched-
ule the airplane will reach it's cruise altitude in the most efficient manner, that is, with
the largest quantity of fuel remaining for cruise.
Range
One of the most critical characteristics of an airplane is its range capability,
that is, the distance that it can fly before running out of fuel. Range is also one of the
most difficult features to predict before flight since it is affected by many aspects of
the airplane/engine combination. Some of the things that influence range are very
subtle, such as poor seals on cooling doors or small pockets of disturbed air around
the engine inlets.
Turns
The aerodynamics of a turn widely misunderstood, since many people think
that the airplane is "steered" by the stick or the rudder pedals (probably the result of

Страницы