Private Pilot Chapter 8 Questions and Answers
Which would provide the greatest gain in altitude in the shortest distance during climb after
takeoff? ** Answ** Vx.
Vx is the best angle-of-climb speed, which provides the greatest gain in altitude for the shortest
distance traveled. Vy is the best rate-of-climb speed. Va is maneuvering speed at which you may
apply full and abrupt control movement without overstressing the airframe and causing structural
damage.
After takeoff, which airspeed would the pilot use to gain the most altitude in a given period of
time? ** Answ** Vy.
Vy is the best rate-of-climb speed, which provides the greatest gain in altitude in the least
amount of time. Vx is the best angle-of-climb speed. Va is maneuvering speed, which is the
maximum speed at which you may apply full and abrupt control movement without overstressing
the airframe and causing structural damage.
What effect does high density altitude, as compared to low density altitude, have on propeller
efficiency and why? ** Answ** Efficiency is reduced because the propeller exerts less force
at high density altitudes than at low density altitudes.
High temperature decreases the density of the air, which increases density altitude and reduces
propeller efficiency--a smaller mass of air is accelerated by the propeller, which reduces the
force exerted.
Which combination of atmospheric conditions reduces aircraft takeoff and climb performance?
** Answ** High temperature, high relative humidity, and low density altitude.
, High temperature increases density altitude with a resulting decrease in aircraft performance. In
addition, high relative humidity decreases the density of the air, which reduces aircraft takeoff,
climb, and landing performance.
What effect does high density altitude have on aircraft performance. ** Answ** It reduces
climb performance.
High temperature decreases the density of the air, which increases density altitude and reduces
aircraft takeoff, climb, and landing performance. A high density altitude decreases engine
performance.
What effect, if any, does high humidity have on aircraft performance? ** Answ** It
decreases performance.
High relative humidity decreases the density of the air, which reduces aircraft performance. For
example, the wing must move through the air faster to develop enough lift for takeoff, resulting
in a longer takeoff roll. Engine power is decreased because the engine must take in a larger
volume of air to get enough air molecules for combustion; and propeller efficiency is decreased.
(Refer to Figure 8.) What is the effect of a temperature increase from 25 degrees F to 50 degrees
F on the density altitude is the pressure altitude remains at 5,000 feet? ** Answ** 1,650-foot
increase.
Follow the line above 25 degrees F up to where it intersects 5,000 feet pressure altitude on the
left identify 3,750 feet density altitude on the left scale. Do the same with 50 degrees F, up to
5,000 feet, and then left to read 5,400 feet. The difference is an increase of 1,650 feet.
(Refer to Figure 8.) Determine the pressure altitude with an indicated altitude of 1,380 feet MSL,
with an altimeter setting of 28.22 at standard temperature. ** Answ** 2,991 feet.
Which would provide the greatest gain in altitude in the shortest distance during climb after
takeoff? ** Answ** Vx.
Vx is the best angle-of-climb speed, which provides the greatest gain in altitude for the shortest
distance traveled. Vy is the best rate-of-climb speed. Va is maneuvering speed at which you may
apply full and abrupt control movement without overstressing the airframe and causing structural
damage.
After takeoff, which airspeed would the pilot use to gain the most altitude in a given period of
time? ** Answ** Vy.
Vy is the best rate-of-climb speed, which provides the greatest gain in altitude in the least
amount of time. Vx is the best angle-of-climb speed. Va is maneuvering speed, which is the
maximum speed at which you may apply full and abrupt control movement without overstressing
the airframe and causing structural damage.
What effect does high density altitude, as compared to low density altitude, have on propeller
efficiency and why? ** Answ** Efficiency is reduced because the propeller exerts less force
at high density altitudes than at low density altitudes.
High temperature decreases the density of the air, which increases density altitude and reduces
propeller efficiency--a smaller mass of air is accelerated by the propeller, which reduces the
force exerted.
Which combination of atmospheric conditions reduces aircraft takeoff and climb performance?
** Answ** High temperature, high relative humidity, and low density altitude.
, High temperature increases density altitude with a resulting decrease in aircraft performance. In
addition, high relative humidity decreases the density of the air, which reduces aircraft takeoff,
climb, and landing performance.
What effect does high density altitude have on aircraft performance. ** Answ** It reduces
climb performance.
High temperature decreases the density of the air, which increases density altitude and reduces
aircraft takeoff, climb, and landing performance. A high density altitude decreases engine
performance.
What effect, if any, does high humidity have on aircraft performance? ** Answ** It
decreases performance.
High relative humidity decreases the density of the air, which reduces aircraft performance. For
example, the wing must move through the air faster to develop enough lift for takeoff, resulting
in a longer takeoff roll. Engine power is decreased because the engine must take in a larger
volume of air to get enough air molecules for combustion; and propeller efficiency is decreased.
(Refer to Figure 8.) What is the effect of a temperature increase from 25 degrees F to 50 degrees
F on the density altitude is the pressure altitude remains at 5,000 feet? ** Answ** 1,650-foot
increase.
Follow the line above 25 degrees F up to where it intersects 5,000 feet pressure altitude on the
left identify 3,750 feet density altitude on the left scale. Do the same with 50 degrees F, up to
5,000 feet, and then left to read 5,400 feet. The difference is an increase of 1,650 feet.
(Refer to Figure 8.) Determine the pressure altitude with an indicated altitude of 1,380 feet MSL,
with an altimeter setting of 28.22 at standard temperature. ** Answ** 2,991 feet.
