Priority after liftoff?
Gain altitude as rapidly as possible. Once leaving the ground, altitude gain is
more important than achieving excess of airspeed.
VX or VY on departure?
VY up to 400-500 AGL for a safe single‐engine maneuvering altitude.
Accelerate-stop distance
runway length required to accelerate to a specified speed (VR or VLOF etc.) > experience an engine failure > bring the airplane to a complete stop.
Accelerate-go distance
horizontal distance required to continue the takeoff and
climb to 50’ AGL., assuming an engine failure occurs at VR or VLOF, as specified by the
manufacturer (see diagram below).
All Engine Service Ceiling
highest altitude at which the airplane can maintain a steady rate of climb of 100 fpm with both engines operating at full power.
All Engine Absolute Ceiling
altitude where climb is no longer possible with both engines operating at full power.
Single Engine Service Ceiling
highest altitude at which the airplane can maintain a steady rate of climb of 50 fpm with one engine operating at full power and one engine’s propeller feathered.
Single Engine Absolute Ceiling
altitude where climb is no longer possible with one
engine operating at full power and one engine’s propeller feathered.
If the airplane is flying above the single‐engine service ceiling and one engine fails in flight?
the airplane will drift down from its current altitude to the single‐engine service ceiling.
What V speed yields the minimum rate of sink?
VYSE
What does FAR 23.67 provide?
single‐engine climb performance requirements to airplane
manufacturers for FAA certification of multi‐engine aircraft.
For aircraft with a maximum weight of 6,000 lbs., or less and a VSO of 61 knots or less:
The single‐engine rate of climb at 5,000’ MSL must simply be determined with the…
- Critical engine inoperative and its propeller in the minimum drag position
- Remaining engine(s) at no more than maximum continuous power
- Gear and flaps up
- Climb speed not less than 1.2VS1
Rate of climb
is the altitude gain per unit of time.
Climb gradient
is the actual measure of altitude gained per 100 ft. of horizontal travel,
expressed as a percentage impacted by wind
E.G. An altitude gain of 1.5 ft. per 100 ft. of horizontal travel (or 15 ft. per 1,000, or 150
ft. per 10,000) is a climb gradient of 1.5 percent.
conventional twins
Twin‐engine airplanes where the propellers for each engine rotate in the same direction
counterrotating propellers combat what two turning tendencies?
torque and P‐factor
What motions are felt when an engine fails?
yaw and roll
Yaw motion when engine fails?
Asymmetrical thrust will cause a yawing moment around the C.G. towards the inoperative engine.
Roll motion when engine fails?
The yawing moment from above will cause the wing with the operating engine to move faster through the air as the airplane yaws. This causes a faster velocity of air over the wing with the operative engine meaning more lift on that wing and results in a roll towards the inoperative engine.
What is the critical engine?
The critical engine is the engine that, if it were to fail, would most adversely affect the performance or handling characteristics of the airplane.
Which engine is the critical engine on a conventional twin?
The left engine
Three factors that determine if an engine is critical
- P‐Factor
- Accelerated Slipstream
- Torque
P‐factor
descending propeller blade creates more thrust than the ascending blade causing asymmetrical thrust on each side of the propeller.
asymetric thrust formula
THRUST x Arm = Moment
