Flying Light Twins Safely

Question 1

What is the major difference between flying a light twin and a single-engine airplane?

Answer 1

how to manage the flight if one engine loses power

Question 2

What is OEI?

Answer 2

one engine inoperative

Question 3

If no rotation speed is published, what speed shall you rotate at?

Answer 3

use a minimum of minimum control speed (Vmc) plus 5 knots for Vr. As a rule,
light twins should not be airborne before reaching Vmc.

Question 4

What is the Critical Engine?

Answer 4

the engine whose failure would most adversely affect the airplane’s performance or handling qualities

Question 5

At cruise airspeed, where is the thrust center line located?

Answer 5

Through the prop hub

Question 6

Where is the thrust center line located at low air speeds and high angles of
attack?

Answer 6

the effective thrust center line shifts to the right on each engine because the descending propeller blades produce more thrust than the ascending blades (P-factor)

Question 7

Loss of power on one engine creates both control and performance problems. Control problems include the need to counteract the following:

Answer 7

Yaw. Loss of power on one engine creates yaw due to asymmetrical thrust.
Roll. Loss of power on one engine eliminates propeller blast over the wing. This elimination affects the lift distribution over the wing, causing a roll toward the inoperative engine

Question 8

What is side slip?

Answer 8

the angle at which the relative wind meets the longitudinal axis of the airplane

Question 9

When you want zero side slip during OEI flight what must you do?

Answer 9

zero side slip occurs with the ball slightly out of center, deflected toward the operating engine

Question 10

What is the best zero side slip configuration in OEI flight?

Answer 10

the suggested zero sideslip configuration at best single-engine rate of climb airspeed (Vyse) for most light twins is approximately two to three degrees of bank toward the operating engine, with the ball displaced about one-half of its diameter from center, also toward the operating engine

Question 11

Aircraft Flight Manual/Pilot’s Operating Handbook (AFM/POH) performance figures
for OEI flight were determined at zero sideslip. T/F?

Answer 11

True

Question 12

What is Vmc greatly affected by?

Answer 12

Bank Angle

It is reduced significantly with increases in bank angle, and it increases significantly as the wings approach level. Tests have shown that Vmc may increase more than 3 knots for each degree of bank less than 5 degrees. Loss of directional control may be experienced at speeds almost 20 knots above published Vmc when the wings are held level

Question 13

Conditions that lower Vmc INCREASE control but DECREASE performance

Answer 13

• CG Forward, longer arm = more rudder control
• Density altitude, high DA decreases engine power and thrust
• Engine Power reduction on OE decreases asymmetric thrust
• Feathering failed engine reduces drag and yaw
• Maximum takeoff weight helps resist yaw
• Zero sideslip can help reduce Vmc by 3 knots per degree of bank angle

Question 14

What is the purpose of Vxse?

Answer 14

Best single engine angle of climb speed, it is the speed you want when clearing obstacles during OEI initial climbout because it gives the greatest amount of altitude gain per unit of travel, operates very close to Vmc

Question 15

What is the purpose of Vyse?

Answer 15

Best single engine rate of climb speed, normally indicated with a blue radial line on most airspeed indicators, gives the greatest gain of altitude per unit of time

Question 16

What factors effect Vyse negatively?

Answer 16

Drag from a windmilling propeller, extended landing gear, flaps extended beyond optimum, or any sideslip will reduce or even eliminate any modest single-engine performance that may exist. Turbulence and maneuvering of the airplane will further erode performance.

Question 17

What is Vsse?

Answer 17

Safe single-engine speed (Vsse) is the minimum speed at which intentional engine failures are to be performed.

Question 18

What is Accelerate-Stop Distance?

Answer 18

the runway required to accelerate to either Vr or Vlof and, assuming an engine failure at that instant, to bring the airplane to a complete stop.

Question 19

What is Accelerate-Go Distance?

Answer 19

Accelerate-go distance is the distance required to accelerate to either Vr or Vlof and, assuming an engine failure at that instant, to continue the takeoff on the remaining engine and climb to a height of 50 feet

Question 20

Loss of power on one engine represents a 50-percent loss of thrust, but it often results in how much of a percentage for climb performance?

Answer 20

80-90

Question 21

Define the Single-Engine Ceiling.

Answer 21

The single-engine service ceiling is the altitude at which twins can no longer climb at 50 feet per minute in smooth air, with one engine feathered, at maximum certificated takeoff weight. The single-engine absolute ceiling is where the rate of climb is zero

Question 22

If one engine were to fail on takeoff with the landing gear down, what is the recommended course of action?

Answer 22

it is recommended that the pilot close both throttles and land on the runway or overrun remaining.

Question 23

Steps for “Landing Gear Selected Up, OEI Climb Performance Inadequate”

Answer 23

When operating near or above the single-engine ceiling and an engine failure is experienced shortly after lift-off, a landing must be accomplished on essentially whatever lies ahead.

Question 24

Steps for “Landing Gear Selected Up, OEI Climb Performance Adequate”

Answer 24

• Control, pitch for Vyse, aggressive rudder, bank 5 degrees not to exceed 10
• Configure
• Climb, Maintain Vyse, Reduce bank angle to achieve zero sideslip,
• Checklist, On reaching 400 feet AGL, refer to the printed checklist. Review the Engine Failure After Takeoff Checklist items. If workload permits, then accomplish the “Securing Failed Engine” checklist items to turn off systems and accessories no longer required.