Procedures, Systems, and the Checkride

Module 3 · Procedures, Systems, and the Checkride · Lesson 1 of 4

Engine Failure Procedures

A fixed sequence, flown from memory: control, power, drag, identify, verify, feather.

Every twin's POH has its own memory items and their exact order varies. The logic behind them is the same in all light twins, and knowing the logic helps you fly them correctly under stress. Always learn and use your airplane's checklist.

Control

1. Directional control and airspeed
   Rudder to stop the yaw, pitch for blue line. Raise the dead.
   Vyse

Power up

1. Mixtures, props, throttles
   Full forward, in that order. You do not know yet which engine failed.
   FORWARD

Clean up

1. Flaps
   Up, to cut drag.
   UP
2. Gear
   Up, unless you are landing on the runway ahead.
   UP

Find it and confirm it

1. Identify
   Dead foot, dead engine.
   DEAD FOOT
2. Verify
   Slowly close the throttle on the engine you think failed. No change in yaw or sound confirms it.
   THROTTLE IDLE

Fix or feather

1. Troubleshoot if altitude and time allow
   Fuel selector, fuel pump, mixture, carb heat or alternate air, magnetos.
   FIX?
2. Prop on the dead engine
   Feather it. Pull the right lever: you already verified with the throttle.
   FEATHER
3. Mixture on the dead engine
   Idle cutoff.
   CUTOFF
4. Secure, declare, land
   Engine secure checklist, cowl flap, fuel and electrical load. Declare an emergency and land at the nearest suitable airport.
   CHECKLIST

Single-engine approach and landing

• Fly a normal-looking pattern, a little higher and closer if you can. Keep at least blue line until landing is assured.
• Delay gear and flaps until you are sure of reaching the runway, per your POH. Many pilots extend the gear on final when the runway is made, and use partial or no flaps.
• Trim out as much rudder pressure as the airplane allows. As you reduce power on the good engine in the flare, release rudder smoothly.
• Decide on a point below which you are committed to landing. A single-engine go-around from low and slow, with gear and flaps down, may not be possible.

Module 3 · Procedures, Systems, and the Checkride · Lesson 2 of 4

Propellers and Feathering

Twin propellers are built to fail safe. When oil pressure goes away, the blades go to feather.

The constant-speed props on light twins work like the ones on complex singles, with one big difference. In most single-engine airplanes, oil pressure drives the blades toward high pitch and losing oil sends them to low pitch (high RPM). On most light twins it is reversed: oil pressure from the governor drives the blades toward low pitch, and a nitrogen or air charge in the hub, a spring, and blade counterweights drive them toward high pitch and feather.

• Feathering: pull the prop lever fully aft past the detent. The governor dumps oil and the blades rotate to about 80 to 90°, edge-on to the airflow. The prop stops.
• Lost oil pressure: with nothing holding them in low pitch, the blades feather on their own.
• Feathering lock (anti-feather) pins: centrifugal latches that engage below roughly 800 to 1,000 RPM (about 1,000 RPM in the Duchess, Module 4). They keep the blades from feathering during a normal shutdown on the ground, so the next start isn't against feathered blades. In flight, feather before RPM decays below the lock speed, or the blades stay locked in low pitch.
• Unfeathering: move the lever forward and use the starter, or in airplanes with an unfeathering accumulator, let stored oil pressure drive the blades out of feather so the prop windmills.
• Synchronizer or synchrophaser: on some twins, matches the RPM or blade position of both props to reduce noise and vibration.

Module 3 · Procedures, Systems, and the Checkride · Lesson 3 of 4

Twin Systems

Two engines mean two of most things, and ways to share them when one engine stops.

Fuel and crossfeed

Normally each engine feeds from tanks on its own side. Crossfeed lets an engine draw from the opposite side's tanks. You use it during single-engine operation to reach fuel on the dead engine's side, extend range, or correct an imbalance. In most light twins it does not pump fuel from one tank to another. Many POHs limit crossfeed to straight and level flight, and you normally turn the electric fuel pump on before changing selector positions.

Other systems

Module 3 · Procedures, Systems, and the Checkride · Lesson 4 of 4

Checkride Maneuvers

What you will fly for the multi-engine practical test, and what the examiner is looking for.

The multi-engine add-on uses the Airman Certification Standards for your certificate level, plus the multi-engine tasks. Expect the familiar maneuvers (steep turns, slow flight, power-on and power-off stalls, emergency descent) flown in the twin, and these multi-engine tasks:

Vmc demonstration, step by step

A general sequence. Your school's procedure and the POH set the exact power settings and speeds.

Setup

1. Altitude and area
   High enough to recover no lower than 3,000 feet AGL. Clearing turns.
   ≥ 3,000 AGL
2. Configuration
   Gear up, flaps as specified (often takeoff or up), cowl flaps as for takeoff, props high RPM, trim for takeoff.
   CONFIG
3. Slow down
   Reduce power and slow to about 10 knots above Vsse or Vyse.
   SLOW
4. Simulate the failure
   Critical engine to idle, then the operating engine to full power. Hold heading with rudder and up to 5° of bank toward the good engine.
   IDLE / FULL

Demonstration

1. Slow about 1 knot per second
   Raise the nose gradually, holding heading as rudder runs out.
   1 KT/SEC
2. Recognize
   First sign of loss of directional control, stall warning, or buffet.
   FIRST SIGN

Recovery

1. Reduce power and lower the nose together
   Operating engine throttle back as far as needed while pitching down to regain speed and control.
   SIMULTANEOUS
2. Recover to blue line
   Above Vsse, bring the operating engine back to full power, adding rudder as you go. Fly straight at Vyse with minimum altitude loss.
   Vyse

Module 3 · Procedures, Systems, and the Checkride · Knowledge Check

Module 3 Knowledge Check

Nine questions an examiner could ask about this module. Each answer comes with the reason. Pass mark: 80% (8 of 9).