Taxiing

Pre-Taxi Checks

The pre-taxi checks are normally completed using the aircraft's checklist. Depending on airport procedures, it may be necessary to obtain ATC clearance by radio before starting to taxi.

Effects of Inertia

You will notice that increased power is needed to get the aircraft moving, particularly on a grass surface. Much less power is needed once the aircraft is rolling.

When taxiing, be aware that changes in speed or direction must be anticipated — the aircraft's inertia makes it want to continue in the original direction at the original speed.

Engine Handling

The throttle is the primary means of controlling speed while taxiing. Key points:

• Set the throttle friction loose when taxiing for smooth adjustments.
• When slowing or stopping, close the throttle first, then apply brakes.
• Keep carburetor heat at cold when taxiing — the hot air inlet is unfiltered and can ingest debris, grass, and dust.
• Monitor engine temperatures carefully, especially in hot weather. Most light aircraft engines are air-cooled and rely on airflow to stay at the correct operating temperature.
• Do not idle on a fully closed throttle — this causes spark plug fouling. Use the RPM setting specified in the checklist.

Control of Direction

Most light aircraft have a nosewheel linked to the rudder pedals (directly or via springs). A nosewheel aircraft has its center of gravity ahead of the main wheels, making it directionally stable while taxiing.

To turn, apply and maintain rudder pedal pressure in the direction of the turn. When pressure is released, the aircraft straightens out.

Differential Braking

Where fitted (most aircraft), differential braking can assist turns by applying the brake on one side only. This gives a tighter turning radius than nosewheel steering alone.

Some nosewheel aircraft have a free-castering nosewheel with no linkage to the rudder pedals. These aircraft rely on rudder effect and much more differential braking for directional control, especially in crosswinds.

Parking Area Procedures and Taxiing in Confined Spaces

Take great care when taxiing near other aircraft with engines running:

• Even a light aircraft's propeller slipstream can damage the controls of another aircraft behind it.
• Jet blast from an airliner can reach 80 mph up to 120 feet behind it.
• Consider your wingspan and tail length — a small direction change can cause large wing-tip and tail movements.

Effect of Wind and Use of the Flight Controls

Light winds have little effect on taxiing. In stronger winds, directional control becomes more challenging:

• A crosswind causes the aircraft to weathercock — the wind striking the fin pivots the aircraft into the wind.
• Use rudder pedals and differential braking to counter the weathercock tendency.

Control Column Positions in Wind

Correct positioning of the flight controls relative to wind direction prevents the wind from lifting the upwind wing. This is especially important with a quartering tailwind.

Practice using the recommended control positions even in light winds — it builds good habits and helps you appreciate wind direction, which is important during takeoff.

Effects of Ground Surface

Slope and surface type significantly affect taxiing:

• Downslope: Less power needed; anticipate increased speed.
• Upslope: More power required.
• Hard surfaces: Less power needed than grass.
• Grass: Avoid long grass (may hide obstructions). Avoid gravel or loose stones — they can damage the propeller and airframe.

Apron and Maneuvering Area Markings

Common airport ground markings you should recognize:

Marking	Meaning
Orange/white marker boards or flags	Boundary of an area unsafe for taxiing
Two or more white crosses	Disused taxiway or runway
Holding point marker board (e.g., "A 05/23")	Hold position for the designated runway
Single or double yellow lines across taxiway	Runway holding position markings

Marshaling Signals

You may receive marshaling signals, usually when parking at the end of a flight. Common signals include:

Signal	Meaning
Arms raised, palms forward	This bay / Come ahead
Right arm sweeping forward	Turn left
Left arm sweeping forward	Turn right
Arms crossed overhead	Stop
Right hand drawn across throat	Stop engine(s)
Arms down, palms forward	Marshaling finished

ATC Light Signals

Light signals are used primarily during radio failure. The principal signals to an aircraft on the ground:

Light Signal	Meaning (Aircraft on Ground)
Steady Red	Stop
Green Flashes	Authorized to taxi at pilot's discretion
White Flashes	Return to starting point on the airport

Rights of Way on the Ground

Regardless of these rules and any ATC instructions, it is ultimately the pilot's responsibility to avoid collisions.

Priority Order

1. Aircraft landing and taking off
2. Aircraft being towed
3. Aircraft taxiing
4. Vehicles and pedestrians

Converging Traffic Rules

Situation	Action
Head-on approach	Each aircraft alters course to the right
Converging at an angle	Aircraft on the right has right of way ("on the right, in the right")
Overtaking	Overtaking aircraft alters course to the left

Rudder Check

On aircraft where the rudder pedals are directly linked to the nosewheel, a rudder check cannot be done while stationary. Instead, perform it while taxiing:

• Ensure the area is clear of other aircraft and obstructions.
• Tax slowly.
• Apply full rudder deflection in each direction.
• Do not use differential braking during the rudder check.

Instrument Checks

During taxi turns, four flight instruments can be checked. Your instructor will demonstrate how to verify:

1. Turn indicator (or turn coordinator), including the balance ball
2. Attitude indicator (artificial horizon)
3. Heading indicator (directional gyro)
4. Magnetic compass

These checks are normally done during routine taxi turns — each instrument is verified in both a left-hand and right-hand turn.

Taxiing Emergencies

Although rare, there are three types of emergencies to be prepared for:

Steering Failure

In the event of a steering failure, you should still have some directional control through the rudder and differential braking (where available). Stop the aircraft and request assistance.

Brake Failure

If brakes fail — there will usually have been warning signs beforehand — take these steps:

1. Steer clear of obstructions.
2. Close the throttle immediately.
3. Look for an open area where the aircraft can come to a halt.
4. If a collision cannot be avoided, shut down fuel, engine, and electrical systems. Steer to lessen impact force — avoid a head-on collision with a solid obstruction.

Emergency Stop

Close the throttle and apply brakes evenly — hard enough to stop without locking the main wheels. Factors that increase braking distance:

• High taxi speed
• Strong tailwind
• Slippery surfaces (wet grass, slush, ice)
• Downhill slope
• Standing water