Takeoff and Climb to Downwind

Forces During Takeoff

During the takeoff roll, the engine produces thrust which must overcome the aircraft's inertia and rolling friction. As the aircraft accelerates along the runway, airspeed increases and the wings begin generating lift. When the lift produced equals or exceeds the weight of the aircraft, the aircraft is ready to fly.

The sequence is straightforward: thrust overcomes inertia, the aircraft accelerates, and when sufficient airspeed is achieved, back pressure on the control column rotates the aircraft to a climbing attitude. The aircraft lifts off when enough lift is being generated to support its weight.

Takeoff Distance vs Takeoff Run

It is important to understand the difference between these two performance figures, both of which are published in the Pilot's Operating Handbook (POH):

Takeoff Run (Ground Roll)

The distance from the start of the takeoff roll to the point at which the aircraft becomes airborne. This is the runway length consumed on the ground.

Takeoff Distance

The total distance from the start of the takeoff roll to the point at which the aircraft clears a 50-foot obstacle. This includes both the ground roll and the initial climb segment.

When assessing whether a runway is long enough, always use the takeoff distance figure — not just the ground roll — and apply appropriate safety factors. A common rule of thumb is to ensure you have at least 1.5 times the calculated takeoff distance available.

Factors Affecting Takeoff Distance

Several factors increase or decrease the distance required for takeoff. You must assess these conditions before every flight:

Factor	Effect on Takeoff Distance
Headwind	Shortens takeoff distance — the aircraft achieves flying speed sooner
Tailwind	Lengthens takeoff distance — more ground speed required to achieve flying speed
High temperature	Lengthens — reduced air density means less lift and less engine power
High density altitude	Lengthens — same effect as high temperature (thinner air)
Heavy weight	Lengthens — more lift required, longer acceleration time
Grass surface	Lengthens — more rolling friction than paved runway
Uphill slope	Lengthens — a component of gravity opposes acceleration
Downhill slope	Shortens — gravity assists acceleration
Flap setting (initial)	Shortens ground roll — more lift at lower speed. May increase total distance due to drag.

Pre-Takeoff Checks

Before taking the runway, complete the pre-takeoff (run-up) checks in accordance with the POH checklist. These checks verify that the engine and systems are operating correctly:

• Engine run-up: Set power to the specified RPM (typically 1700-1800 RPM for Cessna 172) and check for smooth operation.
• Magneto check: Select each magneto individually (LEFT, then RIGHT, then BOTH). Maximum allowable RPM drop is specified in the POH (typically 125 RPM per magneto, 50 RPM differential between magnetos).
• Carburetor heat check: Apply full carburetor heat and verify a drop in RPM (indicates the system is functioning). Return to cold.
• Flight controls: Free and correct — full deflection in all axes, verify correct movement.
• Instruments: Set altimeter to field elevation or current barometric pressure. Heading indicator aligned with compass. Attitude indicator erect.
• Briefing: Brief the takeoff procedure, departure direction, and emergency plan (what you will do if the engine fails on takeoff).

Effect of Power During Takeoff

When full power is applied for takeoff, several yawing and rolling tendencies appear. These are collectively known as left-turning tendencies (for aircraft with a clockwise-rotating propeller as seen from the cockpit):

Torque Reaction

Newton's third law — the engine turns the propeller clockwise, so the aircraft tends to roll left (counterclockwise). This is most noticeable at high power and low airspeed.

P-Factor (Asymmetric Thrust)

At high angles of attack, the descending blade (right side) produces more thrust than the ascending blade (left side), creating a yaw to the left.

Spiraling Slipstream

The propeller slipstream spirals around the fuselage and strikes the left side of the vertical stabilizer, pushing the tail right and yawing the nose left.

Gyroscopic Precession

When a force is applied to the spinning propeller disc (such as raising or lowering the nose), the resulting movement is felt 90 degrees ahead in the direction of rotation. During rotation (pitching up), this creates a left yaw.

Use of Rudder and Elevator During Takeoff

Rudder

The rudder is used throughout the takeoff roll to maintain the aircraft on the runway centerline. Apply right rudder to counteract left-turning tendencies. The amount required will vary with power setting, airspeed, and crosswind component. Smooth, progressive inputs are essential — avoid abrupt corrections.

Elevator

During the initial takeoff roll, the elevator position depends on the aircraft type and conditions. For most nosewheel aircraft in calm conditions, maintain a neutral or slightly aft elevator position. As the aircraft accelerates toward rotation speed (V_R), apply gentle back pressure to raise the nosewheel and rotate to the climb attitude.

Checks During Takeoff

During the takeoff roll, monitor the following:

• Engine instruments in the green: Oil pressure, oil temperature, and other engine gauges should indicate normal. If not — abort the takeoff.
• Airspeed alive: The airspeed indicator should show increasing airspeed early in the takeoff roll. If the airspeed is not increasing — abort the takeoff (possible pitot blockage or instrument failure).
• Directional control: The aircraft should track the centerline. If directional control is lost — abort the takeoff.

ATC and Radio Procedures

At a controlled airport, you must receive a takeoff clearance before entering the runway. The typical sequence:

1. Complete run-up checks at the hold-short line.
2. When ready, advise the tower: "[Airport] Tower, [Callsign], ready for departure runway [number]."
3. Receive takeoff clearance: "[Callsign], runway [number], cleared for takeoff."
4. Read back the clearance and taxi onto the runway.
5. After departure, contact the departure frequency if instructed, or remain on tower frequency for pattern work.

At an uncontrolled airport, announce your intentions on the CTAF (Common Traffic Advisory Frequency) before taxiing onto the runway and again when departing.