Short-Field takeoffs are incredibly useful useful maneuver for whenever you need to get the maximum performance out of the airplane during the takeoff roll and initial climb out. It's important, however, to properly understand how to do the maneuver and the limitations that they have.
Completion Standards
The private and commercial ACS include a section for the "Short-Field Takeoff and Maximum Performance Climb" with nearly the same completion standards, the only difference being tighter tolerances for airspeed in the commercial ACS, which is shown below.
Objective
To determine that the applicant exhibits satisfactory knowledge, risk management, and skills associated with a short-field takeoff, maximum performance climb operations, and rejected takeoff procedures.
Knowledge
- Effects of atmospheric conditions, including wind, on takeoff and climb performance
- Vx and Vy
- Appropriate airplane configuration
Risk Management
- Selection of runway based on pilot capability, airplane performance and limitations, available distance, and wind
- Effects of crosswind, windshear, tailwind, wake turbulence, runway surface/condition
- Abnormal operations, to include planning for: rejected takeoff and engine failure in takeoff/climb phase of flight
- Collision hazards, to include aircraft, terrain, obstacles, wires, vehicles, persons, and wildlife
- Low altitude maneuvering including stall, spin, or CFIT
- Distractions, loss of situational awareness, or improper task management
Skills
- Complete the appropriate checklist
- Make radio calls as appropriate
- Verify assigned/correct runway
- Ascertain wind direction with or without visible wind direction indicators
- Position the flight controls for the existing wind
- Clear the area, taxi into takeoff position and align the airplane on the runway centerline utilizing maximum available takeoff area
- Apply brakes while setting engine power to achieve maximum performance
- Confirm takeoff power prior to brake release and verify proper engine and flight instrument indications prior to rotation
- Rotate and lift off at the recommended airspeed and accelerate to the recommended obstacle clearance airspeed or VX, +10/-5 knots (private) or VX ±5 knots (commercial)
- Establish a pitch attitude that will maintain the recommended obstacle clearance airspeed or VX, +10/-5 knots (private) or ±5 knots (commercial) until clearing the obstacle or until the airplane is 50 feet above the surface
- Establish a pitch attitude for VY and accelerate to VY +10/-5 knots (private) or ±5 knots (commercial) after clearing the obstacle or at 50 feet AGL if simulating an obstacle
- Configure the airplane in accordance with the manufacturer’s guidance after a positive rate of climb has been verified
- Maintain VY +10/-5 knots (private) or ±5 knots (commercial) to a safe maneuvering altitude
- Maintain directional control and proper wind-drift correction throughout takeoff and climb
- Comply with noise abatement procedures
Calculating Takeoff Distances
Use Our Cessna 172S Short Field Takeoff Distance Calculator
Takeoff distances in the 172S are only given for the short field configuration, and include figures for the ground roll and the total distance to clear a 50 foot tall obstacle. These calculations must take into account the pressure altitude, temperature, wind, runway surface, and weight. Also, remember that all of these figures were calculated using ideal conditions and a test pilot who was trained specifically for this task, so you need to add a little bit of margin to the figures.
When to Use the Short-Field Takeoff
Any time there is a consideration of a short runway or obstacles off the departure end of the runway is a perfect time to do a short-field takeoff. However, careful consideration needs to be made to ensure that you are within safe margins of safety.
The Procedure
Configuration
Short-field takeoffs should be done with 10 degrees of flaps in the 172S. Double check the flaps are set correctly before entering the runway, and when completing the line up checklist.
Use ALL of the Runway
Runway behind you is always wasted. When you line up, make sure that you are giving yourself the maximum amount of distance available down the runway as reasonably possible. Square off your turn to line up with the runway so that you aren't taxiing forward on the runway before starting the takeoff roll.
Applying Full Power
First, make sure that you are firmly and equally applying brakes to ensure that when adding power the airplane does not move forward. Then smoothly apply full power and check that the RPMs are between 2300 and 2400, call out "Engine Instruments Normal."
The Takeoff Roll
Once the engine instruments are checked, release the brakes. Make sure to mainly control direction on the ground with rudder and not the brakes. Other than that, the first part of the takeoff roll until rotation will be very similar to a normal takeoff. Instead of allowing the nose wheel to rise, however, make sure to hold it on the ground with the elevator until rotation speed (55 kts) is reached.
Lift Off and Initial Climb
Once you have reached rotation speed, pitch up to maintain the Obstacle Barrier Speed (56 kts). This will look like a slightly higher Vx pitch. Maintain this pitch and airspeed until you have cleared your selected obstacle. Once clear, establish a Vx pitch and retract the flaps. Slowly transition to a Vy pitch once the flaps are retracted and continue a normal climb.
Common Errors
- Failure to review AFM/POH and performance charts prior to takeoff
- Failure to adequately clear the area
- Failure to utilize all available runway/takeoff area
- Failure to have the airplane properly trimmed prior to takeoff
- Premature lift-off resulting in high drag
- Holding the airplane on the ground unnecessarily with excessive forward-elevator pressure
- Inadequate rotation resulting in excessive speed after lift-off
- Inability to attain/maintain VX
- Fixation on the airspeed indicator during initial climb
- Premature retraction of landing gear and/or wing flaps