Soft-Field Takeoff and Climb

DEFINITION

Soft-field takeoffs and climbs require operational techniques to get the airplane airborne as quickly as possible to eliminate drag due to grass, sand, mud, snow, etc., and/or minimize damage from rough surfaces

SAFETY FACTORS

Review airplane performance
Do not attempt takeoff requiring performance beyond the capabilities of airplane or pilot
Visually CLEAR approach and departure paths
Care must be exercised immediately after airborne to avoid settling back to surface by releasing back pressure too much or by attempting to climb out of ground effect at an airspeed below VX

TOLERANCES

Private Pilot PTS, IV C
Explain elements, including significance of appropriate airspeeds and configurations, emergency procedures, and hazards associated with climbing at an airspeed less than VX
Select recommended flap setting
Taxi onto runway surface at a speed consistent with safety
Align the airplane with the takeoff path, without stopping and advance the throttle smoothly to maximum allowable power
Adjust and maintain a pitch attitude which transfers the weight from the wheels to the wings as rapidly as possible
Maintain directional control on centerline
Lift off at the lowest possible airspeed and remain in ground effect while accelerating
Accelerate to and maintain VX, +5, -0 knots, if obstructions must be cleared, otherwise to VY, +/- 5 knots
Retract flaps as recommended or at safe altitude
Retract gear after positive rate of climb established and safe landing can no longer be made on remaining runway
Maintain takeoff power to safe maneuvering altitude
Maintain straight track over extended runway centerline
Complete after-takeoff checklist
Commercial Pilot PTS, IV B, adds:
Adjust mixture control as recommended for conditions
Note any obstructions or other hazards in takeoff path and review takeoff performance
Check engine instruments

OBJECTIVES

To develop the student's knowledge and skill in planning and performing safe soft-field takeoffs and climbs to meet the appropriate practical test standards
To provide thorough knowledge of takeoff and climb principles that will help prevent an attempt to takeoff under conditions requiring performance beyond the capability of airplane or pilot

PROCEDURES

Discuss elements of soft-field takeoff and climb
Demonstrate soft-field takeoff and climb
Factors related to the transfer of airplane weight from the landing gear to the wings as rapidly as possible
Establish and maintain relatively high angle of attack with back elevator pressure
Flaps
Taxi onto takeoff surface as fast as possible, consistent with safety, and keep moving
Review of wind conditions and takeoff surface
Determine, estimate wind
Consider walking over takeoff surface to look for hazards
Use of wing flaps
PA-38-112: 21°, first notch
TR182: 20°
Visually check flap extension
How to align the airplane with the takeoff path without stopping
Flaps, hold nose up and throttle forward to keep moving as fast as possible consistent with safety and surface while
Turning smoothly to align with takeoff path
Initial positioning of flight controls
Trim set for takeoff
PA-38-112: elevator tab slightly aft of neutral (depends on loading)
Ailerons full into any crosswind
Elevator back pressure to hold nose up
Power application
PA-38-112
Fuel selector proper tank, Mix rich, PumpON, Carb heat OFF
Smooth application of full power
TR182
Carb heat OFF, Mix RICH, Prop in high RPM
Smooth throttle advance to 30-31" MP
Check engine instruments
Directional control during acceleration on the surface
Align with centerline
Note heading and ground references
Control direction with rudder, heels on floor, off brakes
Crosswind control technique during acceleration on the surface
Gradual reduction of aileron pressure into wind
Downwind rudder
Lift-off attitude and airspeed
As elevator becomes effective, reduce back pressure somewhat to
Lift off in ground effect at slowest possible safe airspeed
Acceleration in ground effect to climb airspeed
Significant ground effect: < ½ wingspan from ground
Once airborne, "level off" by reducing pitch to about 5-10°
Hold airplane just off ground without climbing until
PA-38-112:
VX= 61 KIAS until obstacle cleared
Then accelerate to VY= 70 KIAS and
Retract flaps slowly
TR182
VX= 60 KIAS until obstacle cleared
Apply brakes, retract gear after obstacle cleared
To 70 KIAS
Flaps up slow
Track during climb
Climb out along extended runway centerline
In crosswind, sideslip takeoff converted to crab into wind for climbout
Use of checklist
Pre-takeoff checklist
On takeoff note outside references, airspeed, power settings, engine instruments
Transition to cruise check
Coach student practice
Critique student performance

COMMON ERRORS

Improper initial positioning of flight controls or wing flaps
Elevator full aft
Aileron into wing
Flaps 20°
Hazards of allowing airplane to stop on the takeoff surface prior to initiating takeoff

Airplane may bog down, sink, be difficult to get moving again with damage to gear

Improper power application
Inappropriate removal of hand from throttle
Poor directional control
Do not neglect crosswind correction
Proper initial alignment important as "light" nosewheel makes rudder less responsive
Improper use of brakes

Usually not needed at for soft-field takeoff

Improper pitch attitude during lift-off

Note that pitch adjustment during soft-field takeoff requires

full aft elevator to
reduced elevator back pressure during roll to
slight further reduction in elevator back pressure after lift-off

Hazards of settling back to takeoff surface after becoming airborne
Nose wheel digging in (airplane may flip over)
Side loads on landing
Reduced takeoff performance
Failure to establish and maintain proper climb configuration and airspeed
Accelerate in ground effect to VX, obstacle, or VY, no obstacle
Above 100-200 AGL, over obstacles, climbing at VY, flaps up slow
Gear up over obstacles, out of runway
Drift during climb