Soft and Short Fields, I
Most aircraft accidents occur during the take-off and landing phase of the flight. Collisions with obstacles during climb out, runway overruns on landing occur every now and then. In this section of the site we will take a look at the various factors contributing to the performance of the aircraft in this part of the flight. Hopefully we help the pilot ensuring safe operation during these phases of the flight as the rules require that of the pilot in command.
Executing good soft and short field landings isn't black art. It is a maximum performance maneuver which most of us learned to do for their checkride but it is not practiced very often afterwards. We start our discussion with soft field landings as pilots operating from a grass runway use this technique more often than others.
Precise airspeed control and minimum float in ground effect is important during these maneuvers and used with finesse for the soft field and precision for the short field landing and approach.
Mandatory item at the end of a flight as take-offs are optional. As a pilot flying cross country you will likely encounter a multitude of runways, grass or sealed, either short, long, up or downhill and what not. The techniques described below will hopefully help you land safely without any incident, but do remember that enough practice makes perfect.
Short or rough grass field
This type of landing is used whenever the runway surface is rough (tall grass, gravel) or otherwise soft (grass runways after a rain shower, snow, slush). The purpose is to transfer the weight of the aircraft from the wings to the wheels as gently as possible thereby making sure that the nose wheel keeps off the ground for as long as possible.
Which is good advise for all aircraft types as the nose wheel is not constructed to take the initial landing load as the main gear does. Some RV-types are known to nose/flip over if the touchdown speed is too high in combination with rough surfaces. Read the NTSB report of the RV-9A flip over in Alaska.
Precise airspeed control is very important. If we approach too fast we use up more runway during the flare and ballooning could occur, the nose wheel will then settle hard and could be causing damage or worse. If we approach too slow we risk stalling and ending up 'landing' before reaching the runway, or even a tail strike due to the nose high attitude.
The trick is to approach in a slightly nose high attitude (the use of flaps can be helpful if the runway is short too) with a touch of power to ease the touchdown and helping airflow over the tail. Full elevator is needed during roll out as the aircraft slows and the nose is kept off the runway for as long as possible. After landing keep the aircraft rolling (to prevent bogging down in the soft ground) and turn off the runway gently.
This is what we use when the aircraft must be stopped in the shortest possible distance available. Approach at the correct airspeed (1.3 VS, add half the wind gust factor if any turbulence), full flaps and with minimum power, touching down at the very beginning of the runway (not somewhere in the first third) so that the remainder can be used for braking. At the moment of touchdown retract flaps and cut power so braking can be at its maximum.
A runway can be defined as short if the runway length is equal or less than the combined landing and take-off distance for your aircraft at the specific circumstances (wind, temperature, altitude).
Touching down at the correct point means aiming some 100 to 200 ft ahead of that point. This is because the aircraft needs time and distance in the flare before touchdown and it still has some forward speed to bleed off.
A good landing follows a stabilized approach. Its just that simple. Get into the landing configuration early enough, do not change aircraft configuration on final below 500' AAL. Fly a steady downwind at around 1.5VS. Use smooth power reductions and keep the airspeed between VREF and VREF+5 kts.
Some pilots use an angle of attack (AOA) indicator showing them the exact AOA the aircraft will stall, which is always the same. So they fly by the AOA i.e. the airspeed indicator. As a result they can fly more precise at lower airspeeds, and as a result they need less runway.
Trim the aircraft
To ease airspeed control, trim the aircraft for its stable final approach speed. But be prepared that in case of a go-around the aircraft really wants to climb out at the trimmed approach speed, which could lead to a nose high attitude. Stabilize climb out at VX or VY and re-trim.
With all these maneuvers airspeed control is important, remember: power controls altitude and yoke/stick controls airspeed. So if you are getting low, add power and if you are too high on the glide path reduce power and possibly add flaps. Slipping or shallow s-turns are also perfectly good options for the pilot to use.