Home

Aviation News

Flight Training

Aviation History

Theory Of Flight

Airframes

Powerplants

Civilian Aircraft

Military Aircraft

Aviation Wallpapers

Aviation Links

Contact


 

 

 

Short, Soft, and Rough landings
It is very unlikely that during your training you have been prepared for short, soft or rough runways. Any field not paved should be considered both soft and rough. You cannot evaluate an unpaved airport from the air. Walking or driving the strip may not suffice either. Paved runways tend to long enough, firm enough and smooth enough; an unpaved runway is likely to be short, soft and rough. On the unpaved surface every landing should be made softly with the nose high and some power. The approach should be steep, at minimum float airspeed and for a full stall landing. You should practice the control of the slower airspeed and steeper approach path of the short field for this landing on a paved runway before you are going to need it for real. Get the power off and the flaps up immediately on ground contact. Don't lock the wheels by too much braking. Keeping the nose wheel off the ground is more important than braking if the ground is soft. Add 20% to the performance figures from the POH to allow for your less than perfect speed control and brake application.

Call locals and use reference material to learn as much as you can about the field to be used. Wind conditions must be balanced against such features as clear approach path, up vs. down slope. The only way to determine field conditions is by walking. Practice the required approach and landing on a similar paved runway or a similar unimproved runway with similar characteristics before trying the real thing. In doing this you will learn what to expect from your aircraft in performance and yourself in flying capability.

A high proportion of airport accidents occur during the bad weather months of winter. The root cause lies with airspeed control. Add 1/2 the gust speed to your approach speeds when winds make airspeed control a problem. You still want to be slow at touchdown. You will be better off if you are without flaps. You must have the axis of the aircraft parallel to the centerline. Use the correct yoke position for the wind direction involved. Keep the aircraft straight during rollout. Failure to prevent directional changes of over 10 degrees can result in a rollover or ground loop.

Speed is the critical consideration for any landing. A short field landing can be made in steady wind conditions at 1.15 Vso. A 10% lower speed can reduce landing roll by up to 30%. Many pilots make a practice of holding power until touchdown. Having power on during a short-field touchdown will be counterproductive to your short-field intent. You can reduce landing distance by quickly dumping your flaps since this gets the weight on the tires for braking. The practice of having a bit of power on short final may cause a short field landing not to be as short as it should be.

Second Opinion:
The critical part of a "short" field landing is the approach. Minimum airspeed, just enough to kill your descent and flare before you run out of speed.

The critical part of a "soft" field landing is the touchdown. Nose high and gently. If the field is actually "soft" you roll out WILL be surprisingly short! That isn't a problem. A following TAKEOFF may well be much longer than usual, if it is even possible.

I would use a "short" field approach and a "soft" field landing. It always worked well for me when landing on a short soft grass strip.

Controversial options for short field landings:
--Dump flaps while in ground effect to 'plant' wheels firmly.
--Pull mixture to reduce any idle thrust.

POH Emergency Landing
The ability to conqueror the POH limitations gives us a competent pilot who can land an aircraft at a slow speed on a long and wide runway in a short distance. The final examination related to such summation of limitations is the pilot who can execute a successful emergency landing at a slow speed and no runway. Does he know the extent a lighter aircraft total weight reduces the stall speed? With a lower stall speed and applied flaps the descent angle can be steeper and more accurate. With lower stall speed, applied flaps, and power, a slower landing speed and reduced landing roll is possible. In only one of every six emergency landings is anyone hurt.

Power-off Landings (Instructor)
In the mid-60s the FAA changed its 'approach' to the way landings were to be made as 'standard' for the practical flight test. Prior to then landings were made power-off. Abeam the numbers, apply carburetor heat and reduce the power to off, glide and slip to a landing. With the advent of flaps the steeper, more accurate glide angle for the approach could be made without slips. The power off approach made the engine susceptible to carburetor ice and shock cooling. So the change was made to recommend partial power landings into the flare. Every power change was to be a reduction and every yoke movement was to be back and up. Maximum flaps for the wind conditions is the norm.

Today, just when all the power-off instructors are in short supply the designated examiners are again requiring power-off landings as part of their emergency simulation. The reason for this proficiency test is that today's instructors predominately teach the power-on landing. The ability of power-on students to execute a power-off landing, as in an engine failure simulation was detected as an instructional weakness caused by the emphasis on power-on landings. Engines last longer without shock cooling. Power-off landings can be less damaging if the downwind is flown at lower power settings

The power-off approach requires that the pilot pull the power off when abeam the numbers. From this point the pilot will make his turns and descent to the runway. This approach is relatively tight when compared with the power-on. It makes a safe landing possible even with engine failure. The hazard of the power-on approach is that the pattern will be such that the runway will be beyond reach in the event of engine failure. Combining the engine failure with the power-on approach allows the student to plan how the failure makes it necessary to re-plan the approach. Beginning with flap removal and flying directly to the runway.

The throttle setting is an initial constant for the power-on approach and is not the variable used to correct minor errors of judgment. Power reductions should occur only on short final and in the flare. Full power is the best correction for being low on the glide path. Students learn the power-on method more easily than the power-off but the landing program should, of necessity, include what to do in the event of engine failure at any point in the pattern. Once the power is off, the student is expected to make the runway as in a real failure.  However, the need to "clear the engine" at any point is a way to get a burst of power needed to reach the runway.

--A pilot's ability to judge descent angle is major aspect of all landings but ultimate factor when power is off
--Margin of safety is based upon need to perform maneuvers.
--Best approach reaches landing area with minimum float
--Not three, just two ways to lose altitude configuration and speed
--No way to extend glide other than possible ground effect
--Effectiveness of ground effect is dependent on having excess speed.
--Practice simulated engine failures so that you learn to match your judgment with aircraft performance.
--Airspeed is controlled with pitch, which affects glide angle. Practice for wind allowances.
--It is the base turn that determines the successful outcome. Don't let winds blow you away.
--Most useful but least practiced approach is the 360 over touchdown point. 90 and 180 common.
--Base all practice using only medium turns that are varied as required by winds
--Practice in variety of wind conditions to develop required judgment skills
--All of the should be considered specific to the aircraft and pilot.

Continue To Next Page

 


Copyright 2003-Now www.airman.us All rights reserved. Reproduction in any form is prohibited.