Flight Seven is an introduction to more sophisticated ways
of getting into the air and back onto the ground. These new techniques
include soft-field takeoffs and landings, short field takeoffs and landings,
no-flap takeoffs and landings , an introduction to forward slips to landing,
and crosswind landings. You need to be
proficient at working in the traffic
pattern and to have developed reasonable proficiency at normal
takeoffs and landings as covered in Flight Six
before you start work on these more advanced skills.
Soft Field Takeoff and Landing techniques are good skills
to have even if you have no intention of exposing yourself or your airplane
to the challenge of a real soft field. Most people will learn these techniques
on a regular paved runway and seldom, if ever, get to put their skills
to work on a real soft field. However, you will definitely be tested on
this as part of the private pilot practical test and, in the event of
an emergency landing off airport, you will be glad to have this skill
available.
To develop your soft field technique, visualize mud. Your
objective is to maintain directional control and not get stuck. With just
three small wheels and a propeller to work with, this could be challenging.
Fortunately, all of your control surfaces can be of use in keeping things
rolling and pointed in the right direction. Before you start your taxi,
get organized and complete all necessary pre-takeoff checklists so, that
at least in theory, you can keep rolling all the way to the runway and
take off without stopping. Because of constraints imposed by control towers
and crowded tie-down areas etc., you probably will not get to practice
this part. A real soft field taxi will require more power than usual to
get started and probably more than usual to keep rolling. In a tricycle
gear airplane, taxi with the control
wheel held all the way back to minimize weight on the nose
wheel. The nose wheel is the most likely to get bogged down, so do what
you can keep it light.
In many airplanes such as the Cessna 152, the soft field
takeoff is performed with 10 degrees of flaps extended. If flaps are to
be used, extend them as you taxi onto the runway. In a real soft field
situation, tower and traffic permitting, you would taxi onto the runway
without stopping and, once lined up on the centerine, apply full power
with the control
wheel still in the full aft position. You want the nose wheel
to come off the ground at the first possible opportunity, but not so swiftly
that the airplane rears up and scrapes it’s tail on the ground. Most trainers
have a tail tie down skid installed to lessen the consequences of scraping
the tail. As you add power and accelerate, airflow over the elevator
will increase and it will become more effective at raising the nose --
so much so that you will probably need to reduce the backpressure on the
control
wheel slightly to allow the nose wheel to lift off without
the tail scraping. As you add power, you also need to add right rudder
to prevent your airplane from unexpectedly exiting the runway to the left
due to normal left-turning tendencies that are at their most noticeable
in high power/high angle
of attack situations.
The idea is to get unstuck from the runway at the first
possible opportunity and then build up airspeed in ground
effect before attempting to climb out. So, you accelerate down
the runway with the control
wheel positioned further back than for a normal takeoff. The
nose wheel will lift off first and, as you continue to accelerate and
maintain directional control with rudder the main wheels will lift off.
This happens at a lower airspeed than for a normal takeoff and below the
speed at which it is safe to climb out. As soon as all three wheels are
off the ground, move the control
wheel forward to lower the nose into a straight and level attitude.
This allows the airplane to build up more airspeed in ground
effect before attempting to climb out.Lowering the nose at
this point takes some willpower, since it is not intuitive to lower the
nose immediately after liftoff when very close to the ground.
It is important, however, that you do not attempt to climb
out of ground
effect until your airspeed is at least at best rate of climb
speed, Vy.
For the purpose of learning/demonstrating your soft field takeoff technique,
if the runway environment permits, you may fly along in ground
effect a little longer than is strictly necessary. Contrary
to what every bone in your body is telling you as you try this the first
time, you are unlikely to fly yourself back into the ground unless you
are really heavy-handed and not paying attention. You may be heavy-handed
but it’s safe to say you’ll definitely be paying attention during this
challenging task. Once the desired airspeed is attained, pitch to begin
your climb by applying a little backpressure; then climb out at best rate
of climb speed, Vy.
Once a positive rate of climb is established, retract the flaps and continue
the departure as normal.
For a soft field landing, the objective is to land as gently
as possible on the main gear and to keep the nose wheel off the ground
as long as possible during the rollut to minimize the chances of getting
bogged down or flipping the airplane over in severe situations where the
nose wheel digs in. Fly a stabilized approach at the recommended speed
for the airplane being used and plan on using full flaps. Just before
touchdown, add a little power to reduce the sink rate and to provide more
elevator
authority to help hold the nose wheel off the runway. A power setting
just slightly above idle should be sufficient. Touchdown should occur
gently in a nose-high attitude. Maintain extra backpressure on the control
wheel after touchdown to hold the nose wheel off the runway
as long as possible. Don’t overdo the backpressure or you will cause the
tail tie-down skid to scrape the ground. You will need to be particularly
attentive to rudder input to maintain directional control since you will
not have the benefit of nose wheel steering initially. It’s particularly
important that the airplane’s longitudinal axis is perfectly aligned with
the centerline on touchdown. Eventually, as your speed diminishes, there
will be insufficient air flowing over the elevator
to maintain the nose-high attitude necessary to keep the nose wheel off
the ground. The nose wheel should touch down smoothly while you hold the
control
wheel full aft to minimize the weight on the nose wheel. Exit
the runway with the control
wheel held full aft and, local conditions permitting, taxi
without stopping to the place you intend to tie down the airplane. Once
you stop on a truly soft field, you may have trouble moving again.
Once you master the soft field techniques, you can move
on to short field takeoffs and landings. Be careful to distinguish between
soft field and short field procedures. They are quite different and not
interchangeable.
Short field takeoffs are utilized when it is necessary to
get off the ground in the minimum distance and climb relatively steeply
to clear obstacles. Many trainers such as the Cessna 152 call for use
of 10 degrees of flaps for the short field takeoff. Once pre-takeoff checks
are complete, set flaps as appropriate prior to taxiing onto the runway.
Taxi onto the runway and stop at the very beginning of the runway so no
distance is wasted.
While using your toes to apply the brakes and hold the airplane
in position gradually add full power. Check the engine instruments and
tachometer for normal indications prior to releasing the brakes. In a
real short field situation, it’s important to know the airplane is developing
full power before attempting to take off with a short runway or obstacles
to clear. Hence the run-up to full power prior to brake release. The run-up
also prevents wasting runway while you add power. Assuming all indications
are normal, release the brakes and accelerate down the runway to rotate
as normal and commence a climb out at the recommended obstacle clearance
speed or best angle of climb speed, Vx.
This will be a more nose high attitude than you have used previously and
you will need to be attentive to precise airspeed control. Also, because
of the high power setting and high angle
of attack, you need to use plenty of right rudder to overcome
left-turning tendencies. After clearing obstacles, lower the nose slightly
and accelerate to best rate of climb speed, Vy.
With a positive rate of climb established, retract the flaps and continue
the upwind climb as normal.
In a real short field situation, be particularly attentive
to maintaining the correct airspeed. Only the recommended obstacle clearance
speed, or Vx,
will give you the best angle of climb. Anything faster or slower will
not work as well.
The objective of a short field landing is to clear obstacles
on final and to land and stop in the minimum distance possible. Landing
on a short field and clearing any obstacles on final
approach entails setting up a stabilized full-flap approach
at the recommended short field approach speed for your airplane. This
speed is generally slower than that used on normal approaches and the
descent will be steeper than usual, thanks to the lower groundspeed. Once
obstacles have been cleared and landing is assured, reduce power to idle
and continue to descend at the minimum recommended speed until ready to
flare.
If your airspeed gets too slow, lower your nose. If you are too low and
in danger of not making it to the runway, add some power. Once you are
very close to the ground, flare
as usual to land main gear first. After touchdown, retract flaps while
applying maximum braking. By retracting the flaps, the load is more rapidly
transferred from the wings to the wheels, thereby allowing you to brake
harder without skidding. Do not allow the wheels to lock up. Bring the
airplane to a full stop before exiting the runway.
Because of the greater sink rate associated with short field
landings, the touchown is firmer than for soft field or normal landings.
As long as the touchdown is main gear first and there is no bounce, it's
acceptable for it to be a bit firm. In windy conditions, it may be appropriate
to use a higher approach speed and, under gusty conditions, some pilots
prefer to use less than full flaps.
No-Flap Landing
For some pilots, typically those flying old tail draggers,
every landing is a no-flap landing. However, even those of us lucky enough
to fly airplanes equipped with flaps should learn how to land without
using them. In an airplane such as the Cessna 152, a loss of electrical
power will prevent you from using the flaps. Also, electric motors that
power the flaps sometimes will malfuction.
No-flap landings start with a stabilized approach at the
recommended speed for your airplane. Typically, this will be 5-10 knots
faster than that used with flaps. In the absence of flaps, your stall
speed will be higher, hence the need for a higher final
approach speed. Once obstacle clearance and landing is assured,
reduce power to idle and flare
to touch down as usual.
Because of the higher approach speed, you will use more
runway than normal. If you allow your speed to get too fast, you will
find your airplane "floating" as you flare,
and you could use up a lot of extra runway.
If you find yourself high on final or need to fly a steeper
approach to clear obstacles without flaps you can use a forward slip to
steepen your descent.
A forward slip is a way of creating extra drag in the absence
of flaps as a means of achieving a steeper descent. Forward slips are
done with the power at idle. The purpose of the slip is to increase the
rate of descent;therefore, to have power applied at the same time would
be counterproductive. A forward slip is a descent with one wing lowered
using aileron and the longitudinal axis of the airplane yawed at an angle
to the flight path using opposite rudder. To initiate a forward slip on
final approach,
lower one wing using aileron and yaw the longitudinal axis of the airplane
in the opposite direction using rudder. If there is crosswind, lower the
wing on the side from which the wind is coming. Yaw the nose in the opposite
direction to the bank just enough to maintain the desired ground track.
Be attentive to your angle
of attack/airspeed while slipping. This is a cross-control
maneuver, so it is important to avoid getting too slow or too close
to the critical angle
of attack. A stall from a slip at final approach altitude
would probably develop into an unrecoverable spin.
Because the pitot
tube and static ports will not be correctly aligned with the
airflow during the slip, you cannot depend on accurate airspeed indications
in this configuration. So, be particularly attentive to other indications
of getting too slow, such as mushy controls or buffeting. If you get too
close to a potential stall speed, lower the nose to increase airspeed
and reduce the angle
of attack.
Prior to touchdown, it will be necessary to realign the
longitudinal axis of the airplane with the runaway centerine. To straighten
out prior to flaring, level the wings and release rudder pressure simultaneously
to align the longitudinal axis of the airplane with the centerine and
then flare
to touch down as normal.
Slips are also used in crosswind
landings, in which cases a sideslip can be used to create a sideways force
that is equal to and opposite to the force of the wind drift.
To land when the wind is not aligned with the runway requires
a technique for overcoming the sideways drift that the wind tends to induce.
On final
approach, this wind drift can be counteracted by either a crab
or sideslip. A crab simply entails selecting a heading towards the direction
the wind is coming from while flying wings level. The Wind
Correction Angle selected should be enough to prevent drift
and maintain a straight ground track along the extended centerline. Adjust
the Wind
Correction Angle as necessary to achieve zero drift. If you
fly your final
approach with a crab, it will be necessary to align the longitudinal
axis of the airplane with the runway prior to touchdown. This alignment
needs to be made just prior to touchdown. It requires precise timing to
avoid drifting if the crab is terminated too soon or landing out of alignment
with the center line if you leave it too late. The landing gear is not
designed to handle side loads, so it is very important that the airplane
be longitudinally aligned with the centerline and not drifting on touchdown.
The alternative to the crabbed approach and last minute
correction is to use a sideslip to counteract wind drift. This can be
done for the whole final
approach or just for the last part after starting out using
a crab. The idea is to lower the wing on the side from which the wind
is coming, using aileron to counteract wind drift, and to use opposite
rudder to maintain longitudinal alignment with the centerline. The extent
to which the wing is lowered will depend on the force of the wind. If
you get to the point where to counteract wind drift you need to lower
the upwind wing so much that full opposite rudder is insufficient to maintain
alignment with the runway, it means the wind is too strong for a safe
landing and you should select an alternate runway with less crosswind.
During the flare,
you need to maintain wing low crosswind
correction to avoid drifting and, in strong crosswinds,
this means the main wheel on the side of the airplane from which the wind
is coming (upwind) will touch down momentarily before the other wheel
does. Once on the ground, be sure to follow through with control inputs
to counteract the wind. That is, position the control
wheel as if turning the airplane into the wind, using full
deflection of the ailerons. At slower speeds, it takes bigger deflections
of the control surfaces to have an effect. Use the rudder to maintain
directional control during the rollout.
Crosswind landings are challenging,
and it will take considerable practice to master these techniques. During
your solo training, you can expect your instructor to place limitations
on your solo privileges based on a maximum crosswind
component.
Better to use your superior judgment to select a runway aligned
with the wind than to count on using superior skill to land in a strong
crosswind.
After developing skill with these advanced takeoff and landing
techniques, your next challenge is to learn about cross-country flying.
Flight Eight will introduce pilotage,
dead reckoning, weather briefings and in-flight communications with flight
service stations.
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First Flight online lessons are
not a substitute for study of the Pilots Operating Handbook/Airplane
Flight Manual for the airplane you intend to fly.
It is essential you refer to the Pilots Operating Handbook/Airplane
Flight Manual for the airplane you intend to fly for the procedures
and checklists that currently apply to your airplane.
