Back to Basics
By Bud Weisbrod 1994
Editors note: Bud is a friend of mine. Bud has many years of
experience and many aircraft types, much of it in Hawaii. Bud sent me this
article some time ago. I did a bit of editing on it and I liked it so much I
thought that I would publish it here alsot.
Your Attitude, including the Aircraft!
More than a few Flight
Instructors and Flight Examiners (both FAA and Designated) are very concerned
about the current lack of emphasis on basic attitude flying. Overemphasis on
the use of instrument references to control flight, coupled with an apparent
lack of respect for seat-of-the-pants flying results in many unnecessary
stall/spin accidents. Some students (and even rated pilots) cannot believe that
an airplane can be flown with NO instruments at all. (OK, I would like to have
an oil pressure gauge.) By using attitude control and all of your senses
(sight, sound, feel, smell, etc.) you can actually control climb speed, glide
speed, turns, etc., and even judge pattern altitude. Of course, if you don't
believe you can do this, then you can't. But if you try, you will be pleasantly
surprised at how precisely your airspeed and altitude can be maintained with
attitude control. By establishing and holding a "reference distance"
between the nose and horizon most students can accurately hold airspeed within
a few MPH after a couple of minutes--usually much better than when they are
chasing the airspeed indicator.
"Chasing the
needle" is often inadvertently caused by the instructor, who says
"Watch your airspeed!" when he really means, "watch your
attitude". The airplane’s attitude is incorrect and as a result, your
airspeed is also wrong. Of course, the student does as he is told, fixates on
the airspeed indicator and only sees the desired airspeed as he is going past it
from too slow to too fast! However, once the instructor’s shorthand has been
explained, the student knows what is meant and immediately corrects his
ATTITUDE. How? By looking over the cowling at the horizon, setting the proper
spacing, or reference distance based on the airplane, his line of eyesight, the
power setting, altitude, etc., and bingo! – He is right on airspeed as if by
magic. And maybe more important, he is doing it by looking out the window where
potential mid-air traffic is lurking. Level turns are done the same way--set
the bank angle by the cowling angle with the horizon (correcting as necessary
if you are seated side-by-side, of course) and add enough back pressure to keep
the nose on the horizon. Of course, this is also possible with the instruments,
but it's EASIER with the real horizon not the artificial one! (Sneak a peek at
the instruments in a good turn to calibrate the "seat of your pants",
then when you are under the hood later on it will be much easier!)
Once you have established
the proper cowl/horizon reference distance you can easily maintain any desired
airspeed and it won't change unless you change power or configuration. This is
especially helpful on final approach when--if you hold a constant
attitude--there will be a place on the windshield along your line of sight that
can be aligned with your touchdown point. If that point is fixed and moving
only toward you, then you are on the proper glide path. If the point of
touchdown is moving up in the windshield, you are going to be short, and if
it's moving down, you will be long. Adjust power, add flaps, etc., and you can
put it right on the numbers from almost anywhere. This is especially helpful
when you have not set up the perfect approach. (Which, truthfully, is MOST of
the time, right? Be honest!) While a good approach is desirable goal, a
competent pilot should be able to make a good landing even from a bad approach.
Sure, a "go-around" is occasionally necessary, but if you are doing
them often you need some practice salvaging less than perfect arrivals. Use
flaps if you have them, slips, even a bit of a dive on final will get you down
and with full flaps, the drag will slow you up quickly when you level off. In
any case, you should use all the safe techniques available to land if you can
rather than keep the airport congested with your traffic as you mill around the
field because you didn't have enough "feel" for the airplane to get
it on the ground. An airline captain friend with aerobatic and tailwheel
experience told me of an occasion where ATC gave him a very high turn to final
and asked if he could make it in from there. He actually was able to gently
side-slip a 747 down to final and land safely and uneventfully. Better and
SAFER than going around with a load of passengers, in my opinion. (His co-pilot
who only flew "heavy iron", didn't even recognize the maneuver!) Seat
of the pants, right?
What are these Pedals for?
What is the most difficult
to use (and teach!), non-intuitive, unnatural flight control in an airplane?
The rudder pedals. What is the most important control surface to keep you out
of serious trouble? The rudder. Why? Because it has several uses depending on
airspeed, aircraft configuration, and the particular situation. For example,
when flying at cruise speed, the rudder is only used to correct for very small
amounts of aileron (adverse) yaw entering and leaving turns, and for any
mis-rigging of the airplane. (If the plane is properly rigged or rudder trim is
available, no rudder input is required.) However, when climbing, continuous
right rudder is needed to give a wings-level efficient climb. The rudder is
needed because of several factors erroneously summarized as "torque".
Failure to correct for the left-turning tendency (in American airplanes)
results in a right aileron, right wing down, slipping climb--which is NOT
efficient (and is uncomfortable for seat-of-the-pants pilots who feel a
"sideways" slipping sensation in their fanny). Rudder is also used to
eliminate the turn when slipping while the ailerons maintain bank angle. The
forward slip is used to lose altitude especially in no-flap airplanes. (A
forward slip is when the nose is pointed to the side but the airplane's ground
track is straight ahead.) The side slip is used to correct for wind drift on
cross-wind landings. (The nose points forward, with the fuselage kept parallel
to the runway. Your ground track without crosswind would be to the side toward
the low wing.) The trick is to get the sideways drift exactly equal and
opposite to the amount of crosswind drift so you can touch down on the upwind
wheel with zero sideways movement or skidding. And for you instrument purists,
try doing some slips and cross-wind landings by instrument reference only!
Last, and maybe most
important, the rudder is used to make the nose drop straight ahead in a stall.
The airplane cannot spin if it is used properly. If used incorrectly (wrong
direction or not enough) a wing will drop and around you go. OK to do at
altitude but a definite "no no" in the pattern! You should also remember
the use of ailerons in the stall usually creates more problems than it solves,
especially in older airplanes with less forgiving designs. The lowered aileron
(on the wing you are trying to raise!) has increased drag, which yaws the
airplane in the direction of the low wing. That is just opposite from what you
wanted to happen!
But, How Do You Turn this Thing?
Ailerons do NOT make the
airplane turn. All they do is ROLL it into a bank and displace the center of
lift toward the lowered wing, or the center of the turning circle causing the
airplane to turn. Ailerons also cause the aircraft to YAW away from the
direction of turn (i.e., ADVERSE yaw.) The rudder is used to cancel this
effect--NOT to make the nose yaw INTO the turn. If the rudder and ailerons are
properly applied (harmonized or coordinated) the airplane will only roll
without yawing in either direction. When the desired bank angle is reached,
both controls are neutralized and then used as necessary to maintain the bank
angle and yaw coordination as shown by the "ball" (and the
instructor's fanny!).
Again, the instruments are
being used to calibrate your "pants." If you try to coordinate (keep
the ball centered) by watching the "ball", you only see it centered
as it passes from left to right and back again! Look out the window, establish
your "reference distance", eliminate aileron yaw by watching the
horizon (and for traffic!) and the ball will center as if by magic. When you
roll out, add simultaneous rudder and aileron and gradually reduce the back
pressure to keep the nose on the horizon and eliminate the yaw. (Sometime, try
dangling a hand mike from a sun visor and watch as it points straight down
toward the cabin floor in both a proper turn and level flight. If it is on a
coiled cord, it also serves as a very inaccurate "g" meter as it
stretches out in a steep turn!) It's also VERY important to sit up straight
(head vertical over your fanny) so you can coordinate your body and the
airplane simultaneously. If you lean your head and/or body when you turn, you
will HAVE to use the instruments to coordinate the controls since your natural
sense of balance will feel wrong when the airplane is correctly balanced, i.e.,
ball centered. In a "head level" coordinated turn you will feel exactly
the same as in level flight except a little heavier in steep turns. (This is
why instruments are absolutely necessary for flight when a horizon reference is
not available--at night, in clouds, oil on windshield, etc.)
There are More Controls?
Elevators control the pitch
attitude up to and until stall speed is reached at which time they can cause
bad things to happen. Recognizing pre-stall buffet or feedback through the
controls or your rear-end does not require use of the airspeed or attitude
instruments. In fact, when you do a steep base-to-final turn you are almost
certainly looking at the approach end of the airport and not at the
instruments. Then when you overshoot "final" a little and
(mistakenly) add some extra rudder to "help the turn along" without
increasing the bank angle, you can stall and spin in at an airspeed that had
been "safe" in level flight. Again, reference to attitude and proper
coordination will help you avoid this fatal error. When you add back pressure
to bring the nose around toward the runway the airspeed will decrease AFTER you
looked at it and saw it was OK since it takes a few seconds for the plane to
slow to a dangerous speed after the attitude has been increased.
Flaps are used for two main
purposes: Increase both rate and angle of descent, and to minimize the
stalling, or touchdown speed. However, about half-flaps (20 to 30 degrees)
provides almost the minimum stall speed. More flap angle (full flaps) mainly
increases drag to provide a steeper descent without speed increase allowing more
power to be carried or for obstacle clearance. Some airplanes have such
effective flaps (early Cessna's, for example) that they slow the aircraft
rapidly unless the pilot applies significant power and/or pitches down to what
appears to be an excessively steep attitude. By the time the airspeed indicator
reflects the error (unless you are fixated on it!) you may be too slow to
safely recover. However, if you already KNOW the attitude required, you can
pitch right down to it and avoid all of the thrills, even if it does look sort
of steep. Flare when you are near the ground and hold it a few inches off---you
will slow down quickly and touch softly.
Trim is set for climbs,
glides, and level flight, so the pilot does not have to hold forward or back
pressure for extended periods of time. When the aircraft is properly trimmed,
it also lets the pilot relax on the controls and feel smaller changes in
pressure. However, trim should not be used to obtain an attitude. Use trim to
eliminate control pressure AFTER the elevators have been used to establish the
desired pitch angle and the aircraft has stabilized at the new airspeed. If you
trim to an attitude, you will invariably have to trim again, probably several
times, as the airplane either accelerates or slows to the new speed. (For you
scientists, several phugoid oscillations will ensue until you get stabilized
and trimmed.)
And What About that Noisy Thing Up
Front?
The mixture control
provides the correct ratio, by weight, of air and fuel so the engine runs smoothly,
efficiently, and with the best available power. Some students are taught to not
lean below 5000 feet altitude to make it less likely that they will overheat
the engine or cause detonation. Yet, leaning is both permissible and desirable
whenever possible, even during climbs. The engine and airplane manufacturers
provide tables that show when leaning is OK. Generally, when using less than
75% power, it's fine. Failing to lean can cause spark plug fouling, loss of
power, rough running, and excess fuel consumption. Incorrect and/or excessive
leaning can cause overheating, detonation, valve erosion or failure, piston
failure, etc. So, learn when and how to lean properly at any altitude and
eliminate all of the above problems.
Constant Speed Props are
wonderful, efficient, and actually easier to use most of the time than
fixed-pitch props. On take-off, just remember to not add too much throttle with
the RPM set too low. How much? Check your manuals, it varies from plane to
plane and with different engine/prop combinations. When landing, always have
the pitch set at the highest RPM (full forward) setting in case of a go-around
so full power can be added without damaging the engine. But PLEASE don't put
the prop control forward with so much airspeed and power that the RPM increases
abruptly. If you have the proper combination of power and airspeed, you can
select max RPM without having the actual RPM change...it's just ready for MAX
in case you need it. Besides sounding terrible to your passengers and those on
the ground, it puts a reverse bending load on the prop and could eventually
lead to a blade failure.
Climb airspeeds should be
selected for the proper reason. Best ANGLE of climb is rarely used unless you
have obstacles directly ahead. It's very slow, the nose is high, you can't see
traffic ahead, and cylinder and oil temps can increase dangerously. It's also
not very efficient. More efficient than hitting something, but less efficient
than everything else. Best RATE of climb gives you the most altitude in a given
time but is still nose high with the same reduced visibility and possible
overheating problems. It should only be used when hauling skydivers and you are
being paid per jumper! If you are going somewhere in your plane, (the usual
case!) use CRUISE CLIMB once you have cleared the airport obstacles and are out
of the valley. Cruise climb speed gives about 90% of the best climb rate and is
about 10 or 15% faster over the ground than best rate of climb. You can easily
recognize cruise climb because now you can see traffic ahead of you and your
engine temperatures are a lot lower. You are making better time toward your
destination and with the better visibility, you are more likely to get there
alive! Same thing when descending. Keep your power at cruise, pitch down until
you get 300 to 500 feet per minute descent, and then trim. You will get a 10 to
20% increase in airspeed (Which is good--but if it's turbulent, slow down) your
engine will stay toasty warm, and you'll get home to Momma sooner! Just be sure
to watch the throttle and mixture settings as you descend into more dense
air...don't over power the engine or let it get too lean.
Carburetor Heat/Induction
Air Heat. You don't need instruments to tell you to apply carb heat. If you
gradually begin to lose power during cruise or descent and more throttle
doesn't seem to help much, apply FULL carb heat. If the engine momentarily
begins to run rough, that's good news: It was ice and the roughness was caused
by the ice water you just sent into the engine and on to the spark plugs! In a
few seconds it will smooth out (although it seems like hours if you are over
water!) and you can turn the carb heat off. However, if it iced up once, it
probably will ice again under the same conditions. So keep an eye and ear open
so you can prevent excess ice from forming rather than removing it after it
becomes significant. Flying is exciting enough without doing it to yourself.
And icing does occur in Hawaii, usually on cool moist days. It also is more
common on some engines because of the air induction configuration.
How Fast Am I Going?
True Airspeed (TAS) is
handy to know, but you seldom need accuracy to two decimal points. Most flights
are affected significantly by the wind, and besides, what you really want to
know is your ground speed to figure arrival time and determine if you need to
stop for fuel. When you compute TAS with a calculator or circular slide rule
you have to stop looking outside. However, you can figure TAS accurately enough
for most requirements (except the FAA written exams!) in your head. Just add 2%
to your indicated airspeed for every thousand feet of indicated altitude.
Forget the temperature. It is not very significant most days. No, you don't
need a calculator to do the percent calculations. At 5000 feet, it's 10%,
10,000 feet it's 20%, and 7500 feet, halfway between, or 15%. In between those
altitudes, just add or subtract a few MPH as appropriate. Most important, you
can do these calculations while looking out the window and watching for traffic!
(And your traffic might be ME!)
Breaker, Breaker Good Buddy!
Radio procedures: Simple.
Just say who you want to talk to (so they can put down their coffee, stop
reading their Playboy, and listen to you), say who you are (so they know who
interrupted them), then tell 'em where you are and what you want. BUT, imagine
you are dictating a telegram that is costing you a dollar a word! You want to
be sure you give them an accurate and unambiguous message but you don't want to
waste a lot of money. So, you will leave out a lot of the "We are
at", "We want to go to" "Roger, Wilco, over and out"
terminology, and just provide the necessary minimum of information so you can
get the help you requested and then let some other guys get in a word or two.
"Tower, Cherokee 18445, 8 west, with Bravo" is better than
"Honolulu International Airport Tower, This is Piper Cherokee 140 November
18445, We are 8 miles west of your field for landing instructions. We have ATIS
information Bravo, over." The same important information is in the short
version, and if you paid a buck a word, $20.00 cheaper!
Now Where Was I, Oh Yes, the Seat of
Your Pants!
One of the best ways to
sensitize the seat of your pants is to take some aerobatic lessons with a
qualified aerobatic instructor in an aerobatic airplane. It's safe, and you
will quickly see why the instruments aren't used very much. After some
aerobatic dual instruction you will be able to fly any airplane better, holding
attitude and heading easier than ever before. And you will be much more
confident in your ability to handle unexpected situations with much less
stress. A good way to improve your regular flying and prepare for aerobatic
lessons is to do some simple coordination exercises. These exercises are best
done below cruise speed, somewhere near best rate of climb speed since it's
easier on the airplane and is more difficult, so you learn more. My favorite
series I've named the "Bakery"...and consists of a Dutch Roll (which,
technically, can't be done in a non-swept wing airplane, but give me a break,
OK?), a Danish Pastry (for want of a better name), and a Brownie (which is
square.) The Dutch roll consists of a "crisp" medium bank in one
direction followed by an immediate bank in the opposite direction (before a
turn can start) then back to the original bank. This is repeated until you can
keep the airplane headed in the same direction with no yawing or pitch changes
(or your instructor gets queasy!). It's done with aileron and rudder applied in
the same direction and at approximately the same time. (Sometimes on entry into
the initial bank, no rudder is used, so that the aileron yaw can cancel the turn.
Depends a little on your airplane and technique.) After you get the proper
control inputs figured out, you will find a place in the windshield that
doesn't move, it just seems to rotate on a place in the sky. That is your line
of sight. Remember it!
Next, try yawing the
airplane sideways with rudder and use opposite aileron to keep the wings
perfectly level. You will also need some elevator to keep the pitch constant.
Once you have mastered that, try adding a pitch up and pitch down at each end
of the yaw so your line of sight traces a square (Brownie!) in the sky with
about half of the square above and half below the horizon. You will find that
it isn't easy with constantly changing control pressures required to square off
the corners and maintain vertical pitch lines. However, when you finally get a
recognizable square you will find that you have significantly improved your
coordination and now turns, stalls, slips, etc., will be much easier and feel
very natural---again, without looking at the instruments! (Before all of you
instrument purists begin to write me or the FAA, be advised that I'm an
Instrument Instructor, SE/ME and Glider.) Just remember that you can get some
important messages from your fanny, messages that can keep you from busting yours!
"Seat of the pants" flying is using all of your senses to control the airplane, not just the eyes observing the instrument panel. Flying is NOT a big noisy video game!