Despite the relative safety of general aviation, each year several people are injured or killed on the ground by spinning propellers. Plus, when it comes to hand-propping engines to get them started, there are all kinds of dangers involved. AVweb's Howard Fried takes a look at the
May 18, 2001
|About the Author ...
Howard Fried started flying with the Army Air Corps in WWII, where he
served both as a multi-engine instructor pilot and in combat piloting B-17s.
After a stint teaching sociology and on-the-air and management jobs in the
radio business after the war, he turned to teaching flying again full-time.
Over 40,000 general aviation hours later, he is still instructing
and running his own flight school. Along the way he administered over 4,000 flight tests
as a Designated Examiner until victimized by rogue FAA
He has authored two popular flying books aimed at student pilots and
instructors, Flight Test Tips and Tales and Beyond The Checkride, and a
series of audio tapes, Checkride Tips from
Flying's Eye Of The Examiner.
the most dangerous thing about general aviation is that one must be around
propellers -- after all, they are attached to airplanes -- and when a human
being encounters a rotating propeller, the prop invariably wins. The result is
usually disastrous to some part of the human body. I personally know two --
not one, but two -- one-armed flight instructors, each of whom donated an arm
to a propeller. I am also acquainted with one fatal encounter with a prop and
another very serious injury. Another acquaintance, a flight instructor, caused
a great deal of damage when he hand-propped an airplane that started up and
proceeded across the ramp, striking and severely damaging two other airplanes.
In another instance, an airplane taxied down a narrow taxiway damaging an
entire row of airplanes tied down alongside.
Although not a really big factor in the total general aviation accident
picture, encounters between props and people continue to occur, and when they
do they are almost always invariably fatal. Such encounters account for the
majority of airplane accidents that occur on the ground. Some 15 percent of
prop injuries are the result of pilots attempting to start an airplane by
hand-propping it without a competent individual at the controls, but the
majority result from pilots or passengers deplaning while a prop is spinning
or from pedestrians crossing the ramp when an idling or taxiing airplane can
strike them with its dangerous weapon -- the prop. The FAA has an excellent
movie clip of what can happen when an airplane is propped without a qualified
person at the controls. If you haven't already seen it, be sure to do so. The
Safety Program Manager at your local FSDO (Flight Standards District Office)
either has one or can readily obtain it for you, and it is well worth viewing.
in the "good old days" when the J-3 Cub and the 7AC Champ were the
primary trainers in general use throughout the land, everybody was trained in
the proper procedure for propping an airplane, since the trainers didn't have
electric systems and, hence, they lacked starters. (Larger trainers had
inertial starters, which required quite a bit of muscle power to wind up.)
Thus, students of that era were taught from the very start not only how to
properly hand-prop an airplane to start it, but to respect the propeller.
Today, one of the most common types of accidents involving contact between a
spinning prop and some part of the human anatomy occurs when an individual is
attempting to start an airplane by propping it.
I believe that all pilots who operate light airplanes (200 HP or less)
should be properly trained in hand-propping techniques and procedures, and
most modern pilots have never been so taught. This is no doubt because most
modern instructors don't teach this because they were never taught themselves.
Since one never knows when it might become necessary, it is something everyone
should know. A few years ago the former office manager of our local FSDO told
the following story to a group of DPEs (Designated Pilot Examiners):
Before he joined the FAA, he had been a civilian pilot examiner. One day, a
young lady came to him for a private check ride. She had brought a Cub (no
starter), and after the completion of the oral portion of the examination,
they went out to the airplane. The applicant performed a satisfactory
pre-flight inspection, climbed into the rear seat, buckled up, and sat there.
The examiner asked her if she didn't intend to start the airplane. She replied
that her instructor had always done that for her, and had never taught her how
to do it. The examiner inquired as to what she had done when off on a solo
cross-country flight or her instructor was otherwise not available. Her answer
was that she had always been able to find someone willing to do it for her. I
guess she must have been quite an attractive young lady. In any event, the
examiner disapproved her application and sent her back to her instructor for
more training. I wonder just what this young lady expected to do when -- not
if -- she found herself in a situation where it was necessary to start an
airplane and there was no one around to prop it for her.
Personally, I'm terrified of props. I guess I'm actually paranoid -- I
believe every propeller on the airport is alive and out to get me. I walk
around airports looking over my shoulder, waiting to be attacked by a spinning
prop. This doesn't mean I won't hand-prop an airplane -- I will, but I do so
very, very carefully. I have performed this task hundreds, even thousands of
times, for I gave many hundreds of hours of dual instruction in J3 Cubs and
7AC Champs, neither of which has an electrical system or starter.
Propping is not particularly complex, no is it particularly difficult, but
it does require extreme care, and there are certain procedures which should be
- One should always assume that the prop is hot (alive) and may start
of its own volition at any time.
- There should always be a knowledgeable person inside the airplane at the
controls. Most hand-propping accidents occur when an unattended airplane
is propped or an unqualified person is at the controls. If it is not
possible to have a qualified person at the controls, the airplane should
be firmly secured, and I don't mean merely chocked, but actually tied
down, and the airplane should be on a firm, level surface. You don't want
to slip and fall into the spinning prop.
assume the prop is hot.
- Communications between the person inside the airplane at the controls
and the one doing the propping must be crystal clear. There must be
absolutely no misunderstanding regarding whether or not the magneto switch
is on or off.
- Always assume the prop is hot.
- With the switch off, grasp the prop near the hub and give a good healthy
tug to make sure the airplane is firmly anchored (brakes being held by
person inside, or securely tied down-- preferably both).
- Always assume the prop is hot.
- With fingers flat on the blade (not wrapped around the edge of the prop
blade), and the switch off, the prop should be pulled through. This will
serve to prime the engine and to give the person doing the propping a feel
for the compression resistance offered by the engine. This "pulling
through" should be stopped at the top of a compression stroke of the
- Always assume the prop is hot.
- Call for "Switch on" or "Contact" and receive
acknowledgment from the responsible person at the controls.
- Now you know the prop is hot.
- Then, with the mag switch on and fingers flat on the blade, not curled
around it, the prop should be sharply pulled through again as the one
propping the airplane steps back away from the airplane (and the
- Always assume the prop is hot. (Are you getting a message here?)
- If the engine fails to start, the procedure should be repeated until it
Normally, of course, an airplane is hand-propped from the front, but there
are situations when an airplane must (or should) be propped from behind. For a
few years we used a Taylorcraft BC12D (no starter) with Edo floats for the
trainer on our seaplane curriculum. With the airplane floating on the water,
the technique involved standing on the right float, grasping the wing strut
with the left hand, and propping the airplane from behind the prop with the
right hand, then scrambling across the right seat to settle in the left seat
as the airplane taxied slowly across the lake (or other body of water). By the
bye, this airplane had a great big 85-HP engine (it was certified with a 65-HP
powerplant) and was an excellent performer on floats. For several years I had
a Mooney Model 18 (a Mooney Mite), a one-place airplane that I kept as my
personal toy. It, too, lacked a starter and had to be hand-propped. I found
the best way to do this was also to prop it from the rear. I would stand with
my butt against the right wing root and my left hand at the base of the
windscreen, and prop the airplane with my right hand.
The FAA recommends, and I think it's a good idea, that prior to start-up
one should always turn on the rotating or flashing beacon to alert anyone
outside that the prop is about to be set in motion. Also, it is imperative
that an airplane only be started when the area behind it is clear. I have
observed careless pilots start an airplane with its rear end pointed at an
open hangar, and blow dust, sand and gravel into the hangar, damaging
course, starting an airplane parked on a sandy or gravel surface can seriously
damage the prop. (When flying in Australia, I was told that since many of the
unimproved sod strips aren't really sod at all, but gravel, it is necessary to
replace props often.) Even starting or taxiing through puddles of water can,
and often does, damage props. And, of course, if an airplane is started or
run-up with spectators standing nearby (to the rear), the people there can be
hit by flying debris. Even when the area is clear, it is best to start up and
taxi using the absolute minimum of power necessary, until you are in a clear
area on a firm surface and you are ready for the engine run-up.
Several years ago a renter pilot had taken one of our school airplane from
Michigan to Florida. On the way back he made a fuel stop at Charlie West
(Charleston, West Virginia). When departing that airport, he thoughtlessly
accomplished his run-up at a location where there were several spectators
standing behind the airplane, blowing sand and small stones back into the
crowd. By happenstance, unknown to the careless pilot, another of our
customers was there and observed this. The witness returned first and reported
the matter to me. When the guilty pilot got back I greeted him and counseled
him rather severely regarding what he had done. He said, "Gee whiz,
Howard, do you have spies everywhere?"
I replied, "Of course I do! Don't think for a second that you can get
away with anything without your Old Dad finding out."
I'm sure that pilot never again has started an airplane without first
carefully checking the area all around.
it goes without saying that any nicks in the prop blades should be thoroughly
dressed down with a file to prevent a crack expanding into a fractured blade.
Airplanes don't fly very well with less than full-length prop blades, and the
resulting unscheduled landing can be harmful to the overall health of the
human anatomy. I remember an occasion many years ago when I was alone flying a
J-3 Cub with a wooden prop. The metal binding around the tip of one of the
blades separated and departed in flight. The resulting vibration from the
imbalance was enormous. It happened shortly after takeoff and, with great
care, I managed to nurse the airplane around to a safe landing on the airport.
On examination, the first several inches of the prop blade looked like a bunch
of wooden toothpicks. It was pure luck that the vibration hadn't shaken the
engine loose from its mounts. When an airplane sheds a prop blade it is a good
idea to shut down the engine and turn the airplane into a glider. It may not
be a very efficient glider, but it will glide to (hopefully) a safe
Usual Boilerplate: If you have a comment regarding this
column, please post it here rather than sending it to me by direct email. That
way others may benefit from your input.