Figure 2-11. A jet fuel filler nozzle is flared at the end to prevent an inadvertent insertion into an AVGAS tank.
Using the proper, approved grade of fuel is critical for safe, reliable engine operation. Without the proper fuel quantity, grade, and
quality, the engine(s) will likely cease to operate. Therefore, it is imperative that the pilot visually verify that the airplane has the
correct fuel quantity for the intended flight plus adequate and legal reserves, as well as inspect that the fuel is of the proper grade and
that the quality of the fuel is acceptable. The pilot should always ensure that the fuel caps have been securely replaced following
each fueling.
Many airplanes experience sensitivity to attitude when fueling for maximum capacity. Nosewheel or main landing gear strut
extension, both high as well as low, and the slope of the ramp can significantly alter the attitude of the aircraft and therefore the fuel
capacity. Always positively confirm the fuel quantity indicated on the fuel gauges by visually inspecting the level of fuel in each tank.
The pilot should be aware that fuel stains anywhere on the wing or any location where a fuel tank is mounted warrants further
investigation—no matter how old the stains appear to be. Fuel stains are a sign of probable fuel leakage. On airplanes equipped with
wet-wing fuel tanks, evidence of fuel leakage can be found along rivet lines. [Figure 2-12]
Figure 2-12. Evidence of fuel leakage can be found along rivet lines.
Checking for water and other sediment contamination is a key preflight item. Water tends to accumulate in fuel tanks from
condensation, particularly in partially filled tanks. Because water is heavier than fuel, it tends to collect in the low points of the fuel
system. Water can also be introduced into the fuel system from deteriorated gas cap seals exposed to rain or from the supplie r’s
storage tanks and delivery vehicles. Sediment contamination can arise from dust and dirt entering the tanks during refueling or from
deteriorating rubber fuel tanks or tank sealant. Deteriorating rubber from seals and sealant may show up in the fuel sample as small
dark specks.
The best preventive measure is to minimize the opportunity for water to condense in the tanks. If possible, the fuel tanks should be
completely filled with the proper grade of fuel after each flight, or at least filled after the last flight of the day. The more fuel that is in
the tanks, the less room there is for condensation to occur. Keeping fuel tanks filled is also the best way to slow the aging of
rubber fuel tanks and tank sealant.
Sufficient fuel should be drained from the fuel strainer quick drain and from each fuel tank sump to check for fuel grade/color, water,
dirt, and odor. If water is present, it is usually in bubble or bead-like droplets, different in color (usually clear, sometimes muddy
yellow to brown with specks of dirt), in the bottom of the sample jar. In extreme water contamination cases, consider the possibility
that the entire fuel sample, particularly if a small sample was taken, is water. If water is found in the first fuel sample, continue
sampling until no water and contamination appears. Significant and/or consistent water, sediment or contaminations are grounds for
further investigation by qualified maintenance personnel. Each fuel tank sump should be drained during preflight and after refueling.
The order of sumping the fuel system is often very important. Check the AFM/POH for specific procedures and order to be followed.
Checking the fuel tank vent is an important part of a preflight assessment. If outside air is unable to enter the tank as fuel is drawn into
the engine, the eventual result is fuel starvation and engine failure. During the preflight assessment, the pilot should look for signs of
vent damage and blockage. Some airplanes utilize vented fuel caps, fuel vent tubes, or recessed areas under the wings where vents are
located. The pilot should use a flashlight to look at the fuel vent to ensure that it is free from damage and clear of obstructions. If
there is a rush of air when the fuel tank cap is cracked, there could be a serious problem with the vent system.
Aviation oils are available in various single/multi-grades and mineral/synthetic-based formulations. It is important to use the
approved and recommended oil for the engine at all times. The oil not only acts as a lubricant but also as a medium to transfer heat as
a result of engine operation and to suspend dirt, combustion byproducts, and wear particles between oil changes. Therefore, the
proper level of oil is required to ensure lubrication, effective heat transfer, and the suspension of various contaminants. The oil level
should be checked during each preflight, rechecked with each refueling, and maintained to prevent the oil level from falling below the
minimum required during engine operation.
During the preflight assessment, if the engine is cold, oil levels on the oil dipstick show higher levels than if the engine was warm and
recently shutdown after a flight. When removing the oil dipstick, care should be taken to keep the dipstick from coming in contact
with dirty or grimy areas. The dipstick should be inspected to verify the oil level. Typically, piston airplane engines have
oil reservoirs with capacities between four and eight quarts, with six quarts being common. Aside from the level of oil, the
oil’s color also provides an insight as to its operating condition. Oils darken in color as the oil operating hours increase —this
is common and expected as the oil traps contaminants. However, oils that rapidly darken in the first few hours of use after an oil
change may indicate engine cylinder problems. Piston airplane engines consume a small amount of oil during normal
operation. The amount of consumption varies on many factors; however, if consumption increases or suddenly changes, qualified
maintenance personnel should investigate
It is suggested that the critical aspect of fuel and oil not be left to line service personnel without oversight of the pilot responsible for
flight. While line personnel are aviation professionals, the pilot is responsible for the safe outcome of any flight. During refueling or
when oil is added to an engine, the pilot should monitor and ensure that the correct quantity, quality, and grade of fuel and oil is
added and that all fuel and oil caps have been securely replaced.
Landing Gear, Tires, and Brakes
The landing gear, tires, and brakes allow the airplane to maneuver from and return to the ramp, taxiway, and runway environment in a
precise and controlled manner. The landing gear, tires, and brakes should be inspected to ensure that the airplane can be positively
controlled on the ground. Landing gear on airplanes varies from simple fixed gear to complex retractable gear systems.
Fixed landing gear is a gear system in which the landing gear struts, tires, and brakes are exposed and lend themselves to relatively
simple inspection. However, more complex airplanes may have retractable landing gear with multiple tires per landing gear strut,
landing gear doors, over-center locks, springs, and electrical squat switches. Regardless of the system, the pilot should follow the
AFM/POH during inspection to determine that the landing gear is ready for operation.
On many fixed-gear airplanes, inspection of the landing gear system can be hindered by wheel pants, which are covers used to reduce
aerodynamic drag. It is still the pilot’s responsibility to inspect the airplane properly. A flashlight helps the pilot in peering into
covered areas. On low-wing airplanes, covered or retraceable landing gear presents additional effort required to crouch below the
wing to inspect the landing gear properly.
The following provides guidelines for inspecting the landing gear system; however, the AFM/POH should be the pilot’s reference for
the appropriate procedures.
⦁ The pilot, when approaching the airplane, should look at the landing gear struts and the adjacent ground for
leaking hydraulic fluid that may be coming from struts, hydraulic lines from landing gear retraction pumps,
or from the braking system. Landing gear should be relatively free from grease, oil, and fluid without any
undue amounts. Any amount of leaking fluid is unacceptable. In addition, an overview of the landing gear
provides an opportunity to verify landing gear alignment and height consistency.
⦁ All landing gear shock struts should also be checked to ensure that they are properly inflated, clean, and
free from hydraulic fluid and damage. All axles, links, collars, over-center locks, push rods, forks, and
fasteners should be inspected to ensure that they are free from cracks, corrosion, and rust, and are in an
airworthy condition.
⦁ Tires should be inspected for proper inflation, an acceptable level of remaining tread, and normal wear
pattern. Abnormal wear patterns, sidewall cracks, and damage, such as cuts, bulges, imbedded foreign
objects, and visible cords, render the tire unairworthy. For airplanes that are flown by more than one pilot,
what happened to the tires on previous flights becomes a significant unknown. Therefore, when possible,
the airplane should be moved slightly to allow for evaluation of the complete tire circumference.
⦁ Wheel hubs should be inspected to ensure that they are free from cracks, corrosion, and rust, that all
fasteners are secure, and that the air valve stem is straight, capped, and in good condition.
⦁ Brakes and brake systems should be checked to ensure th at they are free from rust and corrosion and that
all fasteners and safety wires are secure. Brake pads should have a proper amount of material remaining and
should be secure. All brake lines should be secure, dry, and free of signs of hydraulic leaks, and devoid of
abrasions and deep cracking.
⦁ On tricycle gear airplanes, a shimmy damper is used to damp oscillations of the nose gear and should be
inspected to ensure that it is securely attached, is free of hydraulic fluid leaks, and is in overall good
condition. Some shimmy dampers do not use hydraulic fluid and instead use an elastomeric compound as
the dampening medium. Nose gear links, collars, steering rods, and forks should be inspected to ensure the
security of fasteners, minimal free play between torque links, crack-free components, and for proper
servicing and general condition.
⦁ On some conventional gear airplanes, those airplanes with a tailwheel or skid, the main landing gear may
have bungee cords to help in absorbing landing loads and shocks. The bungee cords must be inspected for
security and condition.
⦁ Where the landing g ear transitions into the airplane’s structure, the pilot should inspect the attachment
points and the airplane skin in the adjacent area—the pilot needs to inspect for wrinkled or other damaged
skin, loose bolts, and rivets and verify that the area is free from corrosion.
Engine and Propeller
Properly managing the risks associated with flying requires that the pilot of the airplane identify and mitigate any potential hazards
prior to flight to prevent, to the furthest extent possible, a hazard becoming a realized risk. The engine and propeller make up the
propulsion system of the airplane —failure of this critical system requires a well-trained and competent pilot to respond with
significant time constraints to what is likely to become a major emergency.
The pilot needs to ensure that the engine, propeller, and associated systems are functioning properly prior to operation. This starts
with an overview of the cowling that surrounds the airplane engine. The pilot should look for loose, worn, missing, or damage d
fasteners, rivets, and latches that secure the cowling around the engine and to the airframe. The pilot should be vigilant as fasteners
and rivets can be numerous and surround the cowling requiring a visual inspection from above, the sides, and the bottom. Like other
areas on the airframe, rivets should be closely inspected for looseness by looking for signs of a black oxide film around the rivet head.
The pilot should pay attention to chipped or flaking paint around rivets and other fasteners as this may be a sign of a lack of security.
Any cowling security issues need to be referred to a competent and rated airplane maintenance mechanic.
From the cowling, a general inspection of the propeller spinner, if so equipped, should be completed. Not all airplane/propeller
combinations have a spinner, so adherence to the AFM/POH checklist is required. Spinners are subjected to great stresses and should
be inspected to be free from dents, cracks, corrosion, and in proper alignment. Cracks may not only occur at locations where fasteners
are used but also on the rear-facing spinner plate. In conditions where ice or snow may have entered the spinner around the propeller
openings, the pilot should inspect the area to ensure that the spinner is internally free from ice. The engine/propeller/spinner is
balanced around the crankshaft and a small amount of ice or snow can produce damaging vibrations. Cracks, missing fasteners, or
dents result in a spinner that is unairworthy.
The propeller should be checked for blade erosion, nicks, cracks, pitting, corrosion, and security. On controllable pitch pr opellers, the
propeller hub should be checked for oil leaks that tend to stream directionally from the propeller hub toward the tip. On ai rplanes so
equipped, the alternator/generator drive belts should be checked for proper tension and signs of wear.
When inspecting inside the cowling, the pilot should check all surfaces for oil leaks or deterioration of oil and hydraulic lines, and
make certain that the oil cap, filter, oil cooler, and drain plug are secure. The pilot should look for signs of fuel dye, which may
indicate a fuel leak. Note that both fuel and oil stains may appear on a cowling inner surface. Observation may be difficult without the
aid of a flashlight, so even during day operations, a flashlight is handy when peering into the cowling. The pilot should also check for
loose or foreign objects inside the cowling, such as bird nests, shop rags, and/or tools. All visible wires and lines should be checked
for security and condition. The exhaust system should be checked for white stains caused by exhaust leaks at the cylinder head or
cracks in the exhaust stacks. The heat muffs, which provide cabin heating on some airplanes, should also be checked for general
condition and signs of cracks or leaks. An isolated area of oxidized darkened paint on the engine may indicate an area experiencing
excessive heat. If visible, the condition of the firewall may be checked for integrity.
The air filter should be checked to ensure that it is free from substantial dirt or restrictions, such as bugs, birds, nests, or other causes
of airflow restriction. In addition, air filter elements are made from various materials. In all cases, the element should be free from
decomposition and properly serviced.
Risk and Resource Management
Ground operations also include the pilot’s assessment of the risk factors that contribute to safety of flight and the pilot’s management
of the resources, which may be leveraged to maximize the flight’s successes. The Risk Management Handbook (FAA-H-8083-2)
should be reviewed for a comprehensive discussion of this topic. A review of key points follows.
Approximately 85 percent of all aviation accidents have been determined by the National Transportation Safety Board (NTSB) to
have been caused by “failure of the pilot to...” As such, a reduction of these failures is the fundamental cornerstone to risk and
resource management. The risks involved with flying an airplane are very different from those experienced in daily activities, such as
driving to work. Managing risks and resources requires a conscious effort that goes beyond the stick and rudder skills requi red to
pilot the airplane.
Risk Management
Risk management is a formalized structured process for identifying and mitigating hazards and assessing the consequences and
benefits of the accepted risk. A hazard is a condition, event, object, or circumstance that could lead to or contribute to an unplanned
or undesired event, such as an incident or accident. It is a source of potential danger. Some examples of hazards are:
1. Marginal weather or environmental conditions
2. Lack of pilot qualification, currency, or proficiency for the intended flight.
Identifying the Hazard
Hazard identification is the critical first step of the risk management process. If pilots do not recognize and properly identify a hazard
and choose to continue, the consequences of the risk involved is not managed or mitigated. In the previous examples, the hazard
identification process results in the following assessment:
⦁ Marginal weather or environmental conditions is an identified hazard because it may result in the pilot
having a skill level that is not adequate for managing the weather conditions or requiring airplane
performance that is unavailable.
⦁ The lack of pilot training is an identified hazard because the pilot does not have experience to either meet
the legal requirements or the minimum necessary skills to safely conduct the flight.
Risk
Risk is the future impact of a hazard that is not controlled or eliminated. It can be viewed as future uncertainty created by the hazard.
⦁ If the weather or environmental conditions are not properly assessed, such as in a case where an airplane
may encounter inadvertent instrument conditions, loss of airplane control may result.
⦁ If the pilot’s lack of training is not properly assessed, the pilot may be placed in flight regimes that exceed
the pilot’s stick-and-rudder capability.
Risk Assessment
Risk assessment determines the degree of risk and whether the degree of risk is worth the outcome of the planned activity. Once the
planned activity is started, the pilot needs to consider whether to continue or not. A pilot should always have viable alternatives
available in the event the original flight plan cannot be accomplished. Thus, hazard and risk are the two defining elements of risk
management. A hazard can be a real or perceived condition, event, or circumstance that a pilot encounters. Risk assessment is a
quantitative value weighted to a task, action, or event. When armed with the predicted risk assessment of an activity, pilots are able to
manage and mitigate their risk.
In the example where marginal weather is the identified hazard, it is relatively simple to understand that the consequences of loss of
control during any inadvertent encounter with instrument meteorological conditions (IMC) are likely to be severe for a pilot not
prepared to fly on an instrument flight plan. A risk assessment for any such pilot in this example would determine that the risk is
unacceptable and as a result, mitigation of the risk is required. Proper risk mitigation would require that flight be canceled or delayed
until weather conditions were not conducive for inadvertent flight into instrument meteorological conditions.
Risk Identification
Identifying hazards and associated risk is key to preventing risk and accidents. If a pilot fails to search for risk, it is likely that he or
she will neither see it nor appreciate it for what it represents. Unfortunately, in aviation, pilots seldom have the opportunity to learn
from their small errors in judgment because even small mistakes in aviation are often fatal. In order to identify risk, the use
of standard procedures is of great assistance. Several procedures are discussed in detail in the Risk Management Handbook
(FAA-H-8083-2).
Risk Mitigation
Risk assessment is only part of the equation. After determining the level of risk, the pilot needs to mitigate the risk. For example,
the VFR pilot flying from point A to point B (50 miles) in marginal flight conditions has several ways to reduce risk:
1. Wait for the weather to improve to good VFR conditions.
2. Take a pilot who is more experienced or who is cer tified as an instrument flight rules (IFR) pilot.
3. Delay the flight.
4. Cancel the flight.
5. Drive.
Resource Management
Familiarity with crew resource management (CRM) and single-pilot resource management (SRM) enables a crew or pilot to manage
all available resources effectively and leads to a successful flight. In general aviation, SRM comes into play more often. The focus of
SRM is on the single-pilot operation. SRM integrates the following:
⦁ Situational Awareness
⦁ Human Resource Management
⦁ Task Management
⦁ Aeronautical Decision-making (ADM)
Situational Awareness
Situational awareness is the accurate perception of operation al and environmental factors that affect the flight. It is a logical analysis
based upon the airplane, external support, environment, and the pilot. It is awareness on what is happening in and around the flight.
Human Resource Management
Human resource management requires an effective use of all available resources: human, equipment, and information.
Human resources include the essential personnel routinely working with the pilot to ensure safety of flight. These people include, but
are not limited to: weather briefers, flight line personnel, maintenance personnel, crew members, pilots, and air traffic personnel.
Pilots need to communicate effectively with these people. This is accomplished by using the key components of the communication
process: inquiry, advocacy, and assertion. Pilots should recognize the need to seek enough information from these resources to make
a valid decision. After the necessary information has been gathered, the pilot’s decision should be passed on to those concerned, such
as air traffic controllers, crewmembers, and passengers. The pilot may have to request assistance from others and be assertive to
resolve some situations safely.
Equipment in many of today’s aircraft includes automated flight and navigation systems. These automatic systems, while providing
relief from many routine tasks, present a different set of problems for pilots. The automation intended to reduce pilot workload
essentially removes the pilot from the process of managing the aircraft, thereby reducing situational awareness and leading t o
complacency. Information from these systems needs to be continually monitored to ensure proper situational awareness. Pilots should
be aware of both equipment capabilities and equipment limitations in order to manage those systems effectively and safely.
Information workloads and automated systems, such as autopilots, need to be properly managed to ensure a safe flight. By planning
ahead, a pilot can effectively reduce workload during critical phases of flight and prevent erosion of performance. The pilot who
effectively manages his or her workload completes routine tasks as early as possible to preclude the possibility of becoming
overloaded and stressed in the later, more critical stages of the flight.
Task Management
Pilots have a limited capacity for information. Once information flow exceeds the pilot’s ability to process the information mentally,
any additional information becomes unattended or displaces other tasks and information already being processed. In addition,
distraction and fixation impede the ability to process information. For example, if a pilot becomes distracted and fixates on an
instrument light failure, the unnecessary focus displaces capability and prevents appreciation of tasks of greater importance.
Aeronautical Decision-Making (ADM)
Flying safely requires the effective integration of three separate sets of skills: stick-and-rudder skills needed to control the airplane;
skills related to proficient operation of aircraft systems; and ADM skills. The ADM process addresses all aspects of decision-making
in the flight deck and identifies the steps involved in good decision-making. While the ADM process does not eliminate errors, it
helps the pilot recognize errors and enables the pilot to manage the error to minimize its effects. These steps are:
1. Identifying personal attitudes hazardous to safe flight;
2. Learning behavior modification techniques;
3. Learning how to recognize and cope with stress;
4. Developing risk assessment skills;
5. Using all resources; and
6. Evaluating the effectiveness of one’s own personal ADM skills.
Ground Operations
The airport ramp can be a complex environment with airport personnel, passengers, trucks, other vehicles, aircraft, and errant people
and animals. The pilot is responsible for the operation of the airplane and should operate safely at all times. Ground operations
subject the pilot to unique hazards, and mitigating those hazards requires proper planning and good situational awareness in the
ground environment. A mitigation tactic involves reviewing the airport diagram prior to operating and having it readily available at
all times. Whether departing to or from the ramp, the pilot needs to understand and capably manage the following:
1. Refueling operations
2. Passenger and baggage security and loading
3. Ramp and taxi operations
4. Standard ramp signals
During refueling operations, it is advisable that the pilot remove all passengers from the aircraft and witness the refueling to ensure
that the correct fuel and quantity is dispensed into the airplane and that any caps and cowls are properly secured after refueling.
Passengers may have little experience with the open ramp of an airport. The pilot should ensure the safety of the passengers by
cautioning them to move on the surface only as directed. If not under the pilot's direct supervision, passengers should have an escort
to ensure their safety and ramp security. Baggage loading and security should also be supervised by the pilot. Unsecured baggage or
improperly loaded baggage may adversely affect the center of gravity of the aircraft.
Ramp traffic may vary from a deserted open space to a complex environment with heavy corporate or military aircraft. Powerful
aircraft may produce exhaust blast or rotor downwash, for example, which could easily cause a light airplane to become
uncontrollable. Mitigating these hazards in a light airplane is important to starting off on a safe flight.
Some ramps may be staffed by personnel to assist the pilot in managing a safe departure from the ramp to the taxiway. Figure 2-13
shows standard aircraft taxiing signals, such as those published in the Aeronautical Information Manual (AIM). There are othe r
standard signals, such as those published in Advisory Circular 00-34, as revised, and by the Armed Forces. Furthermore, operation
conditions in many areas may call for a modified set of taxi signals. The signals shown in Figure 2-13 represent a minimum number
of the most commonly used signals. Whether this set of signals or a modified set is used is not the most important consideration, as
long as each flight operational center uses a suitable, agreed-upon set of signals.
Figure 2-13. Standard hand signals used to assist pilots in managing a safe departure from the ramp to the taxiway or runway. Note
that at night, the Emergency Stop signal is used for all stop indications .
Engine Starting
Airplane engines vary substantially and specific procedures for engine starting should be accomplished in reference to the
approved engine start checklist as detailed in the airplane’s AFM/POH. However, some generally accepted hazard mitigation
practices and procedures are outlined in this section.
Prior to engine start, the pilot needs to ensure that the ramp area surrounding the airplane is clear of persons, equipment, and other
hazards that could come into contact with the airplane or the propeller. Also, the pilot should check what is behind the airplane prior
to engine start as standard practice. A propeller or other engine thrust can accelerate objects to substantial velocities, causing damage
to property, and injuring those on the ground. The pilot should mitigate the hazard of debris being blown into persons or pr operty. At
all times before engine start, the anti-collision lights should be turned on. For night operations, the position (navigation) lights should
also be on. Finally, just prior to starter engagement, the pilot should always call “CLEAR” out of the side window and wait for a
response from anyone who may be nearby before engaging the starter.
When activating the starter, the wheel brakes need to be depressed and one hand kept on the throttle to manage the initial starting
engine speed. Ensuring that properly operating brakes are engaged prior to starter engagement prevents the airplane from rapidly
lunging forward. After engine start, the pilot manipulates the throttle to set the engine revolutions per minute (rpm) to the AFM/POH-
prescribed setting. In general, 1,000 rpm is recommended following engine start to allow oil pressure to rise and to minimize undue
engine wear due to insufficient lubrication at high rpm. It is important to service an airplane engine with the proper grade of oil for
the seasonal conditions and to apply engine preheat when temperatures approach and descend below freezing.
The oil pressure should be monitored after engine start to ensure that pressure is increasing toward the AFM/POH -specified value.
The AFM/POH specifies an oil pressure range for the engine. If the limits are not reached and maintained, serious internal engine
damage is likely. In most conditions, oil pressure should rise to at least the lower limit within 30 seconds. To prevent damage, the
engine should be shut down immediately if the oil pressure does not rise to the AFM/POH values within the required time.
Engine starters are electric motors designed to produce rapid rotation of the engine crankshaft for starting. These electric motors are
not designed for continuous duty. Their service life may be drastically shortened during a prolonged or difficult start as an excess
buildup of heat can damage internal starter components. Avoid continuous starter operation for periods longer than 30 seconds
without a cool down period of at least 30 seconds to 1 minute (some AFM/POH specify longer cool down routines). The smell
of burning insulation from a starter may indicate that the recommended cranking time has been exceeded. After repeated
unsuccessful start attempts, the pilot should seek advice from a qualified person to determine the cause for the difficulty.
Although quite rare, the starter motor may remain electrically and mechanically engaged after engine start. This can be detected by a
continuous and very high current draw on the ammeter. Some airplanes also have a starter engaged warning light specifically for this
purpose. The engine should be shut down immediately if this occurs.
The pilot should be attentive for sounds, vibrations, smells, or smoke that are not consistent with normal after-start
operational experience. Any concerns should lead to a shutdown and further investigation.
Hand Propping
The procedur es for hand propping should always b e in accordance with th e AFM/P OH and performed only by persons who are
competent with hand propping procedures. The consequences of the hazards associated with hand propping are serious to fatal.
Historically, when aircraft lacked electrical systems, it was necessary for pilots and ground personnel to “hand prop” an aircraft for
starting. Today, most airplanes are equipped with electric starters, and the starter should be working if the airplane is airworthy. If
not, a certificated Aviation Maintenance Technician should be called to make a repair. However, vintage airplanes may be
encountered, and an airplane manufactured without an electric starter needs to be hand propped. Since a number of these airplanes
have been produced, the procedures for hand propping are described in this section.
A few simple precautions help to avoid accidents when hand propping the engine. While touching a propeller, always assume that the
ignition is on. The switches that control the magnetos operate on the principle of short-circuiting the current to turn the ignition off. If
the switch is faulty, it can be in the “off” position and still permit current to flow in the magneto primary circuit. This condition could
allow the engine to start when the switch is off.
Hand propping an aircraft is a hazardous procedure when done perfectly. Not mitigating the hazards associated with hand prop ping
can lead to serious injury and a runaway airplane. A spinning propeller can be lethal should it strike someone. Persons not trained, not
competent, or who do not understand how to mitigate the hazards associated with hand propping should never perform this
procedure!