Lesson Overview

The student should develop knowledge of the elements related to engine starting as required in the ACS/PTS.

References : Airplane Flying Handbook (FAA-H-8083-3C, page(s) 12-2), Pilot’s Handbook of Aeronautical Knowledge (Chapter(s) : 7), ** INVALID TAG :: ac-91-55 **, POH/AFM

Key Elements

  1. Checklist

  2. Safety

  3. Hand on the Throttle
Elements

  1. Safety Precautions

  2. Atmospheric Conditions

  3. Checklists

  4. Engine Controls During Start

  5. Preventing Aircraft Movement

  6. Starting with External Power

  7. Hand Propping Safety
Schedule

  1. Discuss Objectives

  2. Review material

  3. Development

  4. Conclusion
Equipment

  1. White board and markers

  2. References
IP Actions

  1. Discuss lesson objectives

  2. Present Lecture

  3. Ask and Answer Questions

  4. Assign homework
SP Actions

  1. Participate in discussion

  2. Take notes

  3. Ask and respond to questions
Completion Standards

The student shows the ability to safely start the engine using the appropriate checklist and understands different conditions and their effect on starting.

Instructor Notes

Attention

Starting the engine of an airplane is not as simple as starting the engine of your car. A plane can’t just be turned on anywhere, the proper precautions and procedures must be followed for safety reasons.
Overview

Review Objectives and Elements/Key ideas
What

Engine Starting discusses the safety precautions necessary when starting an airplane, different conditions which affect starting the engine, as well as different ways to start the engine.
Why

Proper engine starting is necessary for the safety of people and property as well as to prevent engine damage. There are certain situations which require special procedures and some procedures can be dangerous. It is very important to know the proper engine starting procedures, precautions, and adjustments.

Lesson Details

Aircraft engines are simple, but specifically due to that simplicity require more knowledge to effectively and safely operate than your average automobile engine. Safety is the top concern, of course.

Safety

Numerous things need to be remembered to safely operate an aircraft engine. The first thing to address is aircraft positioning. When the engine starts a blast of air will be thrown behind the aircraft. Therefore position the aircraft such that the blast of air generated is not pointed at things which might get damaged such as open hangars, automobiles, bystanders, or other aircraft.

Prior to starting set the parking brake (if available), and clear the area. Actually take the time to look around to ensure nothing will be in the vicinity of the propeller or propeller blast. Turn on strobe or other anti-collision lights to warn people that the engine is about to start, and yell "CLEAR" to give an audible indication as well. Always keep one hand on the throttle to be able to quickly respond to an issue such as unexpectedly high RPM, or other hazardous situation.

Atmospheric Conditions

Cold weather is often a challenge when starting an aircraft engine. Oil thickens as it gets cold. The best advice when temperatures are low are to preheat the engine to warm the oil. Some recommend pulling the prop through by hand to loosen the oil, but this must be done with great care (mags/master OFF, fuel OFF, and throttle CLOSED) but there are questions as to the efficacy of this so a preheat is the preferred recommendation.

In an unheated engine it is possible that the spark plug electrodes can become iced over. The only remedy for this is heat. What can happen is that the engine will fire and quit, and leave enough moisture in the cylinder that it condenses and freezes. This shorts out the plugs causing the engine to become impossible to start.

Hot weather can cause the cylinders to become flooded. If this occurs use the flooded start checklist to clear the excess fuel and start the engine. Fuel injected engines can suffer from vaporization of the fuel in hot conditions. When the engine is shut down temperatures in the cowl can climb fast, thus heat soaking the fuel lines and causing the fuel in them to vaporize. This vapor does not flow well and can cause the cylinders to be unable to get fuel. This can sometimes be remedied with an electric fuel pump to purge the vapor from the system. Vapor problems may be evident after start due to insufficient amounts of cooling air through the cowl. Monitor the fuel flow gauge for any fluctuations and use the electric fuel pump to insure adequate fuel flow.

Checklists

Since there are numerous situations encountered during the engine start, there are differing procedures for these various situations. Use the published checklists to insure the proper procedure is used under each situation. Checklists insure that all steps are taken, and are done so in the proper order.

Engine Controls during Start

During engine start always keep a hand on the throttle. This allows quick reaction to events, such as overly high RPM, an engine stumbling, or a hazardous condition developing. After the engine start monitor engine gauges, particularly the oil gauge to insure oil pressure becomes available quickly. If oil pressure is not evident within a short period of time shut the engine down as it may not be getting adequate lubrication.

During engine start avoid excessive RPM, and retard the throttle if high RPMs are experienced. High RPMs at engine start put excessive wear on the engine internal components, risk throwing excessive debris behind the aircraft, and risk aircraft movement.

During the actual cranking of the engine, be aware of the load placed on the starter. The starting process generates heat within the starter motor, and excessive heat can destroy a starter. Know the manufacturer recommendations for starter duty cycle and adhere to those guidelines to avoid melting the starter windings.

Preventing Aircraft Movement

Set the parking brake (if available) or hold the brakes with your feet. As the engine starts look outside to ensure the aircraft is not moving. Too much "heads down" time can leave you unaware of movement. This has caused accidents, which can become very expensive very quickly.

Hand Propping Safety

Before anything else, get proper experienced training. Hand propping isn’t hard, but is utterly unforgiving of mistakes or sloppiness. Hand propping should be performed only on those aircraft for which this is a normal starting procedure (i.e. Cub, Champ, or other aircraft without an electrical starter). This should not be performed as an emergency procedure or on an aircraft that would normally be started with an electrical starter.

BEFORE hand propping, have two people both familiar with hand propping techniques available. Never allow a person unfamiliar with the aircraft controls to occupy the pilot’s seat during hand propping. The person pulling the blades through directs all activity and is in control of the procedure. Chocks or tying down the tail can provide additional security, but be careful removing them.

The ground surface near the prop should be stable and free of debris. Loose gravel, wet grass, mud might cause the person pulling the prop to slip into the blades. Both participants should discuss the procedures, and be in agreement on how the process will proceed.

The engine should be set for a normal start. Check to ensure that the ignition and magnetos are OFF. The descending blade should be rotated to a position slightly above the horizontal. The person doing the propping should face the blade squarely and stand less than an arm’s length away (standing too far away would require the person to lean forward creating an unbalanced condition).

Once the engine is set to start, the script generally goes as follows :

  • Person out front calls "GAS ON, SWITCH OFF, THROTTLE CLOSED, BRAKES SET"

  • Person inside ensures that the fuel is on, the mixture is rich, the magneto switch is off, that the throttle is closed, and that the brakes are set. He then repeats the call

  • Person out front checks brakes by pushing on the prop, and then pulls the prop through to prime the engine

  • Person out front calls "BRAKES AND CONTACT"

  • Person inside confirms brakes are set, and ignition is on, and repeats the call

At this point the engine is ready to start, and the person outside rotates the prop by forcing the blade downward as rapidly as possible. Use the palms of the hand and do not curl the fingers over the blade, and take a step backward on the follow-through from turning the prop.

If the engine does NOT START repeat the process, but DO NOT TOUCH THE PROP until the ignition/magneto switch is confirmed OFF.

Common Errors

  • Failure to use the appropriate checklist

  • Failure to use safety precautions related to starting

  • Improper adjustment of engine controls during start

  • Failure to ensure proper clearance of the propeller

Conclusion

Always ensure safety when starting the engine in any situation.

ACS Requirements

To determine that the applicant:

  1. Exhibits instructional knowledge of the elements of engine starting, as appropriate to the airplane used for the practical test by describing:

    1. Safety precautions related to starting.

    2. Use of external power.

    3. Effect of atmospheric conditions on starting.

    4. Importance of following the appropriate checklist.

    5. Adjustment of engine controls during start.

    6. Prevention of airplane movement during and after start.

    7. Safety procedures for hand-propping an airplane.

  2. Exhibits instructional knowledge of common errors related to engine starting by describing:

    1. Failure to properly use the appropriate checklist.

    2. Failure to use safety precautions related to starting.

    3. Improper adjustment of engine controls during start.

    4. Failure to assure proper clearance of the propeller.

  3. Demonstrates and simultaneously explains engine starting from an instructional standpoint.