Commercial Pilot ACS Study Guide: –Preflight Procedures

Engine Starting

Engine starting is more than turning a key or pressing a starter. At the commercial pilot level, the FAA expects applicants to demonstrate disciplined checklist use, sound judgment, and awareness of the hazards associated with starting and operating an aircraft engine on the ground.

At Angel Aviation, commercial students are expected to understand not only how to start the aircraft they are flying, but also why each step is performed and how to recognize conditions that require a different procedure or an immediate shutdown.

What You Should Know

Before Engine Start

Before starting, verify the aircraft is properly positioned and the surrounding area is clear. Complete the appropriate pre-start checklist and confirm items such as:

  • Parking brake or brake control as appropriate
  • Fuel selector and fuel system configuration
  • Mixture and throttle position
  • Electrical equipment configuration
  • Propeller area clear
  • Aircraft-specific procedures from the POH/AFM

Never allow the checklist to replace situational awareness. The pilot remains responsible for ensuring the start can be completed safely.

Clearing the Propeller Area

Before engaging the starter, visually confirm that no people, equipment, or other hazards are within the propeller area. Announce “CLEAR PROP!” loudly enough to warn anyone nearby and allow adequate time for them to move away.

Remember that a propeller should always be treated as if the engine could start unexpectedly.

Engine-Starting Conditions

A commercial pilot should understand that starting technique may change depending on aircraft and environmental conditions.

Cold Engine: Cold temperatures can affect oil viscosity, battery performance, fuel vaporization, and starting effectiveness. Follow the POH/AFM for cold-weather starting and preheating requirements.

Hot Engine: A recently operated engine may require a specific hot-start procedure. Improper technique can result in excessive cranking or difficulty starting.

Flooded Engine: Recognize the indications of a flooded engine and use the manufacturer-recommended flooded-start procedure rather than repeatedly attempting a normal start.

Always follow the procedure specified for the aircraft being operated.

Immediately After Start

Once the engine starts, attention should immediately shift to engine indications and aircraft control.

Verify:

  • Oil pressure rises within the manufacturer-specified time
  • Engine indications are within acceptable limits
  • Electrical system operation is normal
  • RPM is properly controlled
  • Avionics and electrical equipment are configured as required
  • The aircraft remains stationary and under positive control

An abnormal indication should never be ignored simply because the engine is running.

Risk Management

The ACS evaluates more than procedural knowledge. Applicants should be prepared to identify and manage risks associated with engine starting, including:

  • Propeller hazards
  • Starting near people, buildings, or other aircraft
  • Aircraft movement during start
  • Fire during engine start
  • Excessive starter engagement
  • Incorrect fuel or mixture configuration
  • Distractions and checklist interruptions
  • Abnormal engine or electrical indications

If an engine fire occurs during start, follow the aircraft’s POH/AFM emergency procedure. Commercial pilots should know the procedure for the specific aircraft they operate rather than relying on a generic response.

Commercial Pilot Standard

For the practical test, be prepared to explain your engine-starting procedure while demonstrating organized checklist use, proper clearing procedures, aircraft control, and continuous monitoring of engine indications.

A strong commercial applicant does not simply memorize a sequence. You should be able to explain why each major action is performed, what could go wrong, and what you would do if the start does not proceed normally.

Study Questions

Before your checkride, make sure you can answer:

  1. What precautions should be taken before starting the engine?
  2. Why do you call “clear prop” before engaging the starter?
  3. How does a hot, cold, or flooded engine affect the starting procedure?
  4. What indications should you check immediately after engine start?
  5. What would you do if oil pressure does not rise after start?
  6. What hazards exist when starting near people or other aircraft?
  7. What is the engine-fire-during-start procedure for your aircraft?
  8. When should you discontinue a start attempt?

FAA References

Review the current Commercial Pilot – Airplane Airman Certification Standards (FAA-S-ACS-7) along with the applicable:

  • Pilot’s Operating Handbook/Airplane Flight Manual (POH/AFM)
  • FAA Airplane Flying Handbook
  • FAA Pilot’s Handbook of Aeronautical Knowledge

Engine starting should be approached with the same professionalism as every other phase of flight. Consistent checklist discipline, aircraft-specific knowledge, and strong situational awareness demonstrate the level of judgment expected from a commercial pilot. Know the procedure. Understand the risks. Start every flight with professional habits.