This is your Captain speaking…

The Importance of Understanding the Ignition System

 

You have envisioned sitting in the left seat announcing to the passengers, “This is your Captain speaking, sit back, relax, and enjoy the ride.” Awaking from your dream, you look over at the mounds of study material open on the desk.

Nothing as an Earthling prepares a student for the amount of what seems like alien knowledge and skills required to become a pilot. A few examples of this knowledge required to earn a certificate are the Federal Aviation Regulations (FARs) comparable to studying a legal document; then understanding weather as an amateur meteorologist; and one of my favorite examples, knowing aircraft systems.

In addition to knowledge, learning how to maneuver the airplane in three dimensions often provides an eye-opening experience for new student pilots.

A student may do a good job of how to push, pull, and turn knobs but might lack the knowledge on why and what makes the airplane do what it does. If a pilot makes the airplane do what it’s supposed to do, then why is it important to know more?

I vividly recall my first revelation on the importance for learning the how and the why. I arrived at the local airport having already envisioned myself flying that cute little Cessna 150 (C150). I was really excited meeting my flight instructor for the first time. We were going to plan expectations, go over the syllabus, and review study materials.

When the flight instructor introduced the text book, I stared at the pages and stated in a matter of fact manner, “I don’t want to learn about aircraft systems.” He calmly smiled and said, “Too bad. Want to be a pilot then you will learn.” At that moment I resolved to delve into whatever it took to fly that C150.

Shortly after earning my private pilot license, I was looking forward to experiencing the freedom of this new earned privilege. I rented an airplane from the flight school, did a through preflight and taxied to the run-up area.

It was at that moment when I discovered why a student must have the knowledge for not only passing the FAA Knowledge (written), Practical (check ride) exams, but also how critical this knowledge was for the safety of a flight.

I had learned one of the essential items on a preflight checklist was the magneto check. The magneto check is for checking the health of the entire ignition system.

Ignition System Diagram

Ignition System Diagram (FAA Pilot Handbook Aeronautical Knowledge)

These marvelous magnetos had been around for over 100 years. Magnetos produce the electrical power for the spark plugs simply by a magnet and coiled wires. The airplane’s ignition system includes two magnetos providing better performance, more efficient combustion, and greater safety through redundancy.

A car uses the same battery for starting the engine and powering all electrical items. If the battery on a car fails, the ignition and electrical systems fail and the car would stop. Unlike cars, a piston engine ignition system is the source of electricity for the spark plugs and separate from the electrical system.

For this reason, piston engine airplanes are equipped with an independent ignition system and with dual magnetos. Once the engine starts, the battery and alternator could be removed from the airplane and the engine will continue to run.

During the preflight checklist on this beautiful day, I was in the process of checking the right magneto when the engine ran very rough and almost stopped. I quickly switched back to the left magneto and the engine ran smoothly. I knew the right magneto was not producing the amount of electricity needed for the smooth operation of the flight. It was time to see the mechanic.

Indeed, the right magneto needed replaced. Had I continued the flight, the right magneto would have failed inflight and the engine running on only one magneto. If the left magneto also failed then an emergency landing would had been necessary. I rented another airplane and proceeded on with my flight.

Forty years later, as a flight instructor, aircraft systems is one of my favorite topics to teach. I also enjoy working on my own airplane, in accordance to FAR Part 43 Preventive Maintenance.

Earning each certificate or rating, including type-ratings, are milestone and new levels of learning. Those with the dedication, focus, and desire to learn will discover flying as one of the biggest confidence builders, as well as most humbling experiences.

A lifetime isn’t long enough to learn everything aviation has to teach. What a grand journey for those earning the privileges!