Read on below to find out more about maintenance cycles, their importance, and one of the coolest and most important checks for aircraft: magnetos.
Magneto inspections are key to keeping aircraft operational for the long term. Keeping aircraft up to date with its maintenance cycle and making sure that the aircraft is well-serviced isn’t just a mandatory duty of every pilot; it is also a safety operation that forms the backbone of the aviation industry.
Stringent measures and careful checks are part of the reasons why flying is one of the safest forms of travel around the world. These safety checks and maintenance tasks ensure the quality of the aircraft and help focus the pilot on what is most important: piloting.
Read on below to find out more about maintenance cycles, their importance, and one of the coolest and most important checks for aircraft: magnetos.
WHAT IS A MAGNETO?
If you read “magneto” and magnets come to mind, then you aren’t that far off! A magneto is a self-contained electrical generator that uses permanent magnets to produce the high-voltage pulses necessary to ignite an aircraft piston engine via the spark plugs.
We will spare you the technical and engineering footnotes of this machine and focus on just how it works, its importance, and what you need to keep in mind about it.
Magnetos are one of the coolest inventions because they generate energy through nothing but magnets. If you are familiar with electric cars, then you have already seen magnets in action. The powertrain of electric cars is powered by electrical motors that have permanent magnets in them. These magnets generate the power required to turn the rotors and propel the car forward.
In aircraft, magnetos, in the same way, use magnetic induction. As the engine turns, the magneto’s rotor spins near a coil of wire and triggers a physics 101 lesson: a magnet passing through a coil of wire develops an electric current due to the simulation of a flow of electrons.
A primary coil, which is just a few turns of thick wire, holds the initial magnetic energy, and when the breaker points open, the magnetic field collapses quickly, producing 200-300 volts. This spike transfers to the secondary coil, which has even more wire turns, leading up to 30 kV of energy, enough to spark the plug and start the engine – cool, right?
The magneto also has a distributor mechanism, which includes a rotating distributor that sends the high-voltage pulse to each cylinder’s spark plug in a precise sequence. Since magnetos are engine-driven and don’t rely on the aircraft’s electrical system like the battery or the alternator, the engine continues firing even in the event of an electrical failure, hence acting as a safety mechanism as well.
MAGNETOS IN AIRCRAFT
There are not one but two magnetos in an aircraft. Why? Well, this is because the aviation industry doesn’t take risks and would do everything to keep everyone safe in the air.
Most aircraft piston engines use two magnetos; each powering one of the two spark plugs per cylinder. So, even if one magneto fails, the engine can still run, although less efficiently. When both magnetos are operating, you get better combustion since the dual spark plugs provide smoother and more complete combustion (or burns) and improved performance.
WHY MAGNETO CHECKS MATTER FOR PILOTS
Since magnetos power the engine, pilots ought to know more about them. Magneto checks are automatically conducted whenever you turn on the aircraft. The pre-flight magneto checks validate both ignition systems and help catch early issues such as fouled plugs, timing faults, or a “hot” magneto that requires attention.
Pilots will typically perform this during the run-up on the ground. This is how the checks happen in sequence:
- The pilot taxis into the run-up area, aligned into the wind.
- After alignment, the pilot sets the throttle to recommended RPM (for example, 1700 RPM for Continental engines; 1800–2000 RPM for Lycomings).
- When the engines reach appropriate RPMs, pilots will monitor each engine:
- By switching to Right only, then back to both.
- Then switching to Left only, then back to both.
The key for pilots here is to monitor the performance of the magneto by ensuring that there is no RPM drop. A drop in RPM would lead to the suspicion of a “hot” magneto, posing a potential hazard. Uneven drops in RPMs may indicate a timing issue or internal magneto wear.
Pilots use the right magneto or MAG first in order to avoid accidental take-off with just one magneto. These step-by-step checks ensure that the pilot always engages both MAGs before taking off.
Even after taking off, pilots can perform in-flight magneto checks. This is a more precise check and can be done at cruise power, especially if you have an appropriate EGT monitor on board.
COMMON SIGNS OF TROUBLE FOR MAGNETO ISSUES
Here are four common problems that pilots may face with magnetos:
- No RPM drop during magneto isolation, which hints towards grounding failure or a hot mag.
- Excessive or imbalanced RPM drop, which is a sign of timing issues or internal wear, including fouled plugs.
- Rough running on just one magneto, which indicates bad leads or fouled plug(s).
- Rough running on both magnetos, which suggests a broader and more serious engine issue, such as in the induction or valve train.
It is important to keep in mind that any of these issues warrants an immediate check, and the pilot must ensure that they don’t take off or proceed with the flight in any way until the magneto issue is solved.
MAINTENANCE CYCLES FOR AIRCRAFT
In the UK, maintenance cycles must align with CAA-approved schedules such as the CAP 411 for aeroplanes. However, specifics like magneto intervals often come from manufacturers or service bulletins. These are advanced checks that are done by professionals, so if you are the owner of an aircraft, your manufacturer will reach out to you for any interval changes or alerts.
As a rule, the CAA recommends that pilots perform checks before 500 flight hours. Pilots are required to perform internal inspections or overhauls of points, capacitors, distributors, etc. If the aircraft faces sudden engine stoppage or kickback, then the pilot must have the magnetos inspected for internal damage.
MANAGING YOUR PRIVATE AIRCRAFT
Aircraft maintenance is a crucial activity that allows the aircraft to remain problem-free and the pilot stress-free. It is mandatory as per CAA regulations and is one of the cornerstones of modern aviation. Deep inspection, which includes checks for magnetos, allows pilots to maintain their aircraft for the long term and even save money.
For example, if you overlook an issue in the engine and keep ignoring it to save costs in the short term, then you can bet that the problem will accumulate and come back to haunt you with a large bill.
Many comprehensive flight schools, like Sherburn Aero Club, operate their own fleet of aircraft and maintain them to the Tee. This allows for all aircraft to remain operational and therefore profitable in the long run.
Sherburn Aero Club also features an in-house engineering unit that services planes for members. This convenience is one of the reasons why the school is so well known in the region!
By using in-house services, you don’t have to do your own research or run around for procuring parts. Professionals will inspect your aircraft and provide you with a detailed report. For example, if there is a problem with the magnetos, then you will be given options for a repair or replacement. These professional aircraft engineers will guide you through the process and help you get your aircraft back in running position in no time.
If you are someone looking to own an aeroplane, then first of all, congratulations!
Aircraft owners should know that securing the funds to purchase the aircraft is only half the story. While it's cool to have your own aircraft, it comes with a lot of financial burden. As you can imagine, car prices are soaring, so just think about how the aircraft market is right now.
We highlight this for two reasons:
- Your aircraft will bound to have problems down the line since it’s a machine
- And you will need to stick to the maintenance schedule of your aircraft to save money for the long term.
As mentioned above, if you put a problem on the back burner, then you will eventually have to bear the full cost when it rears its ugly head down the road.
When you purchase your aircraft and deal with hangarage and storage, you will also have to look into a good engineering team that can look after your aircraft – and this is where flight clubs like Sherburn come in. Sherburn Aero Club proudly provides its own hangarage services along with maintenance services. So, you get everything under one roof!
WHY DO YOU NEED TO KEEP YOUR PLANE WELL-MAINTAINED?
Keeping your aircraft maintained has several obvious benefits. Let’s go over a few of the most important ones:
Avoid Delays
In aviation, timing is everything. Whether it is weather conditions or booking issues, scheduling your flight according to your timings requires that you keep a well-maintained aircraft at all times.
If your aircraft is as ready to go as you are, then you will never have to reschedule or deal with the annoyance of cancelling flights. Even a fifteen-minute delay can become a huge problem, especially if there is a significant amount of traffic in the skies and the flights are scheduled relatively close together.
This is why you should ensure that your aeroplane is well-maintained and there is no issue before take-off.
Pilots must also ensure that they strictly follow their aircraft’s maintenance cycle to avoid compliance problems as well.
These problems can not only ground the aircraft but may also ground the pilot until they get their maintenance documentation in order, such as the Certificate of Airworthiness or the Airworthiness Review Certificate. These problems can cause you to lose out on precious time and suffer financial losses in penalties, airfield costs, staff costs, and fuel.
Airworthiness
Your aircraft must be deemed worthy to fly! Airworthiness is an important aspect in aviation because it enables pilots to fly safely, knowing that their aircraft is free from any problems. Conducting a detailed inspection goes towards ensuring that your aircraft is airworthy. This step is necessary for both the aircraft and the pilot and ensures that the aeroplane will not cause harm to the pilot or those on the ground.
A certificate of airworthiness is issued by a licensed aircraft maintenance engineer after a thorough inspection of the aeroplane. If the aircraft fails the inspection, then it will be deemed unfit for flight until the necessary servicing is done.
How important is the certificate of airworthiness? Well, if you plan to fly or fly outside of the UK, then it is a must-have. Without this document, you will not be allowed to enter another country with your aircraft.
If you think you can get away by flying without this certificate, then think again. Flying an unworthy aircraft is not only dangerous but also may lead to prosecution since it is an important compliance and legal practice.
Maintaining the Market Value
Just like the maintenance of your car goes towards its market value, aeroplanes are the same. Most pilots don’t sell their first purchases, but if you are in the market for an upgrade, then you will have to maintain the aircraft if you want to secure a good price for it.
A poorly maintained aircraft will depreciate its market value each time you miss a scheduled maintenance activity. Over time, you may end up incurring a loss!
This is why we recommend that you treat your aircraft with the respect it deserves. Every enthusiast looks forward to the maintenance activity of their aircraft; even pilots-in-training will take time out of their schedule to check out the maintenance wing in the flight school and see all the professionals at work.
WHY CHOOSE SHERBURN AERO CLUB?
Sherburn Aero Club has been operational since 1964 and is the ideal place for all of your training and flying needs.
We cater to brand new flyers who have just started their journey to the skies, as well as seasoned flyers who have been operating aircraft for decades.
Sherburn offers a dedicated day-long Flight Radiotelephony Operator’s Licence (FRTOL) course for those wishing to get the certification, running on the first Sunday of every month.
The club also has a dedicated weather webcam that constantly monitors the meteorological conditions in the aerodrome to help pilots decide whether it's safe to take to the skies or not.
The club’s dedicated engineering facility offers pre-buy inspections, with Sherburn helping guide members with regard to what kind of aircraft and mode of ownership is best-suited to their needs.
Sherburn provides members with the option to advertise aircraft that they wish to sell through the club’s website, as well as options for aviation enthusiasts looking to purchase aircraft or shares for fractional ownership.
For those who wish to experience the thrill of a flight for fun or to help fuel their aviation dreams, Sherburn offers experience flights for the newbie, as well as the veteran. The flight experience option is also available for people who wish to take to the skies for special occasions, even if they aren’t into aviation in the long run.
Call us on 01977 682 674, email us at flightdesk@sherburnaeroclub.com, or message us via our online contact form for more information on private aircraft maintenance and plane ownership, as well as the club’s engineering facility.
Photo by Marie Martin on Unsplash
