Keep on reading to find out more about the electrical system of an aircraft, its ignition system, the problems that pilots can face with these systems, and how the ignition harness makes modern aviation possible.
- AIRCRAFT IGNITION HARNESS
- IGNITION HARNES SYSTEMS IN ACTION
- COMMON PROBLEMS OF A FAILING HARNESS
- CAN YOU TROUBLESHOOT IGNITION HARNESS ISSUES?
- WHAT IS THE REPLACEMENT WINDOW FOR IGNITION HARNESSES?
- THE BENEFITS OF MAINTAINING THE IGNITION HARNESS AND MAINTENANCE
- Sherburn Engineering
- WHY CHOOSE SHERBURN AERO CLUB?
Aircraft are a marvel of engineering, and while looking at them, you might only notice a simple design; there is a lot of engineering that goes behind the scenes to successfully enable pilots to fly.
The chassis of the aircraft is a feat of engineering in and of itself; however, the systems under the hood are what make aviation possible today. Take the example of the electrical system within the aircraft.
Much like the central nervous system of the human body, the electrical system of an aircraft allows various components to communicate with each other and work together in unison. However, this also makes maintenance and inspection of these systems incredibly crucial, particularly when it comes to the ignition system itself.
Keep on reading to find out more about the electrical system of an aircraft, its ignition system, the problems that pilots can face with these systems, and how the ignition harness makes modern aviation possible.
AIRCRAFT IGNITION HARNESS
If you look under the hood of your car, you will notice a wiring system that goes all around the vehicle – from the front of the car to the end. All these wires are concealed within the design and chassis of the car, allowing the user to see only a clean and beautiful silhouette.
The electrical system within an aircraft is more or less the same, except that it is way more complex.
Take the ignition harness as an example. The aircraft ignition harness is a specialised assembly of wires designed to carry high-voltage sparks from the aircraft’s magnetos to the spark plugs in each cylinder.
A magneto is a machine that uses permanent magnets to generate current using wound-up copper wires. This current is generated and then transported through the ignition harness, which is just a bunch of wires tied together in a tight harness.
The harness plays a much bigger role than just transporting this current to the spark plugs; it also acts as a shielded distribution system that protects sensitive avionics from electromagnetic interference.
IGNITION HARNES SYSTEMS IN ACTION
The ignition harness is directly connected to the magnetos of the aircraft. There are two magnetos in most light aircraft, which are responsible for conducting electricity through magnet conduction. The harness carries the high-voltage spark (which can reach over 30kV!) from the magneto to the corresponding spark plugs for each cylinder.
This continuous firing of the spark plugs allows for a more complete and successful combustion, which enables a smoother performance and better engine efficiency.
While the current is being transferred, the harness also acts as a shield or a Faraday cage that contains and grounds stray electromagnetic fields generated by the ignition system. This not only protects the system from electromagnetic harm over time but also prevents interference with radios and avionics.
The ignition harness is designed to have a flexible core and is surrounded by robust shielding to allow it to withstand severe environmental stresses like heat, vibration, and even exposure to fluids. This ensures long service life and consistent performance – without fail!
It is important to note that these harnesses are custom-made for specific engine types and installed according to the part number and orientation labels. This is why they must be regularly inspected and replaced if they are worn or damaged.
COMMON PROBLEMS OF A FAILING HARNESS
How do you spot a problem in an electrical system that you can’t visually see from the cockpit? Well, you rely on the visual symptoms.
Just like the human body, if there is a problem in the central nervous system, the body will show symptoms which will prompt a checkup.
There are primarily two main symptoms of a failing harness:
-
Rough Running or “Bumps”
Bumps or misfires are common symptoms in cars and aircraft that hint towards a problem within the electrical system or engine. These are often caused by compromised insulation due to chafing or a hardened inner conductor. In this case, the sparks may stray to the engine structure instead of the plug, causing damage over time.
-
Intermittent Spark Issues
A single failing lead can cause intermittent ignition loss, which can cause problems in the engine over the life of the aircraft. This problem is difficult to detect for laypersons and requires professional monitoring. This issue can be so specific that engineers have traced rough runbacks to just one damaged ignition lead, which is enough to throw the engine out of sync.
CAN YOU TROUBLESHOOT IGNITION HARNESS ISSUES?
Although a professional inspection is your best bet, if you have just started to notice issues in your aircraft and suspect that it might be something to do with the electrical system, then there are a few troubleshooting tips.
The first thing you need to do is a visual inspection.
The key here is to look for ageing, hardening, kinks, or chafing. These problems are common culprits for issues, and while the system may look “fine” from a glance, the existence of these issues is enough to cause a problem in the harness.
We recommend that you look around the mounting points in the harness or where the harness contacts the engine parts and components, since that is where you are most likely to see issues.
The second thing to do is to replace suspected leads if necessary. While replacing just one lead may seem cost-effective, most aircraft engineers suggest that you replace the entire harness to avoid any possible problems while in the air.
Redundancy and extra safety precautions are a common mantra in aviation, and pilots must take these matters very seriously if they want to continue flying safely and efficiently.
Finally, pilots can also use a tester for deeper diagnostics.
A tester is a simple tool that confirms the presence of a current. Tools like the Power-To-Lite can test exciter output and lead performance. These tools can provide spark rate and energy metrics to pinpoint faults before they fail.
However, it is important to note that these tasks should not be DIYs. The best way to go about them is to opt for professional help from aircraft engineering services – such as the ones provided by comprehensive flight schools like Sherburn Aero Club.
WHAT IS THE REPLACEMENT WINDOW FOR IGNITION HARNESSES?
Flight ignition harness is not meant to be replaced frequently. In fact, they are designed to last a long time. Typical replacement window for the harness is about 1,000 to 1,200 flight hours or sooner if there are signs of damage or the symptoms discussed above. Most manufacturers recommend replacing harnesses if they show age-related hardening or are 12-15 years old, even if they haven’t accumulated the required flight hours criteria.
The aim isn’t to replace the system frequently but to continuously monitor it for problems so that you can get the most out of your aircraft. This is why pilots are recommended to follow scheduled maintenance cycles and inspect their aircraft regularly, especially at each annual or 100-hour inspection.
If there are issues in the system, the best way to keep track of them is to document the findings and replace harnesses proactively if they show age-related signs. Don’t wait for complete failure.
We recommend that pilots always use correct routing and secure every fastening to prevent chafing and keep an eye on manufacturer bulletins for reference during maintenance activities.
THE BENEFITS OF MAINTAINING THE IGNITION HARNESS AND MAINTENANCE
Aircraft maintenance is crucial to keep the aircraft running smoothly. Unlike car maintenance that you may put on the back burner, aircraft maintenance must be dealt with urgency.
The reason why aviation is one of the safest forms of travel is that the industry is built on strict regulations that involve several safety considerations. One of these considerations pertains to the maintenance of aircraft.
Every modern aircraft in existence has its own maintenance cycle that is provided by the manufacturer. This schedule enables the pilot to not only safely maintain the aircraft for the long term but also enables them to obtain and continuously renew the aircraft’s airworthiness.
The Airworthiness Review Certificate, for example, is only issued to aircraft that meet strict criteria, which involve submitting maintenance records and all relevant documents that show evidence of frequent maintenance. The Airworthiness Review Certificate not only helps provide peace of mind but is also legally required for pilots, especially pilots who wish to fly outside of the UK.
Here are four main reasons why you should regularly maintain your aircraft with a professional engineering team:
Maintain the Value of Your Aircraft
Not only does aircraft maintenance continuously enable pilots to fly in an airworthy aircraft, but it also plays a vital role in the overall market value of your asset as well.
As with everything in life, the more you take care of something, the more its perceived value is, even as it ages. Whether it's houses, cars, or aircraft, these assets are subject to the ravishes of time and depreciation. The only way to maintain their value is to continuously be on the lookout for wear and tear. This not only allows pilots to maintain value but also speaks volumes about their passion for aviation.
If you are a passionate enthusiast, then you will never have to worry about skipping maintenance activities. Most pilots cherish these moments with their aircraft on the ground, and being part of the maintenance activities provides a greater sense of pride and involvement.
Avoid Needless Delays
Grounding an aircraft due to problems is the worst feeling ever for pilots. Think about it. You put so much thought and effort into building the right flight plan and planning everything, only to have everything cancelled due to a problem in your aircraft.
Not only does it waste time, but it can also potentially cost you money, especially if you have pre-booked things for your trip. Pilots may also face problems rescheduling their trip due to either scheduling conflicts or just bad weather.
The good news is that most of these unforeseen issues can be managed if an aircraft is regularly serviced and maintained. By following the maintenance schedule of the aircraft, pilots can make sure that their aerial vehicle is in top condition and as ready to go as they are.
Sourcing the Right Team
Owning an aircraft is no walk in the park. It’s a serious financial investment and an important asset. So, why spend all that money only to ignore the small amounts that could go into preserving the long-term life of your asset?
As mentioned above, every pilot wants to maximise the aircraft’s resale value. The best way to do this is through regular maintenance by a professional team.
Your engineering team will become an important aspect of your aviation journey, especially if you solely own an aircraft. The team must be highly professional and ready to help you out with the smallest issues.
Great engineering teams are hard to find, especially if you are new to aviation; however, many comprehensive flight schools, like Sherburn, provide their own in-house engineering services. These engineering teams have the benefit of having a lot of experience since they regularly work on the fleet of aircraft for the school. With these professionals on your side, you can be sure to speed up diagnostics and fixes rather than having to wait for amateurs to break apart your aircraft for even the smallest problems.
Long-Term Savings
Maintenance activities may seem costly, but if you do the math, you will realise that it's much cheaper to have your aircraft inspected and maintained regularly than to wait for total failures to occur.
Not only is this dangerous, but it can also prove to be expensive over the long term. For example, a problem in the ignition harness that can be fixed with a simple inspection is much cheaper than the faulty system wreaking havoc on the engine itself, which can lead to considerable costs and ground time.
Sherburn Engineering
Here at Sherburn, we share our airfield with a dedicated engineering facility that specialises in fixed-wing aircraft. The facility ensures that the club’s fleet is functioning to the best of its ability and offers pre-buying inspections for pilots looking to purchase their own aircraft.
The facility helps keep the resale value of the aircraft up and ensures the airworthiness of the aircraft. Sherburn Engineering issues Airworthiness Review Certificates (ARC) as well.
Apart from maintaining the club’s own fleet, the engineering facility at Sherburn caters to private pilots who own their own light aircraft as well. The services also include CAA approvals, scheduled maintenance, as well as unscheduled maintenance.
Located conveniently on the premises of the club, the facility provides members with easy access to a world-class engineering facility as well as top-of-the-line certified maintenance engineers.
WHY CHOOSE SHERBURN AERO CLUB?
Sherburn Aero Club, which has been operational since 1964, is the ideal place for most of your training and flying needs. It is one of the largest flying clubs in the North of England and also one of the largest in the country.
If you wish to begin your career in aviation or wish to take to the skies as a hobby, Sherburn’s flight training school offers private and commercial licences, along with pilot medicals to ensure a smooth journey going forward.
With a large fleet of new aircraft and an airfield refurbishment with new runways, hangars, and an extended clubhouse, 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.
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.
In addition to that, if you are looking for a hangarage for your own aircraft, need servicing or repairs, want to buy a new aircraft or aviation equipment, or are just looking to enjoy and watch the aircraft, Sherburn Aero Club is the place to be.
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.
Call us on 01977 682 674, email us at flightdesk@sherburnaeroclub.com, or message us via our online contact form for more information on light aircraft maintenance as well as the club’s engineering facility.
