Cockpit avionics are a lot different now than when I started as a newly minted mechanic and pilot, more than 40 years ago. The most sophisticated avionics system that I experienced back then was a NavCom radio with a VOR Indicator.Back to Articles
It was a few years after my start in aviation when they came out with the latest and greatest navigation aid, the Apollo LORAN. Some of you may recall LORAN, but the only place to find these units today is in an aircraft that is on display at a museum.
It is common knowledge that flight crews like to improve the safety of flight with all the bells and whistles that do more than just look pretty. Head-Up Displays, infrared/thermo cameras, traffic, weather and ground avoidance systems, are now relatively common, with the Future Air Navigation System (FANS), Automatic Dependent Surveillance-Broadcast (ADS-B) being the latest technologies that will soon be a requirement in the cockpit to reduce human error and improve safety. But there is a price to pay to keep all this technology performing the way it was intended.
Cockpit avionics maintenance can become a costly challenge when you need to diagnose where a failure originated. There are Avionics Maintenance Programs that cover the repair of the aircraft electronics and some may include troubleshooting allowances. For an annual and/or hourly fee, these programs offer repairs and, if necessary, loaner units, and they can be a good cost-effective program for many operations. If you have no avionics repair needs, these programs may look expensive, but it does not take many equipment failures to make a program worthwhile over a period of time.
Today, most avionics boxes are exchanged with a loaner as long as the problem is isolated to the black box or instrument, but when it turns into wiring, circuit breakers, or some other component that provides information to the black box, it usually means extended hours of troubleshooting that may or may not be covered by a maintenance program and can become an expensive fix.
In the good old days, a technician could climb into the bowels of the aircraft with the trusty Volt/Ohm meter and perform minor tests. With today’s complex wiring, transistors, diodes and computers, the old troubleshooting methods do not even come close to adequate. Now it takes special training, sophisticated test equipment, laptops or tablets with special software that many shops may not have at their disposal. So troubleshooting labor hours can run into astronomical numbers, and budgeting for this can be a major challenge for the maintenance department.
For older equipment, there are still ‘Mom and Pop’ avionics shops across the country, but for newer, more complexly equipped aircraft, you need access to trained and knowledgeable technicians. Several of the large non-OEM-associated maintenance shops go through the extra expense to obtain repair authority and factory train their technicians. This allows them to provide in-house advanced avionics troubleshooting and repair.
Some of these shops also have remote locations and provide road service, if requested. When your selected shop sends technicians to a remote location, you should expect to pay for their travel cost, labor hours for the travel, and their expenses, but it can be well worth it to get the airplane back in the air.
Avionics repairs in remote areas of the world should be considered in your maintenance budget planning too. Consider the capabilities of the shops in the regions you plan to visit, and then consider worst-case scenarios. (This caution should be applied to all aspects of maintenance on these types of international or remote flights.)
Your passengers can live through a flight without movies or the internet functioning, but a failure of your HF radios below your minimum number can cause you to not only cancel the flight, but require both loaner units and technicians to be brought to your aircraft... Needless to say, it can be costly.
Thankfully, today’s sophisticated equipment is very reliable, with redundant systems along with a Minimum Equipment List (MEL) for your aircraft, so you can usually get the aircraft to a location that is qualified to work on your equipment. A problem can occur when a company has a MEL that is not specific for their aircraft.
Using the manufacturer’s MEL or a “Generic MEL” that can be obtained easily through the OEM or on the internet without a lot of expense is sufficient 90% of the time. If you have a Minimum Equipment List specifically designed for your aircraft with its current avionics, it should allow you to relocate to another location with facilities that have appropriate capabilities to make the repairs.
A well thought out and approved Minimum Inspection List is even more critical when you are operating in locations like Africa or Asia.
Avionics in today’s aircraft are the most reliable that I have seen in my aviation maintenance career. Gone are the days of a gyro tumbling or a needle sticking on the indicator glass. But troubleshooting any related failures on cockpit systems today is more complex, calling for qualified and experienced technicians to avoid any unexpected budget-breaking maintenance events.