Here at JETechnology, we strive to increase safety at all levels of the aeronautical industry — for your technicians on the ground and passengers in the air. We know that having a reliable fleet means developing a bulletproof maintenance program and equipping your crew with the right tools. We supply quality maintenance stands that keep technicians safe and let them work on aircraft the right way.
We made this quick guide for our customers and those curious about aircraft maintenance as an overview of what goes into safe and thorough checks. We’ll cover the fundamentals of aircraft inspections and maintenance and how the pros keep a fleet in peak condition.
Types of Aircraft Inspections
For many fleet managers, an aircraft's maintenance schedule revolves around the inspection standards set in Title 14 of the Code of Federal Regulations — 14 CFR. You might also hear these regulations sometimes referred to as the FARs.
As according to 14 CFR, there are three primary types of inspections:
1. Annual Inspections
These routine inspections apply to most aircraft, except those with a valid progressive inspection plan, special flight permit, experimental certificate or provisional airworthiness certification. The inspection must be signed off by a mechanic with an inspection authorization, or IA.
If your aircraft is outside of the prescribed annual inspection period, but you need to transfer it to another facility, you may be able to get a ‘ferry permit.’ These permits allow you to move your aircraft outside of the inspection period legally. Contact your local Flight Standards District Office (FSDO) for application instructions.
2. 100-Hour Inspections
The FAA requires 100-hour inspections for any aircraft that carry passengers for hire, other than the crew members. For example, if a student uses an instructor's aircraft for training, that aircraft would be subject to the 100-hour definition. On the other hand, if a student provides their aircraft and brings an instructor along, that aircraft would not be subject to the rule. You can find 100-hour inspection checklist in 14 CFR Part 91.
If an aircraft has surpassed the 100-hour mark but needs to transfer to another maintenance facility where mechanics can perform an inspection, there is a ten-hour grace period in which the transfer is legal. However, the excess time it takes to complete the transfer counts toward the next 100 hours.
3. Progressive Inspections
A progressive inspection is only available for select applicants — you must apply to the Flight Standards District Office with a maintenance plan and the appropriate documentation. With this type of inspection, you designate the aircraft maintenance schedule and adhere to all manufacturer standards.
With a progressive inspection program, checks of aircraft components happen at fixed intervals. And for each check, you're responsible for what your maintenance plan specifies for inspection.
Progressive inspection programs are often the choice of owners of high-usage aircraft fleets like those for corporate uses and flight schools. These programs help to minimize downtime, as aircraft are out of service for a shorter period. If your plane would normally require a 100-hour inspection, for example, you could divide it into four phases instead. That would mean an inspection every 25 hours that would cover a portion of the 100-hour. At the end of the four-phase cycle, the 100-hour inspection would be complete.
Progressive maintenance plans are non-transferrable if you sell or buy an aircraft. The new owner must go through the application process for approval of a progressive maintenance plan themselves. Also, the new maintenance plan will have to be endorsed by the FSDO within a year or the last completed maintenance cycle of the previous owner.
One of the last types of inspections a plane goes through before it can fly is the preflight inspection. Every pilot must make this final check to ensure the general integrity of their aircraft. Here’s a brief overview:
1. Cabin Inspection
First, check that you have the required paperwork. The acronym ARROW can help you remember the five documents you need to bring:
- Airworthiness Certificate
- Registration Certificate
- Radio Station License (only required for operations outside the U.S.)
- Operating Handbook
- Weight and Balance Data
Legally, these documents and certificates must be inside the aircraft, and the airworthiness certificate needs to be on display where passengers can see it.
- Make sure the cockpit switches and valve toggles are in the right position.
- Switch the battery on and record fuel gauge readings — to compare to your visual inspection later.
- Turn off the battery and make sure the magnetos are off.
- Clean the cockpit of all trash and any unsecured tools and make sure your seatbelts aren’t fraying or loose.
- If your plane has fuses, find the location and number of spares.
2. Exterior Inspection
All pilots should do a walk-around of their aircraft before a flight — even if it was recently serviced and approved, it is always a good idea to double check all components. Pre-flight inspections ensure nothing is damaged or overlooked.
Here’s what to check:
- Look for loose rivets, bolts, nuts and safety-wired devices and any residue around these items.
- Check brake pads and discs for thickness and look for rust and grooves.
- Check tires for wear and flats by rolling the plane forward and backward.
- Check oleo struts for proper inflation.
- Test rigged controls for free movement with no chafing — don’t forget to remove the control lock.
- Make sure control hinge fasteners are secure.
- Check the propeller for oil leaks, significant damage and loose blades.
- Inspect the engine — check oil levels and make sure air intakes are free of debris.
- Check the exhaust pipe — make sure it’s free of oil and black buildup.
- Fuel system — Check the fuel quantity and compare to cockpit gauges, look for correct octane color and debris and make sure fuel vents aren’t obstructed.
- Drain sumps and sample fuel — be sure fuel doesn’t keep dripping after.
- Clean your windows, inside and out.
- Review your aircraft's performance data and emergency procedures.
Once you complete a thorough preflight inspection, you can take to the air with confidence.
Aircraft Inspection Checklist
Exactly what does the FAA require for 100-hour or annual inspections? Here are some of the common components technicians must inspect for routine aircraft checks:
Your team will need to review and test the altimeter as well as the static system and automatic altitude-reporting system. You can view the requirements for these inspections and how to check the components in 14 CFR Part 43 Appendix E.
Every 24 calendar months, or every other annual inspection, technicians will need to test and confirm the function of your transponder and look for data errors. Also, if one of your technicians installs a new transponder or modifies the existing one, it will require an official inspection before it’s legal to use.
3. Emergency Locator Transmitter
One essential aircraft maintenance requirement is your emergency locator transmitter, or ELT, which must undergo several tests to verify its signal strength. The ELT must be inspected within 12 calendar months after its last inspection. Testing requirements include battery corrosion, the function of controls, the crash sensor and signal strength. While this check doesn’t have to take place during your annual inspection, it’s a convenient time to do it since the aircraft is already out of use.
According to 14 CFR Part 43 Appendix D, the following are additional items that need to be checked during routine inspections and maintenance and what to look for:
4. Fuselage, Hull, Empennage, Wings
- Skin and Fabric — deterioration, failures and loose fittings
- Systems and Hardware — proper function, installation and integrity
5. Engine and Nacelle
- Engine — signs of leaking oil, fuel or hydraulic fluids, cylinder compression and debris on screens and sump drain plugs
- Dampeners — deterioration or damage
- Cowling — cracks or defects
- Exhaust — proper attachment and cracks or defects
- Studs and nuts — loose or missing
- Engine mount — cracks and loose mounting
- Hoses, lines and fittings — leaks or loose attachment
6. Cabin and Cockpit
- Seats and safety belts — sturdy attachments and signs of damage
- Windows — cracks, damage and proper sealing
- Loose tools and equipment — anything that may foul controls or mechanisms
- Instruments and controls — mounting, marks and function
- Batteries — charge capacity and proper mounting
7. Radio and Electronic Equipment
- General — function and proper mounting
- Bonding and shielding — condition and mounting
- Antennas — proper mounting, operation and condition
8. Propeller Assembly
- General — cracks, binding and excess oil
- Bolts — proper torque and safetying
- Anti-icing system — integrity and operation
- Control systems — function and mounting
9. Landing Gear
- Wheels — bearing function and cracks
- Tires — worn areas or cracking
- Brakes — proper adjustment and function
- Hydraulic lines — leakage
- Suspension — damage and fluid levels
- Linkages — wear and distortion
- Retracting mechanism — proper function
- Electrical — line wear and switch function
Types of Aircraft Maintenance
To keep up with the maintenance of the components above, fleet managers have a few different options to keep their aircraft well-serviced:
1. Preventative Maintenance
Preventative maintenance includes operations that don’t require complex disassembly or significant repairs. In other words, preventative maintenance means small tasks that a pilot or mechanic can do to keep an aircraft functioning properly on a day-to-day basis — tasks like replacing small hardware, cleaning, adding fluids or resealing. Under 14 CFR Part 61, someone who holds a pilot certificate may perform these types of maintenance on an aircraft as long as it isn't used to carry non-crew passengers. A mechanic certified by the FAA must complete more substantial forms of maintenance.
Other than maintenance defined as preventative, the FAA defines repairs as either major or minor, depending on their complexity and importance to critical systems. Both types must be completed by an FAA-approved mechanic, but with minor maintenance, the aircraft can return to the air with only the approval of the mechanic or repair facility. Major repairs must be inspected by a mechanic who holds an Inspection Authorization or is a representative of the FAA.
2. Progressive Maintenance
A progressive maintenance routine allows aircraft to undergo FAA and manufacturer inspections continually, as opposed to one all-encompassing check. This type of maintenance is useful for large fleets because aircraft can be strategically serviced at times that are more convenient for the owner of the fleet. A well-developed progressive maintenance plan keeps a large fleet in continuous operation with less downtime.
This type of maintenance is common for aircraft that are in constant use, such as passenger planes and flight instruction aircraft. Privately-owned planes that aren't in continuous use may not benefit from this type of maintenance plan, as it requires more frequent inspections and constant upkeep.
Fleet managers must establish a progressive maintenance program and receive FAA approval. To find the list of requirements for this type of plan, refer to 14 CFR Part 43.
If any repair or alteration to an aircraft could affect its flight characteristics, then the person responsible for approving the maintenance must decide if the plane is compromised. If so, it must be tested for in-flight safety before it can carry non-crew passengers, according to 14 CFR 91.407. A test pilot must check the in-flight performance and systems and record everything in the aircraft's logbook.
The FAA issues different certifications for aircraft depending on their purpose. The maintenance requirements for these different types of uses vary, so it’s crucial to know which one you're applying for and how to keep up with the right maintenance:
- Standard Airworthiness — The FAA approves applications for a standard airworthiness certificate if your registered aircraft complies with one of the following aircraft categories: normal, commuter, utility, transport or acrobatic. You must also maintain a condition that's safe for operation, as well as conduct preventative maintenance — any modifications you make to your aircraft must meet the requirements of 14 CFR Parts 21, 43 and 91.
- Special Airworthiness — The FAA issues special airworthiness certificates for primary, restricted, multiple, limited, experimental, provisional and special flight aircraft. To qualify for this certificate, your aircraft must meet several standards detailed in 14 CFR Part 21, 45, 48, 91 and 375, as well as policies that specify additional aircraft maintenance requirements.
Recordkeeping is a critical part of your aircraft maintenance routine. The FAA and EASA enforce several record-keeping standards, and mechanics must provide the following information:
- Description of Work — Everything the mechanic does must be recorded, whether it seems relevant or not. And if multiple mechanics work on the aircraft, each should log their work in detail.
- Date of Work — The includes the entire maintenance process if it spans several days, not just the completion date.
- Certificate Number and Type — Each mechanic has a certificate number and type that must be written in the aircraft logbooks along with the above information.
- Mechanic’s Signature — The mechanic responsible for the work must sign the entry in the aircraft logbook.
The above details are then accessible to regulatory agencies. It’s crucial for mechanics to be honest in all of their recordkeeping and be transparent and detailed. Leaving out key information or falsifying maintenance records can leave them at risk of losing their license.
To complete proper aircraft maintenance checks and requirements, your certified technicians and mechanics need the proper tools to inspect, maintain and approve your fleet. When your crew has the proper equipment, they can work with the precision needed to keep a fleet in top condition.
The most important part of any business is its employees. And we’re proud to say that our ground support equipment is the safest available. At JETechnology Solutions, we have more than 75 years of combined aeronautical engineering experience, and we’ve been increasing safety in the aircraft maintenance sector for years with our unparalleled equipment.
With more than seven decades of combined experience, JETechnology Solutions understands the necessity of routine aircraft maintenance checks, as well as the challenges that some aircraft can present to mechanics and technicians. That's why we do it all ourselves and never outsource. We deliver, design, engineer and manufacture aircraft maintenance equipment at our 12,000-square-foot facility in Orlando, FL, which will arrive at your location with a comprehensive warranty. We have a trusted network of shipping professionals who get your equipment to you quickly and safely.
We even offer on-site assistance for setup and instruction of our equipment, so your maintenance team can make a seamless transition.
Our customers keep coming back because we earn their business with nothing less than the best products and the best service. We've worked with every sector of the aviation industry, including the military, business and commercial airlines. No matter your ground support equipment challenge — we know how to help you solve it.
Learn more about our custom and American-made solutions by contacting us today to receive a free proposal or talk with one of our aircraft engineers.