An easy way to remember what inspections are required for an aircraft to remain airworthy is to remember “A1TAPE”:
A - Annual Inspection (end of last day of month - must be signed by Inspection Authorization holder [aka "IA"])
1 - 100 Hour Inspection (if the airplane is for hire - must be signed by A&P)
T - Transponder (every 24 months)
A - Altimeter - (every 24 months)
P - Pitot/Static (every 24 months)
E - ELT (every 12 months replace the battery OR if 50% of battery has been used)
Additionally, all Airworthiness Directions (aka "AD's") must be complied with.
If an airplane is being used for hire, an inspection is required every 100 hours. If it turns out that the airplane is going to have its annual inspection before the airplane hits the 100 hour mark, that annual inspection will suffice and the airplane can reset its 100-hour timer after the annual is complete. This does NOT work in reverse. A 100 hour inspection does NOT take the place of an annual.
The 100-hour inspection may be exceeded by no more than 10 hours IF en route to the place at which the 100 hour may be performed. However, this excess time must be included towards next 100 hour. For example, if the airplane reaches the inspection location at 106 hours since its last 100 hour, It will now need its next 100-hour inspection after only 94 hours.
So, what does "for hire" mean? A rental airplane used for non-commercial purposes is not for hire, and thus it does not require a 100-hour inspection. What about flight instruction?
You can follow a three-part test to decide if a 100 hour inspection is required during flight instruction:
Operation of aircraft after maintenance (even preventative), rebuild, or alteration is prohibited unless:
The owner/operator of the airplane is responsible for maintaining aircraft airworthiness. The “operator” is the person who will use, cause to use, or authorize to use aircraft for the purpose of air navigation including the piloting of the aircraft, with or without the right of legal control (as owner, lessee, or otherwise). The Pilot in Command is responsible for making sure the aircraft is airworthy after inspections or repairs and before every flight
The following must be kept until work is superseded by other work, or for one year after work is performed:
The following records must be retained and transferred with aircraft when it is sold:
Preventative Maintenance is considered that which does not alter the weight, CG, or flight controls and does not require tampering with key components (prop, struts, etc.). Private Pilot or higher may perform this kind of maintenance if the airplane is not used in air carrier service. This includes oil changes, wheel bearing lubrication, hydraulic fluid refills. A maintenance entry must be made in records and must include:
All installed equipment must be operational. If it is not, the aircraft is no longer airworthy and the broken equipment must be repaired OR removed or placarded.
Airworthiness Directives and SAIB’s
Airworthiness Directives (AD’s) are the FAA’s medium of communicating with pilots and maintenance personnel that there are unsafe conditions that may exist due to design defects, maintenance, or other. AD’s specify conditions under which the produce may continue to be operated. They are either emergency & require immediate compliance, or less urgent and are given longer time period to comply.
Special Airworthiness Information Bulletins (SAIB’s) are simply alerts that educate and recommend actions to aviators and people within the aviation community. They are not mandatory.
Special Flight Permits
Special Flight Permits are needed to fly an aircraft when the aircraft is otherwise unairworthy. It may be obtained through the the FSDO, or some air carriers employ authorized personnel who can issue them. Reasons for obtaining a SFP include:
This topic and other similar FAR-related topics can be kind of a dry grind when learning or reviewing them. You may want to check out this interactive course, which includes practical explanations, videos, and animations - all of which can help make this subject a little more interesting. Or, if you are studying for your biannual flight review, this Flight Review course bundle includes the FAR course as well as a few others that will cover all the topics that you need to study for a successful flight review. Good luck!