The concept of required inspection items (RII) has been around for a long time, primarily in the airline industry. However, the key elements that constitute an RII system are applicable at all levels of the maintenance industry. An RII item is specific inspection of any maintenance action that, if improperly done, could result in immediate danger to an aircraft. If you are rigging flight controls, installing a propeller, or performing another maintenance action that affects flight critical systems then it’s certain that they involve an RII.
RII is defined in Part 135.427 and Part 121.369 of the FARs. These rules pertain to having the RII program described in the operator’s manual. If you are a Part 91 operator with an aircraft having 10 or more passenger seats, then these rules will apply under provisions in Part 91.401(c). Fractional Owner operating under a Continuous Airworthiness Maintenance Program (CAMP) will find RII mentioned in Part 91.1427. An RII item is defined as: A designation of the items of maintenance and alteration that must be inspected (required inspections) including at least those that could result in a failure, malfunction, or defect endangering the safe operation of the aircraft, if not performed properly or if improper parts or materials are used.
These programs are common to air carriers, but many general aviation technicians and managers would find the concept useful to incorporate as a routine activity. The implementation of an RII program as a safety enhancement is useful for any maintenance operation and, by definition, reduces the risk of avoidable maintenance errors.
An RII program
RII by definition is a key maintenance safety concept. The key elements of RII include:
• A list of items that are designated as “Required Inspection Items.”
Prior to operation of a new aircraft type the operator’s management will assemble a list of items that they feel meets the definition of RII. It includes mostly the systems or subsystems broken out by ATA category. Windows, flight controls, landing gear, engines, and propellers are good examples of what make the list. In selecting these items consider the key elements of each system as a critical point of control. These elements are defined in the method described in RII procedures.
• The method of performing required inspections.
The manual should define the scope of the required inspection as well as list the items — often the RII listing includes the method of inspection required. There are many formats that have been accepted. The list can include methods that correspond to the applicable item. For example: “ATA 71, Engine change, installation and rigging;” or a more specific example: “ATA 61, Propeller installation, verify propeller nut is properly threaded, witness the torque, and record torque wrench serial number and calibration. Verify that nut is properly safe tied with .032 stainless safety wire.” The latter example provides a more effective and efficient method for assuring work is done properly.
• A designation by occupational title of personnel authorized to perform each required inspection. People have to be designated as RII qualified inspectors.
Both maintenance repair and overhaul (MRO) organizations and airlines have inspectors, but they cannot do RII unless they have been trained and authorized to accomplish required inspections. A quality inspection is not a required inspection. Remember the definition? In fact someone outside the quality unit of the organization can be designated as RII, if they have had training and meet the qualifications deemed necessary by the operator’s procedures. Once the quality unit authorizes that person, they may accomplish RII.
There are rules for RII performance that each authorized inspector must follow:
• An inspector may not accomplish a required inspection on his own work; including training someone on that work.