What the FAA Expects to Maintain a Public Aircraft Drone Operation

A friend at the FAA forwarded me a document that applies to all public safety drone operations that fly under a COA as a public aircraft operation.

While the guidance was issued a while ago, it is the guidance specifically related to public aircraft operations and that sucks in drones.

Unless someone can find an FAA exemption for Public Aircraft Operations of drones from AC 91-91 the searching I did found that it applies to all COA and PAO drone operations.

In fact, AC 00-1.1B specifically states unmanned aircraft are subject to public aircraft statutes if used in a public aircraft capacity.

Let me hit the highlights of AC 91-91 for you to save you reading time.

Who Does This Apply To?

Title 49 of the United States Code (49 U.S.C.) § 40102(a)(41) states that a public aircraft is (1) an aircraft used only by the United States (U.S.) government, or (2) an aircraft owned or operated by the government of a state, the District of Columbia, or a territory or possession of the United States, or a political subdivision of one of these governments.

The FAA enhances safety through certification of aircraft per Title 14 of the Code of Federal Regulations (14 CFR) part 21, and we encourage public aircraft operators to obtain appropriate airworthiness certification. An operator makes an airworthiness certificate effective when the operator complies with all terms and conditions of the certificate. This advisory circular (AC) provides guidance that government entities can use if they choose to maintain their aircraft per 14 CFR regulations.

This AC applies to any person/owner/operator-known here as “operator”-who engages in the operation and maintenance of public aircraft as part of a governmental function.

Responsibility for Airworthiness

Title 14 CFR part 91 states that the owner/operator of a civil aircraft is primarily responsible for maintaining that aircraft in an airworthy condition, including compliance with FAA Airworthiness Directives (AD). We recommend that public aircraft operators use one of the inspection or maintenance programs specified in part 91, § 91.409, as described in chapter 2 and subsequent paragraphs. The safety benefits gained from following the regulations are derived from structured procedures for performing maintenance that will ensure the continued airworthiness of an aircraft. The economic benefit comes from the structured program itself, where expenditures can be planned in the most cost effective manner. This includes maintenance planning, obtaining replacement parts, and scheduling the aircraft for maintenance at repair facilities. Regardless of regulatory requirements, safety is paramount and you will enhance the safety of your operations by following the regulations.

Inspection Program Recommendations

The aircraft inspection program should contain at least the following:

  1. The instructions and procedures to conduct the inspection.
  2. Necessary tests and checks.
  3. Inspection items and areas of the airframe, engines, propellers, appliances, and emergency equipment.
  4. A schedule for the inspections in terms of time in service of aircraft, engines, parts (life-limited parts), calendar time, number of airplane and engine cycles, or any combination of these.
  5. Additional program content, such as:
    • Special inspections for hard or overweight landings, turbulent air, extended out of service inspection, etc.;
    • System for controlling life-limited parts;
    • AD compliance control;
    • System for recordkeeping, and
    • Creation, approval, and recording of program revisions.

Aircraft Maintenance

Types of Maintenance

Aircraft maintenance generally applies to the maintenance, preventive maintenance, and alterations, including inspections associated with specific products (i.e., airframes, engines, propellers, and appliances). Operators may tailor one of the programs described above for their particular use, depending on the environment and usage rates of the aircraft. By using one of these programs, operators will ensure the safety and continued airworthiness of the aircraft.

Approved Maintenance Personnel

If a public aircraft operator (PAO) is operating an aircraft that has an airworthiness certificate, it should be maintained by an FAA certificated personal or repair station and the maintenance and/or inspection must be documented IAW part 43 or 145.

If a PAO aircraft with an airworthiness certificate is not maintained IAW part 43, it cannot operate under civil use until all maintenance is documented and returned to service by a FAA certificated personal or repair station.

If the PAO is operating an aircraft that does not have an airworthiness certificate, then it does not have to be maintained by an FAA-certificated personal or repair station or meet the documentation requirements of parts 43 or 145. The requirements of part 43 do not restrict an FAA-certificated personal or repair station from maintaining a public aircraft that do not have an airworthiness certificate.

Scheduled and Unscheduled Maintenance

The maintenance performed may be scheduled or unscheduled maintenance.

Scheduled maintenance consists of maintenance tasks performed according to a maintenance schedule, and should include procedural instructions for the maintenance task and a method of recording the results of inspection checks, tests, and other maintenance. Operators may use the aircraft manufacturer’s job/task cards or develop their own. These should include procedural instructions for accomplishing maintenance and inspection tasks. Operators may also develop and use non-routine item job cards to document discrepancies found when performing maintenance and inspection tasks.

Unscheduled maintenance includes procedures, instructions, and standards for maintenance performed because of unscheduled or unforeseen circumstances. A need for unscheduled maintenance may result from scheduled maintenance tasks, pilot reports, or unforeseen events such as hard or overweight landings, or ground damage.

Airworthiness Limitations

Airworthiness Limitations (AL). Operators can locate mandatory inspections, replacement times and other maintenance specified in the Airworthiness Limitation Section (ALS) of a manufacturer’s maintenance manual or ICA. For aircraft TC’d prior to January 28, 1981, the ALs were contained in an FAA-approved section of the AMM. Not all aircraft have ALs. An aircraft manufacturer’s inspection program should contain the ALs for that aircraft. Owner/operators of public aircraft are encouraged to comply with the aircraft’s ALs if they have them.

Aircraft Records

Recordkeeping. Title 14 CFR part 91 provides record keeping requirements for civil aircraft operators. Public aircraft owner/operators, while not required, are also encouraged to keep aircraft records. The information in this AC can be used as a guide to establishing a recordkeeping system. Aircraft records provide continuity of maintenance on an aircraft. The records can be used to plan future maintenance as well as show completion of past maintenance and to what criteria that maintenance was performed. Records allow the owner/operator to ensure that proper data and procedures are used in maintaining the aircraft and to identify the person performing the maintenance. In addition, records allow owner/operators to track and identify components that are repaired or replaced and if an AD is issued, to determine applicability of that AD to their aircraft. For public aircraft, a recordkeeping system similar to that of a civil aircraft will facilitate transfer from public to civil operations and back. It should also provide for a seamless transfer of ownership from public to civil operators if the aircraft records are kept in a format similar to a civil aircraft operation. Maintenance records may be kept in any format that provides record continuity, includes required content, lends itself to addition of new entries, and provides for signature entry. Aircraft records should contain at least the following:

  1. Record of maintenance for each aircraft, engine, propeller, rotor, and appliance of an aircraft. As a practical matter, many owner/operators find it advantageous to keep separate or individual records since it facilitates transfer of the record with the item when ownership changes.
  2. The maintenance record entry should include a description of the work performed. The description should be in sufficient detail to permit a person unfamiliar with the work to understand what was done, and the methods and procedures used in doing it. A reference to the technical data used such as manufacturer’s manuals, service letters, service bulletins, work orders, FAA ACs and other data, which accurately describe what was done, or how it was done, should be referenced.
  3. The maintenance record entry should contain the date the work was completed. This is normally the date upon which the work is approved for return to service.
  4. The maintenance record entry should include the signature and certificate number of the person approving the work for return to service.

NOTE: Prior to a PAO aircraft being returned to civil operations a maintenance record entry is required for the completion of a conformity inspection, stating that all maintenance performed while under government contract meets all civil regulations. This record provides for a seamless transfer of ownership from public use to civil operation; a conformity inspection is required to ensure the aircraft meets all civil regulations.

Total Time in Service

The maintenance record entry should contain the total time in service for each airframe, engine, propeller, and appliance (as applicable). Time in service, with respect to maintenance records is that time from the moment an aircraft leaves the surface of the earth until it touches down at the next point of landing and is expressed in hours, cycles, or both.

Current Inspection Status of the Aircraft

The current inspection status of the aircraft means a record that contains at least the following information:

  1. The time in service since the last inspection required by the inspection program under which the aircraft is maintained.
  2. The time in service remaining until the next required inspection under which the aircraft is maintained.

Major Alterations and Major Repairs

A record of major alterations and repairs should be recorded in the aircraft maintenance records. These records should also be transferred when the aircraft is sold. The record may consist of FAA Form 337, which will contain the details of a repair or alteration. If an owner/operator is using an air carrier’s continuous airworthiness maintenance program to maintain the airplane, the air carrier’s internal documentation such as Engineering Orders, Repair Orders, and Repair Authorizations may be used to record the major repair or alteration.

Return to Service

This is a term that is used in civil aircraft operations when an aircraft is put back into service after maintenance, preventive maintenance or alterations are performed. Prior to aircraft return to service the owner/operator should prepare an appropriate entry in the aircraft log. Part 43 prescribes the rules governing the maintenance of aircraft having a U.S. Airworthiness Certificate and must be followed if the aircraft has a U.S. Airworthiness Certificate. The FAA recommends that public use owner/operators utilize those persons for return to service of their aircraft.