Regulations of interest
The FARs have tens of thousands of separate sections, many used by large numbers of researchers on any given day. A few of the regulations particularly relevant to laypersons, to political issues, or of historical interest are listed here.
Part 1
Many other FARs depend on definitions, which are found in Part 1.1[4]
Part 21
This part prescribes:
- (1) Procedural requirements for issuing and changing:
- (i) Design approvals;
- (ii) Production approvals;
- (iii) Airworthiness certificates;
- (iv) Airworthiness approvals;
- (2) Rules governing applicants for, and holders of, any approval or certificate specified above
- (3) Procedural requirements for the approval of articles.
Part 23
Part 23 contains airworthiness standards required for issuance and change of type certificates for airplanes in these categories :[5]
- nine or less passengers, 12,500 pounds or less MTOW :
- normal : nonacrobatic operation (bank angle < 60°);
- utility : limited acrobatic operation (60° < bank angle < 90°);
- acrobatic : no restrictions
- commuter category: multiengine airplanes, 19 or less passengers, 19,000 pounds or less MTOW, nonacrobatic operation (bank angle < 60°).
In 2016 the FAA proposed a new system of performance-based airworthiness standards instead of prescriptive design requirements. The familiar weight and propulsion classifications of small airplane regulations would be replaced by performance and risk-based standards for aircraft weighing less than 19,000 pounds and seating 19 or fewer passengers.[6] On August 30, 2017, a revised Part 23 ruling went into effect, changing the aircraft classifications. The new passenger classifications are: Level 1, seating for 0 to 1 passenger; Level 2, 2 to 6; Level 3, 7 to 9; Level 4, 10 to 19. Speed classifications are: low speed, Vc or Vmo equal to or less than 250 knots CAS and equal to or less than Mmo 0.6 Mach; high speed, Vc or Vmo greater than 250 knots CAS and Mmo greater than 0.6 Mach.[7]
Prior to August 30, 2017, Part 23 had a large number of regulations to ensure airworthiness in areas such as structural loads, airframe, performance, stability, controllability, and safety mechanisms, how the seats must be constructed, oxygen and air pressurization systems, fire prevention, escape hatches, flight management procedures, flight control communications, emergency landing procedures, and other limitations, as well as testing of all the systems of the aircraft.
It also determined special aspects of aircraft performance such as stall speed (e.g., for single engine airplanes – not more than 61 knots), rate of climb (not less than 300 ft/min), take-off speed (not less than 1.2 x VS1), and weight of each pilot and passenger (170 lb for airplanes in the normal and commuter categories, and 190 lb for airplanes in the acrobatic and utility categories).
The Cessna 177, Cirrus SR20 and Piper PA-34 Seneca are well-known airplanes types that were certified to standards set out in FAR Part 23.
Most of the Federal Aviation Regulations, including Part 23, commenced on February 1, 1965. Prior to that date, airworthiness standards for airplanes in the normal, utility and acrobatic categories were promulgated in Part 3 of the US Civil Air Regulations. Many well-known types of light airplane, like the Cessna 150 and Piper Cherokee are certified to these older standards, even though they remained in production after 1965.
Part 25
This part contains airworthiness standards for airplanes in the transport category. The Boeing 737 and later types, and Airbus A300 series, are well-known airplane types that were certified according to standards set out in FAR Part 25. Transport category airplanes are either:
- Jets with 10 or more seats or a maximum takeoff weight (MTOW) greater than 12,500 pounds (5,670 kg); or
- Propeller-driven airplanes with greater than 19 seats or a MTOW greater than 19,000 pounds (8,618 kg).
This Part is organized into six subparts, to specify design criteria for each of
- A - General
- B - Flight
- C - Structure
- D - Design and Construction
- E - Powerplant
- F - Equipment
For example, Part 25, Subpart D has section headings for
- General
- Control Surfaces
- Control Systems
- Landing Gear
- Floats and Hulls
- Personnel and Cargo Accommodations
- Emergency Provisions
- Ventilation and Heating
- Pressurization
- Fire Protection
- Miscellaneous
Most of the Federal Aviation Regulations, including Part 25, commenced on February 1, 1965. Prior to that date, airworthiness standards for airplanes in the transport category were promulgated in Part 4b of the US Civil Air Regulations which was in effect by November 1945. Effective August 27, 1957, Special Civil Air Regulation (SR) 422 was the basis for certification of the first turbine-powered transport airplanes, such as the Boeing 707, the Lockheed Electra, and the Fairchild 27. SR 422A became effective July 2, 1958, and was superseded by SR 422B, effective August 29, 1959. Only a few airplanes were certified under SR 422A, such as the Gulfstream I and the CL-44. First generation turbine-powered transport category airplanes such as the DC-8, DC-9, and B-727, were originally certified under SR 422B. SR 422B was recodified with minor changes to 14 CFR part 25, which became effective February 1965.[8]
Part 27
This part contains airworthiness standards for rotorcraft in the normal category. Rotorcraft up to 7,000 lb Maximum takeoff weight and 9 or fewer passengers are type certified in this part.
Examples of rotorcraft certified in this part are the Robinson R44, Schweizer 300 and the Bell 429.
Part 29
This part contains airworthiness standards for rotorcraft in the transport category. Rotorcraft with more than 7,000 lb (3,200 kg) maximum takeoff weight and 10 or more passengers are type certified in this part. Rotorcraft with more than 20,000 lb (9,100 kg) maximum takeoff weight must be certified to additional Category A standards defined in this part.
Part 91
Part 91 defines a Part 91 Operator.[9] These are the regulations that define the operation of small non-commercial aircraft within the United States, however, many other countries defer to these rules. These rules set conditions, such as weather, under which the aircraft may operate.[10]
Section 91.3(b)
This regulation states that the pilot-in-command is the party directly responsible for, and is the final authority as to, an aircraft being operated.
Additionally, this regulation states that in an emergency requiring immediate action, the pilot-in-command may deviate from any regulation contained within Part 91 to the extent required to handle the emergency.
Temporary flight restrictions
The pertinent sections of the FAR (14 CFR Sections 91.137, 91.138, 91.139, 91.141, 91.143, 91.145, 99.7)[11][12] describe temporary flight restrictions (TFR). A TFR is a geographically-limited, short-term, airspace restriction, typically in the United States. Temporary flight restrictions often encompass major sporting events, natural disaster areas, air shows, space launches, and Presidential movements. Before the September 11, 2001 attacks, most TFRs were in the interest of safety to flying aircraft with occasional small restrictions for Presidential movements. Since 9/11, TFRs have been routinely used to restrict airspace for 30 nautical miles around the President, with a 10-nautical-mile (18.5 km) radius no-fly zone for non-scheduled flights. They are also available to other high-profile figures such as presidential and vice-presidential candidates (though not all do so, as Senator John Kerry, who did not ask for any TFR during the 2004 election).[13]
TFRs are deeply unpopular with pilots in the general aviation sector. Presidential TFRs are nearly 70 miles in diameter, and frequently close off not only the airport Air Force One is using but nearby airports as well. Others, including the Transportation Security Administration, argue that they are necessary for national security.[14] TFRs can also be instituted for special military operations, such as with the 2023 Chinese balloon incident, where the FAA put into place one of the largest airspace restrictions in U.S. history, with an area approximately twice the size of Massachusetts and more than five times the restricted airspace surrounding Washington, D.C.[15]
The responsibility for screening requests for TFR and for subsequent granting or denying them, lies with the FAA's Office of System Operations Security.[16]
Two-way radio communications failure
Section 91.185 of the Federal Aviation Restrictions deals with loss of radio communications while in flight. If a loss of radio communications were to be encountered during VFR conditions, or if VFR conditions are encountered after loss of communication with the ground and other aircraft, the pilot of the aircraft shall continue the flight under VFR and land as soon as practicable. If, however, the failure occurs in IFR conditions and/or the VFR conditions are not forthcoming, the pilot should continue under the following conditions:
- Route – The pilot will follow:
- The route assigned in the last contact with ATC before loss of communication, or, if being radar vectored, continue direct to the radar fix specified in the vector clearance;
- In the absence of an assigned route, the pilot will follow the route advised by ATC;
- In the absence of an ATC assigned or advised route, the pilot will follow the route set down in the flight plan.
- Altitude – The pilot will continue at the highest of the following altitudes or flight levels:
- The altitude assigned in the last contact with ATC before loss of communication;
- The minimum altitude for IFR operations;
- The altitude advised by ATC to be expected in a further clearance.[17]
Part 121
Part 121 defines a Part 121 Operator. These are generally large airlines, regional air carriers, and all cargo operators.[18]
Part 135
Part 135 defines a Part 135 Operator. These regulations define on-demand, unscheduled air service for passengers or freight.[19]
