What is the Aeronautical Information Manual (AIM)?

Definition

The Aeronautical Information Manual (AIM) is the FAA’s official guide to basic flight information and ATC procedures in the US National Airspace System.

The FAA wrote it for the aviation community. It holds the fundamentals that a pilot needs to fly in US airspace. It also holds health and medical facts, factors that affect flight safety, a pilot and controller glossary, and information on safety, accident and hazard reporting.

This page covers the FAA manual. The aeronautical information page covers the data that States publish for air navigation, which is a different subject.

What the AIM is not

The AIM is not a regulation. The FAA’s Flight Information Publication Policy says that the publication is not regulatory. It gives examples of operating techniques and procedures. Other federal publications or regulations may make them requirements. It exists to help pilots meet the duties that those other publications set.

Three FAA publications play different roles.

• The Code of Federal Regulations (CFR) holds the regulatory requirements.
• Advisory circulars (AC) hold non-regulatory material. An AC does not bind the public unless a regulation incorporates it.
• The AIM holds basic flight information and ATC procedures. Its text points to the regulation where a rule applies. Paragraph 5-4-5 points to 14 CFR 91.175 for instrument approaches, for example.

An airport engineer reads the AIM for the pilot’s view of the airfield. The design values, such as spacing and intensity of lights, belong to design standards and not to the AIM.

What the chapters cover

The AIM has 12 chapters, numbered 0 to 11, and 5 appendices.

A paragraph number has three parts. They are the chapter, the section and the paragraph. Paragraph 2-1-4 is chapter 2, section 1, paragraph 4. It covers runway edge light systems.

Airport lighting in the AIM

Chapter 2, section 1 is titled Airport Lighting Aids. It describes each lighting system from the pilot’s side.

Runway edge lights and night operations

Paragraph 2-1-4 says that runway edge lights outline the edges of the runway in darkness or restricted visibility. It sets out four facts.

• The FAA classes the systems by the intensity that they can produce. The classes are high intensity (HIRL), medium intensity (MIRL) and low intensity (LIRL).
• HIRL and MIRL have variable intensity controls. LIRL normally has one setting.
• The lights are white. On an instrument runway, yellow replaces white on the last 610 m (2,000 ft) or half the runway length, whichever is less. This forms a caution zone for landings.
• The lights at the runway ends show red toward the runway. They show green outward from the end, to mark the threshold for landing aircraft.

The paragraph gives no spacing or intensity values. The runway edge light page covers those values, the fixtures and the inspection, against EASA, ICAO and FAA rules.

In-runway lighting

Paragraph 2-1-5 adds three runway lighting systems for low visibility.

• Centreline lights stand at 15 m (50 ft) intervals. They are white until the last 914 m (3,000 ft). They then alternate white and red for 610 m (2,000 ft). The last 305 m (1,000 ft) shows red only.
• Touchdown zone lights are two rows of white transverse light bars. They start 30 m (100 ft) beyond the threshold. They end 914 m (3,000 ft) beyond it, or at the runway midpoint, whichever is less.
• Land and hold short lights are a row of pulsing white lights across the runway at the hold short point. They are on whenever land and hold short operations are in effect.

Who switches the lights

The control tower controls the approach light systems and the runway lighting. At some places the flight service station controls them where no tower is in operation (2-1-7). Pilots may ask for the lights on or off. The runway edge lights, in-pavement lights and approach lights have intensity controls that the controller sets to meet the request.

At selected airports a pilot keys the aircraft microphone to control the lights by radio (2-1-8). All radio-controlled lighting at one airport uses the same frequency.

How the AIM relates to other publications

• The AIP. The Aeronautical Information Publication is the international version of the AIM. It contains parallel information and specific information on the international airports. See Aeronautical Information Publication .
• The Chart Supplement. The AIM is complemented by separate publications. The Chart Supplement U.S. holds data on airports, communications, navigation aids, instrument landing systems, VOR receiver check points, preferred routes and special notices.
• Instrument approach charts. AIM paragraph 5-4-5 explains the instrument approach procedure charts.

Updates

The FAA publishes the AIM as a basic manual and then as changes. The schedule in the October 2023 edition lists effective dates from 20 April 2023 to 9 July 2026. Each date follows the previous one by 24 weeks. The sequence is a basic manual, then Change 1, Change 2 and Change 3, and then a new basic manual.

The online AIM shows Change 3, effective 9 July 2026. The FAA posts the manual by its effective date on the Air Traffic Plans and Publications website. It also sends email notices to subscribers when a change appears. Each organisation is responsible for viewing, downloading and subscribing.

The AIM and drone work at airports

Chapter 11 covers unmanned aircraft systems. Paragraph 11-1-2 covers a UAS under 55 pounds (about 25 kg) maximum gross takeoff weight. It may generally fly in visual line of sight up to 400 feet (122 m) above ground level in Class G airspace. In controlled airspace the operator needs an authorisation from ATC.

A Part 107 operator can ask for an airspace authorisation through LAANC or DroneZone. This applies to flights in Class B, Class C or Class D airspace. It also applies to the surface area of Class E airspace that is designated for an airport. The UAS facility map gives the maximum altitude that ATC can approve without further coordination.

These rules apply to US airspace only.

What it means on an airfield

An airfield lighting system serves pilots who read the AIM. A pilot expects the colours, the caution zone, the intensity steps and the radio control that paragraphs 2-1-1 to 2-1-10 describe. An inspection checks that the lights match the design standard. The AIM tells the inspector what the pilot sees at night.

TarmacView’s runway edge lights inspection flies the rows by drone. It measures each unit.