Aeronautical Information

The integrated package uses several products because permanent information, urgent short-notice changes and advisory material need different publication methods.

Electronic publication

The AIP, its amendments, supplements and AIC may be provided as an electronic AIP. The electronic form must remain controlled and suitable for screen display, printing and digital exchange. Electronic delivery changes the medium, not the authority or effective-date discipline.

The AIP is arranged so that the same kind of information appears in the same place. Its three principal parts are GEN, ENR and AD.

AIP India layout described by Bali

Bali describes AIP India as an English loose-leaf publication in two volumes. Volume I contains GEN and ENR. Volume II contains AD. A current-page checklist helps the user confirm that the publication is complete. Hand amendments are kept to a minimum because replacement sheets or controlled electronic revisions provide a clearer record.

Amendment service

Permanent changes are published as AIP amendments. Each amendment receives a consecutive serial number. An AIRAC amendment also displays its effective date. If no amendment will be issued at the established interval, a NIL notification is carried through the monthly plain-language list of valid NOTAM.

The correct product is chosen from the nature, duration, urgency and presentation needs of the information, not simply from whether the change is called temporary.

AIP amendment versus AIP supplement

If time does not permit distribution of a supplement, a NOTAM provides the immediate warning. When the supplement replaces that NOTAM it identifies the NOTAM serial. A checklist of valid AIP supplements is issued at intervals of not more than one month.

Aeronautical Information Circular

An AIC is used when information does not qualify for AIP inclusion or NOTAM. It may announce a long-term forecast of a major change in legislation, regulation, procedure or facilities; explain or advise on flight-safety matters; or cover technical, legislative and administrative subjects. It has a consecutive calendar-year serial, separate series may have letters, and a checklist of current AIC is issued at least annually. Bali records that DGCA publishes Indian AIC.

A NOTAM is a rapidly distributed notice about the establishment, condition or change of an aeronautical facility, service, procedure or hazard when timely knowledge is essential to flight operations.

New, replacement and cancellation

NOTAMN introduces new information. NOTAMR replaces an earlier NOTAM and carries a new number. NOTAMC cancels an earlier NOTAM. Each NOTAM deals with one subject and one condition of that subject. Its identifier uses a lettered series, a four-digit consecutive number, a stroke and the year.

When to originate one

Issue promptly for short-duration temporary information, or for an operationally significant permanent or long-duration temporary change made at short notice. Give at least seven days' advance notice for planned activation of established danger, restricted or prohibited areas and planned temporary airspace restrictions, except emergency operations. Where practicable, at least 24 hours is desirable for airspace planning. An outage notice should estimate its duration or expected restoration time.

What is normally excluded

Do not burden NOTAM with matters that do not affect safe operation, such as routine apron or taxiway maintenance that does not affect aircraft movement, marking work on a non-duty runway where operations remain safe, removable temporary obstructions, partial lighting failures without operational effect, known alternative communication frequencies, lack of apron marshalling, or other similarly minor local matters.

Control and distribution

A checklist of valid NOTAM is issued for each series at intervals of not more than one month over the aeronautical fixed service. It refers to the latest AIP amendments, AIP supplements and internationally distributed AIC. A monthly plain-language list of valid NOTAM is also prepared. The originator selects notices for international or selective distribution.

A NOTAM has a machine-sortable qualifier line and human-readable fields. Read both: the Q line helps systems select the message, while Item E states the operational information.

Q-code structure

The five-letter NOTAM code begins with Q. The next two letters identify the subject, and the final two identify the condition. The following qualifier groups say which traffic is affected, why the notice is selected, and whether its scope is aerodrome, en-route, navigation warning or a combination. Vertical limits use flight-level values in the qualifier line. The coordinate and radius define the geographic selection area.

Trigger NOTAM

When an AIRAC AIP amendment or AIRAC supplement is issued, a trigger NOTAM gives a brief description, effective date and publication reference. It comes into force on the same date and appears in the PIB as a reminder that an operationally significant change is about to take effect.

Aeronautical Information Regulation and Control, AIRAC, makes planned operationally significant changes effective everywhere on known common dates.

The timing rule

AIRAC effective dates occur every 28 days. Information is distributed at least 42 days before the effective date, with the objective that recipients receive it at least 28 days before it becomes effective. For major changes, 56 days' advance distribution should be used where desirable and practicable. Information should not be changed again for at least 28 days after the effective date unless the circumstance is temporary and will not persist for the full period.

Operational use

Before the effective date, crews must recognise that the current procedure remains controlling. On and after the date, charts, navigation databases, briefing material and operational documents must agree with the new state. A trigger NOTAM connects the publication to the briefing system.

Special-series messages use standard formats for hazards whose operational detail must be recognised quickly and consistently.

SNOWTAM and runway condition reporting

A SNOWTAM is a special-series NOTAM reporting the presence or cessation of hazardous conditions caused by snow, slush, ice, frost, standing water or water associated with those contaminants on the movement area. The aerodrome operator assesses each runway third and reports the Runway Condition Code, contaminant type, depth and coverage needed for aircraft performance calculations.

RWYCC 6 represents a dry runway. Codes reduce stepwise as braking capability worsens, with 0 representing less than poor. The code is an assessment, not a promise of stopping performance. Crews combine it with the aircraft manufacturer's performance data and current operational conditions.

ASHTAM

An ASHTAM reports an operationally significant change in volcanic activity, an eruption or an ash cloud. It identifies the volcano, location, alert level, eruption details, ash-cloud extent and movement, affected routes and flight levels, and the source of information. Its maximum validity is 24 hours, and a new ASHTAM is issued when the alert level changes.

AIS completes the information cycle by placing current data in the pre-flight briefing and by receiving defects and hazards reported after flight.

Pre-flight information and PIB

At an aerodrome normally used for international operations, information needed for safe, regular and efficient navigation over route stages originating there must be available to crews, operators and briefing services. It includes relevant elements of the integrated package, maps and charts. A PIB summarises current NOTAM and other urgent information in plain language for the planned route and time window.

Bali identifies pre-flight information availability at Kolkata, Chennai, Delhi and Mumbai. An Automatic Self Briefing System can receive, store and retrieve data for selected stations and routes. A briefing away from the aerodrome must still cover crew fitness, meteorology, fuel and alternates, aircraft performance and loading, route and navigation planning, NOTAM, operational documents, and emergency or contingency planning.

Post-flight information

After flight, crews should promptly report malfunction or unserviceability of visual and non-visual navigation aids and other facilities important to safety. Birds, wildlife and other hazards observed on or near an aerodrome must also be reported so the information can be evaluated and distributed.

Telecommunications and digital products

NOTAM offices connect to the aeronautical fixed service and to area control centres, flight information centres and aerodromes with an information service. Digital products include AIP data, terrain data, obstacle data, aerodrome mapping data and instrument flight procedure data sets.

WGS 84 and data quality

Published latitude and longitude are referenced to World Geodetic System 1984 so charted points, satellite positions and airborne databases share one geodetic datum. Relevant aerodrome entries also include elevation relative to mean sea level and geoid undulation where required. Data quality includes accuracy, the closeness to the true value; resolution, the smallest displayed or stored unit; integrity, protection against undetected alteration; completeness; timeliness; format; and traceability to the originator.