Detailed Guide FIRs and ETPs and Their Impact on Air Navigation

by Admin on October 13, 2022

It is important to thoroughly study ETP and FIR for a safe flight, and no detail should be overlooked. Listed in this article, you can find these procedures and formats, which are indispensable elements of aviation.

The flight time points (ETPs) and the flight information region (FIR) boundary information are both important elements of a flight planning and should be taken into consideration when reviewing a flight plan format. In the case of an emergency or flight diversion, a flight plan format should contain specific information and relevant calculations for ETPs, which are used when entering regions with limited landing options. As well as showing the air traffic control in a region, FIRs play an important role as well.

1. Equal Time Points (ETPs)

In case of an emergency, flight plans should contain specific information and calculations regarding emergency landing points (ETPs), which can be used when entering into regions with minimal landing options.

If a pilot needs to proceed to an airport as quickly as possible, Equal Time Points provide them with decision aids. ETPs are geographic locations along a flight route where returning to an airport behind an aircraft is equal to proceeding to an airport in front of it. The following three contingencies need to be considered when creating ETPs for each location:

  • Loss of Engine ETP: Drift down procedures and Loss of Engine ETP are usually used in the event of an engine loss.
  • Loss of Level ETP: The airplane may be required to use either Loss of Level ETP if the pressurization is lost or if another problem requires a rapid descent without an engine failure. In most flight planning programs, a rapid descent is computed to 10,000 or 15,000 feet, depending on the user’s preferences. The occupants of an airplane are not required to use supplemental oxygen during a descent to 10,000 feet. Flight crews must remain on supplemental oxygen with a descent to 15,000 feet, but passengers are able to breathe without assistance.
  • Maintain Level ETP: The airplane may be required to turn to either Maintain Level ETP or Drop to Level if it needs to land immediately without descending, such as in a medical emergency.


Plotting ETP’s

ETPs should be noted along the flight route if a plotting chart is needed. It will be easy to determine a course of action if a diversion decision is necessary with a perpendicular line pointing to the route and arrows pointing to the ETP airports.

An alternative method of identifying the ETP should be used in the absence of a plotting chart. It is usually sufficient to make a pencil mark on the enroute chart. Non-flight plan points can be displayed electronically on some FMS units for easy reference.

A Guide to Selecting ETP Airports

According to aircraft requirements, airport capabilities, and weather, suitable diversion airports should be identified for oceanic or remote flight routes. When operating under 14 CFR 135, an aircraft must be able to hold 1,500 feet above all obstacles and meet the weather requirements in order to be considered an alternate airport.

2. Flight Information Regions (FIRs)

The Flight Information Region (FIR) is the boundary between two air traffic control authorities. It is typically the upper region of this boundary that is referred to as a FIR. As some FIR regions can cover multiple countries, they should not be confused with political boundaries (countries).

FIRs are three-dimensional areas where aircraft are under control of one authority, according to the EUROCONTROL SASS-C Glossary. Each FIR is divided into several geographical regions called sectors. Upper flight information regions (UIRs) are sometimes combined with one or more FIRs.

Procedures for Detecting and Mitigating Errors in Flight Plans

If messages are not received, appropriate procedures must be followed to resolve the issue. In order to resolve that issue, duplicate or erroneous messages must be prevented from entering the system. ATC units should use the RQP message to request an unknown FPL if they receive a movement message for a movement that is in an unknown FPL rather than creating their own FPL.

To complete flight transference without creating a new FPL, LOAs between ANSPs should provide a clear and appropriate process for exchanging FPL messages via AFTN/AMHS. It is recommended that this practice be used when adjacent FIRs do not communicate via AIDC or on-line data interchange, and when the receiving ATC unit is not equipped with the FPL while verbal coordination is occurring between ATC units.


Regions of Global Flight Path

In each of the hundreds of FIRs spread throughout the world, the communication, navigation, and surveillance (CNS) and ATM environments differ. When aircraft cross these FIR boundaries, operational inconsistencies in separation standards and procedures, disparities in flight plan filing procedures, incompatibility between adjacent automation platforms, and inconsistent airspace structures can negatively impact safety and reduce efficiency.

Flight Plans and Movement Messages

Ensure that flight plans and associated messages are seamlessly and efficiently transmitted, processed, and transferred across FIR boundaries in order to facilitate seamless air traffic organization across FIR boundaries.

ANSPs should consider delegating full responsibility to the operators during the validation and operational phases to avoid confusion by having one single point of coordination to correct possible errors:

  • The movement messages and the associated FPL are originated and sent via AFTN/AMHS to all involved ATS units.
  • In accordance with ICAO’s Procedures for Air Navigation Services Air Traffic Management, distribute the involved movement messages to the relevant FIRs and units.

Surveillance to Non-Surveillance Boundaries in FIR

A transition from surveillance to non-surveillance world air route map may result in a significant increase in the longitudinal separation between a flight and the preceding one. The minimum longitudinal separation in non-surveillance airspace can increase from 5 miles to 120 miles, or 15 minutes.

When the transition between surveillance and non-surveillance airspace occurs at a FIR boundary, there is a significant increase in minimum separation standards because of the different ATM automation systems, the requirements for navigation performance (RNP)/RNAV, the airspace classification system, the airspace structure, and the communication systems.

iJET Air Control Operation and Service

IJET’s continuous and regular controls ensure a healthy and safe flight by minimizing all negative risks related to ETP and FIR. iJET combines a variety of flight planning so you can have a custom-tailored flight plan that meets your requirements wherever you are flying.

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