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AIM 

4/20/23

 

10

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6

Helicopter IFR Operations

routes are routinely defined by just 4 segments: departure point (lat/long), first en route grid waypoint, last en
route grid waypoint prior to approach procedure, and destination point (lat/long). There are over 4,000 possible
offshore landing sites. Upon reaching the waypoint prior to the destination, the pilot may execute an Offshore
Standard Approach Procedure (OSAP), a Helicopter En Route Descent Areas (HEDA) approach, or an Airborne
Radar Approach (ARA). For more information on these helicopter instrument procedures, refer to FAA AC
90

80B, Approval of Offshore Standard Approach Procedures, Airborne Radar Approaches, and Helicopter En

Route Descent Areas, on the FAA website http://www.faa.gov

 

under Advisory Circulars.

 

The return flight plan

is just the reverse with the requested stand

alone GPS approach contained in the remarks section.

1.

The large number (over 300) of waypoints in the grid system makes it difficult to assign phonetically

pronounceable names to the waypoints that would be meaningful to pilots and controllers. A unique naming
system was adopted that enables pilots and controllers to derive the fix position from the name. The five

letter

names are derived as follows:

(a)

The waypoints are divided into sets of 3 columns each. A three

letter identifier, identifying a

geographical area or a NAVAID to the north, represents each set.

(b)

Each column in a set is named after its position, i.e., left (L), center (C), and right (R).

(c)

The rows of the grid are named alphabetically from north to south, starting with A for the northern

most row.

EXAMPLE

LCHRC would be pronounced “Lake Charles Romeo Charlie.” The waypoint is in the right

hand column of the Lake

Charles VOR set, in row C (third south from the northern most row).

2.

In December 2009, significant improvements to the Gulf of Mexico grid system were realized with the

introduction of ATC separation services using ADS

B. In cooperation with the oil and gas services industry,

HSAC and Helicopter Association International (HAI), the FAA installed an infrastructure of ADS

B ground

stations, weather stations (AWOS) and VHF remote communication outlets (RCO) throughout a large area of
the Gulf of Mexico. This infrastructure allows the FAA’s Houston ARTCC to provide “domestic

like” air traffic

control service in the offshore area beyond 12nm from the coastline to hundreds of miles offshore to aircraft
equipped with ADS

B. Properly equipped aircraft can now be authorized to receive more direct routing,

domestic en route separation minima and real time flight following. Operators who do not have authorization
to receive ATC separation services using ADS

B, will continue to use the low altitude grid system and receive

procedural separation from Houston ARTCC. Non

ADS

B equipped aircraft also benefit from improved VHF

communication and expanded weather information coverage.

3.

Three requirements must be met for operators to file IFR flight plans utilizing the grid:

(a)

The helicopter must be equipped for IFR operations and equipped with IFR approved GPS

navigational units.

(b)

The operator must obtain prior written approval from the appropriate Flight Standards District Office

through a Letter of Authorization or Operations Specification, as appropriate.

(c)

The operator must be a signatory to the Houston ARTCC Letter of Agreement.

4.

Operators who wish to benefit from ADS

B based ATC separation services must meet the following

additional requirements:

(a)

The Operator’s installed ADS

B Out equipment must meet the performance requirements of one of

the following FAA Technical Standard Orders (TSO), or later revisions: TSO

C154c, Universal Access

Transceiver (UAT) Automatic Dependent Surveillance

Broadcast (ADS

B) Equipment, or TSO

C166b,

Extended Squitter Automatic Dependent Surveillance

Broadcast (ADS

B) and Traffic Information.

(b)

Flight crews must comply with the procedures prescribed in the Houston ARTCC Letter of

Agreement dated December 17, 2009, or later.