Chapter 10. Helicopter Operations
Section 1. Helicopter IFR Operations
10-1-1. Helicopter Flight Control Systems
a. The certification requirements for helicopters to
operate under Instrument Flight Rules (IFR) are
contained in 14 CFR Part 27, Airworthiness
Standards: Normal Category Rotorcraft, and 14 CFR
Part 29, Airworthiness Standards: Transport
Category Rotorcraft. To meet these requirements,
helicopter manufacturers usually utilize a set of
stabilization and/or Automatic Flight Control
Systems (AFCSs).
b. Typically, these systems fall into the following
categories:
1. Aerodynamic surfaces, which impart some
stability or control capability not found in the basic
VFR configuration.
2. Trim systems, which provide a cyclic
centering effect. These systems typically involve a
magnetic brake/spring device, and may also be
controlled by a four-way switch on the cyclic. This
is a system that supports “hands on” flying of the
helicopter by the pilot.
3. Stability Augmentation Systems (SASs),
which provide short-term rate damping control
inputs to increase helicopter stability. Like trim
systems, SAS supports “hands on” flying.
4. Attitude Retention Systems (ATTs), which
return the helicopter to a selected attitude after a
disturbance. Changes in desired attitude can be
accomplished usually through a four-way “beep”
switch, or by actuating a “force trim” switch on the
cyclic, setting the attitude manually, and releasing.
Attitude retention may be a SAS function, or may be
the basic “hands off” autopilot function.
5. Autopilot Systems (APs), which provide for
“hands off” flight along specified lateral and vertical
paths, including heading, altitude, vertical speed,
navigation tracking, and approach. These systems
typically have a control panel for mode selection, and
system for indication of mode status. Autopilots may
or may not be installed with an associated Flight
Director System (FD). Autopilots typically control
the helicopter about the roll and pitch axes (cyclic
control) but may also include yaw axis (pedal control)
and collective control servos.
6. FDs, which provide visual guidance to the
pilot to fly specific selected lateral and vertical modes
of operation. The visual guidance is typically
provided as either a “dual cue” (commonly known as
a “cross-pointer”) or “single cue” (commonly known
as a “vee-bar”) presentation superimposed over the
attitude indicator. Some FDs also include a collective
cue. The pilot manipulates the helicopter's controls to
satisfy these commands, yielding the desired flight
path, or may couple the flight director to the autopilot
to perform automatic flight along the desired flight
path. Typically, flight director mode control and
indication is shared with the autopilot.
c. In order to be certificated for IFR operation, a
specific helicopter may require the use of one or more
of these systems, in any combination.
d. In many cases, helicopters are certificated for
IFR operations with either one or two pilots. Certain
equipment is required to be installed and functional
for two pilot operations, and typically, additional
equipment is required for single pilot operation.
These requirements are usually described in the
limitations section of the Rotorcraft Flight Manual
(RFM).
e. In addition, the RFM also typically defines
systems and functions that are required to be in
operation or engaged for IFR flight in either the single
or two pilot configuration. Often, particularly in two
pilot operation, this level of augmentation is less than
the full capability of the installed systems. Likewise,
single pilot operation may require a higher level of
augmentation.
f. The RFM also identifies other specific limitations associated with IFR flight. Typically, these
limitations include, but are not limited to:
1. Minimum equipment required for IFR flight
(in some cases, for both single pilot and two pilot
operations).
2. Vmini (minimum speed - IFR).
NOTE-
The manufacturer may also recommend a minimum IFR
airspeed during instrument approach.
3. Vnei (never exceed speed - IFR).
4. Maximum approach angle.
5. Weight and center of gravity limits.
6. Aircraft configuration limitations (such as
aircraft door positions and external loads).
7. Aircraft system limitations (generators,
inverters, etc.).
8. System testing requirements (many avionics
and AFCS/AP/FD systems incorporate a self-test
feature).
9. Pilot action requirements (such as the pilot
must have his/her hands and feet on the controls
during certain operations, such as during instrument
approach below certain altitudes).
g. It is very important that pilots be familiar with
the IFR requirements for their particular helicopter.
Within the same make, model and series of helicopter,
variations in the installed avionics may change the
required equipment or the level of augmentation for
a particular operation.
h. During flight operations, pilots must be aware
of the mode of operation of the augmentation
systems, and the control logic and functions
employed. For example, during an ILS approach
using a particular system in the three-cue mode
(lateral, vertical and collective cues), the flight
director collective cue responds to glideslope
deviation, while the horizontal bar of the “cross-pointer” responds to airspeed deviations. The same
system, while flying an ILS in the two-cue mode,
provides for the horizontal bar to respond to
glideslope deviations. This concern is particularly
significant when operating using two pilots. Pilots
should have an established set of procedures and
responsibilities for the control of flight director/autopilot modes for the various phases of flight. Not only
does a full understanding of the system modes
provide for a higher degree of accuracy in control of
the helicopter, it is the basis for crew identification of
a faulty system.
i. Relief from the prohibition to takeoff with any
inoperative instruments or equipment may be
provided through a Minimum Equipment List (see
14 CFR Section 91.213 and 14 CFR Section 135.179,
Inoperative Instruments and Equipment). In many
cases, a helicopter configured for single pilot IFR
may depart IFR with certain equipment inoperative,
provided a crew of two pilots is used. Pilots are
cautioned to ensure the pilot-in-command and
second-in-command meet the requirements of
14 CFR Section 61.58, Pilot-in-Command Proficiency Check: Operation of Aircraft Requiring More
Than One Pilot Flight Crewmember, and 14 CFR
Section 61.55, Second-in-Command Qualifications,
or 14 CFR Part 135, Operating Requirements:
Commuter and On-Demand Operations, Subpart E,
Flight Crewmember Requirements, and Subpart G,
Crewmember Testing Requirements, as appropriate.
j. Experience has shown that modern AFCS/AP/FD equipment installed in IFR helicopters can, in
some cases, be very complex. This complexity
requires the pilot(s) to obtain and maintain a high
level of knowledge of system operation, limitations,
failure indications and reversionary modes. In some
cases, this may only be reliably accomplished
through formal training.
10-1-2. Helicopter Instrument Approaches
a. Helicopters are capable of flying any published
14 CFR Part 97, Standard Instrument Approach
Procedures (SIAPs), for which they are properly
equipped, subject to the following limitations and
conditions:
1. Helicopters flying conventional (non-Copter) SIAPs may reduce the visibility minima to
not less than one half the published Category A
landing visibility minima, or 1/4 statute mile
visibility/1200 RVR, whichever is greater unless the
procedure is annotated with “Visibility Reduction
by Helicopters NA.” This annotation means that
there are penetrations of the final approach obstacle
identification surface (OIS) and that the 14 CFR
Section 97.3 visibility reduction rule does not apply
and you must take precaution to avoid any obstacles
in the visual segment. No reduction in MDA/DA is
permitted. The helicopter may initiate the final
approach segment at speeds up to the upper limit of
the highest approach category authorized by the
procedure, but must be slowed to no more than
90 KIAS at the missed approach point (MAP) in
order to apply the visibility reduction. Pilots are
cautioned that such a decelerating approach may
make early identification of wind shear on the
approach path difficult or impossible. If required, use
the Inoperative Components and Visual Aids Table
provided in the front cover of the U.S. Terminal
Procedures Volume to derive the Category A minima
before applying the 14 CFR Section 97.3(d-1) rule.
2. Helicopters flying Copter SIAPs may use the
published minima, with no reductions allowed. The
maximum airspeed is 90 KIAS on any segment of the
approach or missed approach.
3. Helicopters flying GPS Copter SIAPs must
limit airspeed to 90 KIAS or less when flying any
segment of the procedure, except speeds must be
limited to no more than 70 KIAS on the final and
missed approach segments. Military GPS Copter
SIAPs are limited to no more than 90 KIAS
throughout the procedure. If annotated, holding may
also be limited to no more than 70 KIAS. Use the
published minima, no reductions allowed.
NOTE-
Obstruction clearance surfaces are based on the aircraft
speed and have been designed on these approaches for
70 knots. If the helicopter is flown at higher speeds, it may
fly outside of protected airspace. Some helicopters have a
VMINI greater than 70 knots; therefore, they cannot meet
the 70 knot limitation to conduct this type of procedure.
Some helicopter autopilots, when used in the “go-around”
mode, are programmed with a VYI greater than 70 knots,
therefore when using the autopilot “go-around” mode,
they cannot meet the 70 knot limitation to conduct this type
of approach. It may be possible to use the autopilot for the
missed approach in the other than the “go-around” mode
and meet the 70 knot limitation to conduct this type of
approach. When operating at speeds other than VYI or VY,
performance data may not be available in the RFM to
predict compliance with climb gradient requirements.
Pilots may use observed performance in similar
weight/altitude/temperature/speed conditions to evaluate
the suitability of performance. Pilots are cautioned to
monitor climb performance to ensure compliance with
procedure requirements.
4. TBL 10-1-1 summarizes these requirements.
5. Even with weather conditions reported at or
above landing minima, some combinations of
reduced cockpit cutoff angle, minimal approach/runway lighting, and high MDA/DH coupled with a
low visibility minima, the pilot may not be able to
identify the required visual reference(s) during the
approach, or those references may only be visible in
a very small portion of the pilot's available field of
view. Even if identified by the pilot, these visual
references may not support normal maneuvering and
normal rates of descent to landing. The effect of such
a combination may be exacerbated by other
conditions such as rain on the windshield, or
incomplete windshield defogging coverage.
6. Pilots are cautioned to be prepared to execute
a missed approach even though weather conditions
may be reported at or above landing minima.
NOTE-
See paragraph 5-4-21, Missed Approach, for
additional information on missed approach procedures.
TBL 10-1-1
Helicopter Use of Standard Instrument Approach Procedures
Procedure
|
Helicopter Visibility
Minima
|
Helicopter MDA/DA
|
Maximum Speed Limitations
|
Conventional
(non-Copter)
|
The greater of: one half
the Category A visibility
minima, 1/4 statute mile
visibility, or 1200 RVR
|
As published for
Category A
|
The helicopter may initiate the final
approach segment at speeds up to
the upper limit of the highest
Approach Category authorized by
the procedure, but must be slowed
to no more than 90 KIAS at the
MAP in order to apply the visibility
reduction.
|
Copter Procedure
|
As published
|
As published
|
90 KIAS when on a published
route/track.
|
GPS Copter Procedure
|
As published
|
As published
|
90 KIAS when on a published route
or track, EXCEPT 70 KIAS when
on the final approach or missed
approach segment and, if annotated,
in holding. Military procedures are
limited to 90 KIAS for all segments.
|
NOTE-
Several factors effect the ability of the pilot to acquire and
maintain the visual references specified in 14 CFR
Section 91.175(c), even in cases where the flight visibility
may be at the minimum derived by TBL 10-1-1. These
factors include, but are not limited to:
1. Cockpit cutoff angle (the angle at which the cockpit or
other airframe structure limits downward visibility below
the horizon).
2. Combinations of high MDA/DH and low visibility
minimum, such as a conventional nonprecision approach
with a reduced helicopter visibility minima (per 14 CFR
Section 97.3).
3. Type, configuration, and intensity of approach and
runway lighting systems.
4. Type of obscuring phenomenon and/or windshield
contamination.
10-1-3. Helicopter Approach Procedures
to VFR Heliports
a. Helicopter approaches may be developed for
heliports that do not meet the design standards for an
IFR heliport. The majority of IFR approaches to VFR
heliports are developed in support of helicopter
emergency medical services (HEMS) operators.
These approaches can be developed from conventional NAVAIDs or a RNAV system (including GPS).
They are developed either as a Special Approach
(pilot training is required for special procedures due
to their unique characteristics) or a public approach
(no special training required). These instrument
procedures are developed as either an approach
designed to a specific landing site, or an approach
designed to a point-in-space.
1. Approach to a specific landing site. The
approach is aligned to a missed approach point from
which a landing can be accomplished with a
maximum course change of 30 degrees. The visual
segment from the MAP to the landing site is evaluated
for obstacle hazards. These procedures are annotated:
“PROCEED VISUALLY FROM (NAMED MAP)
OR CONDUCT THE SPECIFIED MISSED
APPROACH.”
(a) This phrase requires the pilot to either
acquire and maintain visual contact with the landing
site at or prior to the MAP, or execute a missed
approach. The visibility minimum is based on the
distance from the MAP to the landing site, among
other factors.
(b) The pilot is required to maintain the
published minimum visibility throughout the visual
segment.
(c) Similar to an approach to a runway, the
missed approach segment protection is not provided
between the MAP and the landing site, and obstacle
or terrain avoidance from the MAP to the landing site
is the responsibility of the pilot.
(d) Upon reaching the MAP defined on the
approach procedure, or as soon as practicable after
reaching the MAP, the pilot advises ATC whether
proceeding visually and canceling IFR or complying
with the missed approach instructions. See paragraph 5-1-15, Canceling IFR Flight Plan.
(e) At least one of the following visual
references must be visible or identifiable before the
pilot may proceed visually:
(1) FATO or FATO lights.
(2) TLOF or TLOF lights.
(3) Heliport Instrument Lighting System
(HILS).
(4) Heliport Approach Lighting System
(HALS) or lead-in lights.
(5) Visual Glideslope Indicator (VGSI).
(6) Windsock or windsock light(s). See
note below.
(7) Heliport beacon. See note below.
(8) Other facilities or systems approved by
the Flight Technologies and Procedures Division
(AFS-400).
NOTE-
Windsock lights and heliport beacons should be located
within 500 ft of the TLOF.
2. Approach to a Point-in-Space (PinS). At
locations where the MAP is located more than 2 SM
from the landing site, or the path from the MAP to the
landing site is populated with obstructions which
require avoidance actions or requires turns greater
than 30 degrees, a PinS procedure may be developed.
These approaches are annotated “PROCEED VFR
FROM (NAMED MAP) OR CONDUCT THE
SPECIFIED MISSED APPROACH.”
(a) These procedures require the pilot, at or
prior to the MAP, to determine if the published
minimum visibility, or the weather minimums
required by the operating rule, or operations
specifications (whichever is higher) is available to
safely transition from IFR to VFR flight. If not, the
pilot must execute a missed approach. For Part 135
operations, pilots may not begin the instrument
approach unless the latest weather report indicates
that the weather conditions are at or above the
authorized IFR minimums or the VFR weather
minimums (as required by the class of airspace,
operating rule and/or Operations Specifications)
whichever is higher.
(b) Visual contact with the landing site is not
required; however, the pilot must maintain the
appropriate VFR weather minimums throughout the
visual segment. The visibility is limited to no lower
than that published in the procedure, until canceling
IFR.
(c) IFR obstruction clearance areas are not
applied to the VFR segment between the MAP and
the landing site. Obstacle or terrain avoidance from
the MAP to the landing site is the responsibility of the
pilot.
(d) Upon reaching the MAP defined on the
approach procedure, or as soon as practicable after
reaching the MAP, the pilot advises ATC whether
proceeding VFR and canceling IFR, or complying
with the missed approach instructions. See paragraph 5-1-15, Canceling IFR Flight Plan.
(e) If the visual segment penetrates Class B,
C, or D airspace, pilots are responsible for obtaining
a Special VFR clearance, when required.
10-1-4. The Gulf of Mexico Grid System
a. On October 8, 1998, the Southwest Regional
Office of the FAA, with assistance from the
Helicopter Safety Advisory Conference (HSAC),
implemented the world's first Instrument Flight
Rules (IFR) Grid System in the Gulf of Mexico. This
navigational route structure is completely independent of ground-based navigation aids (NAVAIDs)
and was designed to facilitate helicopter IFR
operations to offshore destinations. The Grid System
is defined by over 300 offshore waypoints located 20
minutes apart (latitude and longitude). Flight plan
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 web
site 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.
NOTE-
The unique ADS-B architecture in the Gulf of Mexico
depends upon reception of an aircraft's Mode C in addition
to the other message elements described in 14 CFR 91.227.
Flight crews must be made aware that loss of Mode C also
means that ATC will not receive the aircraft's ADS-B
signal.
5. FAA/AeroNav publishes the grid system
waypoints on the IFR Gulf of Mexico Vertical Flight
Reference Chart. A commercial equivalent is also
available. The chart is updated annually and is
available from a FAA chart agent or FAA directly,
web site address:
http://www.faa.gov/air_traffic/flight_info/aeronav.
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