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AIM 

4/20/23

 

10

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Helicopter IFR Operations

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

Com-

mand 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.

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2. Helicopter Instrument Approaches

a.

Instrument flight procedures (IFPs) permit helicopter operations to heliports and runways during periods

of low ceilings and reduced visibility (e.g. approach/SID/STAR/en route). IFPs can be designed for both public
and private heliports using FAA instrument criteria. The FAA does recognize there are non

FAA service

providers with proprietary special criteria. Special IFPs are reviewed and approved by Flight Technologies and
Procedures Division and may have specified aircraft performance or equipment requirements, special crew