Helicopter Instrument Approaches — AIM 10-1-2 Explained

AIM Text

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 training, airport facility equipment, waivers from published standards, proprietary criteria and restricted access. Special IFPs are not published in the Federal Register or printed in government Flight Information Publications.

Helicopters are capable of flying any published IFPs, for which they are properly equipped, subject to the following limitations and conditions:

Helicopters flying conventional (i.e. non-Copter) IAPs may reduce the visibility minima to not less than one-half the published Category A landing visibility minima, or ¹/₄statute 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 at any time. 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 inside the front cover of the U.S. Terminal Procedures Publication to derive the Category A minima before applying the 14 CFR section 97.3 rule.
Helicopters flying Copter IAPs should use the published minima, with no reductions allowed. Unless otherwise specified on the instrument procedure chart, 90 KIAS is the maximum speed on the approach.
Pilots flying Area Navigation (RNAV) Copter IAPs should also limit their speed to 90 KIAS unless otherwise specified on the instrument procedure chart. The final and missed approach segment speeds must be limited to no more than 70 KIAS unless otherwise charted. Military RNAV Copter IAPs are limited to no more than 90 KIAS throughout the procedure. Use the published minima; no reductions allowed.

NOTE-

Obstruction clearance surfaces are based on the aircraft speed identified on the approach chart and have been designed on RNAV approaches for 70 knots unless otherwise indicated. If the helicopter is flown at higher speeds, it may fly outside of protected airspace. Some helicopters have a V_MINIgreater than 70 knots; therefore, they cannot meet the 70 knot limitation to conduct these RNAV approaches. Some helicopter autopilots, when used in the “go-around" mode, are programmed with a V_YIgreater than 70 knots. Therefore, those helicopters when using the autopilot “go-around" mode, cannot meet the 70 knot limitation for the RNAV approach. It may be possible to use the autopilot for the missed approach in other than the “go-around" mode and meet the 70 knot limitation. When operating at speeds other than V_YIor V_Y, 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.

NOTE-

V_MINI- Instrument flight minimum speed, utilized in complying with minimum limit speed requirements for instrument flight
V_{YI -}Instrument climb speed, utilized instead of V_Yfor compliance with the climb requirements for instrument flight
V_{Y -}Speed for best rate of climb
TBL 10-1-1 summarizes these requirements.
Even with weather conditions reported at or above minimums, under some combinations of reduced cockpit cutoff angle, 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), or those references may only be visible in a very small portion of the available field of view. Even if identified by the pilot, the 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.

Pilots should always be prepared to execute a missed approach even though weather conditions may be reported at or above minimums.

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 maximum when on a published route/track.
RNAV (GPS) Copter Procedure	As published	As published	The maximum speed for a Copter approach will be 90 KIAS or as published on the chart. Note: Higher approach angles may require a lower approach speed and aircraft V_MINI. Military procedures are limited to 90 KIAS for all segments.

Source: FAA Aeronautical Information Manual · current edition · paragraph 10-1-2.

The short answer

This AIM section is FAA advisory guidance on how helicopters fly published instrument approaches. Flying conventional non-Copter IAPs, a helicopter may cut Category A visibility to half, but not below 1/4 statute mile or 1200 RVR, and must slow to 90 KIAS at the MAP. It supports 14 CFR 97.3 and 91.175.

Research Notes

Common Questions

How much can a helicopter reduce approach visibility minimums?

On conventional non-Copter IAPs a helicopter may reduce visibility to not less than one-half the published Category A landing minima, or 1/4 statute mile / 1200 RVR, whichever is greater. This guidance does not apply where the chart is annotated "Visibility Reduction by Helicopters NA," and no reduction in MDA/DA is ever permitted.

What is the maximum speed on an RNAV Copter approach?

The AIM advises limiting RNAV (GPS) Copter IAPs to 90 KIAS unless otherwise charted, with final and missed approach segments held to no more than 70 KIAS unless otherwise charted. Obstruction clearance surfaces are designed for 70 knots; flying faster may take the aircraft outside protected airspace. Military RNAV Copter IAPs are limited to 90 KIAS throughout.

Why might a helicopter not be able to use the 70-knot RNAV Copter approach?

Some helicopters have a VMINI greater than 70 knots and cannot meet the limitation. Some autopilots in "go-around" mode use a VYI greater than 70 knots, so they cannot meet it either, though the missed approach may be flyable in another mode. The AIM cautions pilots to monitor climb performance for compliance.

10-1-2. Helicopter Instrument Approaches