400 feet/NM (standard)
200 feet/NM (standard)
20:1 OCS
40:1 OCS
During testing for helicopter holding, the optimum
airspeed and leg length combination was determined to
be 90 KIAS with a 3 NM outbound leg length. Consideration
was given to the wind drift on the dead reckoning entry
leg at slower speeds, the turn radius at faster airspeeds,
and the ability of the helicopter in strong wind conditions
to intercept the inbound course prior to the holding fix.
The published minimums are to be used with no visibility
reductions allowed. Figure 7-11 is an example of a Copter
GPS PinS approach that allows the helicopter to fly VFR
from the MAP to the heliport.
The final and missed approach protected airspace providing
obstacle and terrain avoidance is based on 70 KIAS, with
a maximum 10-knot tailwind component. It is absolutely
essential that pilots adhere to the 70 KIAS limitation
in procedures that include an immediate climbing
and turning missed approach. Exceeding the airspeed
restriction increases the turning radius significantly and
can cause the helicopter to leave the missed approach
protected airspace. This may result in controlled flight into
terrain (CFIT) or obstacles.
If a helicopter has a V MINI greater than 70 knots, then
it is not capable of conducting this type of approach.
Similarly, if the autopilot in “go-around” mode climbs at a
VYI greater than 70 knots, then that mode cannot be used.
It is the responsibility of the pilot to determine compliance
with missed approach climb gradient requirements
when operating at speeds other than V Y or V YI. Missed
approaches that specify an “IMMEDIATE CLIMBING TURN”
have no provision for a straight ahead climbing segment
before turning. A straight segment results in exceeding the
protected airspace limits.
Protected obstacle clearance areas and surfaces for the
missed approach are established on the assumption that
the missed approach is initiated at the DA point and for
non-precision approaches no lower than the MDA at the
MAP (normally at the threshold of the approach end of
the runway). The pilot must begin the missed approach at
those points. Flying beyond either point before beginning
the missed approach results in flying below the protected
obstacle clearance surface (OCS) and can result in a collision
with an obstacle.
The missed approach segment U.S. Standard for Terminal
Instrument Procedures (TERPS) criteria for all Copter
approaches take advantage of the helicopter’s climb
capabilities at slow airspeeds, resulting in high climb
gradients. [Figure 7-12] The OCS used to evaluate the
missed approach is a 20:1 inclined plane. This surface is
twice as steep for the helicopter as the OCS used to evaluate
the airplane missed approach segment. The helicopter
climb gradient is, therefore, required to be double that of
the airplane’s required missed approach climb gradient.
A minimum climb gradient of at least 400 ft/NM is required
unless a higher gradient is published on the approach
chart (e.g., a helicopter with a ground speed of 70 knots
is required to climb at a rate of 467 fpm (467 fpm = 70
KIAS × 400 feet per NM/60 seconds)). The advantage of
using the 20:1 OCS for the helicopter missed approach
20:1 versus 40:1 Obstacle clearance surface (OCS) for nonprecision missed approach procedures
MAP
96 feet/NM
48 feet/NM
The Copter 20:1 OCS provides for a lower MDA for the helicopter than for the airplane if the controlling
obstacle is in the missed approach area. A climb gradient of 400 feet/NM will allow a required
obstacle clearance (ROC) of 96 feet/NM for each NM of flightpath.
Figure 7-12. Obstacle clearance surface (OCS).
segment instead of the 40:1 OCS used for the airplane is
that obstacles that penetrate the 40:1 missed approach
segment may not have to be considered. The result is
the DA/MDA may be lower for helicopters than for other
aircraft. The minimum required climb gradient of 400 ft/
NM for the helicopter in a missed approach provides 96
feet of required obstacle clearance (ROC) for each NM of
flightpath.
Helicopter Approaches to VFR Heliports
Helicopter approaches to VFR heliports are normally
developed either as public procedures to a PinS that may
serve more than one heliport or as a special procedure to
a specific VFR heliport that requires pilot training due to its
unique characteristics. These approaches can be developed
using very high frequency omni-directional range (VOR)
or automatic direction finder (ADF), but area navigation
(RNAV) using GPS is the most common system used today.
RNAV using the WAAS offers the most advantages because
it can provide lower approach minimums, narrower route
widths to support a network of approaches, and may
allow the heliport to be used as an alternate. A majority
of the special procedures to a specific VFR heliport are
developed in support of HAA operators and have a “Proceed
Visually” segment between the MAP and the heliport.
Public procedures are developed as a PinS approach with a
“Proceed VFR” segment between the MAP and the landing
area. These PinS “Proceed VFR” procedures specify a course
and distance from the MAP to the available heliports in the
area.
Approach to a PinS
The note associated with these procedures is: “PROCEED
VFR FROM (NAMED MAP) OR CONDUCT THE SPECIFIED
MISSED APPROACH. ” They may be developed as a special
or public procedure where the MAP is located more than 2
SM from the landing site, the turn from the final approach
to the visual segment is greater than 30 degrees, or the VFR
segment from the MAP to the landing site has obstructions
that require pilot actions to avoid them. Figure 7-13 is an
example of a public PinS approach that allows the pilot to
fly to one of four heliports after reaching the MAP .
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 or VFR
minimums as required by the class of airspace, operating rule
and/or OpSpecs, whichever is higher. Visual contact with the
landing site is not required; however, prior to the MAP , for
either Part 91 or 135 operators, the pilot must determine if
the flight visibility meets the basic VFR minimums required
by the class of airspace, operating rule and/or OpSpecs
(whichever is higher). The visibility is limited to no lower
than that published in the procedure until canceling IFR. If
VFR minimums do not exist, then the published MAP must
be executed. The pilot must contact air traffic control (ATC)
upon reaching the MAP , or as soon as practical after that, and
advise whether executing the missed approach or canceling
IFR and proceeding VFR.
To proceed VFR in uncontrolled airspace, Part 135 operators
must observe minimum regulatory VFR conditions, but
under some conditions, such as provided for in 14 CFR
135.613 for HAA operators, specific weather minimums are
required when near the MAP and the heliport of intended
landing. These minimums apply regardless of whether the
approach is located on the plains of Oklahoma or in the
Colorado mountains. However, for heliports located farther
than 3 NM from the heliport, Part135 HAA operators are
held to an even higher standard and the minimums and
lighting conditions contained in Figure 7-15 apply to the
entire route. Mountainous terrain at night with low light
conditions requires a ceiling of 1,000 feet and either 3 SM or
5 SM visibility depending on whether it has been determined
as part of the operator’s local flying area.
In Class B, C, D, and E surface area airspace, a SVFR clearance
may be obtained if SVFR minimums exist. On your flight plan,
give ATC a heads up about your intentions by entering the
following in the remarks section: “Request SVFR clearance
after the MAP . ”
Approach to a Specific VFR Heliport
The note associated with these procedures is: “PROCEED
VISUALLY FROM (NAMED MAP) OR CONDUCT THE
SPECIFIED MISSED APPROACH. ” Due to their unique
characteristics, these approaches require training. They
are developed for hospitals, oil rigs, private heliports, etc.
As Specials, they require Flight Standards approval by a
Letter of Authorization (LOA) for Part 91 operators or by
OpSpecs for Part 135 operators. For public procedures, the
heliport associated with these procedures must be located
within 2 SM of the MAP , the visual segment between the
MAP and the heliport evaluated for obstacle hazards,
and the heliport must meet the appropriate VFR heliport
recommendations of AC 150/5390-2, Heliport Design.
The PinS optimum location is 0.65 NM from the heliport.
This provides an adequate distance to decelerate and land
from an approach speed of 70 KIAS. Certain airframes may
be certified to fly at reduced V MINI or below V MINI speeds
as a result of flight control design or adherence to AC
29-2, Certification of Transport Category Rotorcraft. In
these cases, an approach procedure stating the minimum
Figure 7-13. COPTER RNAV (GPS) 250° at New York/La Guardia Airport.
Point-in-Space Approach Examples
Under Part 91, the operator flies the published IFR PinS approach procedure that has a charted MDA of 340 mean sea level (MSL)
and visibility of ¾ SM. When approaching the MAP at an altitude of 340 feet MSL, the pilot transitions from Instrument Meteorological
Conditions (IMC) to Visual Meteorological Conditions (VMC) and determines that the flight visibility is ½ SM. The pilot must determine
prior to the MAP whether the applicable basic VFR weather minimums can be maintained from the MAP to the heliport or execute a
missed approach. If the pilot determines that the applicable basic VFR weather minimums can be maintained to the heliport, the pilot
may proceed VFR. If the visual segment is in Class B, C, D, or the surface area of Class E airspace, it may require the pilot to obtain
a Special VFR clearance.
For an operator to proceed VFR under Part 135, a minimum visibility of ½ SM during the day and 1 SM at night with a minimum
ceiling of 300 feet. If prior to commencing the approach, the pilot determines the reported visibility is ¾ SM during the day, the pilot
descends IMC to an altitude no lower than the MDA and transitions to VMC. If the pilot determines prior to the MAP that the flight
visibility is less than ½ SM in the visual segment, a missed approach must be executed at the MAP.
EXAMPLE 1
EXAMPLE 2
Figure 7-15. Point-in-space (PinS) approach examples for Part 91 and Part 135 operations.
certified airspeed or flight below VMINI should be annotated
on the approach procedure. The distance also permits
optimal blending of obstacle clearance criteria with non-
instrument heliport approach areas.
The visibility minimum is based on the distance from the
MAP to the heliport, among other factors (e.g., height
above the heliport elevation when at the MAP MDA). The
pilot is required to acquire and maintain visual contact
with the heliport final approach and takeoff (FATO) area
at or prior to the MAP . Obstacle or terrain avoidance from
the MAP to the heliport is the responsibility of the pilot.
Pilots need to level off when reaching the MDA, which
may occur before arriving at the MAP , until reaching the
visual approach angle on the approach path to clear the
obstacles. If the required weather minimums do not exist,
then the published MAP must be executed at the MAP
because IFR obstruction clearance areas are not applied to
the visual segment of the approach and a missed approach
segment protection is not provided between the MAP
and the heliport. As soon as practicable after reaching
the MAP , the pilot advises ATC whether cancelling IFR and
proceeding visually or executing the missed approach.
Inadvertent IMC
Whether it is a corporate or HAA operation, helicopter pilots
sometimes operate in challenging weather conditions. An
encounter with weather that does not permit continued
flight under VFR might occur when conditions do not allow
for the visual determination of a usable horizon (e.g., fog,
snow showers, or night operations over unlit surfaces such
as water). Flight in conditions of limited visual contrast
should be avoided since this can result in a loss of horizontal
or surface reference, and obstacles such as wires become
perceptually invisible. To prevent spatial disorientation, loss
of control (LOC) or CFIT, pilots should slow the helicopter to a
speed that provides a controlled deceleration in the distance
equal to the forward visibility. The pilot should look for terrain
that provides sufficient contrast to either continue the flight
or to make a precautionary landing. If spatial disorientation
occurs and a climb into IMC is not feasible due to fuel state,
icing conditions, equipment, etc., make every effort to land
the helicopter with a slight forward descent to prevent any
sideward or rearward motion.
All helicopter pilots should receive training on avoidance
and recovery from inadvertent IMC with emphasis on
avoidance. An unplanned transition from VMC to IMC flight
is an emergency that involves a different set of pilot actions.
It requires the use of different navigation and operational
procedures, interaction with ATC, and crewmember resource
management (CRM). Consideration should be given to the
local flying area’s terrain, airspace, air traffic facilities, weather
(including seasonal affects such as icing and thunderstorms),
and available airfield/heliport approaches.
Training should emphasize the identification of
circumstances conducive to inadvertent IMC and a
strategy to abandon continued VFR flight in deteriorating
conditions. This strategy should include a minimum
altitude/airspeed combination that provides for an off
airport/heliport landing, diverting to better conditions,
or initiating an emergency transition to IFR. Pilots should
be able to readily identify the minimum initial altitude
and course in order to avoid CFIT. Current IFR en route
and approach charts for the route of flight are essential.
A GPS navigation receiver with a moving map provides
exceptional situational awareness for terrain and obstacle
avoidance.
Training for an emergency transition to IFR should
include full and partial panel instrument flight, unusual
attitude recovery, ATC communications, and instrument
approaches. If an ILS is available and the helicopter is
equipped, an ILS approach should be made. Otherwise, if
the helicopter is equipped with an IFR approach-capable
GPS receiver with a current database, a GPS approach
should be made. If neither, an ILS or GPS procedure is
available use another instrument approach.
Upon entering inadvertent IMC, priority must be given
to control of the helicopter. Keep it simple and take one
action at a time.
• Control. First use the wings on the attitude indicator
to level the helicopter. Maintain heading and
increase to climb power. Establish climb airspeed
at the best angle of climb but no slower than VMINI.
• Climb. Climb straight ahead until your crosscheck is
established. Then make a turn only to avoid terrain
or objects. If an altitude has not been previously
established with ATC to climb to for inadvertent IMC,
then you should climb to an altitude that is at least
1,000 feet above the highest known object and that
allows for contacting ATC.
• Communicate. Attempt to contact ATC as soon as
the helicopter is stabilized in the climb and headed
away from danger. If the appropriate frequency is
not known, you should attempt to contact ATC on
either very high frequency (VHF) 121.5 or ultra high
frequency (UHF) 243.0. Initial information provided
to ATC should be your approximate location, that
inadvertent IMC has been encountered and an
emergency climb has been made, your altitude,
amount of flight time remaining (fuel state), and
number of persons on board. You should then
request a vector to either VFR weather conditions
or to the nearest suitable airport/heliport that
conditions will support a successful approach. If
unable to contact ATC and a transponder code
has not been previously established with ATC for
inadvertent IMC, change the transponder code to
7700.
A radio altimeter is a necessity for alerting the pilot
when inadvertently going below the minimum altitude.
Barometric altimeters are subject to inaccuracies that
become important in helicopter IFR operations, especially
in cold temperatures.
IFR Heliports
AC 150/5390-2, Heliport Design, provides recommendations
for heliport design to support non-precision, approach with
vertical guidance (APV), and precision approaches to a
heliport. When a heliport does not meet the criteria of AC
150/5390-2, FAA Order 8260.42, United States Standard
for Helicopter Area Navigation (RNAV), requires that an
instrument approach be published as a Special procedure
with annotations that special aircrew qualifications are
required to fly the procedure. Currently, there are no
operational civil IFR heliports in the U.S., although the U.S.
military has some non-precision and precision approach
procedures to IFR heliports.