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· the OCH/OCL for the category
of aircraft
· minimum DH in the Flight
Manual (AFM), if any
· the minimum height without
visual reference
· 200 feet, or any State minima
Visual Reference
You cannot continue a precision
approach below a DH determined as
above, unless you have at least one
of these visual references (for the
intended runway) visible and
identifiable:
· elements of the approach or
runway lights
MDH(ft) Aeroplane Category and RVR(m )
A B C D
250–299 800 800 800 1200
300–449 900 1000 1000 1400
450–649 1000 1200 1200 1600
650 + 1200 1400 1400 1800
Operational Procedures 67
· the threshold or touchdown
zone, their markings or lights
· visual glideslope indicator(s)
Runway Visual Range
Minimum RVR is governed by the
DH, approach lighting and runway
lighting/marking, shown below.
At night, at least runway edge,
threshold and runway end lights
must be on.
Cat 1 Approach vs Facilities & DH
Refer to aeroplane tables for facilities. Nil approach light facilities
comprise runway markings, runway edge, threshold and end
lights or no lights at all. RVR values either as reported, or vis
converted as above. Figures only apply to conventional
approaches with slope below 4°.
The DH refers to initial
calculation; associated RVR
does not have to be rounded up
to the nearest 10 feet, like when
converting to DA.
Class 1 & 2 helicopters
Refer to aeroplane tables for facilities. Figures are reported RVR
or met vis converted using the above. Figures only apply to
conventional approaches with glideslope up to and including 3.5
degrees. At night at least runway edge lights must be available.
The DH refers to initial calculation;
associated RVR does not have to be
rounded up to the nearest 10 feet,
e.g. when converting to DA. The
DH applied must not be less than
1.25 x minimum use height for the
autopilot. Single pilot, minimum
RVR shall be at least 800 m, except
when using a suitable autopilot
coupled to an ILS.
Single-Pilot Operation
Minimum RVR may not be less than
800m, unless a suitable autopilot,
coupled to an ILS or MLS is used, in
which case RVR above may be used,
but DH must be not less than 1.25 x
the min use height for the autopilot.
Commencement and Continuation of
an Approach
An approach may be started
irrespective of the RVR, but not
continued past the outer marker (or
equivalent—see note) unless the
reported controlling RVR/vis is
equal to or better than the minimum
required. Once past the outer
marker, you can continue if your
visual reference has been established
at the DH/MDH, and is maintained.
With no outer marker, you must
make the decision to continue or
abandon before descending below
1000 feet above the aerodrome on
final approach.
Note: The "equivalent position" is a
DME distance, a suitably located
NDB or VOR, SRE or PAR fix, or
anything else that independently
establishes your position.
Visual Manoeuvring (Circling)
Circling is visually manoeuvring to a
runway or FATO (for helicopters)
after an Instrument Approach to
another one, or the same one if the
approach is not straight in (more
than 30o off, in fact). Minima for this
will give the necessary obstacle
clearance, but in mountainous areas,
account will also be taken of its
DH Facilities/RVR
Full Intermediate Basic Nil
200 550 700 800 1000
201–250 600 700 800 1000
251–300 650 800 900 1200
301 + 800 900 1000 1200
Onshore Precision Approach Minima—Cat 1 Facilities
DH(ft) Full Intermediate Basic
200 500 600 1000
201–250 550 650 1000
251–300 600 700 1000
301 + 750 800 1000
68 Operational Flying
height and effect on turbulence.
Remember the minimum RVR is
800 m.
Circling height will be in the Airway
Manual, precalculated to a standard
formula; otherwise, just add 300 feet
to the highest obstacle within 5 nm
of the airfield (provided the result is
above 500 feet agl).
You can get a reasonably accurate
circling visibility in metres by
multiplying the circuit speed in knots
by 20, that is, if speed = 120 knots,
then visibility must be 2400m. You
should not descend below minima
until aligned with the runway, except
down to 500 feet agl on base leg at
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