曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
(ft)
ILS No Glide Path 250
SRA (½ nm) 250
SRA (1 nm) 300
SRA (2 nm) 350
VOR 300
VOR/DME 250
NDB 300
NDB/DME 300
VDF (QDM & QGH) 300
Visual Reference
You cannot continue below MDH
unless you can see (and identify) at
least one of:
· elements of the approach or
runway lights
· the threshold or touchdown
zone, their markings or lights
· visual glideslope indicator(s)
MDH is a height below which you must
not descend, and not one at which you
must fly to comply with the
procedure, so you don't have to go
to it immediately. For a 3°
glideslope, you should be 1642 feet
above the threshold elevation at 5
nm (including a 50-foot screen
height). At 10 nm, the height should
be 3234 feet. Put more simply, for
every nautical mile, you can descend
about 300 feet (actually 318), which
will help with power changes.
Required Runway Visual Range (RVR)
You may get an RVR report with 3
figures, covering the touch-down,
middle and stop end of the runway,
respectively. The touch-down one
must be at least equal to landing
minima, but the others need merely
be enough to stop safely, provided
they are more than that required for
take-off. The RVR for landing from
a visual circuit is 800m (1200 in
Canada), or the lowest Cat 1 RVR
for the intended runway, whichever
is the less, regardless of approach
lighting, time of day or type of
aircraft. As mentioned, this is for
shallow fog, where you may see the
airport from height, but lose sight of
it as you descend on the approach (a
visual approach must be authorised
by ATC). The minimum RVR for a
non-precision approach depends on
the MDH, approach and runway
lighting as shown below. At night, at
least runway edge, threshold and
runway end lights must be on.
66 Operational Flying
NPA Minima – Full Facilities
With runway markings, 720m+
of high or medium intensity
approach lights, runway edge,
threshold and end lights, all on.
NPA Minima – Intermediate
With runway markings, 420–
719m HI/MI approach and
other lights.
MDH(ft) Aeroplane Cat and RVR(m)
A B C D
250–299 1000 1100 1200 1400
300–449 1200 1300 1400 1600
450–649 1400 1500 1600 1800
650 + 1500 1500 1800 2000
NPA Minima – Basic Facilities
With runway markings, <420m
of HI/MI approach lights,
runway edge, threshold and end
lights, which must be on.
MDH(ft) Aeroplane Category and RVR(m)
A B C D
250–299 1200 1300 1400 1600
300–449 1300 1400 1600 1800
450–649 1500 1500 1800 2000
650 + 1500 1500 2000 2000
NPA Minima – Nil Facilities
Runway markings, edge,
threshold & end lights, or none.
MDH(ft) Aeroplane Category and RVR(m)
A B C D
250–299 1500 1500 1600 1800
300–449 1500 1500 1800 2000
450–649 1500 1500 2000 2000
650 + 1500 1500 2000 2000
Tables only apply to approach slopes under 4°. Steeper
ones normally require VASIs or similar to be seen from
MDH. RVR is either reported RVR, or met vis converted
as below. The MDH above refers to its initial calculation.
RVR doesn't need to be rounded up to the nearest 10
feet, as when converting to MDA.
Class 1 & 2 Helicopters
Onshore Non-Precision Approach Minima Facilities
MDH(ft) Full Intermediate Basic
250-299 600 800 1000
300-449 800 1000 1000
450 + 1000 1000 1000
Refer to aeroplane tables for description of facilities.
Only for approaches below 4 degrees. Normally
requires VASIs or similar to be seen from MDH. Figures
are reported RVR or converted met visibility. Where
MAP is within ½ nm of threshold, minima for full facilities
may be used regardless of approach lighting, but you
still need runway edge, threshold and end lights and
markings. At night, ground lighting must illuminate
FATO and obstacles. Single pilot, min RVR is higher of
800 m or Table 3.
Converting Reported Met Vis to RVR*
Lighting in Operation RVR = Met Visibility X
Day Night
HI Approach and Rwy Lighting 1.5 2.0
Any lighting other than above 1.0 1.5
No Lighting 1.0 N/A
*Don’t use for take-off or Cat II/III , or when RVR is available.
Precision Approaches (Onshore)
For these, a Cat I operation uses
ILS, MLS or PAR with a DH above
200 feet, and RVR above 550 metres
(500 for helicopters). The DH is at
least the highest of:
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
飞行员操作飞行手册Pilot_Operational_Flying_Manual上(45)
