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
later.
HELICOPTER IFR TAKEOFF MINIMUMS
A pilot operating under Part 91 has no takeoff minimums with which to comply other than the requirement
to attain VMINI before entering instrument meteorological conditions (IMC). For most helicopters, this
requires a distance of approximately 1/2 mile and an
altitude of 100 feet. If departing with a steeper climb
gradient, some helicopters may require additional altitude to accelerate to V MINI . To maximize safety, always
consider using the Part 135 operator standard takeoff
visibility minimum of 1/2 statute mile (SM) or the
charted departure minima, whichever is higher. A
charted departure that provides protection from obstacles will either have a higher visibility requirement,
climb gradient, and/or departure path. Part 135 operators are required to adhere to the takeoff minimums
prescribed in the instrument approach procedures
(IAPs) for the airport.
Figure 7-6. Example of a Minimum Equipment List (MEL).
7-8
HELICOPTER
IFR ALTERNATES
The pilot must file for an alternate if weather reports
and forecasts at the proposed destination do not meet
certain minimums. These minimums differ for Part 91
and Part 135 operators.
PART 91 OPERATORS
Part 91 operators are not
required to file an alternate if, at
the estimated time of arrival
(ETA) and for 1 hour after, the
ceiling will be at least 1,000 feet
above the airport elevation or
400 feet above the lowest applicable approach minima,
whichever is higher, and the visibility is at least 2 SM. If an
alternate is required, an airport
can be used if the ceiling is at
least 200 feet above the minimum for the approach to be
flown and visibility is at least 1
SM, but never less than the minimum required for the approach
to be flown. If no instrument
approach procedure has been
published for the alternate airport, the ceiling and visibility
minima are those allowing
descent from the MEA,
approach, and landing under
basic VFR.
PART 135 OPERATORS
Part 135 operators are not
required to file an alternate if, for
at least 1 hour before and 1 hour
after the ETA, the ceiling will be
at least 1,500 feet above the lowest circling approach minimum
descent altitude (MDA). If a circling instrument approach is not
authorized for the airport, the
ceiling must be at least 1,500
feet above the lowest published
minimum or 2,000 feet above
the airport elevation, whichever
is higher. For the instrument
approach procedure to be used at
the destination airport, the forecasted visibility for that airport
must be at least 3 SM, or 2 SM
more than the lowest applicable
visibility minimums, whichever
is greater.
Alternate landing minimums for flights conducted
under Part 135 are described in the OpsSpecs for that
operation. All helicopters operated under IFR must
carry enough fuel to fly to the intended destination, fly
from that airport to the filed alternate, if required, and
continue for 30 minutes at normal cruising speed.
Flight visibility
Not applicable
3 SM
3 SM
3 SM
3 SM
5 SM
None
None
1 SM
3 SM
5 SM
None
None
Distance from clouds
Not Applicable.
Clear of Clouds.
500 feet below.
1,000 feet above.
2,000 feet horizontal.
500 feet below.
1,000 feet above.
2,000 feet horizontal.
500 feet below.
1,000 feet above.
2,000 feet horizontal.
1,000 feet below.
1,000 feet above.
1 statute mile horizontal.
Clear of clouds.
Clear of clouds.
500 feet below.
1,000 feet above.
2,000 feet horizontal.
500 feet below.
1,000 feet above.
2,000 feet horizontal.
1,000 feet below.
1,000 feet above.
1 statute mile horizontal.
Clear of clouds.
Clear of clouds.
Airspace
Class A
Class B
Class C
Class D
Class E:
Less than 10,000 feet MSL
At or above 10,000 feet MSL
Class G:
1,200 feet or less above the surface
(regardless of MSL altitude).
Day, except as provided
in §91.155(b)
Night, except as provided
in §91.155(b)
More than 1,200 feet above
the surface but less
than 10,000 feet MSL
Day
Night
More than 1,200 feet above the
surface and at or above 10,000
feet MSL
B, C, D, E Surface Area Airspace
SVFR Minimums
Day
Night
Helicopter VFR Minimums
Figure 7-7. Helicopter VFR Minimums.
7-9
HELICOPTER INSTRUMENT APPROACHES
Helicopter instrument flight is relatively new when
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
Instrument Procedures Handbook (IPH)仪表程序手册下(154)
