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TAKEOFF MINIMUMS FOR
COMMERCIAL OPERATORS
While Part 121 and 135 operators are the primary users of
takeoff minimums, they may be able to use alternative
takeoff minimums based on their individual OpsSpecs.
Through these OpsSpecs, operators are authorized to
depart with lower-than-standard minimums provided they
have the necessary equipment and crew training.
OPERATIONS SPECIFICATIONS
Operations specifications (OpsSpecs) are required by
Part 119.5 to be issued to commercial operators to define
the appropriate authorizations, limitations, and procedures
based on their type of operation, equipment, and qualifications. The OpsSpecs can be adjusted to accommodate the
many variables in the air transportation industry, including
aircraft and aircraft equipment, operator capabilities, and
changes in aviation technology. The OpsSpecs are an
extension of the CFR; therefore, they are legal, binding
contracts between a properly certificated air transportation
organization and the FAA for compliance with the CFR's
applicable to their operation. OpsSpecs are designed to
provide specific operational limitations and procedures tailored to a specific operator's class and size of aircraft and
types of operation, thereby meeting individual operator
needs.
Part 121 and 135 operators have the ability, through the
use of approved OpsSpecs, to use lower-than-standard
takeoff minimums. Depending on the equipment installed
in a specific type of aircraft, the crew training, and the
type of equipment installed at a particular airport, these
operators can depart from appropriately equipped runways with as little as 300 feet RVR. Additionally,
OpsSpecs outline provisions for approach minimums,
alternate airports, and weather services in Part 119 and
FAA Order 8400.10, Air Transportation Operations
Inspector’s Handbook.
HEAD-UP GUIDANCE SYSTEM
As technology improves over time, the FAA is able to work
in cooperation with specific groups desiring to use these
new technologies. Head-up guidance system (HGS) is an
example of an advanced system currently being used by
some airlines. Air carriers have requested the FAA to
approve takeoff minimums at 300 feet RVR. This is the
lowest takeoff minimum approved by OpsSpecs. As stated
earlier, only specific air carriers with approved, installed
equipment, and trained pilots are allowed to use HGS for
decreased takeoff minimums. [Figure 2-9]
CEILING AND VISIBILITY REQUIREMENTS
All takeoffs and departures have visibility minimums
(some may have minimum ceiling requirements)
incorporated into the procedure. There are a number
of methods to report visibility, and a variety of ways to
distribute these reports, including automated weather
observations. Flight crews should always check the
weather, including ceiling and visibility information,
prior to departure. Never launch an IFR flight without
obtaining current visibility information immediately
prior to departure. Further, when ceiling and visibility
minimums are specified for IFR departure, both are
applicable.
Weather reporting stations for specific airports across
the country can be located by reviewing the A/FD.
Weather sources along with their respective phone
numbers and frequencies are listed by airport.
Frequencies for weather sources such as automatic terminal information service (ATIS), digital automatic
terminal information service (D-ATIS), Automated
Weather Observing System (AWOS), Automated
Surface Observing System (ASOS), and FAA
Automated Flight Service Station (AFSS) are published on approach charts as well. [Figure 2-10]
RUNWAY VISUAL RANGE
Runway visual range (RVR) is an instrumentally
derived value, based on standard calibrations, that
represents the horizontal distance a pilot will see down
the runway from the approach end. It is based on the
sighting of either high intensity runway lights or on the
Figure 2-9. HGS Technology.
Figure 2-10. Frequencies for Weather Information are listed on
Approach and Airport Charts.
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visual contrast of other targets whichever yields the
greater visual range. RVR, in contrast to prevailing or
runway visibility, is based on what a pilot in a moving
aircraft should see looking down the runway. RVR is
reported in hundreds of feet, so the values must be converted to statute miles if the visibility in statute miles is
not reported. [Figure 2-11] This visibility measurement
is updated every minute; therefore, the most accurate
visibility report will come from the local controller
instead of a routine weather report. Transmissometers
　
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