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
realized what had happened.”
Quotes from Other ASRS Reports
“Never having used mb before, the significance
of 971 mb wasn’t apparent to me until
I read the equivalent Hg 28.68.”
“Dealing in millibars did not make an
impression…[because of] the very low
[atmospheric] pressure.”
The “copilot who had copied the ATIS gave
me 29.97 when I asked for QNH. Gusty
winds and [the controllers] thick…accent
weren’t helping things. [Obstructions]
seemed unusually close to our altitude. [The]
copilot had assumed 9-9-7 to be 29.97. ” (500
feet low.)
“[Given] altimeter of niner-seven-eight hPa.
The hPa was somewhat muted. We set 29.78
[inches].” (900 feet low.)
4 ASRS Directline
Factors
Several human and procedural factors appear to increase the
possibility of misset altimeters in international operations.
Fatigue
International flights from the United States are generally of
long duration through several time zones. The element of
fatigue in long distance flights is inescapable.
Workload on Approach
Transition from standard altimeter setting flight levels (QNE)
to sea level altimeter setting altitudes (QNH) are generally
much lower than in the United States. Obtaining altimeter
settings and landing data closer to the approach segment
complicates the task of preparing data for landing at the very
time the flight crew may be most fatigued.
Language Difficulties
Rapid delivery of clearances coupled with unfamiliar accents,
and contraction of hPa (hectopascal) or mb (millibars) increase
the potential for error. This also must be true of flights arriving
in the United States from other countries. Other flight
crews communicating in their native tongues contribute to a
lack of awareness of what other traffic is doing.
Communication Procedure
Only one person receiving the approach and landing data, and
passing that information to the rest of the crew means that a
misconception or misunderstanding is less likely to be detected
until too late.
Cockpit Management
There is often inadequate crew briefing for approach and
landing with no mention of how the altimeter setting will be
expressed—that is, Hg, mb, or hPa. Flight crews also may not
adequately review approach charts for information. Some
airlines do not provide the second officer with approach plates;
unless he or she makes an extra effort to look at one of the
pilot’s charts, the altimeter setting standard may be unknown.
Experience Level and Currency
At least one airline experiences a constant turnover in the
international group as senior pilots retire and other crew
members bid off international schedules to upgrade to captain
or first officer. Many of the international reports submitted to
ASRS mention that at least one flight crew member is new to
the operation. Airline training is usually reported as being
adequate, but some of the training for international operations
may not be used or need to be recalled for months after the
training is received.
5
The Question of Q’s
We all tend to forget things we either have not
used in a while, or we don’t use very often. For
those of us who need a memory refresher, here
are three important “Q” altimeter settings:
QNE: The standard altimeter setting of 29.92
inches of mercury (the contraction is Hg.), or
1013.25 hectopascal (hPa for short), or 1013.25
millibars (use mb). See the sidebar on the next
page titled “What’s a Pascal?” to find out why
hPa and mb are the same.
• ON THE GROUND—a variable elevation
reading that is above or below actual elevation
(unless the station pressure happens
to equal 29.92 Hg).
• IN THE AIR—positive separation by pressure
level, but at varying actual or true
altitudes.
QNH: Height above sea level when corrections
are applied for local atmospheric pressure
that is above or below the standard altimeter
setting of 29.92 Hg. QNH is the altimeter
setting provided in the ATIS information and
by ATC.
• ON THE GROUND—the actual elevation
above sea level when the aircraft is on the
ground.
• IN THE AIR—the true height above sea
level (without consideration of temperature).
QFE: An altimeter setting that is corrected for
actual height above sea level and local pressure
variations
• ON THE GROUND—zero elevation when
the aircraft is on ground. Thus, for an aircraft
at the gate at Denver (actual airport
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