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
saying: GOING FROM A HIGH TO A LOW,
LOOK OUT BELOW."
3.3Temperature also has an effect on the accuracy of
altimeters and your altitude. The crucial values to
consider are standard temperature versus the ambient
(at altitude) temperature. It is this difference" that
causes the error in indicated altitude. When the air is
warmer than standard, you are higher than your
altimeter indicates. Subsequently, when the air is
colder than standard you are lower than indicated. It
is the magnitude of this difference" that determines
the magnitude of the error. When flying into a cooler
air mass while maintaining a constant indicated
altitude, you are losing true altitude. However, flying
into a cooler air mass does not necessarily mean you
will be lower than indicated if the difference is still on
the plus side. For example, while flying at 10,000 feet
(where STANDARD temperature is −5 degrees
Celsius (C)), the outside air temperature cools from
+5 degrees C to 0 degrees C, the temperature error
will nevertheless cause the aircraft to be HIGHER
than indicated. It is the extreme cold" difference that
normally would be of concern to the pilot. Also, when
flying in cold conditions over mountainous country,
the pilot should exercise caution in flight planning
both in regard to route and altitude to ensure adequate
en route and terminal area terrain clearance.
3.4TBL ENR 1.7−3, derived from ICAO formulas,
indicates how much error can exist when the
temperature is extremely cold. To use the table, find
the reported temperature in the left column, then read
across the top row to locate the height above the
airport/reporting station (i.e., subtract the airport/reporting
elevation from the intended flight altitude).
The intersection of the column and row is how much
lower the aircraft may actually be as a result of the
possible cold temperature induced error.
3.5The possible result of the above example should
be obvious, particularly if operating at the minimum
altitude or when conducting an instrument approach.
When operating in extreme cold temperatures, pilots
may wish to compensate for the reduction in terrain
clearance by adding a cold temperature correction.
TBL ENR 1.7−3
Reported Temp C
ICAO COLD TEMPERATURE ERROR TABLE
Height Above Airport in Feet
200 300 400 500 600 700 800 900 1000 1500 2000 3000 4000 5000
+10 10 10 10 10 20 20 20 20 20 30 40 60 80 90
0 20 20 30 30 40 40 50 50 60 90 120 170 230 280
−10 20 30 40 50 60 70 80 90 100 150 200 290 390 490
−20 30 50 60 70 90 100 120 130 140 210 280 420 570 710
−30 40 60 80 100 120 140 150 170 190 280 380 570 760 950
−40 50 80 100 120 150 170 190 220 240 360 480 720 970 1210
−50 60 90 120 150 180 210 240 270 300 450 590 890 1190 1500
EXAMPLE− Temperature−10 degrees Celsius, and the aircraft altitude is 1,000 feet above the airport elevation. The chart
shows that the reported current altimeter setting may place the aircraft as much as 100 feet below the altitude indicated by
the altimeter.
ENR 1.7−4 AIP
15 MAR 07 United States of America
Nineteenth Edition Federal Aviation Administration
4. High Barometric Pressure
4.1Cold, dry air masses may produce barometric
pressures in excess of 31.00 inches of Mercury, and
many altimeters do not have an accurate means of
being adjusted for settings of these levels. As noted in
paragraph 3.2, when the altimeter cannot be set to the
higher pressure setting, the aircraft actual altitude
will be higher than the altimeter indicates.
4.2When the barometric pressure exceeds
31.00inches, air traffic controllers will issue the
actual altimeter setting, and:
4.2.1En Route/Arrivals.Advise pilots to remain
set on 31.00 inches until reaching the final approach
segment.
4.2.2Departures.Advise pilots to set 31.00 inches
prior to reaching any mandatory/crossing altitude or
1,500 feet, whichever is lower.
4.3The altimeter error caused by the high pressure
will be in the opposite direction to the error caused by
the cold temperature.
5. Low Barometric Pressure
5.1When abnormally low barometric pressure
conditions occur (below 28.00), flight operations by
aircraft unable to set the actual altimeter setting are
not recommended.
NOTE−
The true altitude of the aircraft is lower than the indicated
altitude if the pilot is unable to set the actual altimeter
setting.
AIP ENR 1.8−1
United States of America 15 MAR 07
Federal Aviation Administration Nineteenth Edition
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