Windshear Alerts
Windshear alerts are available during takeoff, approach, and landing: The GPWS provides a warning when the airplane is in a windshear.
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Warning Systems -System Description 737 Operations Manual
Windshear warnings are accompanied by WINDSHEAR on the attitude indicators
and voice aural alerts.
Windshear cautions are accompanied by a voice aural alert.
Windshear Warning (Airplane in Windshear)
AURAL ALERT VISUAL ALERT DESCRIPTION
Two–tone siren followed by WINDSHEAR WINDSHEAR WINDSHEAR Red WINDSHEAR on both attitude indicators. Excessive windshear at the current airplane position detected by GPWS. Enabled below 1,500 feet RA. GPWS Windshear detection begins at rotation.
Bank Angle Alert
The EGPWS provides the aural alert BANK ANGLE, BANK ANGLE when roll angle exceeds 35 degrees, 40 degrees, and 45 degrees. Once sounded, the alert is silent for that bank angle (35, 40, or 45 degrees) until the system is reset by decreasing bank angle to 30 degrees or less.
Approach Callouts Radio Altitude Callouts
The EGPWS provides the following altitude callouts during approach:
.
1,000 feet – ONE THOUSAND
.
500 feet – FIVE HUNDRED
.
400 feet – FOUR HUNDRED
.
300 feet – THREE HUNDRED
.
200 feet – TWO HUNDRED
.
100 feet – ONE HUNDRED
.
50 feet – FIFTY
.
40 feet – FORTY
.
30 feet – THIRTY
.
20 feet – TWENTY
.
10 feet – TEN
Note: Callouts at 1000 feet and 500 feet are based on radio altitude above the landing field elevation.
DH/MDA Callout
The GPWS provides a MINIMUMS callout at DH/MDA based on radio altitude above the landing field elevation.
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Warning Systems -System Description 737 Operations Manual
Traffic Alert and Collision Avoidance System (TCAS) (as installed)
TCAS alerts the crew to possible conflicting traffic. TCAS interrogates operating transponders in other airplanes, tracks the other airplanes by analyzing the transponder replies, and predicts the flight paths and positions. TCAS provides advisory, flight path guidance, and traffic displays of the other airplanes to the flight crew. Neither advisory, guidance, nor traffic display is provided for other airplanes which do not have operating transponders. TCAS operation is independent of ground–based air traffic control.
To provide advisories, TCAS identifies a three dimensional airspace around the airplane where a high likelihood of traffic conflict exists. The dimensions of this airspace are based upon the closure rate with conflicting traffic.
TCAS equipment interrogates the transponders of other airplanes to determine their range, bearing, and altitude. A traffic advisory (TA) is generated when the other airplane is approximately 40 seconds from the point of closest approach. If the other airplane continues to close, a resolution advisory (RA) is generated when the other airplane is approximately 25 seconds from the point of closest approach. The RA provides aural warning and guidance as well as maneuver guidance to maintain or increase separation from the traffic.
Non–transponder equipped airplanes are invisible to TCAS. RAs can be generated if the other airplane has a mode C transponder. Coordinated RAs require both airplanes to have TCAS.
Advisories and Displays
Annunciations associated with TCAS and the traffic displays are discussed further
in Chapter 10.
TAs are indicated by the aural “TRAFFIC, TRAFFIC” which sounds once and is
then reset until the next TA occurs. The TRAFFIC message appears on the EHSI.
The TA symbol appears at the proper range and relative bearing of the other
airplane. Altitude and vertical motion are included with the symbol if the other
airplane is using transponder mode S or C.
RAs are indicated by one or more aural listed in the RA aural table. The TRAFFIC
message and RA symbol which depicts the traffic’s relative bearing, range,
altitude, and vertical motion are on the EHSI similar to the TA symbol.
Additional symbols are proximate traffic and other traffic. Proximate traffic is 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：737-300机组操作手册Flight Crew Operations Manual FCOM 3(116)
