Display Modes

The navigation display (ND) shows WXR system data in these modes:

· Expanded approach

· Expanded VOR

· Center MAP

· Expanded MAP.

WXR System Display Data

The ND shows these displays:

· WXR data

· WXR system messages

· WXR alert messages.

WXR Displays

The WXR data on the ND shows the weather or the terrain in front of the airplane. Colors show the strength of the RF return signals from the weather or the terrain. These are the four colors for the WXR displays:

· Green - light weather

· Yellow - medium weather

· Red - heavy weather

· Magenta - turbulence.

The WXR system calculates and shows turbulence only to 40 NM.

WXR System Messages

This weather radar data shows on three lines in the bottom left of the navigation display:

· Mode

· Antenna tilt

· Gain.

Line 1 shows mode. Mode shows this data:

· WXR

· MAP

· WX+T

· TEST.

Line 2 shows the antenna tilt value set on the WXR panel.

Antenna tilt shows 0.0 to + 15 or - 15 degrees.

Line 3 shows gain. Gain shows this data:

· VAR - R/T has gain set by gain switch

· Blank - normal operation (gain switch in AUTO).

All WXR system messages show cyan. There is no annunciation for the standby mode.

WXR SYSTEM - PWS OPERATION

General Description

If the PWS detects a windshear threat, it makes an alert. The alert may be a warning or a caution. The alert the crew receives depends upon these conditions:

· Position of the windshear relative to airplane heading

· Distance to the windshear

· Airplane flight phase - takeoff or approach.

PWS Warning Area

During takeoff, PWS gives a warning if it detects a windshear threat in this area:

· Less than 0.25 NM on either side of the airplane projected magnetic heading

· More than 0.5 NM but less than 3 nm ahead of the airplane.

During approach, PWS gives a warning if it detects a windshear threat in this area:

· Less than 0.25 NM on either side of the airplane projected magnetic heading

· More than 0.5 NM but less than 1.5 nm ahead of the airplane.

PWS inhibits new windshear warnings during takeoff and approach if both of these conditions exist:

· Airspeed more than 100 knots

· Less than 50 feet radio altitude.

PWS Caution Area

PWS gives a caution if it detects a windshear threat in this area:

· Within 25 degrees on either side of the airplane projected magnetic heading

· More than 0.5 nm but less than 3 nm ahead of the airplane

· Not in the PWS warning area.

PWS inhibits new windshear cautions during takeoff and approach if both of these conditions exist:

· Airspeed more than 80 knots

· Less than 400 feet radio altitude

All PWS alerts are inhibited above 1200 feet radio altitude.

Дата добавления: 2015-10-26