FLIGHT PATH WEATHER 
The RDR-4000 fills the 3D memory with all the detected weather in front of the aircraft out to 320 nm, and from ground level up to 60,000 feet mean sea level (MSL).  The RDR-4000 designates weather along the flight path as “flight path” weather.  All other weather is designated as “secondary” weather, and is displayed with black stripes through it.  (See diagram on page 13.)
The nominal flight path weather envelope is ±4000 feet with respect to the expected flight path.  To aid the pilot, at certain altitudes and flight path slopes this envelope is expanded.  At cruise altitudes the floor of the envelope is fixed at 25,000 feet MSL.  This ensures the display of convective activity associated with less reflective frozen storm tops.  On the ground and during departure or approach the ceiling of the envelope is fixed at 10,000 feet MSL.  This provides approximately ten minutes of look-ahead.SECONDARY WEATHER 

Secondary weather is displayed for situational awareness and to aid in making changes to your flight plan to avoid "flight path" weather.  See the examples to visualize the displayed weather. 
 
 

 TURBULENCE DETECTION 
Turbulence detection is an automatic function of this weather radar system while in the AUTO mode.
For turbulence detection and evaluation use the following procedure:
1. System Control: L or R (or NORM for single system)

2. Mode: AUTO 

3. Range: As desired 

Turbulence information is limited to the first 40 nautical miles.  Turbulence within this range and inside the turbulence envelope will be displayed in magenta.  Magenta areas may be displayed on top of any color, including black.  The turbulence data is represented in a "blocky" shape, helping to visually differentiate it from reflectivity data. 
The turbulence envelope is ±5000 feet with respect to the aircraft altitude.  At cruise altitudes (above 30,000 feet MSL), the floor of the envelope is fixed at 25,000 feet MSL.  This ensures the display of turbulence associated with less reflective frozen storm tops.  On the ground and during departure or approach (below 5,000 feet MSL), the ceiling of the envelope is fixed at 10,000 feet MSL.  This provides approximately ten minutes of look-ahead. 
 
TYPICAL TURBULENCE DISPLAY
Magenta(Turbulence)

Red
(Heavy Rain)

Yellow
(Medium Rain)

Green
(Light Rain)

Secondary Weather (Red, Yellow, or Green, with Hash-marks)
PLAN A WEATHER AVOIDANCE PATH IN ADVANCE

 
PREDICTIVE WINDSHEAR (PWS) DETECTION 
The Predictive Windshear feature detects the presence of windshear ahead of the aircraft, giving 10 to 60 seconds of warning before the encounter.  Windshear detection mode operates automatically below 1800 ft Above Ground Level (AGL), with alerts available at 1500 ft AGL and below.  If a Windshear event is detected, the system automatically provides the crew with Caution and/or Warning annunciations, and a Windshear icon appears on the weather display.  This system is meant to supplement other means of detecting and avoiding hazardous Windshear conditions.  It will not detect all possible hazardous Windshear conditions such as extremely dry events or events masked by unusual radar clutter. 
AUTOMATIC WINDSHEAR ACTIVATION 
The Windshear mode will automatically be turned on under the following specific aircraft conditions: 
In Air: Below 1800 ft. AGL 
On Ground: Typically Engine at Take-Off Thrust Setting or both Oil Pressure Active and Transponder On.
　
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本文鏈接地址：WX RADAR RDR4000-PILOT GUIDE 氣象雷達 RDR4000飛行員指南(6)