B777 WX Radar

[8che]

ok, so im doing a walkaround on the B777-2LR and my colleague discovers his radar display was selected on his ND.

Do I (or the ground crew) have anything to worry about ? Does anyone have detailed knowledge of the ground function and whether there is forced stby mode with engines off etc ?

No returns showed while in front of the terminal but do on taxi

[FullWings]

Do I (or the ground crew) have anything to worry about ?

Short answer: No.

Slightly less short answer: The radar power levels in modern aircraft are pretty low. As far as we know, the only bad effect from radar exposure is the possibility of heat damage to tissue (volumes with poor blood supply, e.g. eyes are the first to be affected), which I suggest would require orders of magnitude more power than is produced normally. Even at 20ft away, you would only be intercepting a small fraction of the total beam energy and of that, another fraction would be absorbed rather than reflected/scattered.

It is still best practice to turn the things off and limit exposure, though.

[Avionker]

Never worked on a 777 but I have a couple of questions if you don't mind?

1) Is there a separate radar control panel or is the radar controlled via the EFIS control panel?

2) If there is a separate panel what was the radar selected to? Stby, Tx etc.

3) What was the tilt selected to?

[8che]

There is a separate control panel but on/off function is through the EFIS control panel.
The system was in full auto config so tilt was in Automatic mode.

[Graybeard]

Advice above is good. How do you like the auto mode?

[8che]

Vey impressed with it. I touch absolutley nothing and it paints very accurate pictures on a slightly conservative side too !

Thx Fullwings, now can anybody share some knowledge of ground operating/stby logic for it and I will be able to grab a beer and relax.

[forget]

... share some knowledge of ground operating/stby logic.

Why would you need it?

PS. GND/STBY that is - not the knowledge. :hmm:

[Cubbie]

You don’t state what radar you use if it’s the B777 RDR 4000, the Radar is ON (Transmitting) when The System Control knob on the Radar control panel is set to L or R (dual system) or NORM (single system) and WXR is selected display on at least one Electronic Flight Display control panel while the aircraft is on the ground.
• Or the PWS Qualifiers are satisfied while the aircraft is on the ground, Engine at Take-Off Thrust Setting or both Oil Pressure Active and Transponder On.
• Or the aircraft is in the air, regardless of any other settings.

Manufacturers are required to calculate two distances; the MPEL(max permissible exposure level) boundary is determined by the greater of these two distances. The first distance is the near field/far field boundary which is the distance from the antenna that it takes for the beam to form. For the RDR-4000 this distance is 14 feet (4.27 meters). The second is the distance where the radiation level exceeds the U.S. Government standard of 10 milliwatts per square centimeter. For the RDR-4000 this distance is 11.8 feet (3.58 meters) from the antenna. In TEST mode the system transmits two 550 microsecond pulses at the beginning of the test sequence and the safe distance is 0.8 inches (2.1 centimeters) from the antenna during this period. The safe fuel distance is 3.5 feet (1.07 meters) from the antenna.
When approaching a gate, you are recommended to deselect WXR on all displays and/or select TEST on the control panel to prevent the radar from transmitting.

[8che]

Cubbie,

I understand its the Rockwell Collins WXR-2100 MultiScan Hazard Detection System (dual). Any info for this would be greatly appreciated.

Thx

[vapilot2004]

Our 737's are fitted with that unit and I understand the maximum EMF radiation to be under 0.5 mw/cm at less than 3 foot exposure distance. The official Boeing guidance disallows radar operation on the ground within 50 feet of people or fueling operations as I'm sure you are aware.