Slightly late to this party but I've been involved in quite a few incident investigations where aircraft have encountered CBs but didn't have the WXR on (or had the display dimmed) as "it looked clear".:ugh:

Just because it looks clear out front is no guarantee that there's no buildups at lower altitude. It seems often forgotten that these buildups can still cause a some nasty problems for you.

-edit- I want to add, this post isn't directed at anyone else. Just a general comment after reading the thread.

CallmeJB,

I am glad I will never have to fly with you. See Nemrytter's post 63......and learn!

I think CallmeJB's post's in jest, a dig at those who don't believe in wearing things out.

If not then God help us! :)

Stan,

I hope you are right. If so many apologies to CallmeJB.

This American was trying to channel some British sarcasm... I guess it didn't quite go over.

You are forgiven of course. I'm so sorry if I offended you!

Pineteam (and Check Airman) thanks for the link to the Rockwell Collins Multiscan presentation. So far I'm not really a fan of the thing but this gave some good insight. As regards the original question I get the wx radar on on the ground since the flight I had some years ago where we got to the Balkans only to find the radar not working when we turned it on. It's the sort of problem I would rather find out about on the ground before the flight, not at 38000 when presented with a load of active storms
No company SOP regards usage.

For those worried about radiation, I used to fly with a captain who was a fanatic. He carried a radiation detector when he flew. He found that on pur 757s the worst offender was the window heat controllers located above the center of each forward window so he turned the heats off above 10,000 ft since there was no restriction against flying without them there. He turned them back on below 10 because there was a restriction. Takes all kinds I guess. I always just followed the book. Simpler that way.

If he'd carried a solar radiation detector at FL390 he might have made his hair stand on end. Ignorance can be bliss, sometimes.

Concerning the danger of radiation, in the video I posted before, the guy from Rockwell Collins clearly states the radiation are negligible. With max gain and max range, if you stay in front of the radar antenna, it's still safer than standing in front of your home microwave.

You can find it at 1H01M30s --> https://www.youtube.com/watch?v=H_2NruqjQi4

Driving in your car with the headlights on gives you more exposure to electromagnetic energy than flying with the weather radar on, (in both cases, virtually nil).

Same sort of emissions*, same sort of power, same physical set-up with the transmitters mounted in front of reflectors facing away from you, and which are mounted in front of a metal bulkhead between them and you.

No danger.

*Visible light and microwaves are both electromagnetic waves on the electromagnetic spectrum. Visible light has a higher frequency and energy than microwaves. Microwaves as used by radars are not energetic enough to cause ionisation, (potential tissue damage). Only when you get up to X-rays (in your hospital, and way above visible light), are the energies enough to disrupt molecular bonds.

Hi pineteam,
SOPs are often written to prevent the re-occurrence of an avoidable accident/ incident and over time the original reason is forgotten and the SOP appears "dumb" to some.
This weather radar discussion appears "dumb" to those aces who never make mistakes, and so believe they will always remember to turn the system on before they need it. They usually end up mitigating the threat rather than avoiding it in the first place.

Hi Goldenrivett,

Concerning the weather radar, I think there is a misunderstanding. In my company , we take off with radar off when we know for sure the weather is sky clear. In dispatch we check the live satellite image ,the Taf etc... We know from experience especially in winter, we won't find any CBs. Of course now in summer time, no question asked radar is ON. And we only turn it off when we can see the horizon well clear. We only do short/medium flight, so all good!:) And I do mistakes all the time, not ashamed of it, not hiding it, always happy to learn from it and from you guys. :)

@pineteam

That link to that video was really helpful. It's not the type of radar our A320s are fitted (if he's talking about the same radar, as the video Airman posted) so it would be interesting to know if that same information is applicable to our equipment.

It is rather odd as I've found the same behaviour on multiscan radars but not so with the old manual ones. I've cursed the bloody things way too many times for showing/not showing radar returns rather inconsistently.

Regarding the use of radar...for me this is all moot. It's so basic it beggars belief if such question is even worth of asking. If you like it off, fine, but don't forget to turn it on if you need it. If you like it on, fine too, even if it's all clear skies out there. Does it make a difference?

I keep it on, just because even in clear skies, I know it's there, working (or not, to be reported at arrival). I've always heard radars like to be kept on for increased life... In any case, it's company policy to keep it on and to be honest, there are far more important things to be taking care off than if I should keep the thing off or on. If it was that important it would be written somewhere

Pineteam,
With reference to your first post, good to see you're showing some " mechanical sympathy".
With respect to the mechanics of it, personally had 1 physically fail on an A320. Clear morning, not a cloud too be seen. On climb, aircraft started a small rhythmic vibration. Had no idea. After a while got the idea it was about the same frequency as the radar sweep. Pointed the radar down and saw it was stalling in the 1 o'clock position. On the ground the aircraft gave us a fault. For memory something to do with an IRS (needed for radar stabilisation). Engineer lifted the bonnet ( like in airplane the movie) and confirmed it was busted. That's the only physical failure in 20 years on radar equipped aircraft. Glad I had this on clear morning rather than flying around the equator at night.
As for the electronics failure, I've seen it happen at times. Usually switch to other computer or a reset will fix it. As others have said, the on/off cycles can probably kill electronics as much as just leaving it on.
As for radiation sources, can I add the overhead panel on Airbusses that big red sticker that says Caution-high voltage. Does that add any hurtful radiation?

Give it time, the radars of the future probably won't have any moving parts. Like the phased array ones you now see on warships.

Personally I prefer to leave the radar on.
Just like the Nav lights.......

No.
.

Hello,

Thank you for your input. I just tried to fly the most efficient way and treat the aircraft with good care like it was my own. I'm actually very happy to have created that discussion as thanks to everyone inputs, I have learned a lot. :)

I retired years ago, but once we had radar I always had it on mapping (If nothing more imminent) over long ocean crossings.

Other pilots asked why did I have it on if there was nothing to see and I had to recount the RAF aircraft that didn't because they were routed well south over the pond to the USA and there would be nothing to see.

Unfortunately they weren't "well south" when they thought they were and in response to a confused navigator practicing grivation...turned it on. They immediately saw what they thought was a large ice mass...which it was, but unfortunately the one that covers Greenland which should have been many hundreds of miles to the North. They just made Goose Bay!

So if you are not using it for anything else, why not have it on mapping so that where you should have nothing on track...you can see that you really don't.

I had a nasty one circa 1980 while flying a 737-200 Taipei to Guam at night. A Typhoon (the weather, not the aeroplane) was forecast to be on our direct track or thereabouts. The radar was a Bendix monochrome display with 180 miles max range. We switched the scale from 180 to 80 quite frequently and played with the tilt hoping to pick up the tall CB usually surrounding the eye of the typhoon. We even looked through the windscreen although we were in cloud.
The radar showed lots of what we interpreted as sea returns expected with large waves. No evidence of bad weather ahead after 1.5 hours in cruise in calm air in cloud. Where was the forecast typhoon? Without warning we hit savage turbulence and lots of lightning. The flashes illuminated Cb's in all directions. Clearly the radar had failed some time after we had left Taipei and we were over the West Pacific area.

There was no warning of the failure, and because the screen appeared "alive" with tiny echoes we took to be big waves, we trusted it. We turned 90 degrees from the planned track and picking our way between CB tops using lightning flashes, we were able to clear the immediate area and resume track to Guam.

Mechanic upon arrival - "can you turn off the EGPWS? I'm going to be working below the airplane and don't want to get radiated."