Switching Off weather radar
 

V have a trend in our airlines of switching off the weather radar when the weather is clear and then putting it back ON when a weather is expected. And there a an argument also going on weather it does increase the radar's life or does it actually reduce its life by affecting the MTBF. Those in favour of switching off say that why leave the radar scanning when its not required and those who oppose say that MTBF is, apart from some other factors, also dependent on the number of times a radar is switched ON and OFF. So what do u guys say? Pl avoid guessing.
Regards

Honeywell says that if not in use, best to have it switched off as regards to MTBF. And not Standby, either.

GF

RCA and Bendix, likewise.
Then, there are those that proclaim...it repels birds.
Sorry, not supported with facts
Switch it ON when needed, otherwise, OFF....just as you might with engine anti-icing.
Now, having said this, our weather RADAR sets are a twenty five year old design, nevertheless, they work just like a weather RADAR should, superbly....might be different with new(er) models.
Others might like to comment about these new(er) units.

A lot of airspace now want you to have it on to aid in identification of civilian airlines by the military... so best keep it on in that airspace ;)

A Comfy Chair

Quite correct, the US has a NOTAM out for operations in the Persian Gulf region that wx radars should be on for id

GF

Here in the tropics, I always encourage leaving it on at all times. Some have the habit of switching it off when on approach even when significant weather is obvious in the go around area. You can bet that during a go around followed by a serious malfunction the radar would be the last thing on anyone's mind. I don't want to fly into an active cell at the best of times but imagine doing it by mistake on one engine!

I guess it depends on model, but if you have yours switched off do you still get the predictive windshear alerts? I'm guessing you dont (but it may not be installed on the radars you use anyway).

Keep off in clear weather; except when overflying Afghan airspace. :eek:

And Iraq... Funny you should bring this subject up. Our shorthaul fleets have a habit of turning it off when not in use, where the longhaul ones leave it on (even when nowhere near afghan or iraqi airspace).

P.s. What is MBTF? Is that the phsical sweeping of the radar dish? In which case I can understand it wearing out.

Mean Time Between Failure.

Scenario: you are flying in clear weather with radar off. You then enter a thin haze layer that starts to slightly obscure the horizon. You then lose sight of the ground but can just about still see the horizon and the sky above.

Question: at what point before hitting the enbedded CB you can't see do you switch on the radar?

The radar should be on at all times in flight, or at least until path to touchdown and go around paths confirmed clear.

Do none of you remember the UK-bound charter flight a few years ago that flew into an embedded CB with resultant major damage to windscreens and leading edges? Learn the lesson folks, leave it on. MTBF is for others to worry about.:ouch:

And that was 2 training captains flying together!

In this scenario, switch radar ON.
Severe clear, leave OFF/standby.

Our standard ops.
We are a small operator, and MTBF is everyones business, pilots included.

The WX radar antenna if switched on near the TS cell will be the 1st thing that the lightning will strike.Proven fact.

Also consider what those beams make to the most essential part of your body...Your wife/GF will tell you what to do with the switch.

Modern Wx radars are streets ahead of the old stuff. You're at more risk in your kitchen. :)

The (Collins) WXR-2100 power density is half or less than that of the microwave oven standard.

HERE

Ok, so you suggest leaving it switched off near TS now in case it gets you a strike:ugh:

Jeez, you guys:yuk:

Rainboe - when did you EVER switch off the wx radar flying the BA 747's- remember, I've flown with you?

Folks, severe CAVOK for local flights maybe fine, but you cannot see more than about 120nm at altitude. Strategic avoidance on longer flights starts before then - you need a picture (and a plan) for about 20 minutes out.

The wx radar is an in-flight tool in the same way as the rad alt/gpws - maybe you suggest switching them off also?

From my A32x experience, it was not uncommon (say 1 in 50 sectors) to get a 'wx radar' ECAM that required a CB reset. This never happened in the air - but maybe because the radar was already on. Not something you would want when trying to avoid a cell close in!

If I'm in the minority then I am happily there - and safely so....

I suggest you do it if you`re alredy in deep **** (sometimes it happens on all-haul-flights regardless of experience). Cell is not the TS itself (compare it with ass and you`ll understand what I mean).

A growing minority perhaps?

I completely agree with Topbunk.

Stan

Thanks - happy to fly behind you as SLF anytime:D

At our lot the radar goes on when entering the runway and off again when vacating.

Everybody seems quite happy with that.