wx radar off inflite
Thread Starter
Joined: Sep 2006
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From: Mumbai India
wx radar off inflite
I have a question. We fly the 320 family and we have some ol skool pilots who believe tht switchin off the radar above 10000' when wx is clear is a good idea.
is there any logic to it.And is it documented anywhere?
And is there any safe gaurd against the microwaves emitted from the radar in regards to flite creW health?
is there any logic to it.And is it documented anywhere?
And is there any safe gaurd against the microwaves emitted from the radar in regards to flite creW health?
Joined: Oct 2005
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From: Australia
Weather radar points forward. You know this. Does that mean its safe? Who the heck knows.
What I believe is this...if you're worried about wx radar and health issues, you should also be worrying about the affect on your body of all the other electro magnetic thingeys we deal with in aviation and in everyday life. All those wire bundles under the floor in the aircraft...lovely electrical fields! Your mobile phone? Hope you don't get brain cancer (or, for that matter, testicular cancer from having it in your pocket).
I can't really see any reason to turn it off in flight...what little danger there is would be if you were directly in front of it and, at altitude, thats not real likely.
At the end of the day, if you want to turn it off in flight if the weather is nice,and it doesn't violate your ops manual, fill your boots.
(And before you say, 'what does he know about wx radar', my helo has weather radar...I just don't use it at 30,000').
HP
What I believe is this...if you're worried about wx radar and health issues, you should also be worrying about the affect on your body of all the other electro magnetic thingeys we deal with in aviation and in everyday life. All those wire bundles under the floor in the aircraft...lovely electrical fields! Your mobile phone? Hope you don't get brain cancer (or, for that matter, testicular cancer from having it in your pocket).
I can't really see any reason to turn it off in flight...what little danger there is would be if you were directly in front of it and, at altitude, thats not real likely.
At the end of the day, if you want to turn it off in flight if the weather is nice,and it doesn't violate your ops manual, fill your boots.
(And before you say, 'what does he know about wx radar', my helo has weather radar...I just don't use it at 30,000').
HP
Beacon Outbound
Joined: Mar 2002
Aviation Qualifications: ATPL
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From: "Home is were the answer machine is"
wx radar and safety
If it is safe outside the A/C, I'd be very surprised if it isn't safe inside the aircraft.
If it is safe outside the A/C, I'd be very surprised if it isn't safe inside the aircraft.
Joined: Jun 2001
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The thing about switching it off is that you'll probably forget that it's off when you need it. Maybe not a problem on short haul, but on long haul how sure are that you'll remember that it's off when you're looking at those nice fluffy clouds 10 hours later?
"Radar's not showing anything serious in this lot, we'll just nip straight through"!
"Radar's not showing anything serious in this lot, we'll just nip straight through"!
Joined: Dec 2006
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From: E/E Bay
These modern digital radars barely emit any more power than the HF and of course the signal is highly directional.
The old-school analogue radars could output at 10kw+ if I remember rightly. The key to reducing the output was processing power in the T/R.
Come to think of it, ex-Phantom crews do seem to glow in the dark..........
The old-school analogue radars could output at 10kw+ if I remember rightly. The key to reducing the output was processing power in the T/R.
Come to think of it, ex-Phantom crews do seem to glow in the dark..........
Joined: Jul 2007
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From: uk
meikleour
Many moons ago we had a new Fleet captain who advocated this procedure. However it was dropped after it was found that condensation on the scanner array gimbals was freezing in flight and making the weather radar unusable when switched on after a period! Some things just keep coming around.
Joined: Jun 2000
Aviation Qualifications: ATP+Mil
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From: Australia
I recall many years ago writing to the Bendix radar people on the same question. They replied that if you don't need the radar then switch it off. Saves maintenance costs, they said.
Joined: Jan 2001
Posts: 609
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From: Around the world.
Personally with electronics, for me, they always seem to fail being switched on or off. Why push your luck switching these on or off in flight when not necessary. They are certainly useful in the terminal area!
It is like the captains who tell me 'no' when I ask for wing anti-ice on (A320)when I see ice on the icing indicator. I'm told no, on the 737 we had to wait until you could see ice on the wing. Yes, you are not flying a f****** 737 you are flying an A320 with wing anti-ice/de-ice and as per Airbus instructions put it on at visible icing on the indicator!
It is like the captains who tell me 'no' when I ask for wing anti-ice on (A320)when I see ice on the icing indicator. I'm told no, on the 737 we had to wait until you could see ice on the wing. Yes, you are not flying a f****** 737 you are flying an A320 with wing anti-ice/de-ice and as per Airbus instructions put it on at visible icing on the indicator!
Joined: May 2006
Posts: 260
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From: Italy
Radar
Denti:
EGPWS doesn't emit so I don't see the connection to this discussion?
IRRenewal:
Thanks for the informative link. It seems to mainly focus on ground crew though. And consider this from the article:
We are sitting close to the antenna which is basically a microwave oven.
I know microwave ovens are only dangerous to domestic animals in the States (
) but how would you feel about spending 8 hours a day 2 meters from one while it buzzes away at home?
Also, personally I have never experienced a radar not coming on again after being switched off in flight but I might have been lucky.
I say turn it on when you need it.
SAN
EGPWS doesn't emit so I don't see the connection to this discussion?
IRRenewal:
Thanks for the informative link. It seems to mainly focus on ground crew though. And consider this from the article:
...never to place any part of the body in region of the antenna and the feed horn......Doppler X-Band (9300 – 9500 MHz) transmitter with a nominal output of a few hundred watts of microwave power....
I know microwave ovens are only dangerous to domestic animals in the States (
) but how would you feel about spending 8 hours a day 2 meters from one while it buzzes away at home?Also, personally I have never experienced a radar not coming on again after being switched off in flight but I might have been lucky.
I say turn it on when you need it.
SAN
Joined: Nov 2007
Posts: 63
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From: Europe
SEV
I think that wx radar is quite important instrument to help pilots to be aware of situation. I think that switch it off is really a bad idea for many many reasons.Somebody swtch off the gps because sattellites has radiation???
Joined: Apr 2002
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From: Location: Location:
We use it on as a sop as wx radar txmittal can apparently help identify you as a civvie aircraft, introduced after 9/11 and invaluable when operating in the less civilised areas of the world or close to unfreindly borders
Joined: Jul 2007
Posts: 812
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From: uk
Ref: Stator Vane
Just because you have not come across a problem does not mean that it is not valid. The fleet in question was the B747 classic during the eighties whilst being operated in the Far East envirnoment where the ground level humidity was very high. The procedure was dropped because of this problem and didn`t occur with the scanner operating. As an aside to this, excessive water comtamination collecting on the walls of large empty fuel tanks in this area of the world is also a well known problem.
Just because you have not come across a problem does not mean that it is not valid. The fleet in question was the B747 classic during the eighties whilst being operated in the Far East envirnoment where the ground level humidity was very high. The procedure was dropped because of this problem and didn`t occur with the scanner operating. As an aside to this, excessive water comtamination collecting on the walls of large empty fuel tanks in this area of the world is also a well known problem.
Joined: Sep 2001
Posts: 410
Likes: 87
From: EASA territory
Leave the wx-radar on? Why?
Huh? Am I missing something? Are there companies that leave the wx-radar on all the time? What is that good for?
I have been flying 12 years for 3 different companies and I never heard of a SOP to leave it on all the time!
We don't ever turn or leave the wx-radar on when it's obvious that it's not needed.
Regards,
Sabenaboy
I have been flying 12 years for 3 different companies and I never heard of a SOP to leave it on all the time!
We don't ever turn or leave the wx-radar on when it's obvious that it's not needed.
Regards,
Sabenaboy
Joined: Sep 2007
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From: Up left - Down right
From a maintenance point of view, modern WXR has a pencil beam radiation produced by the slotted design of the antenna plate.
It only radiates away from the A/C in a 180 deg arc. The power levels today are in the order of 75 watts compared with the
hundreds / thousands of watts of the older units with many side lobe beams.
Predictive Windshear Operation included in new units operates below about FL200 and would be desirable
to have this function working at altitudes below this.
I have not seen proof of antenna icing up and not scanning, but if it did it would be due to low motor torque due to wear & tear
not to mention very poor seals in the radome.
If your SOP’s allow for turning off (stby) it will extend the life of the servomotors particularly during Your current flight.
P.S. Most A/C the OFF or STBY the T/R's are powered up but transmit is inhibited & antenna stationary
It only radiates away from the A/C in a 180 deg arc. The power levels today are in the order of 75 watts compared with the
hundreds / thousands of watts of the older units with many side lobe beams.
Predictive Windshear Operation included in new units operates below about FL200 and would be desirable
to have this function working at altitudes below this.
I have not seen proof of antenna icing up and not scanning, but if it did it would be due to low motor torque due to wear & tear
not to mention very poor seals in the radome.
If your SOP’s allow for turning off (stby) it will extend the life of the servomotors particularly during Your current flight.
P.S. Most A/C the OFF or STBY the T/R's are powered up but transmit is inhibited & antenna stationary
Last edited by Short_Circuit; 17th November 2007 at 23:56. Reason: PS
Joined: Aug 2004
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From: blue yonder
Wx Radar
Guess 'Wiggy' and 'Short Circuit' have reasons. I recall during and preceding the 1st Gulf War in the '90's it was standard procedure to keep the Radar 'on' to improve the radar signature.
It makes sense in the current climate too. Unless you are doing a polar route at FL 350+, then you and the Radar can chill!
It makes sense in the current climate too. Unless you are doing a polar route at FL 350+, then you and the Radar can chill!