Is it SOP to Have Radars On While On Deck

[Bearfoot]

While being spotted, waiting for T/O, landing, or taxing around, are the aircraft radars on? Or are they forced to be off to protect everyone from all the radiation?

[SUBS17]

WoW no radar emissions.:book:

[joey45]

Weight on wheels switch.

[Rick50]

yea, in normal operations they are never actually emitting while on the ground, landing gear switch as mentioned above. The urban legend suggests the more powerful fighter radars, like the F-15 and Su-27 could microwave a turkey in a couple of minutes! Not sure if anyone tried that, or if it's accurate, but it seems like a bad idea to try!

[Bearfoot]

Interesting. Pretty sure that the radar remains emitting after trapping etc. in the sim, which is why I thought about this. In the grand scale of things, relatively minor!

[Naquaii]

Interesting. Pretty sure that the radar remains emitting after trapping etc. in the sim, which is why I thought about this. In the grand scale of things, relatively minor!

 

The AWG-9 while silent, either via the stby position on the WCS switch or via the WoW (Weight On Wheels) switch will still scan around the selected search volume but will not emit anything via the antenna.

 

It's a quirk of the system and because of that it looks like the antenna is operational when in fact it's just doing the motions without transmitting.

[Bearfoot]

The AWG-9 while silent, either via the stby position on the WCS switch or via the WoW (Weight On Wheels) switch will still scan around the selected search volume but will not emit anything via the antenna.

 

It's a quirk of the system and because of that it looks like the antenna is operational when in fact it's just doing the motions without transmitting.

 

Awesome that this is modeled to this level of detail!

[Nealius]

yea, in normal operations they are never actually emitting while on the ground, landing gear switch as mentioned above. The urban legend suggests the more powerful fighter radars, like the F-15 and Su-27 could microwave a turkey in a couple of minutes! Not sure if anyone tried that, or if it's accurate, but it seems like a bad idea to try!

 

Sometimes I wonder about those stories....which is more powerful, an F-15 radar or all the radars on an aircraft carrier island? If those radars could microwave turkeys, then every member of the deck crew would be microwaved as well....

[cromhunt]

Don't think that radars on aircrafts are micro waves:)

I remember that on a plane that I had to fly equipped with a weather radar, the instruction on the ground and before landing, was to put it out to block the axes of the antenna which could be damaged by the shocks.

Maybe it's the same for the radars of the fighter plane?

that explains why they are groundless in DCS

But this is only an assumption

[Voyager]

Sometimes I wonder about those stories....which is more powerful, an F-15 radar or all the radars on an aircraft carrier island? If those radars could microwave turkeys, then every member of the deck crew would be microwaved as well....

 

It's the proximity and beam path. The radars on the plane are standing right next to you, while the high power radars on the islands are mount a up top where people won't normally walk in front of them. Also there's the aspect of flux density. A big aperture can drive a huge total flux, while still having a lower flux density. Kind of the way elephants halve lower ground pressure than people do. Doesn't necessarily mean it is safe to be infront of at full power, but does make safety considerations more complicated.

[Harlikwin]

Don't think that radars on aircrafts are micro waves:)

I remember that on a plane that I had to fly equipped with a weather radar, the instruction on the ground and before landing, was to put it out to block the axes of the antenna which could be damaged by the shocks.

Maybe it's the same for the radars of the fighter plane?

that explains why they are groundless in DCS

But this is only an assumption

 

Microwave is rather technical definition. Microwave ovens work at specific frequencies specifically to heat water molecules, RADAR tends to avoid those rather specific frequencies because there is in fact water in the air which it doesn't want to detect, AKA humidity. But technically RADAR works in the microwave frequency range.:)

[Nealius]

It's the proximity and beam path. The radars on the plane are standing right next to you, while the high power radars on the islands are mount a up top where people won't normally walk in front of them.

 

They still irradiate the deck. Any carrier footage taken in the old analog days will have a consistent audio glitch every time the island radars sweep in its direction.

 

And "microwave" (used as a verb here) is colloquial. We're not actually talking about literal microwaves. It's just slang for "cooked with radiation."

[Bearfoot]

The straight dope on this:

 

https://boards.straightdope.com/sdmb/showthread.php?t=38817

[Rick50]

Ah thanks Bearfoot!

 

I always wondered if the original claim was...um... "exaggerated" or not!

 

Still, I have to think there are reasons for wanting the weight switch to turn radar on/off. Maybe to reduce likelihood of cancer? I think also to reduce interference with airfield/carrier radar and ground reflections?

[Yeti42]

I've not worked on F14's, I have worked on many other aircraft with radar... It IS SOP for crew to switch off the radar after landing even though most aircraft have Weight On Ground (WOG) or weight on wheels switches which are meant to inhibit radar emissions as well as the inadvertent firing of weapons and stores jettison. Instances of WOG switch failure are rare on the flight line but have occurred. If we found radar switches in emit (ON) during an after flight servicing, the crew were told to come back, make it safe and apologise. This was usually followed by an "interview" with the senior engineering officer and the sqn commander.

[Alicatt]

Ah thanks Bearfoot!

 

I always wondered if the original claim was...um... "exaggerated" or not!

 

Still, I have to think there are reasons for wanting the weight switch to turn radar on/off. Maybe to reduce likelihood of cancer? I think also to reduce interference with airfield/carrier radar and ground reflections?

 

As a radar tech from way too long ago I used to have to wear a lead apron to protect the family jewels when working on ships radars, and we had lead glass inserts to replace some of the covers so that we could see what we were doing inside the transceiver housing while working on them.

 

My family was an early adopter of the microwave oven and the one we had in our house took 6 people to carry it, the cooking chamber was about 4" thick lead, it was powered by a 6kW cavity magnetron at a frequency of 932MHz, we got it in the 1960s and it was about the same size as a washing machine. Cooking time was counted in seconds, and for somethings even a second was too long - many explosions as the flash vaporised water tried to get out of the food :D

[Fri13]

https://core.ac.uk/download/pdf/52132548.pdf

 

ABSTRACT

Part of a crew on a Norwegian naval ship was exposed to the radar waves for approximately 7 min from an

American destroyer during an incident at sea in August 2012. Information about the exposure was not given

by the navy. This is a description of what happened with the crew on board after this event. 14 persons

had been on the ship bridge or outside on the deck during the exposure and the rest of the crew had been

inside the ship. 27 persons were examined at a hospital 6–8 months after the event, as they had developed a large number of symptoms from different organ systems. They were very worried about all types of

possible adverse health effects due to the incident. All were examined by an occupational physician and an

ophthalmologist, by an interview, clinical examinations and blood tests at the hospital. The interview of the

personnel revealed that they had not experienced any major heating during the episode. Their symptoms

developed days or weeks after the radar exposure. They had no objective signs of adverse health effects

at the examination related to the incident. Long-term health effect from the exposure is highly unlikely.

The development of different symptoms after the incident was probably due to the fear of possible health

consequences. Better routines for such incidents at sea should be developed to avoid this type of anxiety.

(Int Marit Health 2013; 64, 4: 177–182)

 

EXPOSURE ASSESSMENT

No one in the navy had any information on the exposure

from the radar, they only informed about the name of the

radar. However, we have deduced the following information:

the radar was a SPY-1D (V), an S-band radar using frequencies 3–4 GHz, wavelength 7.5–10 cm [16]. The peak output

power of this radar is 6 MW and the average power is 58 kW,

which gives a duty cycle of about 1/100.

Edited August 21, 2019 by Fri13

[Tobi1304]

Don‘t know if I understand you correctly as English isn‘t my mother tongue, but a RADAR antenna in several meters height won‘t radiate anything underneath it for quite a big circle, except they put an antenna tilt in it which makes the antenna look down. And that doesn‘t make much sense if they want to look rather far away.

Sure you will get a glitch or interference (we were able to hear it on the radio when the antenna of our Airport Surveillance Radar looked into our direction) but that‘s not the Radarbeam which is pointing at you but interferrences which happen to form around the beam.

It‘s perfectly safe to stand underneath an antenna.

[Alicatt]

Don‘t know if I understand you correctly as English isn‘t my mother tongue, but a RADAR antenna in several meters height won‘t radiate anything underneath it for quite a big circle, except they put an antenna tilt in it which makes the antenna look down. And that doesn‘t make much sense if they want to look rather far away.

Sure you will get a glitch or interference (we were able to hear it on the radio when the antenna of our Airport Surveillance Radar looked into our direction) but that‘s not the Radarbeam which is pointing at you but interferrences which happen to form around the beam.

It‘s perfectly safe to stand underneath an antenna.

 

sidelobes? not all the energy is in the main beam.

 

There is a nice animation of a phased array in operation showing where the energy goes

 

https://en.wikipedia.org/wiki/Side_lobe

[Kirk66]

I always wondered about this. In the F-4 that I crewed the radar was in standby until takeoff (and after landing) and there was also a W-on-W switch; lots of safety briefings about not frying your crewchief, etc..., but, what about being in the lead of a 4-ship in fingertip formation? You look over your shoulder and there is a big radar on each side of you, happily putting out microwaves...

 

Does the metal airframe provide protection? How about the canopy? Nomex?

 

May explain why my kid is so strange...

 

Vulture

[drPhibes]

Does the metal airframe provide protection? How about the canopy? Nomex?

 

 

A metal (or other conductive material) fuselage does shield the pilot to a certain degree. Electromagnetic waves can't pass through a metal surface; instead they induce surface currents in the outer layers of the fuselage panels, where they are either dissipated through resistive losses, or re-emmitted from various parts of the fuselage.

 

 

 

Some aircraft have canopies with thin metal films deposited onto the acryllic (PVD), which provides some shielding. A good example is the hinged canopies on the EA-6 (as opposed to the clear forward facing part), where this is done in order to shield the pilots from emmissions from the EW pods.

[turkeydriver]

Yes big radars can cook you quick- mere weather radars on airliners have interlocks to prevent from radiating on the ground.....and for the latest big VA news, fighter pilots are apprently dropping like flies in their 50s from aggressive cancers......while radar operation in fighters isnt new, these guys would have been flying the long missions in OEF and OIF- and continuous exposure even while in a protected cockpit means something. The MiG-25 radar is extremely powerful- not in range but in TX power- so that its burn through range is closer to maximum than many others- many sources speak of the radar killing rabbits on test ranges during testing.