View Full Version : radar mysteries and loud beeps

stator vane
27th Aug 2002, 14:43
i will try to describe what i have seen and ask if anyone knows a good explanation: will be difficult without drawing it, so bear with me.

Sept 27 northbound at FL330 over France on a flight from MAD to BRU. heading approximately 030 and using radar which is displayed on EHSI (lower EFIS screen which shows map and radar combined) just some light green returns scattered about the area. nothing worth avoiding.

everything normal until suddenly there appears a green streak in the radar presentation from bottom center of EHSI (aircraft position on map) extending in straight line, slightly expanding on a 055 "course" it stays there for three or four sweeps of the radar then disappears. just a few minutes later, it reappears in same position, this time intensified showing a streak of yellow and red still on a 055 "course.

again it disappears and then returns at what seems to be a random sequence but always on the same 055 "course" with varying intensities from time to time.

a few minutes later, we are cleared direct to AVROL and the aircraft turns to a heading of 050 and the streak retains the same "course" 055 as we turn and after stabilized.

i have seen it several times before and didn't know what it was, and surmised that it might have been an internal radar fault due to overheating etc.

i heard one person suggest that it might be some ground military radar "sighting" our aircraft, but said person had no reference or other supporting information.

any help would be appreciated and would prefer some references if possible. i have only seen it over europe while flying the brussel's based 737's with a slight red tint.

surely i am not the only one to have seen such a thing.

and while we are at it, what are those loud high pitched beeps that i hear on a regular basis while over France? reminds me of the hearing test sounds, but way too loud. makes me raise my finger in acknowledgment that i heard the sound.

please minimize the jokes to one or two pages each response!!!!

Golden Rivet
27th Aug 2002, 15:05
I would have a guess at your Radar transceiver being U/S. Not uncommon to see spiking.

27th Aug 2002, 15:47
I was always under the impression that the radiating spikes were due to interaction with other aircraft weather radars. I am only a pilot not a tech wizard but that was how it was explained to me yonks ago.
Ground radar used to make a noise on the radios as it swept .I haven't heard it recently

27th Aug 2002, 18:18
Initially we always thought it to be 'military'interference,having said that, it's not so prevalent lately,Last few years on 320 .:confused:

28th Aug 2002, 00:38
I was told it is an air defence system, either land or sea based, that is using you for tracking practise.

From August 1991 until January 1992, when flying over Syria towards Saudi it was very common to see these 'spokes' coming up from Iraq - they stopped just after January 17th!:D

Have seen them plenty of times over Europe also.

Bally Heck
28th Aug 2002, 13:21
Saw something similar last year. Coincided with the presence of a US aircraft carrier in PMI. QED.

stator vane
29th Aug 2002, 23:27
so i am not alone. flew same course BRU MAD and back today and did not get any spikes at all.

but did get a few loud beeps while over france.

if the mutt or the tullermane read this, they should have an idea.

would like to find some hard info about it.

thanks again

30th Aug 2002, 00:48
At Cardiff, I get a breakthrough over the headsets from their
primary radar...a little like the mobile phone chirping effect.

I haven't noticed this anywhere else...is this a commonplace

Cue stories (not UL) of a frigate in the Pool of London being
asked to switch off its air-defense radar as it was being picked
up and interfering with every dealing screen in the City of

-- Andrew

30th Aug 2002, 13:58
Talked to a Typhoon pilot the other day. He flew them in the RAF on missions over France around D-day. German flak guns radar ranging on him would cause clicking noises on his VHF set. He would then weave like mad and sure enough a few seconds later flak would burst where he had been.

He warned others in his formation (usually four aircraft) never to get immediately behind him during their own weaving as the predicted flak would always initially burst behind him. Unfortunately some inexperienced pilots in his formation did just that and were shot down. So beware - ghostly guns may be tracking you....

30th Aug 2002, 14:37
It is radar jamming from a military unit, they can use it to locate you, and is why you are advised to fly with your wx radar on even in good wx in former balkan countries etc. (So they know you are civvie).

See it all the time in the 757 across the Uk to eastern Med routes.

30th Aug 2002, 20:25
no mystery at all.

next time you notice it, if you are over the sea, look for a large carrier. if you are over land, it is probably an awacs.