Malaysia Airlines MH370 - Missing Plane

[xxMATTGxx]

Yeah but from the ground they'd still surely see that there's multiple?

Like the passenger flight doesn't know but ground radars surely would..

Depending on the country and what ATC systems they have then most likely. But it wouldn't show any of the aircraft information I don't believe.

[scottish]

Yeah I figured without transponder etc it wouldn't show info, but you'd still see the dot on the radar or whatever, especially military radars I'd imagine?

Idk I've never looked into radars or that much into flying, but just seems that the theory is highly unlikely as otherwise tailing commercial planes would be a very easy way of avoiding any radars allowing you to invade any countries airspace with ease.

[xxMATTGxx]

Yeah I figured without transponder etc it wouldn't show info, but you'd still see the dot on the radar or whatever, especially military radars I'd imagine?

Idk I've never looked into radars or that much into flying, but just seems that the theory is highly unlikely as otherwise tailing commercial planes would be a very easy way of avoiding any radars allowing you to invade any countries airspace with ease.

It's why I questioned why did no one pick it up or send jets up when they confirmed they tracked an aircraft turning back on radar.
@le harry; Yeah I've been reading Airliners.net and Pprune since day one. Great places to read anything on there about aviation.

- - - Updated - - -

Found this on Airliners.net in regards of Primary VS Secondary Radar

• Primary radar is based on the original military usage. It sends out a strong (KW to MW) signal and looks for a reflection from something.
• Primary radar provides distance and location. Comparing returns speed can be determined. Strength of return can indicate size.
• Stealth a/c and ships are designed to absorb or miss-direct the reflection so primary radar cannot see them.
• Primary radar does not depend on the transponder, so turning off a transponder will not make an a/c disappear from primary.
• Primary radar is less prevalent than secondary - and more typically military tho ATC's do use it.
• Secondary Radar is really not Radar in the defined sense. It is directional communication.
• In secondary radar a directional signal is sent out (much less powerful than primary). Any a/c with a transponder that receives it will respond (the transponder responds) with information about the aircraft.
• Combined with the direction of the outgoing beam, the time of flight information and returned information, the a/c location and identity (and other info depending on the mode) is returned.
• Secondary radar is the primary method used by ATC.
• If the transponder fails or is turned off - secondary radar will not see the a/c.
In the case of MH370:
• The transponder was turned off - so the a/c disappeared from secondary (ATC) radar.
• A target was tracked west, then northwest using primary radar. That target was correlated with SATCOM pings help determine it was MH370.

@scottish;

[scottish]

Ah, well the primary radar would detect the SIA86 (iirc) flight, and see that it's a lot bigger than a typical 777 surely? So figure somethings up

Unless they ignore primary radar at ATC (in which case military should then notice it)

[xxMATTGxx]

Ah, well the primary radar would detect the SIA86 (iirc) flight, and see that it's a lot bigger than a typical 777 surely? So figure somethings up

Unless they ignore primary radar at ATC (in which case military should then notice it)

I would assume so if that's how it would show up. Hopefully they will find something out sometime soon :/

[Calum0812]

I believe primary radar is used by normal airports in the UK, but it's used as a backup (incase someone doesn't get their transponder correctly) so I'm confused why over there it is military only

[scottish]

Think mattg posted said secondary is used primarily, not that secondary isn't used at all by them?

[Calum0812]

Think mattg posted said secondary is used primarily, not that secondary isn't used at all by them?

He's correct, most airports use secondary radar to identify aircraft and correlate them, but most UK airports that have any sort of traffic going through them will have at least primary radar so they can see what's flying about. Secondary radar gives a bit more info like their callsign, altitude, speed etc whereas primary just gives the blip. I believe primary and secondary work together but don't quote that aha

[scottish]

He's correct, most airports use secondary radar to identify aircraft and correlate them, but most UK airports that have any sort of traffic going through them will have at least primary radar so they can see what's flying about. Secondary radar gives a bit more info like their callsign, altitude, speed etc whereas primary just gives the blip. I believe primary and secondary work together but don't quote that aha

My post failed, what I meant was "Thing mattg posted said secondary is used mainly by the ATC, not that primary isn't used at all"

So the other airports in Malaysia will use the primary I'd imagine.

[Calum0812]

My post failed, what I meant was "Thing mattg posted said secondary is used mainly by the ATC, not that primary isn't used at all"

So the other airports in Malaysia will use the primary I'd imagine.

Sorry it's been a long day haha

Possibly but I'm very confused how an aviation network could work efficiently with just primary radar. If they have no level read out for the aircraft, they can't separate them from other aircraft efficiently, so they have to plan for them to be at every level (so like 0ft to 40,000ft or something) which would cause so much hassle in busy airspace round London because they rely on separation by levels, speed and lat & lon. Obviously they can get the pilot to report their level. idk. I am not hugely familiar with ATC services outside the UK and the ones inside I only understand basic principles of.

I heard somewhere only the military of Malaysia has access to primary radar meaning if they switched the transponder off, they wouldn't show up on civilian radar at all - strange...