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Engineer1
7,175 posts
78 months
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Polrules said: Someone hit on it earlier, most helicopters will max out around 120-140kts in optimum conditions i.e given altitude & windspeed. So if you're evading the plod on a windy night just make sure you are driving into the wind, preferably in the highlands! Any car capable of 150mph+ should escape given enough fuel, time & a clear motorway*. - Disclaimer - this might not work.
Motorway sucks, your car will have been identified, and there are a limited number of exits to watch. I'm fairly sure that a busy airport area during holiday season would get the helicopter off your back.
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TheAlfaMale
406 posts
17 months
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Gene Vincent said: As far as I'm aware we are not talking about a civilian 'copter but a police one right?
There has been Gr-to-Air missiles installed across London (courtesy of IOC) and as such the proximity of the firing would mean that some form of RWR is needed to nullify friendly fire. (buddy signal)
A 'chirp' is not so much a 'lock-on signal' it is an 'pre-acquisition signal', the chirp rate increases to a tone and that is 'lock-on' and the missile is fired, it is all automatic, the operator of a real missile is not listening to either the chirp or waiting for the constant tone, it's part of the operating sequence internally.
The person at the receiving end of the little dart will through RWR hear this pre-acquisition (search) chirp.
Of course, as per my first post the big 'if' is if the have RWR, my guess, and it is only a guess, is that that is more likely today than perhaps a year ago.
It's a bit far fetched and possibly a little off the wall, but not really all that dumb in my opinion. IFF is not the same as RWR... It's normally a transponder of some kind, requiring the friendlies all to "squawk" a common code. Fire control and search radars cause an RWR to trigger an alert. Neither of which would cause a civilian helicopter any concern and the last time I checked the Police weren't a branch of the military and therefore would fall under the "civil" umbrella. P.S. The IFF does not work in the OFF position... 
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Gene Vincent
4,002 posts
27 months
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mini me said: So do you think all the civilian airliners landing at London airports have had this fitted too? My guess is no. 911 was civilian aircraft used as a weapon of terror and the missiles are there to prevent that form of attack happening again, so fitting an RWR buddy signal transmitter is totally counter-productive, don't you think? To turn the mirror upon you, that was really a rather dumb question you asked, don't you think? So, you've been rude and I've been impertinent... honours even, don't you think? Cheers Gene.
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sneijder
4,856 posts
103 months
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mybrainhurts said: Thanks, I'll remember that for next time I'm late for a flight... Guy in India called in a bomb threat last year to make his flight. The police were waiting when he got there.
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Gene Vincent
4,002 posts
27 months
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TheAlfaMale said: IFF is not the same as RWR...
It's normally a transponder of some kind, requiring the friendlies all to "squawk" a common code. Fire control and search radars cause an RWR to trigger an alert. Neither of which would cause a civilian helicopter any concern and the last time I checked the Police weren't a branch of the military and therefore would fall under the "civil" umbrella. I bow to your greater knowledge. But, a squawk only identifies a craft, I thought RWR was a positive negation of known systems in an area not taking you down, the 911 'planes were all squawking who they were quite accurately. My guess is that if the Military have weapons on the ground that can take down craft then friendly craft would need a positive repellent and warning apparatus, an RWR set would do this especially if the 'copter might be called upon to get close for assurity in identity, IFF won't positively blind a weapon to its presence, whereas RWR will... I think... you know more than me.
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TheAlfaMale
406 posts
17 months
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Gene Vincent said: I bow to your greater knowledge.
But, a squawk only identifies a craft, I thought RWR was a positive negation of known systems in an area not taking you down, the 911 'planes were all squawking who they were quite accurately.
My guess is that if the Military have weapons on the ground that can take down craft then friendly craft would need a positive repellent and warning apparatus, an RWR set would do this especially if the 'copter might be called upon to get close for assurity in identity, IFF won't positively blind a weapon to its presence, whereas RWR will... I think... you know more than me. RWR is exactly what it says on the tin: Radar Warning Receiver. It has no jamming (blinding) functionality unless coupled with a DASS (Typhoon's Defensive Aids Sub System) or an AN/ALQ-214 (example) type device which IS a jammer (later systems do more - they also deploy physical countermeasures at an appropriate time). The RWR just warns of the presence of a radar and it's approximate transmission bearing and strength. This allows the aircraft to avoid said radar by remaining out of the detection envelope and sneak past. As you might gather from this; it would be unusual and suspicious if a civil aircraft was to carry either of these! If I remember correctly civil aviation radar relies less on a skin "paint" but more on the response from a transponder carried by most civilian aircraft. IFF is just an identification purposes. It is mainly, as previously stated, an electronic system, but can be optical as well. This can mean anything from a guy with a working knowledge of whose planes look like what and a pair of binoculars to an advanced system as used on the F-14 Tomcat, which used a giant, electro-optically stabilised lens.
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sneijder
4,856 posts
103 months
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Urban Legend time.
I bought a charcoal lined chemical suit thing from an army surplus shop.
Shop owner tells me the police often come in asking him to stop selling them as with the hood up, perps are invisible at night to the helicopter.
You just need to stop the thing taking off in the first place. Stick a banana up its exhaust pipe.
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domgrant
53 posts
43 months
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mattley
2,373 posts
91 months
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Jimmy No Hands said: I'd drive to the Trafford Centre ensuring I drove recklessly enough for the Trafpol to call off pursuit, then straight into the first storey of the multi storey car park, run into Debenhams and then mingle with the shoppers. Maybe buy a new jacket.
I'm not sure if this would work. All this talk of shopping centres is crazy, they're all proper CCTV centres, especially Debenham's, unless you can identify some proper blind spots and a well planned escape route this would never work. I too have thought about this watching police shows and recon the best bet would be a junction like J17 on the M25, assuming 4 guys on the 'job' and good planning and the police cars are not right on back of the chase one could get 4 cars stopped up with a driver waiting for a minute or so, bad guys enter the underpass, abandon the getaway car which will be very hot on IR and jump into the waiting cars which then go 4 ways separately. It won't be hard for the Helicopter crew to work out what happened but which car to follow?
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TheAlfaMale
406 posts
17 months
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sneijder said: Urban Legend time.
I bought a charcoal lined chemical suit thing from an army surplus shop.
Shop owner tells me the police often come in asking him to stop selling them as with the hood up, perps are invisible at night to the helicopter.
You just need to stop the thing taking off in the first place. Stick a banana up its exhaust pipe.  bloody big banana!!
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mini me
553 posts
62 months
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Gene Vincent said: y guess is no.
911 was civilian aircraft used as a weapon of terror and the missiles are there to prevent that form of attack happening again, so fitting an RWR buddy signal transmitter is totally counter-productive, don't you think?
To turn the mirror upon you, that was really a rather dumb question you asked, don't you think?
So, you've been rude and I've been impertinent... honours even, don't you think?
Quite.
Cheers
Gene.
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mph1977
4,795 posts
37 months
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Drive Blind said: paulwoof said: who would get priority a big airport? such as manchester/newcastle etc. obviously if a plane is on desent the helicopter would have to back off but would they send a jet on a circuit or back off if the helicopter was chasing someone. I'm not clued up on police procedure but I think it would need to be a very big priority and immediate danger to hundreds of lives before the air space above an airport was cleared. I very much doubt this would be done to catch a casual thief. You'd need to kidnap the queen to get a whole airport shutdown you'd be surprised what happens for helimeds on Alpha taskings anything pubt an active emergency will be sent away ... not sure if plod have similar priority 'cards' to play ...
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Beartato
505 posts
37 months
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TheAlfaMale said: bloody big banana!! Flatterer.
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TheAlfaMale
406 posts
17 months
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Beartato said: Flatterer.   
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creampuff
1,229 posts
12 months
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jas xjr said: would the helicopter would need permission to enter airspace of the airport ? Oh yes. There would need to be a compelling reason. I don't think a car chase would count as a compelling reason.
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moreflaps
502 posts
24 months
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Dr Mike Oxgreen said: I have often thought that the workload of a police helo pilot must be enormous when on a pursuit. Not only has he got to chase the scrote in the car in such a way that he captures usable evidence, he's also got to fly safely, avoid obstacles, and negotiate ATC clearances for controlled airspace where necessary. He certainly can't just plough straight into the Heathrow zone without clearance, although I imagine that the copilot would handle the obtaining of clearances.
For the most part, I can't see clearances being refused though. The helo is probably flying pretty low (500 feet perhaps?), which will make it much easier for an air traffic controller to offer the required clearances. The standard separation that ATC have to provide is 3 nautical miles horizontally or 1000 feet vertically, so a helo at 500 feet will only be a problem if he needs to cross the final approach path within about 5 miles of the runway threshold. On the climbout path, most aircraft climb fast enough that I doubt there'd be much problem on that side, and a climbing aircraft can be instructed to turn if necessary anyway (or can be held on the ground for an extra 30 seconds until the conflict disappears).
I'd be interested to know if they'd break an aircraft off from an approach if the helo needed to pass close to the landing threshold. Are there any air traffickers on here? You've forgotten about wake turbulence. Going under a heavy landing fan is not a good idea. Cheers
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0000
9,319 posts
60 months
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ArmaghMan
761 posts
49 months
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Potatoes said: your best bet is a rocket propelled grenade Not really. it was always an ambition of the RA to take down a Chinook in South Armagh. They tried to buy missiles on several occasions (usually from undercover FBI agents!!) having tried with both heavy machine guns and some sort of cannon. Both proved inadequate. It would be my guess that you would need to be unbelievably lucky to hit a small traffic chopper with an RPG.
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Dogwatch
3,551 posts
91 months
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Jimmy No Hands said: I'd drive to the Trafford Centre ensuring I drove recklessly enough for the Trafpol to call off pursuit, then straight into the first storey of the multi storey car park, run into Debenhams and then mingle with the shoppers. Maybe buy a new jacket.
I'm not sure if this would work. Debenhams? Don't they have a Maccy D's? I would need fast food....
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wildcat45
2,541 posts
58 months
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This is a real story that happeed 20 years ago on Tyneside.
The police get calls to say there is a fight in one end of a division. Police turn out, find nothing but the control gets more calls to say the guys have baseball bats and have moved alf a mile along the road.....More police are sent in the hope of cutting off the gang. More reports of men fighting in the local park, and more cops join to a new search area. All this is belivable, as the reports to the police follow a logical way people would move through this area. Cops who know the beat get down alleys and rat runs, and the helo is called in to give a top view to cops on the ground over what is a 2 square mile urban search area. Lots of streets, a park, a railway lone, a big block of flats, a lot of area to cover.
As the search is in full swing, police get another 999 call. This time from a security guard at a retail park at the other end of the division. A gang have just made off in a car full of gear after driving a Range Rover into a sports shop.
Someone has to make a decision. The helicopter is mid search for a gang of violent men, all the llocal police are tied up. The helo is probably 2 mins flying time from the ram raid, the raiders within 30 secs of leaving the robbery are on an dual carriageway intersection that could take them North South East or Wrst. . Within 2 mins they are potentially six miles away from the helicopter if it is sent after them. But which direction? did they take the dual carriageway? They could be well under cover by now or in a different car, and the helo has now been on task half an hour. Hovering and searching uses fuel, as does a high speed run. Its already 8 miles from base and fuel. Lots of decisions.
By planning a few belivable hoax calls, the criminals outfoxed the police helicopter. No guns no ESM, just old fashioned deception.
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