Replacement PAR could damage your health

[Briney]

An interesting thread over on the ATC Issues forum has some repercussions for us here and concerns the new GCA radar that has been rolled out to the entire air force (I think). [I have submitted my reply as the starter here]

Has anyone else considered the wider implications other than a few frustrated practice GCAs? I believe that this may be a complete showstopper for the widespread use of GCAs as an 'in anger' recovery aid. Or am I being a drama queen?!

http://www.pprune.org/forums/showthread.php?s=&postid=1170254#post1170254

The ridiculous situation to which jack-oh refers is indeed quite remarkable, even for a defence procurement issue! The RPAR being all swept up and fancy has replaced the need for controllers to 'aim' the radar at the aircraft under control by working it out for itself. One of the problems that has been identified is that if you happen to be on a pairs approach and your wingman overshoots, the RPAR is likely to stay focussed on that aircraft and not the one continuing the approach to land. This could quite easily spoil your day. In addition, other aircraft approaching the airfield could attract the atention of the RPAR and decide not to pay any further attention to you!

Recent instructions to military airfields have laid down criteria that must be applied for RPAR approaches under IFR conditions:

No other aircraft within 5 miles of the aircraft on GCA

No other aircraft within 2000 ft vertically above

No other aircraft to pass underneath RPAR traffic

Singleton approaches only

If these critieria are infringed by any track (known or unknown) the RPAR ac is to be broken off the approach. If these conditions cannot be met, units will offer SRAs instead.

So, Lincolnshire/Vale of York airfields, how are you going to get any successful talkdowns?

Of course this is equally a problem when looking at airfields as diversions. How would you like to be on a pairs actual diversion, short of fuel and trying to decide who is going to take the delay of a split for singleton GCAs. Perhaps you decide not to rely on PAR and choose the SRA option instead - Leuchars RW09 procedure minima 890', can't go there in Green or worse.

A quality, quality situation especially when you consider that this is only coming to light when the whole of the airforce has now gone over to this useless POS.

[12 PSI]

Navy RPARs have just been restricted to VMC only! That will be useful in the gloop then...:rolleyes:

[BEagle]

Why on earth is the military still farting about with GCA? The rest of the country learned how to fly pilot-interpreted approaches years ago - or accept SRAs if there was nothing better. But World War 2 era PARs? Why??

[Briney]

Don't know why, but we do. The point is that when it's the only thing available and unfit for purpose we may be in the pooh.

[keithl]

I've always assumed (perhaps somebody once told me) that the military persisted with ground interpreted aids because, unlike Perf A certified civvy a/c, they might be damaged / wounded crew, etc. In other words because they are warplanes.

This new RPAR sounds apalling, I'm quite shocked to learn about it!

[Briney]

Apparently I was ever so slightly wrong when I said the entire air force had gone over to this new white elephant, Valley are currently in the throes of installing it when this blew up and they are now refusing to decomission their old PAR until the issues have been resolved. They'll be hanging on to that for a while then!

[Mach the Knife]

Get rid of the PAR completely, put an ILS on both ends of the runway and sack a huge number of the Flight Prevention Branch! PARs are awful anyway, constant blabbering while trying to sort out the endless reams of checks, much better to fly a nice quiet ILS.

[Werty]

I like PARs coz they're easy! You just have to do what you're told and look and the altimeter now and then. None of this digging out TAPS, fiddling with the electrickery equipment, doing TITS or STINT or whatever.

Now the TAC to TAC approach - there's a ball ache!

[LOMCEVAK]

Another factor here is that many of our aircraft still have non FM-Immune ILS boxes installed which means that we cannot do an ILS in IMC either! How many of these problems are caused by "Smart Procurement" (a euphemism for not testing new equipment in an effort to save money).

[spekesoftly]

"Cannot do an ILS in IMC and PARs restricted to VMC". :ugh:

QGHs anybody? :E

[BEagle]

How does the UK military get away with such blatant non-compliance with FM-immunity requirements, yet I had to pay £17000 to re-equip 4 light ac to comply?

The UK military is the minority user of UK airspace. They have no excuse whatsoever for non-compliance with FMI requirements.

I've also heard that some think that they can get round the ILS FMI requirements by flying a 'radar monitored ILS' in IMC. OK if it's a PAR, but with SRA only, surely the approach must be terminated and a go-around executed in such a manner that at no time does the ac descend below the associated MDH unless the approach can be completed visually before MDH is reached.

Penny-pinching bean counters - b£oody well comply with the law of the land and stop hiding behind 'exemptions' beacuse you can't afford to re-equip your few aeroplanes to the same standard as every other ac is required to meet.

[spekesoftly]

With PAR, the controller can silently monitor an ILS, and only chip in if a discrepancy is noticed, but how does an SRA monitored ILS work? Wouldn't the controller still have to give all the standard spiel and patter, in which case why not just fly the SRA?

Trusting a non-precision radar to monitor (what should be!) a precision approach aid seems a bit ar$e about face.

[nav attacking]

Beagle

Stirring again I see. Yes you had to pay £17000 for 4 light aircraft. Can you imagine what the tax payer would have said to multiplying that by 200 or what ever the figure is now.

As to no PAR as the way ahead. What about some of the small pointy aircraft that either have never been fitted with or wouldn't have the room or weight alowance to have ILS systems fitted. Then add the extra cost of having ILS installed at all of our airfields compared to one PAR which can be turned for the runway in use. What then about deployed ops? Think of the cost and time involved in fitting and calibrating a full ILS system to places like Kabul and Basra after we have just destroyed the one that was fitted there. Much easier to deploy a mobile PAR system. Therefore we have to train and operate with it in peacetime as in war.

[BEagle]

The figure would have been considerably less than however much was pi$$ed down the BWoS sink on MRA4 and TypHoon...

The fact that some military aerodromes don't have ILS is a reflection of a direct failure to invest in adequate infrastructure in the past. If it's now coming home to bite, then tough. How many front line aerodromes does the RAF have left which don't have ILS in any case?

Bearing in mind that it's only the VHF (localiser) element of ILS which is allegedly susceptible to FM interference, azimuth monitoring should be OK as the glideslope is UHF. But the azimuth monitoring cannot be provided below MDH, hence ac must either level at MDH or go-around in sufficient time to avoid descent below MDH.

Which small pointy things couldn't afford the weight of an ILS receiver? The ones which can carry several thousands of pounds weight of bombs? The ones which haven't had to use Kabul, Baghdad or Basra?

[spekesoftly]

nav attacking,

Surely the real issue here is the tax payers' money that has already been wasted on equipment (ILS & RPAR) that can only be used in fine weather!


BEags,

Thanks for the explanation, and I do see what you're getting at, but I'm still not convinced that you can even apply the SRA MDH, if you are not actually being given a full SRA.

Put another way, if it all went wrong, I bet the BOI report would make interesting reading!

[nav attacking]

It all come back to "poor" procurement in the end. Lets just blame that again then.

[Briney]

Having spent a bit of time in research mode with the red book, you may be interested to know that of 26 military airfields with precision approach facilities, there are 58 PAR equipped runways against only 25 with ILS. Only 3 airfileds have dual ILS's; Brize Norton, Linton On Ouse and Llanbedr. There are 5 airfileds with PAR only; St Athan, Culdrose, Topcliffe, Wittering and Yeovilton.

So which bill do you want to pick up:

a. Trash this new piece of pooh and either repair (if possible) or replace with another PAR.

OR

b. Buy 33 new ILS installations and pay the bill to sort out the FMI issue (if possible) on the aircraft fleet.

[ATC-OPS1]

As a Controller who has used RPAR for over 2 years at 3 stations without any problems, I feel I must respond to some of the wild comments. RPAR replaced the CR-62. The CR-62 was either continually defective or when it worked could see nothing but clutter.

The RPAR is a fantastic PAR will a superb availability record nearly 100% for all stations. It sees things we never ever saw on the CR 62. It makes my life so easy with it auto-tracking, clear display and status reporting.

Where we (the RAF) fall down is we haven't updated our 40 year old procedures to deal with this 21st century PAR. Come on Strike pull your finger out and bring us up to date.

On the few occasions that I have had a defect the ITT folks in Basingstoke have responded very professionally and fast - how refreshing when you have to deal with AMS and Brit Aerospace on other equipment.

Stop whinging and be thankful we have this wonderful piece of reliable kit. Strike Command get your SATCO's together and bring our procedures up to date.

[Feck]

And then there's Harrier / SHar with no ILS at all. D'oh.

How did we not see this coming? Was it not tested before deciding to pull the plug on every PAR out there (Valhalla / Cranditz excepted)?

<screams, then shrugs and exits stage right to wait for the next mind-bogglingly short-sighted idea from above>

[Briney]

used RPAR for over 2 years at 3 stationsJeez, can't you hold a job down?!


superb availability recordIt's always ready to abandon you as you approach DH


we haven't updated our 40 year old procedures to deal with this 21st century PARHow do the procedures, however old they are, make a difference when the kit is fundamentally flawed?


Stop whinging and be thankful we have this wonderful piece of reliable kitAre you sure about this, you don't work for ITT or DPA do you??

[normally left blank]

Here is a comment of mine on the ATC forum:

Spekesoftly

"A complete system" - like CPN4/MPN11? (Ex lease/lend) - time to dust them off again? "

They still work fine over here! Terma updated them about 15 years ago. They never fail. So ask them, if they are not too busy selling death and destruction.

The new ITT PAR, if it worked as advertised!, is an old PAR-controller's dream. No "weather" to bother about. Much easier to work with.

FWA

Sadly USAF PAR controllers became something of a joke in the 70'ies/ 80'ies - at least here in Europe. Pilots didn't trust them, and avoided them when possible. In fairness one in Germany saved a Danish two-seater Draken once. It was snowing and the pilot(s) couldn't believe that the white! in front of them at minima was the runway. They believed him the second time around!

As said you can still have a PAR over here: Aalborg, Karup, Skrydstrup. And ILS to five of the six runways. This is not because we are very clever or rich, but as joint user airfields the civil part put in the ILS'es. When they asked the air force to pay some of the running costs, they got the answer: "Oh no, we don't use the ILS as primary aid, but our own PAR." So I guess it stays.
For some reason the HAT is 100´for the PAR, and 200´ for the ILS, (some pilots/aircraft combination), which is also significant.

Best regards

[Captain Sand Dune]

Of course you could go the way that we in Oz did some years ago - decommission ALL PAR installations in favour of ILS.
I was trained to fly PAR approaches as a young sprog on pilot course, and some years later trained others to do the same. Can't speak highly enough of the PAR as an approach aid (except the piece of kit that's been described above - sounds dodgy!:yuk: ) mostly because (as mentioned above) it's NOT a pilot interpreted procedure. Got to be a plus when trying to land an aircraft with an emergency in c**p weather. Just do as I'm told by the friendly controller and hey presto - out I pop at 100FT above the runway on centreline.
Our ILSs' are only CAT 1 - ie 200FT DA, and their serviceability is just as good (or bad, whichever way you look at it) as the PAR installations were.
All in the name of saving money though..................

[pilot2454]

For all those interested:

Valley and LLanbedr (and cranditz?) still have the old PAR and will have for a year (thats how long they are letting them keep it) until they sort the new one out.

Local orders now state that there are to be no appraoches to land, in IMC, unless you have sufficient fuel for an alternative approach.

Anyone form Linton care to shed light on the problems you are having seeing as you have to have PAR monitoring for your ILS's?!!

[Tourist]

You notive that Yeovilton has found a way to solve the problem in a typically RN gash it kind of way:rolleyes:

[LXGB]

At the risk of flogging a dead horse...

Any news about a fix for RPAR so that it can actually be used in anger without restrictions?


LXGB

[OKOC]

Slightly off-thread admittedly, but why haven't we fitted TCAS to ALL our ac-it is PROVEN to save ac and crews, and how many more Hawks need CFIT before they are allowed a rad-alt despite goodness knows how many BOI's have recommended it. It can only be cash can't it-but just ONE ac saved will pay for both the above.

[16 blades]

From a driver's point of view, I much prefer ILS as an approach aid - everything I need is right in front of me - much better SA. I'm no fan of PARs in general, however, RPAR is a royal pain in the arse. You can go from "Well above glideslope" to "Well below glideslope" in a matter of seconds, with a perfectly acceptable ROD on. It appears to be WAY too sensitive.

There is little point in having an instrument approach aid that has restrictions in IMC. Come the day of sh!te weather and an emergency / limited fuel, RPAR would be my LAST choice, every time.

16B

[LXGB]

With you 100% on that one 16 Blades.

We have to call slightly above/below when your data-block indicates more than 20 feet from the glidepath. Begs the question, what's the height of a C130 from nose wheel to top of tail?
Not really sure why we don't use the old CR62 criteria which are still published in JSP552. As you say the numbers do leap wildly up and down the GP at times. By watching the blip rather than the data-block you get a much better feel for the true profile of the aircraft.

Here's another can of worms. How would you feel being constantly told you were slightly above or below glidepath on an RPAR monitored ILS?

Cheers,
LXGB

[Eric Aldrovandi]

I should hope that an ILS is easier when there are two of you flying the thing, plus two others to help you read the TAPs, mop your brow and wipe your arse and you only do 100 knots anyway.

Try flying an ILS with any (major) emergency in the Tonka and you'll wish you had the extra help...

[16 blades]

Two of us 'flying'? 100kts?

Never flown in Albert then, Eric? All the P2 does is call "200 above", "100 above", and "decision", and monitor. Am I missing something, or aren't there supposed to be 2 of you in a Tonka? Eng plays no part in the approach, Nav gives you a ROD to fly, but otherwise plays no part in a precision approach, except in the event of an overshoot. And sh!t weather is sh!t weather, whatever type you fly. Same for emergencies.

Our approach speeds vary according to AUW, but you can hang your hat on 150kts with 50% flap and 130kts with 100% (or 165kts with no flap - considered an emergency)

LXGB
I'd tell the controller to shut the f**k up, whilst I was flying a pilot-interpreted aid - politely of course! I've always found radar monitoring of an ILS rather curious - it is (in my experience) obvious when something is amiss with an ILS, at either end. A quick bit of mental arithmetic will tell you whether a GS needle is telling you the truth, and good SA will do similar for the localiser. Radar monitoring is just a waste of controller's time, IMHO.

16B

[J Urby]

While controlling at Bruggen during the Kosovo campaign late '91, i wondered why all og the Tonka crews would ask for a PAR at the end of the sortie but the VC10's would normally ask for an ILS, esp when the skys were gin clear with 40km vis. So, one morning at around 6am when we had all retired to the bar after a successful mission, i asked the pilot of a GR1 and the answer was quite simple. After an 7/12 - 8 hour sortie which included 2 refuellings in thunderstorms interspersed with a bombing run with some light flack, they were absolutely knackered and numb (physically and mentally) so when in contact with home ATC they would ask for a PAR because all they had to do was respond to up/down, left/right and look out approaching DH. They also trusted the Controllers to give them a good service:} Of course, the VC10 crews had a slightly easier time of it and so still had a bit more in reserve.:E So i guess there is a good reason for PAR. But while RPAR might be great on paper, it does occasionally jump from one ac to another and that needs sorted pronto. Problem is that the company say there is nothing wrong and that we got what we asked for. also while it has not been commissioned/fitted at Valley etc, we have already paid for them so tough accoding to one engineer!

[16 blades]

I would actually say the opposite is true - an ILS requires much less capacity and concentration to fly. It's all laid out in front of you - all you have to do is chase the needles (not that I would do that of course - I would use the correct techniques as taught to me during training!!). With a PAR you have to listen to the controller, interpret their instructions, translate them into actions, and guess at exactly what rate you were closing on the GS / centreline. I suppose an ILS is a bit trickier in an ac without a flt director, but it's been a long time since I've flown one. Do any FJs have them?

16B

[LXGB]

"shut the f**k up"

I thought you'd say that! :) Wish someone would tell our trappers :(

LXGB

[Canary Boy]

I’ve delivered a few talk downs in the last 20+ years of controlling, to all manner of aircraft types. I’ve done plenty ‘in anger’ to guys with emergencies and/or fuel shortages in p*ss poor weather. In my experience (mainly on CR62) the PAR approach was the favoured way of getting back to the runway. I was always left with a warm feeling of satisfaction when the approach was successful (ie the guy was able to land) and that satisfaction was often underlined with a subsequent phone call from a happy customer, (mind, I learnt quite a lot from the phone calls after my not-so-good talk downs!) Our problem is not so much with the new RPAR kit, as the manner in which (new) controllers are taught to use it. Gone are the days of having a conversation with the pilot with an ability to stamp one’s own persona on the way the approach was controlled. I always tried to picture myself on the receiving end – what would I like to hear? It seemed to work…

[Farfrompuken]

Someone posed the quesion of ILS in the Tin-Can with no PAR monitoring/SRA only monitoring....

You simply have to treat the ILS as a LLZ only procedure and apply the appropriate MDH.

We have a problem with sticking G/S needles (nice!) so you have to constantly refer to the DME vs Ht data on the TAP even on a monitored ILS for that warm and fuzzy feeling.

Basically I don't ever use the PAR, since if it's cr@p there's the monitored ILS and if it's better than that you're practically obliged to use SRA to steer clear of the limitations.

The current RPAR is a fantastic piece of kit for sanitised class D airspace operations, but for the humble MATZ with all it's various traffic it is a waste of space.

Tin-Can due for TCAS which I believe may also provide non-sticking needles - might avoid need of monitoring, lets hope.

[Shagster]

That is a very contentious comment. The training of RPAR controllers is exactly the same as it was for CR62. The problems occur because of the extra restrictions put on the kit because of it's unreliability, and the changes made to passing information on the ac's relation to the GP based on a height/Alt chart rather than the ac's radar/digital response.

WTI can gives good indication of how an ac is correcting to the GP but, we're not allowed to use it! Sensitivity of the equipment leads to a variation in ralation to the GP for high tailed ac ( 1 reading from the tail, 1 from the UC) leading to controllers having to judge a mean. If they don't then the pilot is flooded with GP correction info.

I'd say that RPAR has the potential to be very good...it is accurate and unaffected by weather/clutter. But there is no doubt that software glitches need to be dealt with AND confidence restored in its use both by controllers and aircrew.

[jack-oh]

I have just posted this on the ATC forum, but its about the same subject so I will copy it here as well.

As far as I am aware, the RPAR fix will be rolled out this summer and therefore hopefully the problem will go away. However, the reason that you have to select the ac contact that you are going to provide a talkdown to is fairly simple. When you select the ac the system allocates extra beams from the surveillance side of its workings to track the ac that you are interested in (13 I believe) this enables the system to obtain the level of accuracy required in order to provide a talkdown.
As for going back to CR62, I think the problems with RPAR have made you nostalgic for a past that never existed. If you want: excessive clutter, contacts the size of mars bars, survoing, utter confusion when doing 2 talkdowns at once, a system that you had to physically lock down in high winds, mechanically turning gears that took 10 mins to change runway (if they didn’t stop halfway through), a system that spent half it’s life on maintenance, a DH cursor that you had to be a safe cracker to set right and endless knobs switches and buttons to press in an attempt to make the picture work then you are welcome to it. As far as I can see RPAR is a welcome step forward, yes, it has had its problems but half of them were our own bloody fault. Who trials a new system in the Falkland Islands and then never goes down to see it, or appreciate what it will do in a busy environment. What company gives you a multi-million pound piece of kit but then doesn’t tell you how to operate it until it has been installed for over a month.
The introduction of RPAR has seen its fair share of problems, but has exposed us in ATC to the big bad world of procurement, and we have looked a little naive to its ways to say the least.

Go back to your CR62 Luddite, but I guarantee that within 2 years you will be sitting in front of a blank screen, because no company on Earth will be manufacturing the wiggly bits inside it.

[Flobadob]

Hear hear Jack-oh.

You hit the nail on the head. Which @**%~ ordered the kit to be trailed down the FI? Come on own up!

Probably retired now on full pay and won't ever have to worry about flying his jet back on a dark january Lincolnshire night, fuel priority, hyd fail, and the weather going YLO/AMB, ILS tits up and a No1 div of VLY.

[KPax]

PAR monitored ILS I would only tell you if you were below/well below the Gp. At EGDL we offer IFR/VFR PAR's. Another option that would be easy to initiate is to turn the labels off and control the 'blip'. The C130 appears to jump up and down through the GP and it is often best to give an average, not easy for the new controller. Overall it is much better than the CR62 and when they sort the 'Sim' mode out that will be a great help also.

[Fox_4]

Hey Beagle

Save yourself the cost of the dial-up for your useless posts and then the 17000 quid you spent on fm immunity gizzers wont feel so bad.

Mil ac fly PARs because the moneys not there to fit ILS everywhere and anywhere we go. Plus, a nice female voice on talkdown is a welcome sound after a crappy night.

Maybe Ive got this wrong but it appears you are the ultimate, self professed knowledge on everything.

Frankly Im a bit bored.

[Tourist]

Now Now Fox..
Don't you realise you're on the wrong thread for Beagle abuse?

[BEagle]

Fox_4 and your remora, the last time I made any comment on RPAR was 16 months ago.

Glad you're so sharp.....

[Moe Syzlak]

I'm all for an ILS-but no mil combat ready FJ has a flight director that is cleared for use except the Jag-so why make life difficult. It is much more difficult to deploy an ILS than a mobile PAR-so that might be a factor-no point turning up somewhere and having NO bad wx aid available if the ILS got vandalised in 1984. To say that the military should toe some imaginary ILS line because the owner of some puddle-jumper must do so is a bit silly. Perhaps all aircraft on the civil register should be maintained to mil standards or be procured in the same (smart!?!) manner.