Reduced Seperation....

[twentypoint4]

... in the vicinity of aerodromes. Specifically the "when one aircraft is following another, the pilot of the succeeding aircraft reports that he has the other aircraft in sight and can maintain own separation" part of it.

What do we reckon "following" means?

Does crossing behind another aircraft on a perpendicular track constitute following?? Or does it apply strictly to following on the same course??

I'm curious as to the type of situation you'd use this as opposed to the other 2 options in the reduced sep. rules?

This might only apply to UK ATCO's, I'm not sure. However it would be interesting to know if there are similar rules elsewhere.

[HEATHROW DIRECTOR]

Typically, in a parallel runway situation with an aircraft establishing on runway A and an aircraft behind establishing on runway B, the aircraft at the back maybe asked to report the one ahead in sight. When this is achieved the pilot may be instructed to provide his own separation. That way, standard separation is no longer required and spacing can be drastically reduced. Until the requirements for this separation are achieved, full IFR separation must be applied.

[twentypoint4]

Ah, ofcourse HD, cheers for that.

Was pretty amazed while observing the TEAM stuff being done by the LL guys and gals this morning actually. They're allowed 2 miles diagonally anyway aren't they?

[HEATHROW DIRECTOR]

I don't know.... guess things have changed since I left.

[elandel]

That is correct - they can use 2 miles diagonally.

[Spitoon]

Reduced separation is also very handy for shifting SVFR flights!

[twentypoint4]

Reduced separation is also very handy for shifting SVFR flights!

It's SVFR flights that are the main cause of my confusion with this rule. The situation I'm thinking of is crossing a light SVFR aircraft via the landing threshold behind a landing IFR aircraft. If they're gonna be less than 3 miles separated but the crosser goes above and behind with the IFR lander in sight, is it then following the IFR lander?? Or have I lost separation?

I'll make sure to get clarification from my mentors at work, however I'm interested in different opinions.

[HEATHROW DIRECTOR]

If the SVFR traffic is fixed wing crossing the landing threshold you should have vertical separation. If SVFR helicopters cross behind landing traffic without vertical the controller will have both in sight so the requirements are satisfied.

[twentypoint4]

Cheers for the response. What if we look at it from a radar point of view though?

Say for whatever reason your colleague in the tower wasn't happy with providing the separation (it's a bit misty). Only 2 of the 3 reduced sep. rules are now left to play with. The IFR lander is with tower and the SVFR crosser is with you on radar, visual with the other and happy he can keep his own separation. If the "following" rule is legitimate for this scenario surely this would be the most expeditious way of getting him across without having to phone tower to check with the IFR if he's visual and happy or waiting till he's landed?

Obviously it's better if they're both on tower's frequency for them to sort out however I've experienced a few tower controllers reluctant to work a crosser. Hence my desire to try and get the rules fully understood!

[HEATHROW DIRECTOR]

When you start "real" training everything will become clearer. If it's "misty" a VFR or SVFR flight may not be operating. In CAS SVFR flights must be provided with IFR separation, hence if one needs to pass another IFR or SVFR flight either vertical or horizontal separattion must be provided. Remember, the question of wake turbulence separation maybe a factor.. Local instructions may overrride certain rules with "deemers". E.g. helicopters operating SVFR on defined routes maybe separated visually when the pilots see each other.

I think you should discuss the questions you have raised on PPRuNe with your training officers and accept what they say..

[de facto]

I remember reading an article on eurocontrol website concerning 'visual own separation' and the result wasnt in favor of it.
I personally dont accept it,ie i never report other traffic insight during a parallel approach...
In anyways always follow your TRaffic resolution!

[reportyourlevel]

I think you should discuss the questions you have raised on PPRuNe with your training officers and accept what they say.

The correct attitude is trust, but check. Never, EVER, be discouraged from asking someone to justify their opinion even if they are more experienced than you or are in a position of authority (such as OJTI or UCE). You do not have to simply accept anything, you are entitled to an explanation to aid your understanding. To be good at ATC you need to know the rules, understand the rules and be able to apply the rules. Each of those three aspects builds on the previous one, so remove the understanding and you'll struggle to apply the rules correctly.

No OJTI worth their salt would have a problem explaining anything and helping you to check it out for yourself in the relevant documents. Also, don't accept the reasoning that "we've done it that way since before you were born, lad" - it simply doesn't cut it. If your OJTI refuses to help you check or gets annoyed with you not simply accepting their point of view, get another one before you waste any more of your training time. Imagine being asked on your board why you did something or other and the only answer you could give was "John said so". Your examiner will be inking his FAIL stamp before you've finished speaking.

[HEATHROW DIRECTOR]

<<I personally dont accept it,ie i never report other traffic insight during a parallel approach...
In anyways always follow your TRaffic resolution! >>

How do you manage operating into busy airfields with parallel runways?

[Tarq57]

Once an aircraft is behind the lateral axis of the traffic you are separating it from, it can be deemed to be "behind" it for the purpose of applying the separation. It does not have to be following the same track.

Otherwise you'd never be able to integrate traffic joining from base with traffic joining via a long final.

You must maintain horizontal separation until you have visual. In practice, the aircraft (VFR) joining from the side holds (if required) at a point separated from the instrument final until either the controller has both a/c in sight, or the holding a/c reports sighting the preceding and able to follow.

Subsequent aircraft on the ILS, if they are clos-ish, are then a factor. The moment the VFR aircraft leaves the separated sector to join the circuit, the tower controller must be able to also visually separate it from any following traffic on the ILS. If this is not possible, the joining VFR a/c should be integrated into the landing stream by the approach controller, who will then use the appropriate separation (usually radar) until the aerodrome controller agrees to provide it (usually once the second aircraft is sighted). Obviously both controllers should be reasonably certain that it will work; that the set-up won't require a go-round.

[ILS 119.5]

Is your post referring to a tower controller applying the separation or an approach radar controller applying the separation?

[twentypoint4]

Tarq57, the post I've been waiting for, thank you. The crosser would in fact be holding at deemed separated points (from final approach) before being instructed to cross.

Is your post referring to a tower controller applying the separation or an approach radar controller applying the separation?

Approach radar.

And HD, thanks for the advice. Any query I post on here will no doubt always be put past my instructors too. Why not also make use of this forum for a bit more help though?!

[Tarq57]

Do you have something called "composite visual separation" in your neck of the woods?

[twentypoint4]

I don't believe so. A more experienced UK controller may know if we do or not?

What is composite visual separation?

[Tarq57]

It may be peculiar to NZ, but it's basically a form of reduced separation where one aircraft is sighted by the controller, and the position and intentions of the other can be ascertained by radar or other means. A few provisos etc.

Don't think too much about it, don't want to provide you with red herrings at training stage, if it's not applicable where you work.

[de facto]

How do you manage operating into busy airfields with parallel runways?

Heathrow director,

'visual own separation' is at pilot discretion only.
If under IFR flight plan, I have the right to be provided legal separation guidance by ATC.
If i accept the own separation, ATC is not required to provide separation anymore and I dont accept it.
TCAS(as an extra tool to aid in separation(vortex) is not appropriate so far as it doesnt provide deceleration information of the aircraft you are visual with.

I have operated many years in busy airspace around the world during parallel approaches and never was I told off by not accepting a own visual separation.(undirectly by not having the traffic in sight).

My preference, thats all:)

[LEGAL TENDER]

If the SVFR traffic is fixed wing crossing the landing threshold you should have vertical separation. If SVFR helicopters cross behind landing traffic without vertical the controller will have both in sight so the requirements are satisfied.

HD,
what's the fixed or rotary wing distinction got to do with SVFR separation?

[HEATHROW DIRECTOR]

Legal tender... nothing in the book but would you cross a fixed wing over the threshold without vertical? Blowed if I would!

de facto. OK, I accept what you say. In 31 years of working parallel approaches I never had a pilot refuse separation so it came as some surprise.

[Spitoon]

rice.and.pea, I don't know if this will be of any help but in case it is, here goes....

First the basics - IFR and SVFR flights have to be separated in some way. MATS Part 1 provides a variety of different separations (your Part 2 may authorise some more) - the game is to have at least one of these separations in place at all times.

When you are providing radar services you separate aircraft by a minimum of 3NM (or whatever else is specified for the equipment and airspace). In the vicinity of an aerodrome you are allowed to reduce the separation in certain circumstances. The rules say:In the vicinity of aerodromes, the standard separation minima may be reduced if:
a) adequate separation can be provided by the aerodrome controller when each aircraft is continuously visible to this controller; or
b) each aircraft is continuously visible to the pilots of other aircraft concerned and the pilots report that they can maintain their own separation; or
c) when one aircraft is following another, the pilot of the succeeding aircraft reports that he has the other aircraft in sight and can maintain own separation. If I understand the example you have given correctly you are providing 3 mile separation on radar between crossing traffic and an aircraft on final and you want the crossing traffic to go behind the lander (maybe at right angles to the approach?).

In this case I don't believe you can really say that the crosser is following the lander because, amongst other things, the tracks are diverging.... particularly after the approaching aircraft has landed! So option C can't be used. Option B is out because the pilots of the landing aircraft are not going to be able to see the crosser behind them. Which leaves option A - which is the one which is most useful in this particular situation. All it needs is the tower controller to be able to see the crosser and watch it as it passes through the approach. But if you have an uncooperative TWR or the weather conditions are such that TWR cannot see the crosser then you will have to find one of the other separations in the book to apply.

The 'one aircraft following another' option is particularly useful if you are working in a zone with a lot of SVFR flights and you have perhaps three or four at the hold waiting to go or maybe a couple holding outside CAS wanting to land. In this case, let's use the departures as the example, you can clear the first one out in the normal way and the subsequent aircraft each to follow the one in front of it - now all you have to do is hope that the first one doesn't get lost!

Hope this helps... a bit, but least!

[FlightPathOBN]

Here is an excerpt from AC90-23F...this should get things going...


Per FAA AC 90-23F;
12. PILOT RESPONSIBILITY.
a. Government and industry groups are making concerted efforts to minimize or eliminate the hazards of trailing vortices. However, the flight disciplines necessary to ensure vortex avoidance during VFR operations must be exercised by the pilot. Vortex visualization and avoidance procedures should be exercised by the pilot using the same degree of concern as in collision avoidance.
b. Pilots are reminded that in operations conducted behind all aircraft, acceptance of instructions from air traffic control (ATC) in the following situations is an acknowledgment that the pilot will ensure safe takeoff and landing intervals, and accepts the responsibility for providing wake turbulence separation.
(1) Traffic information,
(2) Instructions to follow an aircraft, and
(3) The acceptance of a visual approach clearance.
c. For operations conducted behind heavy aircraft, ATC will specify the word “heavy” when this information is known. Pilots of heavy aircraft should always use the word “heavy” in radio communications.
d. Heavy and large jet aircraft operators should use the following procedures during an approach to landing. These procedures establish a dependable baseline from which pilots of in-trail, lighter aircraft may reasonably expect to make effective flight path adjustments to avoid serious wake vortex turbulence.
(1) Pilots of aircraft that produce strong wake vortices should make every attempt to fly on the established glidepath, not above it; or, if glidepath guidance is not available, to fly as closely as possible to a “3 to 1” glidepath, not above it.

There are several very deciding issues on responsibilities in this order…

#1 Every pilot is responsible for wake turbulence avoidance in accepting ATC commands.
#2 Every pilot is responsible for their respective wake turbulence.
#3 Every pilot is responsible for the wake created by the aircraft in front of them.

[HEATHROW DIRECTOR]

But that's Stateside. We're talking UK... and herein lies the problem of raising such questions on PPRuNe when they should be directed elsewhere.

[twentypoint4]

Cheers Spitoon. I think you're probably right. I know it must sometimes be hard for the writers and editors of these books to explain the rules clearly however it can be annoying when something slightly ambiguous like this turns up.

HD. Why do you have a problem with me posting such a question on these forums? The header for this particular area of PPrune says...

A place where pilots may enter the 'lions den' that is Air Traffic Control in complete safety and find out the answers to all those obscure topics which you always wanted to know the answer to but were afraid to ask.

I know I'm not a pilot, but I'm pretty sure I'm fulfilling the asking about obscure topics part. I'm also pretty sure I stated in my first post in this topic that I'm applying this to the UK but would be interested to hear from people overseas. If a thread's getting a bit clogged up for you can't you just leave it to others to discuss?