Minimum seperation between IFR and VFR
 

Can someone confirm the minimum separation between an IFR flight on a standard instrument departure from a non radar equiped airfield and a VFR flight flying through the over head of the same airfield?

The initial climb clearance for the IFR SID is 2400ft while the VFR flight is asked to fly through the over head at not less than 2300ft. leaving a 100ft maximum seperation. The IFR SID and VFR flights course, means the IFR aircraft flys directly over the VFR aircraft at the said heights.. Is this correct?

There is no separation given between IFR and VFR traffic in that situation.

Thank you for the reply..I'm very suprised though

So is it reliant on visual seperation between the 2 aircraft? What happens if the SID initially takes you away from the VFR traffic but then turns you into it.. Neither one of you can clearly see the other? Believe me flying a 100ft over a piper warrior is a little too close for comfort!!

I know TCAS may be able to offer an RA for the IFR traffic but it needs to be fitted in the first place.

This is a fairly fundamental part of flying. The class of airspace may affect the details of the answer but, essentially, ATC provides separation between IFR aircraft. There is no separation to be applied between VFR flights or between IFR and VFR. ATC should, subject to workload etc., give the IFR flight traffic information on the VFR flight.

Having said that, many controllers will build some space between VFR and IFR flights by means of the clearances issued to the relevant flights. This is partly because it makes things safer and because it reduces the need to pass traffic information.

It must be said that the airspace allocation used in the UK makes the mixing of IFR and VFR flights more common than in other States.

You asked the question about separation - and you have an answer. Whether the situation you describe is good controlling technique - or the optimum way to handle the traffic situation - may be questionable but that's another issue.

what class of airspace? IFR and VFR are only separated in class B and C (I think!)
In a similar scenario even traffic info will not be available if the warrior is unknown (eg operating a few miles from the end of the runway but outside the ATZ and in class G airspace.)

There's an interesting report in the latest CHIRP about pilot's not being aware of the different classes of airspace.

Re TCAS. not much use if the warrior is not SSR equipped.

Littco

Assuming you are referring to a class of airspace where separation is not effected by ATC between VFR and IFR flights, and that the VFR traffic is known to ATC, each aircraft would be passed traffic information on the other if it were evident that they could conflict. In the case of the departure, this would invariably be before take-off - and you could always elect to delay until the potential for confliction had passed .

You refer to a SID, but at a non-radar airport? And going to only 2400 ft ? Either way, you can always request to deviate from the departure - or request an alternative clearance - for safety reasons.

2 s

My two cents..
I have been working in two different enviroment. The first part of carrier without airspace classification ,i.e. each a/c regardless of flight rules was separated by 1000ft/300m(whatever is more applicable) or any other ICAO based minimum.
Later we "dicovered" airspace classification and we felt like "new born" . Since than, no separation were applicable in classes D,E,F,G , between IFR/VFR.
But you always have to have some "personal" separation. IFR departing on SID and VFR orbiting on rwy hdg 2Nm at 1000 ft. It si not mandatory to separate them but as my friend told me " I would separate them due to religious reasons":ok:

Thanks guys.

Spitoon.. That's exactly the answer I was looking for, thank you.

Where does the 100ft separation mentioned come from?

IFR departure climbing to 2400ft against a VFR flight not below 2300ft says to me that the VFR flight and the IFR flight could both be at 2400ft at some stage with those clearances.

The safest place for an IFR flight to be is in solid IMC. Less VFR traffic in there to worry about.

Yes I did say "less"!

Regards,

DFC

DFC

I agree. The 100ft came from a Maximum. The VFR flight has been told not to go below 2300ft the TMA starts at 2500ft, where's the best place he's going to fly.. In the middle of the two. Where's the clearance, in the middle. I appreciate that we're in class G airspace and there is no seperation other than visually but I just am concerned that we can get so close.. As you say IMC is better, Next time though I will certainly allow more spacing before departure if there is any doubt.

With respect, the discussion about the levels is irrelevant - one of the aircraft is VFR, and traffic information has been, presumably, passed to each. Therefore, if you get adjacent to each other, it will be in VMC (as applicable to at least one of you!) That's the name of the game. The unfortunate bottom line is - if you don't like it (and that is quite understandable) - don't fly there, or better still start lobbying to get CAS, radar service to VFRs, better procedures etc etc..

littco, which airport are you referring to? There maybe some folk on here who work at the airport you mention!

It was Biggin Hill..

But I would like to point out that just because I asked this in the ATC ISSUE section that I am not saying this is anyway an ATC issue, I just figured it was the best place to ask and hopefully some light maybe shed on it, which it has and am grateful for.

Biggin Hill has no SID. You were in class G airspace and as such, you were not separated from other IFR flights, let alone VFR ones, unless those IFR flights happened to be working the same unit.

I thought the situation sounded familiar!

As said by others on here, there is no separation between VFR and IFR whether the IFR is flying on a SDR* or not, in class G airspace.

In the situation you describe, I would imagine the ATCO had issued specific traffic information to both parties and quite possibly the ATCO may have slightly delayed the departure until s/he could see the over flight and or was certain that there was no risk of collision, which is what an ATC service is all about after all.

Regarding the not less than 2,300ft part, normally an over flight is asked to overfly not below 2,000ft (providing VMC can still be maintained of course) this is to keep the over flight out of the way of the Tower ATCOs circuit traffic and above the final approach and immediate climb out which is the whole point of having an ATZ however, I suspect one the few trainees may have been on at the time and possibly slipped up and asked for the wrong level, I suspect this was discussed during the trainee's de-brief by his or her OJTI.

I've personally never heard anyone restricting a VFR over flight to not below 2,300ft given the fact that they also can't go above 2,400ft so I suspect a trainee must have been on at the time.

*Standard Departure Route similar to a SID but for us poor people that do not have controlled airspace!

Dizzee Rascal,

Thanks for the Info. I guess by the way you say it,it sounded familiar and it's not the 1st time this has happened..

Have to say where as we normally are cleared for a right at 1mile we where actually told prior to the takeoff clearance to turn at 1.5 miles, we did actually ask ATC for confirmation of this before we started rolling. So ATC did a good job of giving us extra spacing however, I guess though that it just happened we where at nearly the same point at the same time due to a number of other factors.


Also, pilots must follow SID's(some deviation allowing)... does that mean for an SDR we don't?? can we choose not to turn at 1 mile if we decide it's better...

Mostly correct, bookworm. Thames radar and Biggin Approach will co-ordinate traffic so ensure separation, but that is a local agreement and not guaranteed by the requirements that units are working to.

Correct, its not the first time a VFR over flight and an IFR departure have been operating at the same time, it wont be the last!
It sounds like RWY03 was in use therefore right turn at 1NM for jets, turbo-fan and turbo-props, 1.5NM for everything else. When turning right from any other RWY its at 1NM.
See and be seen when operating in class G, remember, there will be unknown traffic with no transponder operating outside of an ATZ even at night and in IMC at all levels along the route of the SDR that you might be flying on.
Better for who?
The AIP entry says: These procedures may at any time be departed from to the extent necessary for avoiding immediate danger. ATC will expect you to conform to the SDR unless you are avoiding immediate danger but not to get to your destination faster.

Better for who?
The AIP entry says: These procedures may at any time be departed from to the extent necessary for avoiding immediate danger. ATC will expect you to conform to the SDR unless you are avoiding immediate danger but not to get to your destination faster.

Thanks Dizzee.. what I needed to know..

Separation during SID from non-radar field
 

Thought ATC would be the best people to ask here.

Whilst waiting on the runway, i was informed of traffic routing through the overhead at 2300 feet. I ackowledged that i had the traffic in sight. Was then cleared for take-off to follow the SID which climbs me to 2400 feet. The first part of the departure took me in a completely different direction from the traffic and so i lost sight of it. The SID then turned us back towards the traffic which we struggled to locate until we flew over the top of him by 100 feet.:ooh:

Additional information is that I was in a light jet that is not required to have TCAS! A daft loop hole in the legislation. Conditions were VMC and I was obviously on an IFR plan.

- At what point do I know that it is ATC's responibility to provide separation (understanding that a visual lookout should be carried out always)? I assumed because I was on a SID i was protected. Must I listen for the word "identified". Do some fields provide separation from the minute you leave the ground?

- By saying that i had the traffic in sight, did I take responsibility? It was not a "with traffic in sight cleared take-off"scenario.

- If it had been IMC would the traffic have been allowed to route through the zone only 100ft bellow the SID?

- Lastly, how do you know whether the controller on tower and approach frequencies has radar or not?

Your answers will help a great deal, thanks.