I was reading about this incident where a near miss occurred in class B airspace between IFR and VFR flights that were in contact with different controllers.

So I would like to know which controller normally gives the clearance to enter class B airspace to a VFR flight? When entering from class E, does the area controller provide the clearance or the approach controller of the airport whose class B it is? And is the flight then handed off to the appropriate approach controller? And when the aircraft then crosses from one class B airspace to another?

That particular incident happened cut from skyvector showing the location of the abovementioned incident
at 4000 ft amsl. This chart does not list frequency for that airspace, but it is clearly airspace of the (Danish) Kobenhavn/Kastrup (EKCH) airport. But it is in Swedish airspace and Sweden area (ESAA). The VFR flight was flying from east to west, so must have crossed from other class B sector that apparently belongs to Malmo (ESMS) about 5 nm earlier. So does it make any sense it was (still) talking to Swedish controller (the article is not absolutely clear, but seems to say it was Sweden area, not Malmo approach) while the other flight was talking to Kobenhavn approach?

Obviously I am not trying to find what happened; the investigation will hopefully eventually explain that. I'd just like to understand what the normal procedure in such situation is.

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    $\begingroup$ It's class C not class B, according to this part of Swedish AIP describing parts of Swedish national airspace where ATC is delegated to Denmark; see area L2. Class B is not used in Denmark at all. (Not that this matters much because class C does require a working mode A+C transponder as well as ATC clearance for VFR). $\endgroup$ – hmakholm left over Monica Jan 15 '15 at 18:06
  • $\begingroup$ @HenningMakholm: Hm, I just assumed the skyvector chart is consistent and blue borders always mark class B while class C would be purple. $\endgroup$ – Jan Hudec Jan 15 '15 at 20:00
  • $\begingroup$ SkyVector charts are based on the old ONC "1 mill" charts, which use blue lines for ALL types of airspace. You are making assumptions based on US Sectional charts, but these are NOT Us Sectionals. $\endgroup$ – RAC Nov 2 '17 at 10:13
  • $\begingroup$ @RAC, I am pretty sure skyvector was (I don't see it there anymore) showing a key somewhere with those symbols somewhere, though they never applied outside USA. $\endgroup$ – Jan Hudec Nov 2 '17 at 20:58

The airspace in which the mentioned incident took place is not classified B. In fact, no class B airspace exists in Denmark or Sweden at all.

The incident did take place in København TMA (which is airspace class C).

So I would like to know which controller normally gives the clearance to enter class B airspace to a VFR flight?

I don't know how this works in the USA, but in most of the world, it is very easy to figure out which ATC unit is responsible for a specific airspace. All aerodrome specific airspaces, such as control zones, are listed in the appropriate AD 2 section of the AIP. For all other airspaces, including TMA's, you should look at the ENR 2.1 section of the AIP.

If you look up the airspace in question in AIP Denmark, you will see that the responsible ATC unit is Copenhagen APP, specifically the approach east sector (118.450 MHz). So, the specific unit who will give clearances to enter this specific airspace is Copenhagen Approach. There is no general answer to your question, since different procedures are used in different places.

When entering from class E, does the area controller provide the clearance or the approach controller of the airport whose class B it is?

There is no class E airspace to be found around the position of the incident. Plenty of G, though.

The ATC unit responsible for providing service in a certain airspace is the only unit who can give a clearance to enter such airspace. In the specific case, Copenhagen Approach is (naturally) the only unit which can issue a clearance into its airspace. If such a clearance is received by another ATS unit, it has been initially provided by Copenhagen Approach and then forwarded to another unit to pass on to the pilot.

And when the aircraft then crosses from one class B airspace to another?

Again, I think you are assuming that every part of the world works like the USA, which is not the case. What I think you mean is: What happens when an aircraft crosses from one TMA to another? And what you really should be asking is: What happens when an aircraft crosses from one ATC unit area of responsibility to another?

The answer to which is quite simple: the aircraft will be transferred to the next ATC unit, who will then provide appropriate service within its airspace.

So does it make any sense it was (still) talking to Swedish controller (the article is not absolutely clear, but seems to say it was Sweden area, not Malmo approach) while the other flight was talking to Kobenhavn approach?

København TMA - airspace class C - extends from various lower levels to FL195. At the position of the incident, as you have indicated on the chart, the TMA extends from 2500 FT upwards. While Copenhagen Approach provides service within København TMA, service in the airspace below the TMA (which is classified G) is not provided by Copenhagen Approach. Unlike other Danish airports, where the local approach unit will provide service "in, above, below and around" the TMA, Copenhagen Approach is simply too busy dealing with IFR traffic to and from EKCH. Service to traffic below the TMA (which is mainly VFR traffic) is thus provided partly by Malmö ACC (Sweden Control), partly by Copenhagen FIS (Copenhagen Information).

As it so happens, service within Malmö TMA (which is class C, rather than class B as you suggest) is also provided by Sweden Control. There is no approach unit at ESMS - approach control service is provided by Malmö ACC. Therefore, it makes perfect sense that the pilot, coming from the east, was talking to Sweden Control. And since the controllers on the Sweden Control sector had no reason to assume otherwise, they had to believe that the VFR flight in question was in fact below København TMA, in class G airspace, where Copenhagen Approach does not provide service. This is of course not true - the VFR flight was actually in København TMA, for reasons which are beyond the scope of this to discuss - and as such, should have been talking to Copenhagen Approach (and should have been operating a mode C transponder).

At the same time, the IFR arrival (737) was approaching EKCH, within København TMA (class C), and so, was correctly talking to Copenhagen Approach.

What happened then can be read from the incident report. My purpose with this was simply to clear up the misunderstanding concering the airspace in question (which is also what the original question was about).

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  • $\begingroup$ Thanks for clearing things up. My confusion with class B comes from the fact that skyvector uses the symbols it normally uses for that class and the map key does not explain the regional differences. $\endgroup$ – Jan Hudec May 24 '16 at 21:51
  • $\begingroup$ I can definitely see where the confusion comes from. As far as I can tell, Skyvector does not even provide a chart legend/key for areas outside of the US (which I find rather odd!). For someone not familiar with the airspace, that makes their charts more or less useless. Anyway, I'm glad I could clear things up. In case you were looking for a good VFR chat of the area, one is available here: aim.naviair.dk/AIM%20Documents/VFR%20Flight%20Guide%20Danmark/… $\endgroup$ – expeditedescent May 25 '16 at 4:48

I'm assuming you're referring to this where a Cessna 172 had a near miss with a 737: http://www.havarikommissionen.dk/~/media/Files/Havarikommissionen/Havarirapporter/Luftfart%202014/Preliminary%20ATI%20Bulletin%20HCLJ510_2014_273.ashx

Regarding who the VFR pilot should have been talking to, that depends. For example if you're flying in Los Angeles you might get clearance into the bravo for LAX from SoCal Approach if you're taking the "coastal route" through the bravo, or you might get clearance from LAX tower if you're flying the lower altitude "mini route" which directly overfly's LAX runways and tower and you'd be talking to whoever you got clearance from until they handed you off.

It really depends how they've set it up. The terminal area chart (TAC chart) for the bravo airspace contains VFR flyways and procedures including who to contact for clearance. So if you're interested you can get the TAC chart for Kobenhavn and look (usually) on the back of the physical chart where it has more info.

However, having said that: I think this VFR pilot accidentally flew into bravo airspace and will probably lose his/her license. Here's why:

  • Pilot did not have a Mode C altitude reporting transponder which is REQUIRED to fly in to Bravo.

From the report:

Aircraft B was reported to fly at 4000 feet with no radar presented altitude readout.

I'm not sure how "Sweden control" hands off to Denmark, but if he's flying to bravo in Denmark you'd expect him to be talking to someone in Denmark, either the bravo airport's tower or Copenhagen Approach which is who the Boeing 737 involved in the incident was talking to.

If he was in Bravo legally he should have been assigned an altitude, heading and squawk code and ATC should have maintained separation between those two aircraft and the bravo controllers are the best in the world at doing exactly that. So I think he accidentally flew into bravo and was talking to the wrong controller.

Edited: To remove irrelevant detail about VFR altitudes above 3000ft AGL.

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    $\begingroup$ Is the Mode C required in Bravo everywhere or only some countries (including USA)? Because this aircraft clearly flew through lot of Bravo before the incident. Surely if it was a requirement, the controller would have chased him below the floor of the Bravo segment (on SkyVector it looks like he was in Bravo throughout the flight and while it would be possible to fly just below (MSA 1300, Bravo floor 1500) except both his departure and destination airports are Bravo too). $\endgroup$ – Jan Hudec Sep 29 '14 at 12:09
  • $\begingroup$ I think you are making too many assumptions about the cause and speculate about the possible consequences for the pilot involved. The report say there was no radar presented altitude readout. The cause could be either on the transponder side or on the surveillance ground system side. Even if it were on the transponder side, there's no evidence that it was caused by the pilot. I don't know how the Swedish CAA deals with such cases but revoking a license without evidence of misconduct or gross negligence by the pilot seems unlikely to me. $\endgroup$ – DeltaLima Sep 29 '14 at 17:21
  • $\begingroup$ @JanHudec Which controller? Sweden? Which likely doesn't control that bravo. $\endgroup$ – seattle272SP Sep 29 '14 at 21:41
  • $\begingroup$ @DeltaLima If you're suggesting ATC's mode C transponder receiver may have been inoperative, that would have been made very public because it's a potential disaster for bravo airspace. $\endgroup$ – seattle272SP Sep 29 '14 at 21:42
  • $\begingroup$ @seattle272SP I am not suggesting anything, I try not to jump to conclusions prematurely. This aircraft is from 1970, the transponder could be as well. It would not be the first time that an old transponder does not reply to the perfect shaped pulses from a modern Mode A/C/S interrogator while it is responding to interrogations from older Mode A/C radars. There is a long chain of technology between the altimeter and the controller's display. Drawing the conclusion that the pilots license is going to be revoked because of missing Mode C indication is premature. $\endgroup$ – DeltaLima Sep 29 '14 at 22:23

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