DA62 G-MDME calibration flight down - Dubai

The late David Philips posted that they use specialised differential GPS equipment to fly very precise tracks, presumably on autopilot, while recording the LOC/GS signal levels etc.

Not sure if IFR/VFR would have made any difference to wake turbulence encounter?
Or do we expect IFR-IFR lateral/vertical separation to naturally take care of that?

As VFR on “own navigation” one still need to keep lateral/vertical traffic distance as in IFR-IFR (but this guidance fall as PIC responsibility), in the other hand the wake separation is solely based on time & weight categories, I am not sure how you manage both these? surely there are some flying speeds where traffic/wake separation breaks? those DA62 do fly like a badass low & fast over the runways, I once though it was an airshow at Southend…

airways wrote:

Correct, @Malibuflyer. Calibration flights file VFR because they want the flexibility of VFR, and with that flexibility comes greater responsibility.

Here, we do calibration flights under IFR and ATC is responsible for IFR/IFR separation (including wake turbulence).

Guillaume wrote:

Here, we do calibration flights under IFR and ATC is responsible for IFR/IFR separation (including wake turbulence).

What I understand from “VFR maintain own traffic/wake separation”, it is PIC role to ensure separation criteria are met similar to IFR/IFR, or it does mean you can get closer than IFR/IFR separation criteria for wake/traffic?

While VFR, I got suggestions by ATC to relax mine on visual circuits as they seemed too conservative for them (asking to climb when IFR traffic is on final to maintain 1000ft vertical or asking to orbit few minutes on base leg when heavy IFR traffic has just landed for wake)

Ibra wrote:

Or do we expect IFR-IFR lateral/vertical separation to naturally take care of that?

Not necessarily “naturally” but less than half of IFR separation which the plane had at the time of the accident surely did not help!Ibra wrote:

in the other hand the wake separation is solely based on time & weight categories, I am not sure how you manage both these? surely there are some flying speeds where traffic/wake separation breaks?

IFR wake separation minima are defined in terms of distance. And if the following plane is faster than the preceding one (a not so common but no impossible case if the following plane is in a lower wake category…) it is the job of the controller to still maintain separation distance by issuing speed restrictions, planning for more distance in the first place, etc.

But in the case discussed the flight has been performed under VFR. Controller is not responsible for separation. He did, however, give advice to the pilot that separation is below normal IFR limits on the first 5 approaches. In these approaches he realized, that the pilot did not care about this kind of advice and consciously flew with significantly reduced distance (which is legal and at the pilots discretion under VFR). After realizing this, the controller saved the airtime on the frequency by no longer issuing such advice. That is understandable.

Ibra wrote:

What I understand from “VFR maintain own traffic/wake separation”, it is PIC role to ensure separation criteria are met similar to IFR/IFR, or it does mean you can get closer than IFR/IFR separation criteria for wake/traffic?

I think what that means is “don’t hit anybody and don’t crash”. I don’t believe a pilot is ever required to judge distance for legal separation while simultaneously flying the plane. Am I wrong?

Ibra wrote:

What I understand from “VFR maintain own traffic/wake separation”, it is PIC role to ensure separation criteria are met similar to IFR/IFR, or it does mean you can get closer than IFR/IFR separation criteria for wake/traffic?

It does mean it’s the pilot decision. Period! IFR/IFR separation is formally meaningless for VFR operations (obviously with the exception that the OM of the operator does not state that under these ops the IFR-criteria should be applied also for VFR approaches – which is not uncommon. And in the case we discuss here the ops manual said exactly this. But it’s the pilot and not the controller’s responsibility to follow the ops manual). Therefore legally the pilot can fly as close to the IFR traffic as he wants.

It’s a different story, that there is a reason behind those IFR minima and it might be a good advise to stick to them even if one is not legally obliged…

Silvaire wrote:

I think what that means is “don’t hit anybody and don’t crash”. I don’t believe a pilot is ever required to judge distance for legal separation while simultaneously flying the plane. Am I wrong?

The only case I am aware is about “staying closer” than “separating”: lateral 1 km (0.5 nm) and vertical 30 m (100 ft) from formation flight leader when you get clearance to enter VFR in CAS under formation and you are stying “join-up” (SERA.3135), don’t think there are IFR clearances for formation flying, one should leave that to military/gliders inside class G clouds

Malibuflyer wrote:

It does mean it’s the pilot decision. Period! IFR/IFR separation is formally meaningless for VFR operations (obviously with the exception that the OM of the operator does not state that under these ops the IFR-criteria should be applied also for VFR approaches – which is not uncommon….that there is a reason behind those IFR minima and it might be a good advise to stick to them even if one is not legally obliged

Got it thanks, no “legal need” to keep IFR/IFR for VFR private flying in CAS, still highly advisable (a different story)
Obviously at some point one should not get closer than 1km/100ft unless the other guy agrees

Ibra wrote:

What I understand from “VFR maintain own traffic/wake separation”, it is PIC role to ensure separation criteria are met similar to IFR/IFR, or it does mean you can get closer than IFR/IFR separation criteria for wake/traffic?

There are 2 types of separations :
Traffic separation : is provided by ATC according to the flight rules and the class of airspace you are flying in.
Wake turbulence separation : The EASA regulation (Part ATM/ANS) says :

ATS.TR.220 Application of wake turbulence separation
(a)Air traffic control units shall apply wake turbulence separation minima to aircraft in the approach and departure phases of flight in either of the following circumstances:

• an aircraft is operating directly behind another aircraft at the same altitude or less than 300 m (1 000 ft) below it;

• both aircraft are using the same runway, or parallel runways separated by less than 760 m (2 500 ft);

• an aircraft is crossing behind another aircraft, at the same altitude or less than 300 m (1 000 ft) below it.

(b) Paragraph (a) shall not apply to arriving VFR flights and to arriving IFR flights executing visual approach when the aircraft has reported the preceding aircraft in sight and has been instructed to follow and maintain own separation from that aircraft. In those cases, the air traffic control unit shall issue caution for wake turbulence.

Two examples

• A light VFR aircraft taking off behind a medium / heavy wake turbulence aircraft will receive wake turbulence seperation instructions from ATC in a class D CTR (even though ATC will not provide traffic separation once in the air)

• A light VFR aircraft approaching to land in a class B CTR (we don’t have those in France) behind a medium / heavy wake turbulence aircraft will receive traffic separation instructions from ATC but not wake turbulence separation.

When ATC is not in charge of separation, PIC is expected to use it’s own judgement in order to maintain a safe traffic / wake turbulence separation.