Neither fish nor fowl?

[bookworm]

I've just completed a week of training at Bournemouth -- thanks to ATC there for your professionalism and helpfulness.

There was however, something that caught my attention...

On a procedural approach I'm responsible for flying the procedure as charted, which guarantees obstacle clearance. On a radar vectored approach, ATC looks after my obstacle clearance until I'm established on final.

On a few procedural approaches, after reporting beacon outbound I was instructed to maintain the outbound track and level. On at least one occasion I was taken beyond the end of the 6.5 DME outbound leg before being allowed to turn. So the obstacle clearance of the procedural approach is no longer valid.

Who's looking after my obstacle clearance?

[A I]

Well Spotted!!

You are actually because you are the only one who knows where you are. Inevitably, on a procedural approach there will be times when the controller needs to extend you outbound before permitting a turn. It is your responsibility to maintain a safe altitude but the controller, bearing in mind that he/she has an intimate knowledge of the surrounding terrain, will normally take this into account.

If you want proof of my reasoning look at the investigation into G BDAN where a controller changed the clearance very late and gave an extremely poor and misleading clearance which resulted in the B727 flying into a mountan. The inquiry blamed the pilots completely.

A I

[brimstone]

I've no experience of providing procedural approaches but I would imagine that in a completely non-radar environment a controller would be skating on extremely thin ice issuing instructions which took the pilot off a procedure unless the pilot was visual with the surface and happy to comply.

Bournemouth does of course have radar therefore I would guess that Bookworm was asked to extend outbound in order to expedite the commencement of his approach while at the same time allowing another aircraft to pass underneath on the ILS or something similar. This would then provide suitable spacing on final approach.

The radar controller is responsible for ensuring that levels he assigns provide adequate terrain clearance for the phase of flight, therefore I would say that even though Bookworm was carrying out a procedural approach, the controller was taking responsibility for the obstacle/terrain clearance.

[Scott Voigt]

In the US if the controller does anything that would take them outside the confines of the approach, the controller is the responsible.

regards

Scott

[bookworm]

Thanks for the replies

The radar controller is responsible for ensuring that levels he assigns provide adequate terrain clearance for the phase of flight, therefore I would say that even though Bookworm was carrying out a procedural approach, the controller was taking responsibility for the obstacle/terrain clearance.

I agree, and that was certainly my assumption, but I'm always uncomfortable about assumptions. However, looking at MATS Pt 1 Section 1 Ch 5 13.1 (which is effectively what you quote), it looks pretty explicit that when under a Radar Control Service and under IFR, the controller is obliged to look after terrain clearance for any assigned levels. I wonder if it's worth making that explicit as the aircraft is pulled off the procedure?

[normally left blank]

Good question. In effect the controller will often "mix" radar and procedural. That is let the pilots fly the procedures and modify them to get a faster flow. (and using radar separation)

On a CAA check flight here, I believe you would flunk if not asking:
"Confirm this is radar control?", on a modified procedure. (Or below MSA)

Best regards