UK CAA heel dragging on GPS approaches, including LPV, and approaches with no ATC, and CAP1122

Hi there,

Any sign of new LPV approaches in the UK? There seemed to be a lot of momentum at one point planning to release them around this time but I haven’t heard much since.

DMEarc

Liverpool and Lands End look promising for 2016 – consultations just closed according to this

In a baffling design Liverpool propose GNSS approaches which you cannot use without the LPL NDB

I’ve read that missed approaches based on conventional navaids can be placed closer/tighter than missed approaches that are based on RNAV waypoints. Liverpool airport is close to Manchester airport. It could be that to make an an LPV approach to Liverpool RWY 09 without having the missed approach interfering with traffic going into Manchester the missed approach must be based on the locator LPL.

But whats the rational for that?

GPS less accurate than NDB?

Bathman wrote:

GPS less accurate than NDB?

Unless it is an “authorisation required” approach, an RNAV missed approach requires 1 NM accuracy 95% of the time. If I understand PANS-OPS correctly, that is indeed worse than the accuracy you expect when passing overhead an NDB.

Of course in practise most of the time GPS-based RNAV is more accurate than that, but when designing a procedure you have to use the certification figures.

It could be that to make an an LPV approach to Liverpool RWY 09 without having the missed approach interfering with traffic going into Manchester the missed approach must be based on the locator LPL.

I can only see the approach plate for runway 27 (although 09 is also included in the proposal). For runway 27 and with Manchester is to the east of Liverpool, I don’t think the NDB should be relevant (see proposed plate). The missed approach procedure is to climb ahead turning right to 2000 feet, then hold over the beacon. In reality you would be radar vectored around for another attempt. The plate does state “Missed Approach Procedure not available without LPL NDB” so I guess you could argue whether you actually need to have the missed approach procedure available to make the approach in the first place (eg ask for an alternative missed approach procedure either dependent on GPS or radar vectors).

But yes, it does seem there is some real “head in the sand” thinking regarding the design rules for these LPV approaches in the UK. This differs considerably from the 100s developed across France and Germany, never mind the US. Once approved, it would take a lot of time/effort/cost to remove that requirement which then filters through to needing the same obsolete and expensively maintained kit in every aircraft that uses it.

Alternatively, give us blanket approval to substitute GPS for known ground aids like they do elsewhere.

PS: Consultation responses close tomorrow 14th October, so little time to fill in the 2 page form and send it in by post (Document here). I can’t find a fax or email address to use instead.

Bristol has LPV now.