GPS approach question

[glush]

Hi all,
Having looked at the plates for a couple of the UK approaches, I was curious to find out how the procedure works to fly back to IAP or FAF having executed a missed approach? There is no 'outbound leg' shown on any of the approaches I looked at - nor is there any evidence of a procedure turn etc... Is it the case that the GPS sequences the IAP or FAF as the next waypoint after the MAP and therefore you fly direct?
Thanks for any comments....

Cheers
glush

[belowradar]

For some odd reason UK gps approaches require conventional NDB for missed approach. If you look at Shoreham the missed approach is to climb to the NDB, after that you hold, divert or go direct to the IAF for another approach.

GPS Can figure out track direct to IAF (not the one on the straight in approach but hopefully one at either end of the T )so no other course info required.

Hope this helps, any others care to add any other info ?

[glush]

Many thanks Belowradar... I wondered if that would be the answer, but it just seemed too obvious! Aviation isn't supposed to be that simple :-)

[Another_CFI]

Belowradar, Not all GNSS approaches in the UK require the use of an NDB for the missed approach. One such example is at Lydd.

[belowradar]

Another CFI - Thanks for pointing that out ref Lyd

Maybe I have been too harsh on UK GPS - well done Lyd !

[IO540]

There is no outbound leg because if you have decent navigation you don't need one.

In the goode olde dayz, a pilot had only a slight idea of where he was. He would be tracking towards an NDB and he had no real idea how close to it he was until the needle flipped around. Then he could be sure he just went overhead the beacon. So one flew an outbound leg (on the stopwatch) and then tracked back in towards the beacon.

The historical need for the outbound carried over to VOR approaches, even when DME became available.

With RNAV (and GPS is one form of RNAV; others may be INS or Loran, etc) you don't need to waste time doing this. You can self position a few miles out, at a certain height, and just fly the inbound...

One could do the same with a VOR/DME approach by positioning on a DME arc and then "intercepting the localiser" off that, but it didn't happen that way.

GPS approaches usually have several IAFs, which is your initial waypoint that you fly to when cleared for the approach.

The main thing to remember about GPS approaches that have multiple stepdown fixes (for obstacle clearance) is that the GPS reads the distance to the next SDF. Whereas on an old NDB/DME or VOR/DME (or ILS) the DME will read the distance to the runway.

I don't fly GPS approaches because I cannot find an avionics shop capable of generating the paperwork for my KLN94 (3 or 4 have tried already) and because every place I go to that has one also has a normal IAP (which can be flown using a GPS anyway), but I think the UK CAA wants to draft all theirs so as to avoid the above "DME" issue, IOW have no SDFs after the FAF. That's what they did on the Shoreham EGKA one - no SDFs, just one continuous descent.

[xtigs]

Greetings all. Is there any way to check if GPS/RNAV Approaches can be used in the Philippines? Particularly as sole means navigation system while the DVOR in Manila RPLL is out? The Civil Aviation Authority of the Philippines (CAAP) has authorized its use while they are repairing the DVOR but as far as I know the Philippines has not been WGS surveyed in a long time. Is there any way to verify this?

[HueyLoach]

I have never flown there but in general to use the GPS equipment to fly an approach procedure, the civil aviation authority must publish the appropriate charts for the procedure. These should be labeled as VOR/GPS RWY XX or VOR OR GPS RWY XX or in the case of stand alone gps approaches; RNAV (GPS) RWY XX or just GPS RWY XX approach. If the chart is labeled VOR RWY XX, a VOR is required.

[flatfilea4]

I can't see any GPS approaches published for Manila RPLL - no notam for the MIA VOR - but the both 24/06 ILS are notam u/s until the end of July - but this does not mean much seeing as how the system works in the philippines.

I can't see any way to use GPS for an approach at RPLL. The Philippines does not appear to publish overlay approaches. I do know however that some local pilots and instructors there follow FAA guidance for substitution.

Cheers
flatfilea4