View Full Version : Straight in LOC , ALT check
Pitothead
3rd Sep 2009, 12:07
If you do this approach straight in LOC (NO Glideslope) RW07 as the chart dictates. Is it even legal? You have know idea when to descend, and ATC doesn't tell you (radar fix). Ok, in modern aircraft it is easy.. but is this even legal?
In my meaning, the only way to do a LOCALIZER approach here would be to do it full procedure with timing. Any ideas? Thanks for answers.
http://img2.imageshack.us/img2/7184/screenshot20090903at133.png
Intruder
3rd Sep 2009, 13:44
Read note 1. ATC would have to specifically authorize it, and would likely clear you to EDEMO via radar vectors and then descend at TRE. No problem.
I have done this LOC approach, EFIS LNAV a/c. Self positioning FMC approaches were not allowed by SOP's. However, I asked ATC radar to confirm us crossing EDEMO (radar fix). I maintained 3300', which gives a 3 degree path from EDEMO. This was now my TOD, NOT TRE; that's too close. Set up a V/S, re: Gnd Spd, to give 3 degrees and made sure we didn't bust the FAF 1900'. F5. Configured Gear down etc. passing 2000' and confirmed crossing TRE >1900'. All simple and legal, but only with the radar fix. This type of approach is often standard in Scandanavia. If you have a GPS a/c use of the green arc is invaluable. Diving to 1900' can only be done with ATC confirming EDEMO anyway, but it makes it all very rushed if TRE is used as TOD from level flight.
....crossing TRE >1900'.
Looks to me that if you cross TRE at >1900, you would be far too high.
Why not cross TRE at 1350, just as the chart indicates?
And yes, timing is required for the LOC-only approach.
Noting especially unusual about this approach.
Busserday
3rd Sep 2009, 15:50
My read on this is that a straight in LOC can safely be accomplished from EDEMO but it is not technically legal. See note 1. It specifically states STRAIGHT-IN ILS not APPROACH or LOC.
That being said, once past EDEMO, 6.5 nm from TRE and established on the localizer, the crossing altitude for TRE is 1350' so, depending on your SOP what you would actually descend to, 1350' would be your minimum altitude until crossing the LOM (temperature corrected of course) thence the descent to MDA (T. corrected as well plus any other additions/corrections required).
Would the straight-in hold up in court? I don't think so. Would I do it? Only if familiar with the approach and authorized by ATC, otherwise it is the full procedure. If the G/S is out and the wx is down, I will err on the side of caution/ safety.
BD
Pitothead, taking this chart as grounds you will have to proceed to TRE locator and complete the LOC ONLY procedure as depicted on the chart descent to 3000 ft over TRE 1 min outbound for cat C and then down to 1350 Ft once established on final track. Other than that ATC has got the option to provide PAR approach.
Cheers:ok: