essendon 26 ils approach chart

[downwind]

Quick question,

What distance measurement can you use if the glidepath component fails on this approach? ie there is no vor/dme or gps based distance to use only a outer and middle marker?

[AussieNick]

EDITED: No need to confuse someone obviously doing their CIR training :}

[Capt Fathom]

Incorrect AussieNick

No DME/GPS specified or required!

If there is no GP, you only require the PLE NDB and the Markers for descent!

YMEN 26 ILS/LOC (http://www.airservices.gov.au/publications/current/dap/MENII01-115.pdf)

Thanks Dog. PLE it is. I should read the chart! :uhoh:

[AussieNick]

oops, didn't have my chart infront of me, my bad.

[Dog One]

I think Capt F you mean the PLE NDB.

[GABLUES]

YMEN 26 LOC maybe the way to go ??

[Hugh Jarse]

D/W,

If I understand your question correctly, you don't need any distance reference as Capt. Fathom wrote). The LLZ procedure now consists of 3 step-down fixes, being PLE, OM and MM.

The problem you have (and I think this is what you mean) is "how do I work out a pseudo-glideslope?"

You already have a crossing ALT at the OM (1550'), so now all you need is to work out approximately what altitude you want to be at the MM and PLE. The easiest way is to use 320'/nm (for a nice, stable 3 deg path), and work forwards/backwards from the OM using the distance to the threshold on the profile diagram.

e.g. The glideslope check ALT is 1550', so working forwards to the MM (another 3.3nm) that is 1550 minus (3.3x320' (1056) = 494'.

Because the MDA is 770', so you would expect to reach the MDA about 2 1/2 miles past the OM.

To work out your approx crossing ALT at PLE, just work back the other way.

This works for a stable descent path. There might still be a few people around advocating the "get down to the limiting alt as quick as you can", but that's fraught with risk.

Hope this helps.