Non-Standard ILS

[JABBARA]

At the Jeppesen approach chart for RWY 23R ILS in Dusseldorf/Germany (EDDL), there is note in header as
"Non-Standard ILS".
I will be pleased if someone tells me what it does mean.

Many thanks.

[GARDENER]

They are quite possibly referring to one of my ILS approaches!!!:ok:

[willfly380]

maybe the glideslope angle is too steep.or too shallow,i dont have the approach plate. could you please check and let me know also.
good one gardener , its called on deviation no ILS

[JABBARA]

Thanks Willfly,

But I have already checked any parameter like GS angle, TCH, DH, etc. And I have compared with other ILS' in Europe, there is no remarkable defference with this one. However I come across with the following paragraph in ICAO ANNEX 10. Please read and tell me what you think. Could it be the reason if 23 R Localizer width is not corresponding the standards in this ANNEX?

ICAO ANNEX 10 Para2.1.11.4
Extent to which sector centred on course line
may be narrowed. It is considered that a radiation sector 10
degrees each side of the localizer course line would be the
minimum sector that could be accepted operationally. It is
desirable that the characteristics of the signal from the
localizer be identical with those specified in Chapter 3 within
the region in the immediate vicinity (region from DDMs 0.155
to zero) of the course line and approximate closely to them out
to 10 degrees, so that the indications of the ILS indicator and
the signals fed to a coupling device, if used, will correspond to
the STandard ILS throughout any manoeuvres necessary in the
transition from the approach to the localizer to establishment
on course line.

[DJ Mixmaster]

Just a long shot...but, could it be offset LLZ beam?

[JABBARA]

No, DJ Mixmaster, because I have checked that as well. As far as depicted in the chart, magnetic direction of RWY and LOC course are same.

[411A]

IIRC, the procedure is non-standard due to the fact that obstructions penetrate the obstruction clearance plane.
Can't be sure however, as I have not flown there for some time.

[square leg]

Normally the DH is 200 ft for a Cat1 approach. The minimum on DUS 23R is higher and thus "non-standard".

Our company minimums state: DH 220 ft (DA 350) for the "normal Cat1" (normally it would be 200 ft)

Then the other minimum states: DH 230 ft (DA 360). Here it is a question of the A/C's wingspan (being between 60-65m) or the vertical flight path of the wheels and the glide path antenna of 6-7.3 metres.

Thus the reason is a "non-standard" minimum.

There is a 1° difference between the ILS course and RWY course (ILS 234° vs. RWY 233°).

The GP is 3°.

Fly according to what the chart says (provided it is up-dated).

Safe flying;)