ILS

[Sd777]

If the approach chart indicates ILS DME RWY 31 . can I start the app If DME inop? I appreciate any help on this regard.

[TCAS FAN]

The reason for having the DME is to replace an OM and MM. In the absence of the latter if DME is INOP, unless the Instrument Approach Chart (check AIP Saudia Arabia?) permits otherwise (sometimes an adjacent VOR sited DME or radar fix can be used as an alternative-this must be shown on the Chart), the answer would be "negative".

[Capn Bloggs]

sometimes an adjacent VOR sited DME or radar fix can be used as an alternative-this must be shown on the Chart

GPS distance is allowed if stated on the chart.