IAP Question

[HeliHawaii]

Hi All

I'm currently studying for FAA IR and saw some strange figures on this plate.

LANEO is 8.1 DME and PERLY is 6.2 DME

The segment length between these is shown as 2nm on both the Plan and profile views

Is there any reason for the difference between quoted DME distances and segment lengths or is it just a screw up by the FAA?

[EK4457]

Having never seen the plates I'm going to make an educated guess.

The DME given are slant distances. If the segment length given is a horizontal one, then there will be a difference which can be calcuated using Pythagoras' theorem.

I do want to restate that I've not seen the plates and this is just a suggestion!

[HeliHawaii]

Thanks EK, I guess that makes sense, especially as they round to the nearest tenth of a mile!

[SFI145]

Can you give us the name of the plate to which you are referring?

[MCDU2]

Its on the ILS Z for R04R at PHNL. As stated above there is a 2nm distance between LANEO and PERLY on plan view but the distance on the glide between the two when descending from 1700ft to 1500ft is 1.9nm.