RJFO RNAV approach chart intermediate fix altitude question.

[ljh126]

Hi! My first posting!

As we can see this chart has IF altitude(1200) lower than FAF, procedure altitude(1600)

I thought it was misprinted somehow at first time, but trying to think if there is any reason or reference to find out.

Or is there any airport has intermediate, IAF altitude lower than succeeding one?

[aterpster]

Hi! My first posting!

As we can see this chart has IF altitude(1200) lower than FAF, procedure altitude(1600)

I thought it was misprinted somehow at first time, but trying to think if there is any reason or reference to find out.

Or is there any airport has intermediate, IAF altitude lower than succeeding one?
Has to be a misprint.

[eckhard]

The original Japanese version in their AIP has the same figure. I agree it is a misprint and should probably read 2200ft.

[aterpster]

The original Japanese version in their AIP has the same figure. I agree it is a misprint and should probably read 2200ft.

In that case Jeppesen would have been well advised to contact the Japanese aviation authority before deciding to print the chart. Interestingly, the Jeppesen navdatabase show 1600 both at KAREI and KUROZ.

[aterpster]

The original Japanese version in their AIP has the same figure. I agree it is a misprint and should probably read 2200ft.

This is the response from Jeppesen:

[eckhard]

Thanks aterpster.

Jeppesen response makes sense from a technical point of view; however, I can’t help feeling that the published format doesn’t help a pilot trying to fly this approach.
At KAREI, a 3 degree slope puts you at 2755ft.

[RAT 5]

The publication needs careful reading. It is an approach chart incorporating approach information and safe altitude information.

At KABOS (IAF) procedurally you would be at 3000'. The final 3 degree approach path starts at KUROZ at 1600'. At KAREI the minimum safe altitude is 1200'. The symbol is an 'at or above'. Notice the grey block 800' in the KAREI sector. IMHO KAREI is simply a waypoint and forms no part of the vertical profile. Why is it mentioned? No idea. From KABOS the plan would be to descend so as to be 1600' at or before KUROZ. That satisfies the 'above 1200' passing KAREI. Note; the DME v ALT table only starts at KUROZ, i.e. inside the FAF.

It is not the intention to pass KAREI AT 1200'. It is a confusing publication and needs care. It was a good question in days when we want to KISS, especially on NPA's. In an FMC, if you had:

KABOS............/3000
KAREI............./1200A
KUROZ............/1600

then there should not be a problem. VNAV would fly a path to satisfy that.

On some NPA's, with long finals, to avoid step downs, and because I prefer simple CDA's, I would calculate a CDA starting at FAF and extrapolate it out to IAF, or centreline intercept. I'd write down DME v ALT from that point to the start of the charted table. You'd see that, even though it was 'home made' the profile would remain above any minimum safe altitudes. I'd fly that in V/S, because it was not in the FMC and then at, or just prior, FAF simply change to VNAV.

On this chart there is no DME for KABOS, so from KABOS to KUROZ is an unknown angle. Just left VNAV calculate it.

Why KAREI is shown is a mystery to me.

[oggers]

Interesting.

This shows up an ambiguity in the Jeppesen charting. They say they have correctly depicted the approach and the minimum altitude at the IF is 1200. And the extract from the Japanese AIP (that they included in the reply to aterpster) does indeed show an underlined 1200. Ok so far. However, Jepp do not themselves use the convention of underlining minimum altitudes. According to the Jepp chart guide, "all altitudes depicted in the profile view are MINIMUM altitudes unless specifically labeled otherwise". But come the FAF the altitude of 1600 is, according to Jepp's reply to aterpster, not minimum just "recommended".

The pilot armed only with the plate is left to bowl out this ambiguity by realising that the 1600 is advisory for the CDFA and not a minimum altitude. It needn't be that way if they just used the convention of underlining minimum altitudes. We could see at a glance what is advisory and what is a minimum and not have to make any assumptions.

[RAT 5]

What is surprising is there is not a grey block showing 1200' between KABOS & KAREI. It would seem, for the dive & drive pilots, which there could be in light a/c, that it is safe to pass KABOS at 3000' drop it to 1200' until KAREI, the drop it again to 800' to KUROZ and then drop it to MDA until the MAP.

For the 3 degree brigade it is advised to be 1600' at FAF = KAREI. The chart s for all operators.

[ljh126]

Thanks for answers everyone!