GNSS procedure question...

[B737SFP]

Hi guys...

A few days ago I saw the following information on the "briefing strip" of a GNSS procedure published by Jeppesen:

MINIMUM ALTITUDE
(CONDITIONAL)
REFER TO PROFILE

I searched all over and couldn't find what I should refer to nor could find what that information meant (on the Jepp Manual).

Could any smart guy around clarify that for me ?


http://oi60.tinypic.com/10r3ers.jpg

[Starbear]

Not seen that term before either but would guess at something like: There is no single minimum altitude but one for each waypoint of the profile. I realise that my statement could apply to many types of approach so will await others' inputs with interest.

[mustafagander]

I think the "conditional" refers to whether you are legal to fly to Lnav/Vnav minima or just Lnav minima.

In this case it is chicken :mad: but in some other approaches we use there is a significant difference in minima.

[aterpster]

Musta is correct.

It is very common in the U.S.

[B737SFP]

Hmmmm...

What "mustafagander" said makes sense to me, but, look at this chart:

http://oi57.tinypic.com/n4f9yc.jpg

It's a BARO VNAV procedure, just like the other one, but without the MINIMUM ALTITUDE (CONDITIONAL) thing...

So, why is that ?

By the way, both charts are from arpts in Brazil !

:bored:

[aterpster]

You should call Jeppesen and ask them.

[aterpster]

ok465:

However, as to why thay are formatted as they are may only be known to some wild and crazy Brazilian regulator.

"Conditional" is a Jeppesen addition.

[OK465]

"Conditional" is a Jeppesen addition.

aterpster,

That may be true, but the chart format I refer to is the side view which does not use a US convention of an *LNAV only note and a minimum altitude (*xx00) when associated with an altitude restriction at a fix inside the FAF for LNAV.

So is there not then some national input as to these chart depictions? Is 910' not a restriction for the LNAV only approach to RW10?

http://155.178.201.160/d-tpp/1413/06943R31.PDF

(That Baker Muni is a relatively new, current chart)

[B737SFP]

Hmmmm...

http://oi61.tinypic.com/9pq71d.jpg

What about that ? No "intermediate restrictions" between the FAF and the MAPT, but god knows why still a "CONDITIONAL" one.

:ugh:

Anyway, thanks for the answers guys ! :ok:

[aterpster]

ok:

That may be true, but the chart format I refer to is the side view which does not use a US convention of an *LNAV only note and a minimum altitude (*xx00) when associated with an altitude restriction at a fix inside the FAF for LNAV.

So is there not then some national input as to these chart depictions? Is 910' not a restriction for the LNAV only approach to RW10?

That is an LNAV-only step-down, which is on source. "Conditional" also appears in the Jepp briefing strip for this procedure and is associated with the LPV DA.

[aterpster]

"Conditional" is going away. From the horse's mouth:

Thank you very much for contacting us in this context.

The term ‘conditional’ is provided on some ‘older’ approach charts.
The ‘CONDITIONAL’ is there to draw the operator’s attention to that fact so they will check the minimum box to see what those conditions are.
Occasionally the lowest DA(H)/MDA(H) is only available when certain conditions exist.
Some of the conditions which affect the availability of the lowest minimums may be a DME step-down fix, local or remote altimeter, day only minimums, or other special situations.

Taking a look at the KSRQ 13-2 for example, the condition to utilize the 540ft MDA is that the waypoint ANILY can identified (either by FMS or DME). If this cannot be accomplished, the aircrew would have to use the higher MDA.

The ‘conditional’ terminology is successively removed from our charts as we changed or (sic) production regulations to provide a ‘refer to minimums’ in such cases.


Best regards,


Charting Support Team
Advanced Navigation & Display Support

[B737SFP]

aterpster, thank you very much !

You nailed it.

Now we got the right answer... :ok: :ok: :ok: