RNP change terminal to enroute?

[galdian]

Hi all

Just did a sim check with the local cops, all OK but a question that's got me intrigued and can't find reference; aircraft B737-800

We have RNP 1 (terminal), RNP 5 (Enroute although our equipment defaults to RNP 2.)

At what point (altitude, speed, "preset factor", whatever) does the FMC automatically flop over from terminal to enroute RNP, equally when does the FMC RNP automatically flop from enroute to terminal at the other end??
I took a stab at "maybe transition" but no real answer.

Any references would be appreciated


Cheers
galdian

[The Dominican]

Hello Galdian

On the departure it will stay at RNP 1 until the first en route position (the first position of your flight plan before you input the departure runway and your SID) and on the arrival, it will change to PNP 1 when you arrive at the transition to the STAR, then when you are within 30 degrees from the inbound course in the approach it changes again to approach RNP of .3 miles (but it uses raw data fron the ILS of course) It changes to oceanic RNP when you hit the first lat and long position.

I got the info from the systems book of the 767 but I would imagine that it is the same for the 737? I'm giving this information from memory but I'll review it tomorrow and let you know if I made a mistake but I'm pretty sure that is how it works

[galdian]

Hi Dominican

Thanks for the reply, pretty much ties in with advice from someone far, far smarter than myself who said departure was at the last point on the SID/the first point on your filed flight plan (one and the same) OR 15,000FT whichever earliest; for arrival the reverse, last point on filed flight plan/ first point on the star OR 15,000ft whichever earliest.

My guesstimate was transition (around here 14,000ft) so won't beat myself up too much! :cool:

Cheers
galdian

[The Dominican]

As fate has it Galdian, we just got an information bulletin expanding on that very subject.


Take Off.RNP 1.0) A flight plan has been executed on the ground and at least one IRU is in navigation mode

Climb.RNP 1.0) The last waypoint of the SID is sequenced bellow 15,500 ft. Or the aircraft is in takeoff and exceeds 3,000 ft. above departure airport if no SID exists on the active flight plan.
Descend.RNP 1.0)Aircraft sequences bellow 15,000 or first point on
the active arrival
Go Around: (RNP 1.0) When the aircraft is in approach and is above
3,000 ft. if there is no missed approach holding point or the missed
approach holding point is sequenced.

Enroute Domestic.RNP2.0) Aircraft sequences above 15,500 ft while not actively flying a SID or the aircraft sequences the last waypoint of the SID and is already above 15,500 ft.Or the phase of flight is oceanic and radio updating is viable

Oceanic Remote.RNP12) Radio updating is not viable due to limited or non radio coverage

Approach.RNP 0.5)The first waypoint on the active approach or the approach transition is sequenced or the aircraft sequences below 2,000ft above the field


0.3 is the RNP required to performed an RNP approach but the FMC only defaults to 0.5, so if an RNP approach is to be executed, the RNP limit of 0.3 must be manually input.



There you go mate, now we know more than we ever cared or wanted to know about that crap

Good luck with the new gig and don't get cut with all that glass:ok:

Cheers

[galdian]

Hi Dominican

Maybe crap to you and moi, however to JCAB of the utmost importance!

As you would have realised well and truely by now paperwork is paramount - the ability (or lack) to actually fly and command the aircraft almost - I do say, in fairness, almost - a curious western ideology.
Of course with your in-house T&C the JCAB is merely a jumble of letters to you now - maybe yes, maybe no, maybe maybe......?? ;)

Glass not new (doesn't mean still can't get cut) but couldn't find answer easily via Mr Boeing - although sure it's there, somewhere.

Appreciate your time
cheers
galdian