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View Full Version : A320 Nav Mode Dilema!!


mikha169
6th May 2012, 21:11
Hey guys, i was flying with a captain the other day and he did something on the MCDU ( i was communicating at the time and he did it pretty quickly ) so i didn't see what he did. The ND showed the aircraft symbol and the next way point but nothing (empty space between the a/c symbol and the next way point) connecting the two, and the a/c was in NAV mode. How is this possible? i had a bet with the captain that i'll find out....and i really don't wanna loose, so can some one explain to me how that's possible and what he did.

Cheers, mikha169

Dan Winterland
7th May 2012, 02:47
Don't see how this is possible. If there is no track, there should be a discontinuity and the aircraft should revert to HDG.

What is worrying is that he did it without consulting you. In our operation, anything to do navigation changes require the confirmation of the PNF/PM.

ElitePilot
7th May 2012, 05:53
Sounds like he cleared the FROM waypoint and did a DIR TO the next?
Were you in HDG mode before?
Or do you mean all the waypoints or abeam points disappeared before the new one and that would just be a DIR TO.
Either way bad show to not keep you in the loop.

Pontius
7th May 2012, 07:19
I don't have clue about the Airbus but could he have created a waypoint on the other side of the World and the machine was attempting to fly 'through' the Earth to get to it? Clearly the distance to the waypoint is a give away but it is possible on at least some Boeings, so it might be possible on the 'Bus. Of course, I would never condone such misbehaviour!

Dream Land
7th May 2012, 07:31
If your route was basically on the same track following the TO way point, the course extending from the to waypoint extends out to infinity, you can intercept this course without the green line being present.

DL

livetokill22
7th May 2012, 07:38
Yes this happens
If you are in HDG and do a direct To on the mcdu
If the aircraft is close to the waypoint, Nav engages,
there is a blank between the aircraft and the waypoint, the aircraft flies straight to it and follows the flight plan after it.

Skipper in panic
7th May 2012, 20:33
1. Engage HDG mode

2. Delete FROM WPT to make empty space btw a/c symbol and NEXT WPT

3. MANAGE NAV

livetokill22
8th May 2012, 02:51
Yes
And when the a/c is close Nav engages,
If quite far away it arms till the time aircraft is close to the next waypoint.

Natstrackalpha
9th May 2012, 09:13
dude, this was a route or radial intercept and the aircraft was going in "free space to that interecept, or, there was a discontinuity (who invented that word?) and then as in "discontinuities, the aircraft will fly to the next waypoint except for the fact that it would usually do this in HDG. Why HDG? Because it is not in Nav due to the Discontinuity . . .hmmmm? As you say it was in Nav then . . . . . - oh wow, he simply did a Direct To the next Wpt.
Yeh, thats it.:ok: So easy.!!! Nope, wait up, something does not gel here. Maybe, he just cleaned up the box and left the approach, still the thing with HDG and NAV though - maybe, he did not keep you in the loop because he f-----d up and did not want to let you know, only to breathe a sigh of relief when you actually made it to destination without getting lost! I give up (well, not really) I think it is a trick question and you are trying to trick us. However, you can still be in NAV without anywhere to go to . . for example you can tune in a VOR say, and choose a radial and go for it NAV. I doubt he would have missed a discontinuity (although not impossible) so, then if he did, then he selecd nav. like in the example above.

But loopwise - baaaaadd flying!!

mikha169
9th May 2012, 16:50
ok guys, to clear things up....

FMA on PFD showing: MACH / ALT CRZ / NAV

ND showing : a/c symbol->empty space-> next way point (Empty space between a/c symbol and next way point was aprox 50nm)

still cant figure it out :ugh:

hetfield
9th May 2012, 18:23
A real "Dilema",... we all gonna die.:ugh:

Natstrackalpha
10th May 2012, 09:37
I think `Skipper in Panic` has got it.

1. Engage HDG mode

2. Delete FROM WPT to make empty space btw a/c symbol and NEXT WPT

3. MANAGE NAV

Dale Hardale
10th May 2012, 15:19
What is the MSN of this aircraft ?

mikha169
10th May 2012, 21:44
what difference would the msn make? i tried it and skipper had it down...its quite simple actually.

compressor stall
11th May 2012, 07:04
what difference would the msn make?

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