Missed approach alt in MCP during RNAV app

[Sorensen_DK 0]

Hi all.

 

I was trying to fly an RNAV approach into EDDK 32R. The FCTM says that you should put the MDA +50 in the MCP, and when established on VNAV PTH in the final sector (after passing FAF) and 300" below the missed approach altitude ((MAA) 5000" for EDDK 32R)), you can set the MAA in the MCP window.

 

At FAF 32R you start the descend at 3000", so I should be able to set the MAA once descending on VNAV PTH right after the FAF. But this did not happend. When I set the MAA in the MCP the AP just went into ALT ACQ.

 

I cant figure out what I am during wrong here...Any suggestions?

 

Best Regards

Bjarne Sorensen

[Spin737 102]

Hmm, your description and understanding seem correct. Not sure. Sorry.

[zubart 5]

It sounds like the mistake your making is not setting the MCP to altitude window to MDA +50 alttitude first before the MAP altitude.

Make sure you set the MCP altitude to the closes 100 feet above MDA +50 first prior to reaching the FAF. After the VNAV PTH descent starts and the airplane is at least 300 feet below the MAP altitude and prior to reaching the MAP altitude, reset the MCP altitude window to the MAP altitude of 5000 feet.

 

 

John Floyd

[G550flyer 1,015]

how it shoud work on the ng, i guess go a little lower. In the gulfstream, in LNAV VNAV i have to set the maa on the go to keep from leveling off. Only 550 with certifcation delta will allow you to set the maa after selecting app on a l/v.

[Sorensen_DK 0]

Hi Guys.

 

Sorry for the late answer. This still puzzles me. I do set the MCP to MDA + 50 ft, and when well established on VNAV PTH after passing FAF, I try to set the MCP to MAA of 5000". Just wanted to know if I did something wrong, but it seems as the procedures are correct. If anyone had succes with this procedure, then please let me know - in that case I will know that it is not a bug in the NGX.

 

Thanks for help!

 

Best Regards

 

Bjarne Sorensen

[Oliver Branaschky 2]

Just a quick question: did you press the APP button for the approach? As far as I know, you have to do that before resetting the MCP altitude - just like in an ILS approach.

 

Regards,

Oli

 

 

Oliver Branaschky

[davidz 26]

Oliver, that only works if using IAN for the NPA. The procedure is to engage VNAV PTH for a VNAV guided approach.

 

Bjarne, try scrolling the MCP ALT very quickly past your passing altitude and it should stay in VNAV PTH. I'm not sure of what is support to happen in the real aircraft or whether this should be necessary in either the real aircraft or the NGX, but this is what was required to set the MAA in the old NG.

[Oliver Branaschky 2]

Oops, my bad. You're right, of course, and it should work as described above...

 

 

Oliver Branaschky