LNAV/VNAV minimums setting

[wahoo250]

Quick question I cant seem to find the answer written anywhere. When shooting an LNAV/VNAV aproach do you guys set airport elevation or 0' in the window? Is this a written rule to follow to set airport elevation? Or is is it for the missed aproach so you arent spinning up the altitude bug for 10 minutes if at a high altitude airport and executing a missed aproach?

 

[densoo]

Quick question I cant seem to find the answer written anywhere. When shooting an LNAV/VNAV aproach do you guys set airport elevation or 0' in the window? Is this a written rule to follow to set airport elevation? Or is is it for the missed aproach so you arent spinning up the altitude bug for 10 minutes if at a high altitude airport and executing a missed aproach?

It may vary by company. I know one major airline uses zero. Set to zero when certain parameters are met once on final.

 

[Dogwood]

Quick question I cant seem to find the answer written anywhere. When shooting an LNAV/VNAV aproach do you guys set airport elevation or 0' in the window? Is this a written rule to follow to set airport elevation? Or is is it for the missed aproach so you arent spinning up the altitude bug for 10 minutes if at a high altitude airport and executing a missed aproach?

We refer to this just as an RNAV or GPS approach, and set the charted missed approach altitude.

 

[wahoo250]

If you set missed aproach altitude and arm vnav, you will never get the airplane to decend to the DH...at least in the GV. I think you guys have the updated software that allows you to set a dh and still set a missed approach altitude...like an ILS. I was told it was an FAR to set DH. I didnt think it was and have been trying to find it... Im guessing the parameters that you are speaking of are the FMS going to aproach mode once near the FAF...thanks for the replies

 

[Going2Baja]

At Alaska we "dial the dirt" Arpt Elevation.

Baja.

 

[bjack]

Same at QX. We set the dirt rounded up to the hundred, then when the 1000 to go chime hits we set missed approach.

 

[Green Banana]

I used to set the dirt. Now I am on the dirt.

 

[ImbracableCrunk]

On the 737, I've done "dial the dirt" and now it's set the DH/MDA 3-5 miles from FAF and then 300' below missed, set missed app alt.

Dial the dirt works much better, IMHO. It's nice to have the green banana on the rwy.

 

[ImbracableCrunk]

I was told it was an FAR to set DH.

It's one of those "double secret" regs.

 

[igneousy2]

It's a reg only in the sense that there is a reg that says to follow your manual.

 

[PeanuckleCRJ]

At DL we set field elevation rounded up to next hundred, then at 1000 feet AGL we reselect to missed approach altitude.

 

[boman]

At CAL "0000" is set nearing FAF. In the event of GA, the missed approach altitude is called for after gear comes up.

Seems to work just fine.

 

[pianoman]

At CAL "0000" is set nearing FAF. In the event of GA, the missed approach altitude is called for after gear comes up.

Seems to work just fine.

Just on the 737. The 777 I know you set field elev, and the 756 I think is the same. Some software limitation on the 'ultra modern' 737.

 

[HalinTexas]

At ATA on the B737, when we were setting up these approaches, we'd leave the FMS alone, as it would take us to the runway. The MCP would be set to the nearest increment above MDA. That would usually be a little be higher than the MDA, next 100' above. No big deal, you could set it to the field once you have visual, or you could bump the yoke and it would continue. Then, our POI made the "brilliant" observation the if you hit TOGA on path, at MDA, the airplane would still descend below MDA while executing the miss. So his solution was to set the MCP up to 140' above MDA. Here's how it worked: you set the MCP to the next highest altitude increment above MDA as determined by the FMS. If this resulted in less than 50' increase, we set it another 100'. This was a royal pain in the a$$. Really FUBAR. When you reached (captured, but not hold) your MCP MDA the NFP would then spin up the MAA. The FP would "bump" the yoke to continue the descent, on path, to the published MDA. If you "timed" it right, you'd stay on path. Like I said, really screwed up. All that magic only to be trick-f@cked at the most crucial point.

 

[Going2Baja]

At ATA on the B737, when we were setting up these approaches, we'd leave the FMS alone, as it would take us to the runway. The MCP would be set to the nearest increment above MDA. That would usually be a little be higher than the MDA, next 100' above. No big deal, you could set it to the field once you have visual, or you could bump the yoke and it would continue. Then, our POI made the "brilliant" observation the if you hit TOGA on path, at MDA, the airplane would still descend below MDA while executing the miss. So his solution was to set the MCP up to 140' above MDA. Here's how it worked: you set the MCP to the next highest altitude increment above MDA as determined by the FMS. If this resulted in less than 50' increase, we set it another 100'. This was a royal pain in the a$$. Really FUBAR. When you reached (captured, but not hold) your MCP MDA the NFP would then spin up the MAA. The FP would "bump" the yoke to continue the descent, on path, to the published MDA. If you "timed" it right, you'd stay on path. Like I said, really screwed up. All that magic only to be trick-f@cked at the most crucial point.

My God!! Even w/ a fresh cup of coffee that gave me a head ache. I feel for all of you ATA guys. That POI should be shot.

At Alaska: On a published part of the appch, at or past IAF, LNAV/VNAV Path, Dial the dirt and watch the magic.

That Easy - Even a Cave Man Could Do It!!!

Baja.