More VNAV problems--probably my fault again. Anyway, with just about fifty nautical miles to go to my destination (Chicago O'Hare), my aircraft was still at its cruising altitude of FL380 and showed no signs of descent. It did descend when I pressed "Des Now", but even then it was a slow descent and I would have ended up 20,000 over the airport.

Thanks,
boeing247

Did you wind back the altitude on the MCP prior to reaching TOD?

Ah, no. Thanks. I should have thought of that, as I had a similar problem with climbing. Do I change the altitude right after I reach cruising altitude? And do I change it to the landing altitude or zero? (sorry for all the questions--I'm used to ATC directing me so I don't know much about VNAV)

The FMC will alert you to change the ALT on the MCP.  You could change it to zero I'm not 100% sure.

boeing247 wrote on Dec 12^th, 2011 at 12:20am:

Ah, no. Thanks. I should have thought of that, as I had a similar problem with climbing. Do I change the altitude right after I reach cruising altitude? And do I change it to the landing altitude or zero? (sorry for all the questions--I'm used to ATC directing me so I don't know much about VNAV)

You can change it any time you like after reaching TOC. If you are going long haul and need to do Step Climb(s), then don't chamge it until you see that there will not be another S/C and/or the VNAV (CRZ Page) shows the distance to the TOD.

On short hops where I know I won't be doing a S/C, I put the enter the first Transitional altitude (that I will reach after the TOD) in the Altitude Indicator. I'm doubt that this is how real pilots do it, but it is how I do it.

The other method is to wait until the FMS tells you to reset the MCP altitude, as theguz said. ;)

Mark

It's pretty much how they do it. Also in real life you are restricted by atc clearances, so approx. 10 nm before T/D you would normally call them with "ABC123, ready to descend" and they will give you a certain FL that is not necessarily predicted anywhere on the LEGS page (as a constraint).  

mbucholski wrote on Dec 12^th, 2011 at 2:20pm:

It's pretty much how they do it. Also in real life you are restricted by atc clearances, so approx. 10 nm before T/D you would normally call them with "ABC123, ready to descend" and they will give you a certain FL that is not necessarily predicted anywhere on the LEGS page (as a constraint).

If using FSX ATC, you will need to add a new lower altitude at about 150nm to go to the destination so you can descend as soon as the ATC asks you too (then set the altitude to the ATC FL given to you). I have noticed that in the heavies, ATC will ask you to descend when you are somewhere around the 3x rule (e.g. 90nm when at FL300, 110nm @ FL360).

Mark

Well, I currently have an aircraft near where I'd imagine the T/D is, but I did some reading in the manual and found that the T/D will not be calculated until the E/D is calculated. However, the flight plan I am using is imported from the Aivlasoft EFB, which includes the STAR already mapped out. I did this because when I select a STAR in the DEP/ARR page, it sets the last waypoint as the first leg of the STAR, which is not the one directly before the airport. Is there a way to manually enter the E/D? And if so, do I set it to the destination (KLAX) or a waypoint?

The only flights I load that will already include a SID and STAR/TRANS are those I make with the 757/767 FMS. Have a look in the the LEGS pages to see if the STAR/TRANS has the enforced speeds/altitudes in it. If not, add the START/TRANS using the onboard FMS.
When using other programs (like FSC9) to create a plan, I take note of the STAR and TRANS that I will use on arrival, but I do not save the plan with them already in it. I add them when I'm in the cockpit getting ready for a flight (preflight).

Mark

I did a bit more reading and found that it will calculate the E/D and T/D if I put in an altitude constraint.

boeing247 wrote on Dec 18^th, 2011 at 1:24am:

I did a bit more reading and found that it will calculate the E/D and T/D if I put in an altitude constraint.

Have you tried it to see if it works?

Yep. It works beautifully. I did have a bit of a problem with the speed constraints--the aircraft landed much to fast and for whatever reason I couldn't get the reversers to deploy.

Oh, and I have one last question--if you have the approach programmed into your flight plan, can you let the autopilot land the plane like you would for ILS (the landing I recently tried involved ILS)? Do you have to arrange anything, for instance speed constraints?

I use Autoland with ILS and land manually if there is no ILS.

If landing manually, make sure you turn the Autothrottle OFF brfore landing or it will try to maintain the Vref speed entered in the IAS/MACH Indicator. Not good for the you, the plane or your passengers! ;D

Whats this obsession with autoland? You realize that they almost never autoland in real life right? Normally the flightcrews hate the autoland, and handfly it as often as possible. The only time they autoland is when the weather requires it or if its required for either the crew or the airframe to stay current on their license to autoland.

Just handfly the plane. Thats the most fun, and the most realistic way :-)

wims wrote on Dec 22^nd, 2011 at 5:40pm:

Whats this obsession with autoland? You realize that they almost never autoland in real life right? Normally the flightcrews hate the autoland, and handfly it as often as possible. The only time they autoland is when the weather requires it or if its required for either the crew or the airframe to stay current on their license to autoland. Just handfly the plane. Thats the most fun, and the most realistic way :-)

the obsession comes where there's no visibility, and that plane simply Su :-X :-X :-X on autoland...I hate to get to the alternate just for the reason that the plane is not able to autoland!

Landing by hand takes a lot of skill.  I need to try it because ILS is no picnic either. :-[