And this is where we get back to your other post about PROG and VERTICAL BEARING, etc.

 

The gaps are starting to close.

Did someone say on this, the first 2 years hurts the most !!!

 

Yeh its just like a big jigsaw...slowly comes together.

Ok got a question you have left VNAV due to ATC REST. You are at FL 140 descending to FL090 in LVL CHG

 

Now, when would you roll down command speed for the 250 rest below 100? Would you do this at 110 120 ?

 

What techniques can be used here....

If I'm descending in LVL CHG at idle thrust I usually roll the speed back to 250 passing through 12,000 MSL.

How can i work out V/S at FL120 so it reaches 100 at exactly 250 or below? What rules of thumb can i use..

Cheers

Why switch to V/S?  Just roll the speed back to 250 and let LVL CHG do it's thing.

 

 

How can i work out V/S at FL120 so it reaches 100 at exactly 250 or below? What rules of thumb can i use..

 

 

Why switch to V/S?  Just roll the speed back to 250 and let LVL CHG do it's thing.

 

Agreed. About 1500-2000 feet above FL100, just roll the speed back. I usually descend at 280, so a 1500' lead is usually fine.

Thanks matt.

 

Also would like your help for fuel checks along the route? If thats ok...

Thanks matt.

 

Also would like your help for fuel checks along the route? If thats ok...

Fuel checks?

Yeh fuel checks! To see how things are looking at the DEST aerodrome

Yeh fuel checks! To see how things are looking at the DEST aerodrome

What about the PROG page? Won't that tell you how things are looking at your destination airport?

So i've read, some pilots don't use the prog page as it can be off 100-200kg and most pilots subtract that away with whats on the prog page!

Hi, sorry for jumping in a bit late. Like Matt, I drive these for a day job now. My favorite is F10 as in Turkey the winds always change so you get tailwind approaches, etc. F10 is just lovely on an -800 as it gets the LE out fully and give a nice stabilizing drag to help on an approach. Using VNAV PATH we often are on a Continuous descent, so it;s not really simple to follow the Part A or Boeing SOP for flaps.

 

Speed control in ESB is a rarity and often the approach controller will tell you to speed up and the tower asks for minimums on contact. Yesterday we were switched from 21L onto 21R as we were given intercept vector at only 8nm. Fortunately my F/O was a veteran.....

 

What I'm saying is theory is great but real world ops introduce many variables that you simply cannot control. Flaps shouldn't be used to simply slow you, e.g. at 249kts use the speed-brake not F1 to increase deceleration.  However your original question is simpler...

 

"Gear down, Flap 15" ("Speed 15") at the point you want to convert a low drag approach to your landing config. This can be 4NM or 8NM or more as required. Your low drag approach should have bene F5, but with tailwind or steeper approach, F10 is perfectly acceptable .(not that it helps much on SFP...)

 

Whether you ask for F25 next may well be simply a function of how fast you are slowing....if you can't get under your limit for 30 then ask for it. Ditto 30 on a F40 landing. Be above all practical and adaptive, and that works well. Just being Anal is why the fun has gone out of the job for so many....

 

On a side note, I now fly a 737-200ADV in X-Plane rather than use NGX. It's far more fun! Auto- what? nah...

So i've read, some pilots don't use the prog page as it can be off 100-200kg

It is really that critical? Just carry extra fuel for anything out of the ordinary. I usually enter 1000 lbs. in PFPX as extra fuel. Could be as low as low as 500 lbs. or as high as 2000 lbs. for the NGX.

Alot of pilots don't use the FMC for fuel checks and just use the gauges instead.

 

100kgs discrepancy between fuel used on the FMC and the gauges aswell.

 

I add about a tonne depending on the weather so i tend to keep an eye on the TAF around the time i land and also for my alternate. But if the weather is good i tend to be carefull what i take because carrying that extra load means your heavier and and burn slightly more carrying it.

 

Fuel is your friend

 

 

Alot of pilots don't use the FMC for fuel checks and just use the gauges instead.

 

Source?

 

I can't imagine anyone not using all the tools available to them in the cockpit. Today's fuel totalizers are very accurate, with most of the error due to simple physics (they measure flow rather than mass but are designed to compensate).  Even the fuel totalizers in today's GA aircraft are pretty darn good.