Is no one going to talk about a hatless uniform? The allowance of beards? 6 hours per day instead of 5 mpg? 12 day minimum instead of 18 for reserve? Getting rid of the tie?

 

Oh whatever, some guys are so scared of FLCH or VS because you’re not “protected”. It’s kindof funny watching El Jeffe squirm in his seat because god forbid the VNAV isn’t being used. It is possible to use other vertical modes properly in certain circumstances.

What’s with LHR? You leave the hold and VS it down there. Never seen a problem with that. The Speed issue to 4 DME on the other hand...🙄

 

Disagree, the 737 does it way better than the 777. Big foot drives to the bottom altitude in a A/B restriction. 737 feathers it.

Lee

 

VNAV is pretty much the same on all the planes I have flown. Sketchy. But I have not flown the 787 or the latest guppies. It's usually OK, but it's not absolute and there are plenty of times when it's more hassle than its worth.

Today I watched it meander back and forth in both pitch and power while it tried to decide what it wanted to get the job done. DRAG REQUIRED, then thrust added, etc over and over. We were below 18K so I used V/S to fix that. Last week it was clearly going to miss a crossing. I won't let it violate me. I use it, but I have little faith in it. And once we're within 50 miles, it can quickly become more of a distraction than a benefit.

You can create a pretty good power off descent with just a little cranial activity prior to initiating the descent. We did it for decades prior to VNAV.

 

I didn’t get past the fact that The Godfather was working on a holiday... PPU?

 

Just part of my junior maggot line.

 

What I love about the Guppy VNAV is that it will absolutely nail a complicated arrival and all the step downs but completely whiff on a cross X at 10000 clearance.

 

Far Far better than whatever it was they were doing down in the “shoebox”

 

I've flown the Bus, 737 and 777. They all require some monitoring and ALL require help (via the speedbrake) to keep you on the path.

The biggest problem with the Bus is that if you have a speed restriction, the bus only gives you five knots extra to stay on the path. If you have a 280KT restriction it could increase to 285kts and then it just stays at 285 while you drift off the path. The FMA keeps saying DES while the Boeing will go to about 20 kts fast and then give up, but at least your FMA changes from VNAV PTH to VNAV SPEED.

The biggest benefit of the BUS is that after the first idle descent, the path is drawn as a straight line between the fixes as opposed to ALL idle descents on the Boeings. During an RNAV arrival you can change your speed via managed/selected speed and the path doesn't change. The Boeing would draw a new path based on your programmed speed. Doing a 300kt descent and being told to slow to 250 = no problem in the BUS and in the Boeing it means asking the controller if they want the speed or the crossing restriction.

Its sometimes comical to watch someone try to get the airplane back on the path by changing to FLCH/LVL CHNG and not increasing the speed and expect it to somehow get back on the path without any drag. It's far easier to just drag the speedbrake and leave it in VNAV/DES. Just my opinion.

 

While it usually works as advertised (sort of, after the FMC SPEED power addition on the FMA, soon followed by DRAG REQUIRED on the FMC scratch pad) it'll occasionally attempt to leave you hundreds of feet high at a hard altitude or fly you through an altitude on an arrival when it sees it can't make both of the next two restrictions. TK will probably tell you that can't happen, just leave it in VNAV PATH. As has been said, "trust but verify" in VNAV.