(Stupid) E-Jet questions

PhilosopherPilot said:
I've never flown the E175, but our E190s level off just fine in FLCH without over speeding. As soon as it goes into ALT SEL it reduces power and begins a level off.

We are constantly updating the EPIC loads though, so our FLCH logic may be different.
Click to expand...
Ours is the same, overspeed happens if you're hand flying though like I described.
 
If you follow the flight director it shouldn't over speed. It goes to Speed on Thrust as soon as it goes into ALT Sel. If you push over too fast it might over speed, but that's not an automation problem.
 
PhilosopherPilot said:
If you follow the flight director it shouldn't over speed. It goes to Speed on Thrust as soon as it goes into ALT Sel. If you push over too fast it might over speed, but that's not an automation problem.
Click to expand...
That is correct. Let me be more clear in that, if shallowing out to 1000 -1500fpm in the last 1000 feet it will overspeed. If left in FLCH, which you're absolutely right it does what its supposed to do.
Anywho speaking of EPIC. Has anyone else had PDC problems?
 
You guys and your fancy words..PDC, printer.

Nothing is more fun than trying to get updated, or full route clearance from LGA during/after a weather day.
 
When doing level offs like what you get coming out of ORD, I'm commonly still hand flying, and I do the same thing I did in my last jet: lower the nose when we get within 1,000' of our assigned altitude and bring the thrust levers back myself. It requires overriding the autothrottles, but I've found I can make the level off smoother on my own (aiming to be at a 1,000 FPM climb for the last 1,000 of the climb), and holding 250 knots with the power on my own.

This might be evidence of my lack of understanding of the aircraft, but it's worked every time without a problem. Sometimes old tricks (flying the airplane) are the best tricks.
 
jtrain609 said:
When doing level offs like what you get coming out of ORD, I'm commonly still hand flying, and I do the same thing I did in my last jet: lower the nose when we get within 1,000' of our assigned altitude and bring the thrust levers back myself. It requires overriding the autothrottles, but I've found I can make the level off smoother on my own (aiming to be at a 1,000 FPM climb for the last 1,000 of the climb), and holding 250 knots with the power on my own.

This might be evidence of my lack of understanding of the aircraft, but it's worked every time without a problem. Sometimes old tricks (flying the airplane) are the best tricks.
Click to expand...
hqdefault.jpg
 
If the FMS populates an incorrect altitude on a arrival, how do you enter a between altitude at a fix?
 
RORO said:
If the FMS populates an incorrect altitude on a arrival, how do you enter a between altitude at a fix?
Click to expand...

I'll look this up. I know that at or above is 11000A and below is 11000B. I think you maybe enter 13000B then enter 11000A to get a between constraint, but I'll have to double check.
 
ClarkGriswold said:
Make it hard, I don't think you can do a between yourself. Plus those suck anyways.
Click to expand...

That's actually terrible advice. Changing constraints to "hard" constraints are one of the big reasons that people think VNAV doesn't work right. If you futz with the constraints you will absolutely make the VNAV system operate in an inefficient way that is uncomfortable for the passengers. If the constraint is programmed incorrectly, do not use VNAV, and plan your descent manually if you can't fix it.
 
PhilosopherPilot said:
That's actually terrible advice. Changing constraints to "hard" constraints are one of the big reasons that people think VNAV doesn't work right. If you futz with the constraints you will absolutely make the VNAV system operate in an inefficient way that is uncomfortable for the passengers. If the constraint is programmed incorrectly, do not use VNAV, and plan your descent manually if you can't fix it.
Click to expand...
Uh, no its not. Theres other ways to tell if it will be smooth, mental math, perf plan page - w/t for each fix on the right side. If you keep the betweens they will ALWAYS be at the top end at each fix and many have major speed reductions that are hard to do without brakes, what about that passenger comfort again? If its within the restriction its fine, and if you have wind etc, it helps out to make a couple hard. The betweens actually make the ride worse sometimes for the people in the back. VNAV works just fine if you know it's quirks, and watch it.
 
ClarkGriswold said:
Uh, no its not. Theres other ways to tell if it will be smooth, mental math, perf plan page - w/t for each fix. If its within the restriction its fine, and if you have wind etc, it helps out to make a couple hard. The betweens actually make the ride worse sometimes for the people in the back.
Click to expand...

Whatever man. If a guy comes in for recurrent who likes to eff around with the altitudes on an arrival, you can be fairly certain that he doesn't understand the system at all. Those are the guys who say, "I don't trust VNAV." They create their own problems. I spend a lot of time trying to un-screw them in recurrent, but primacy is a biatch.
 
PhilosopherPilot said:
Whatever man. If a guy comes in for recurrent who likes to eff around with the altitudes on an arrival, you can be fairly certain that he doesn't understand the system at all. Those are the guys who say, "I don't trust VNAV." They create their own problems. I spend a lot of time trying to un-screw them in recurrent, but primacy is a biatch.
Click to expand...
It's not a lack of trust in the system, far from it, it's a concern for passenger comfort/ making life easier for slow downs when the airplane is dive bombing for restrictions and cannot meet speed restrictions. There is nothing wrong with changing an altitude within a restriction for planning purposes, theres a reason it's a BETWEEN. You feel I don't know the system but I feel that way about you.
 
ClarkGriswold said:
It's not a lack of trust in the system, far from it, it's a concern for passenger comfort/ making life easier when the airplane is dive bombing for restrictions and cannot meet speed restrictions. You feel I don't know the system but I feel that way about you.
Click to expand...

I teach the system. I understand it very well. If you leave (properly programmed) constraints alone, the system will find the optimum time to descend for whatever angle you program. It will descend at a constant rate through the constraints to the final restriction. It's very smooth, and very stable. If you change the constraints it levels off early, then descends again to the next constraint, depending on how you program it. There's a reason they put at or above altitudes in there.

Obviously you have to take wind and engine A/I into account, but the best way to do that is with descent angle changes. So program a 2.5 decent angle, and it will slow down and go down. There are some arrivals where you have to pay very close attention, like the KRANN arrival into Boston when landing on runway 27. But if you make altitudes hard on that arrival, it will be much like a football bat...effed up.
 
Last edited:
VNAV really is one of those things that takes a while to get your head around in the thing. (Well, it's taken me a while, at least, but I'm slow.) It's been an education watching different techniques.

If there aren't any speed reductions along the way, pretty much anything seems to work out reasonably well.

Put in 3.7 degrees on something like the TWSTD and even I know enough to say "Ummmmm.... that's brave, boss. You sure?" :-)
 
http://flightaware.com/resources/airport/KRDU/STAR/all/pdf

This is more what I am talking about. The system will always keep you at the top of the restriction and GAZER is always at 9,000 feet ( did this flight ALOT) So to meet the restriction at HARSH would you make GAZER 8,000 hard and let the speed bleed off in the 3 miles without the boards or would you use the boards pretty much starting before GAZER? You mentioned passenger comfort.
 
You must log in or register to reply here.
Back
Top