JurgenKlopp

Umm did you consult CAL '83...

450knotOffice

it's not that hard. Come on man.

I've been playing with his numbers and they're spot on. The box gives Opt altitudes based on weight AND winds, so sometimes there may be reasons to go higher than the number that the box spits out. Sometimes you don't gaf about the wind but want to get up to an where altitude the wing is happy AND is as high as possible so you can maybe get out of the tops, or whatever.

and that iPad app is great for the company. Maybe not so much for the scenarios I mentioned. Cost Index Zero, anyone? Just saw that today. Please. No thanks.

450knotOffice

Ho boy. 🙄
I can't eye roll enough.

Do you honestly believe the box in the Bus (a jet I've been on twice as long as you, btw) gives you the best altitude every time? Ohhhh Kayyy.

Affect the safe outcome? Sure. Maybe.

Can knowing the wing's Opt altitude every time possibly allow you to climb up and out of a rough ride when the Box is saying lower is more Optimal (winds anyone?) give your pax a smoother ride? Yes.

The raw number that Slice's rule of thumb gives you is a nice number to have in your pocket when you need it. It's not hard to figure out either. Takes 30 seconds.

450knotOffice

Actually, Not quite.

I flew a Neo from LAX to MIA today. Those airplanes have the latest software update. The REC MAX goes up in 100 foot increments, but the OPT moves in 500 foot increments - 330 to 335 to 340 to 345 to 350 today. Watched it closely since we talked about this.

By the way, turns out the base number is actually about 525 to start the (very easy) math. At least on the Neo. I'll check the other models as I fly them.

It turned out to be advantageous because my flightplan had us at 330 to start, which was actually Optimum, but wanted me to climb to 350 after ABQ, which I quickly realized wasn't realistic at all. Using the formula, I knew it would be about 3-1/2 hours after takeoff, versus 1-1/2 hours after. As Slice mentioned, that flightplanning software was going to ask me to climb to an altitude, that while POSSIBLE, was way above the OPT. No bueno.

Sliceback

Darn. I thought I'd replied several days ago. Must have forgotten to hit send.

Thanks for the head knock. Yes, I forgot at the CAL 83 guys on the UAL list.

Sliceback

That's where the analysis comes in - why is it forcing us to climb later or earlier? Trying to ride the wind because we're late? Or to avoid headwinds? What's the impact of arrival time vs scheduled time of the flight plan vs the current flight status? Does the apparent driving force of the flight plan - on time is #1 - so lower, faster, which is less efficient, doesn't matter if it makes scheduled arrival time. Is the expected taxi in time realistic? If not not adjust the expected on time to reflect the need to get to the gate on time.

Sometimes why above, or below, OPT makes sense. But the flight plan is based on leaving on time. If you're on a speed run because you're getting there 8 minutes late but find yourself making on time without hammering along because you got airborne early, got some short cuts, etc, the 'speed run' becomes the standard 'on time efficiency run.' I've had a couple of crossings with fuel savings in the 10-15,000 lbs range (roughy 30 cents, or slightly more, per pound of fuel saving) because the flight plan was at FL360 at .87 mach to be on time. Get airborne early, reroute because turbulence forecast changes (flight plan released up to 8 hrs before you actually encounter the turbulence/TSTM area), and you can switch to an OPT ALT/efficiency game at FL380, 390, 400 at .85 and still be on time.

Sliceback

You're the Captain of the flight. Weather or turbulence in various sections of an 7-12 hr flight. You need to decide if there's portions of the flight that you'll be in the cockpit. If that's not necessary there's still portions that you might want the aircraft at certain altitudes. Overwater you might have to put the airplane at an altitude that's not the best choice right now, or when the change will occur, but for the overall flight it's the best choice. Being able to tell the guys that in x hrs (2, 3, 4 hrs) that the they need to work on ATC to get FL380, or FL400, is easier to have them buy in when you can show them the OPT and MAX ALT's that the airplane is capable at future time points/fixes. Sometimes it doesn't matter much so it's a judgment call that will have to be made while I'm asleep so I tell them "your big boys. Figure it out."

A fair amount of time on long haul flights, especially on difficult nights, is trying to understand where you might be able to make altitude changes (ie before the tracks), and what will your altitude capability be compared to the altitudes at various points. It might be hours from where you have to make the decision to where the weather is. It's not "ask the next sector on 128.5. Good day." It's hours away. Sometimes you have to make tough decisions, like hanging out near MAX ALT because you REALLY want to be at X altitude or above farther downtrack. Clearance come back - X minus 4000' (if the heart of the bad sector) OR hang out at an altitude that you'd normally not cruise at. Decisions, decisions. That's why you make the big bucks. Knowing your high altitude performance capabilites REALLY helps. And knowing what the numbers will be when you have to deal with the adverse weather/ride. I've been able to work out jumping *2* tracks crossing the pond. :-0 That doesn't happen. Sometimes your stuck but sometimes Oceanic can work with you. Same with dispatch. Keep in mind I'm talking about outlier events. I'd ask for extra gas less than once every 2-3, or more, years. Same with asking for different routes. Dispatch on long haul flights sometimes won't release the flight forcing you to call them - "there's no good path all the way. I want to talk with the options and see what you'd prefer to deal with." Nothing like doing that and listening guys who stuck with the published tracks being miserable for hours. WTF? Overall dispatch does a good job but occasionally they produce some duds.

Werjower

...so is Delta or American better at calculating optimal altitudes?

Margaritaville

So what was the verdict? Did the navykid choose Delta or AA after yall buried his questions in a bunch of meaningless off topic drivel?

ImSoSuss

He doesn't get to choose at all. American is not starting new hire classes for the forseeable future. At this point he needs to get into whatever classdate they get first or risk being locked out.