Mental math calculations in the cockpit?

[tarp]

CA: We dutied off at 11:45 last night right?
FO: Yep, actually it was 11:48.
CA: And we dutied on at 0800, right?
FO: Yep.
CA: So was that reduced rest? Are we contract legal? Do we have compensatory rest coming? When do we duty off today?
FO: Standby. Let me try to work this all out.

Now there's some tough math questions!

I spend far more brain cells working on Timesheets, Crew Rest and Schedules than I ever will figuring temperature, descent rates or the occasional fuel in gallons vs. pounds.

 

[skyboat]

BigFlyr is correct-

As soon as you rely on the FMS some knuckelhead will come along and program a 6 degree glidepath into the thing and before you know it you're almost doing an emergency descent to meet a crossing restriction. I've never actually seen this happen, but i've heard about it....

The FMS is a great tool but I'm sure that there are countless stories of violations and accidents because the technology did not do what the operators thought it was going to do.

 

[BigFlyr]

Skyboat,

It happens all the time... Especially in the 737-800 which does not like to slow down and go down! You need to program the box quickly and correctly... then execute... then do the mental math to see if its going to work or not. If you get the dreaded "Drag Required" message... you might as well go to vertical speed mode and go for the barber pole!

 

[Crusty]

You go out to dinner with your crew. As the Captain you are presented the check. You have your F/O and five F/A's, and you all have the same thing. Everyone tosses in their "share" of the $105.21 tab to include the tip. How much will your share be???

($105.21 + 15%) / 7 x 2. You end up paying $35.00 for your hamburger and two lagers. Works every time.

 

[RM7599]

So, if I'm seeing this right, there is not so much mental math in the cockpit.......I get the point, especially from the last few replies!! Thanks for all the great replies, and if anyone has any real world examples, I would like to see them......besides splitting the bar tap

 

[Eagleflip]

Whoops, you are correct Profile--it is 10%....


I suffer from math lysdixia....duh!

 

[alimaui]

Okay very important mental math problem here (NOT!) but interesting....

Most of the time we descend gradually...on an ILS 3deg but for those of you who land so hard it feels like you are dropping out of the sky here is how you can figure out "how far you were dropped from"

*since no "square" sign anything squared will be shown as sq. ie Vsquared will be shown as Vsq


H=Vsq/231580

Where V=vertical speed in ft/min
H=Height in feet from which the aircraft could be dropped from to create the same intensity of touchdown

To Derive

V Finalsq=V initialsq + 2ad

Where V Final = Touchdown speed
V Initial = Zero (dropped from still)
a = acceleration (9.81 meters/second sq)
d = height (h) we are solving for


Have fun....

Ali