RoD in different flap/speed config - 737

[yippy ki yay]

Hi,

I was wondering if anyone had to hand RoD figures for 737 (737NG would be even better!) with different flap configurations and speeds. I flew with someone once who had a whole list of them but I never got round to photocopying them and in flight I always forget to note down the figures I'm observing!
What would be great would be RoD figures at 220, 200, and maybe 190 at F1 and F5 configurations and also RoD figures at maybe 200kts, 190kts, and 180kts when in F10 config. If you had these figures with and without the use of speedbrake then even better! Or if you know where I could obtain these figures from would you mind letting me know where?

Also could someone remind me the formula for calculating angle of descent?

I'm just trying to get a clear understanding in my head of how, when high on profile to varying extents below FL100, what each flap config gives you RoD wise and descent angle wise.

Thanks in advance!!

[PPRuNeUser0165]

Here is what I have had written down since line training, unfortunately I don't have them for flaps deployed-
3x alt plus 10 mile to slow down will give you your track miles needed to determine if you are on profile or not, all rough, and if your in an NG use VNAV and keep updating all your potential variables, the VNAV path indicator would then be useful, remember though, rubbish in rubbish out, and if you don't keep up to date with adjusting your variables it WILL lie to you, so all in all don't rely on it and keep using what I put above! Still with me???

320/300 kts 2500' ROD
280 kts 2200' ROD
250 kts 1700' ROD
220 kts 1100' ROD

unfortunately no flap figures for you, but if your high, 220 kts with f5 and sprees break works well,
If your close to the field and want the speed back then 180kts f10 and speed break works well too, (pax comfort is somewhat degraded though!)
If its really not happening then taking the gear is always an option, but to be honest it's better just to accept defeat and ask for some extra track miles!

ROD 5 times your ground speed gives you a rough ROD for a 3 degree glide path.

Hope this helps,

Good Luck!

[misd-agin]

What's the tailwind component? What's the headwind component? If you're at 190 kts and it's 60 kts it's either 130 Kts GS or 250 kts GS.

IMO it's a waste of time remembering those values and I like ball park data. But the example above show it could be .7x, x, or 1.3x.(x=GS) for a given ROD.

IMO look outside and evaluate distance to go vs altitude to lose. FMC, VTI, or green arc, are excellent tools. Are you regaining your desired profile in time? Yes = stick with what you got. No? How far off of profile? How much distance is left to regain profile? Make the smallest adjustment(speedbrakes, more flaps or gear) consistent with regaining profile.

[yippy ki yay]

Thanks for the reply and figures - yeah I can't seem to get hold of the flap figures anywhere! FCTM just gives the basic speeds and RoD.

Can anybody verify I'm doing the following correctly to calculate descent angle as its been ages since I last did trigonometry. At least this way I can just note the RoD in different flap configs over the next month or so and calculate the descent angles that I'm after.

Lets say you want to descend 5000ft, and you are currently at 10000'. You have an IAS of 250kts so, lets say, a groundspeed of 300kts - your RoD is 1700fpm - is the following calcuation correct?

Using the right angle triangle - you know the vertical as its the height you want to lose - 5000'
It takes 3 mins to lose the altitude at your RoD. Therefore travelling at 300kts you will travel 5nm/min so you will cover 15nm which is 24135m which is 79183ft. So using TAN can you do Inv Tan (O/A) = descent angle?
Inv Tan x (5000/79183) = 3.61 degrees? sounds about right but maybe its just luck that the wrong calculation brought an answer that looks about right...

[yippy ki yay]

What's the tailwind component? What's the headwind component? If you're at 190 kts and it's 60 kts it's either 130 Kts GS or 250 kts GS.

IMO it's a waste of time remembering those values and I like ball park data. But the example above show it could be .7x, x, or 1.3x.(x=GS) for a given ROD.

IMO look outside and evaluate distance to go vs altitude to lose. FMC, VTI, or green arc, are excellent tools. Are you regaining your desired profile in time? Yes = stick with what you got. No? How far off of profile? How much distance is left to regain profile? Make the smallest adjustment(speedbrakes, more flaps or gear) consistent with regaining profile.

I was just going to assume it was in still air for the time being.
Don't get me wrong I'm not intending to use these values in the air - not sure my brain could cope with that!! I'd always do what you suggested above!
I just wanted to gain more understanding into the mathematics behind it - just out of a personal interest. If I'm using those techniques as you mentioned above I would just prefer for me to have a decent grasp on the dynamics/mathematics at play instead of letting myself just doing it because it worked...if that makes sense?