RangerMateo Posted March 25, 2009 Posted March 25, 2009 So, I think we came across a error in the new Vol 3. Can anyone verify the TAS calculations on Pg 52 and 53? I'm showing that 250 KIAS at 9000 should be around 292 KTAS (250*(1.02)^8) instead of 430 KTAS and 250 KIAS at 12,000 should be closer to 317 (250*(1.02)^12)as opposed to 490 or 500?!?. Came across this when someone called me tonight asking for help figuring decent gradients and said based on the 217 that he would have 340 KTAS at 180 indicated and 8,000 MSL. Something no smelly right.
Butters Posted March 25, 2009 Posted March 25, 2009 So, I think we came across a error in the new Vol 3. Can anyone verify the TAS calculations on Pg 52 and 53? I'm showing that 250 KIAS at 9000 should be around 292 KTAS (250*(1.02)^8) instead of 430 KTAS and 250 KIAS at 12,000 should be closer to 317 (250*(1.02)^12)as opposed to 490 or 500?!?. Came across this when someone called me tonight asking for help figuring decent gradients and said based on the 217 that he would have 340 KTAS at 180 indicated and 8,000 MSL. Something no smelly right. Easy! Invert the third fraction then multiply straight across like this (3x^2-27)(8x^2) 6 ------------------------------------- 4(9-3x) (x^2+3x) but first we can factor and cross cancel (3(x-3)(x+3)(8x^2) 6 --------------------------------------... -12(x-3) x (x+3) after we cross cancel we get =-12x
Riddller Posted March 25, 2009 Posted March 25, 2009 Sorry RM, I think your higher math skills are lost on most who frequent this forum. You're right, those number definitely don't look right, but try just doing it on the wiz-wheel, I think you'll get more support.
RangerMateo Posted March 25, 2009 Author Posted March 25, 2009 Sorry RM, I think your higher math skills are lost on most who frequent this forum. You're right, those number definitely don't look right, but try just doing it on the wiz-wheel, I think you'll get more support. LoL. We looked it up in the blue pages in the IFG too (For those of us still stuck using a T-1 IFG, jerk) and it's nowhere close.
Riddller Posted March 25, 2009 Posted March 25, 2009 And Nole, you might want to check your math... ... (For those of us still stuck using a T-1 IFG, jerk) ... Yeah, my mission computer computes ALL that stuff for me now... :)
Whitman Posted March 25, 2009 Posted March 25, 2009 What's the 217???? I just do half my altitude, added to my KIAS for true. Works marvelously. 300KIAS + 120 (FL 240) = 420KTAS. TLAR Pilot Math is where it's at!
discus Posted March 25, 2009 Posted March 25, 2009 Easy! Invert the third fraction then multiply straight across like this (3x^2-27)(8x^2) 6 ------------------------------------- 4(9-3x) (x^2+3x) but first we can factor and cross cancel (3(x-3)(x+3)(8x^2) 6 --------------------------------------... -12(x-3) x (x+3) after we cross cancel we get =-12x OUCH, my head hurts just trying to figure out if he's joking or not.
RangerMateo Posted March 25, 2009 Author Posted March 25, 2009 (edited) What's the 217???? I just do half my altitude, added to my KIAS for true. Works marvelously. 300KIAS + 120 (FL 240) = 420KTAS. TLAR Pilot Math is where it's at! According to the new 217 you're actually doing 300 KIAS + .02*24000 = 300 + 480 = 780 KTAS. Little did you know how fast the mighty T-1 actually is! Why are you on Baseops now anyway, you should be studying for your nav check! Edited March 25, 2009 by RangerMateo
Butters Posted March 25, 2009 Posted March 25, 2009 And Nole, you might want to check your math... OK, Start by inverting the last fraction and multiplying: 3x² - 27 .. 8x² ....... 6 ----------- * -------- * ---------- .... 4 ...... 9 - 3x . x² + 3x Now you can do some factoring and canceling: 3(x² - 9) .. 8x² ...... 6 ----------- * -------- * ---------- .... 4 ..... 3(3 - x) . x(x + 3) You can cancel the 4 with the 8, remove the 3's and the x's. (x² - 9) .... 2x ........ 6 ----------- * -------- * ---------- .... 1 ...... (3 - x) . (x + 3) Now x²-9 is a difference of squares which can be rewritten as (x - 3)(x + 3): (x-3)(x+3) .... 2x ........ 6 -------------- * -------- * ---------- ....... 1 ...... (3 - x) . (x + 3) Cancel the x+3: (x - 3) .. 2x .... 6 ------- * -------- * --- ...1 ... (3 - x) .. 1 Now notice if you factor out a -1, you have 3-x which will cancel: -1 .. 2x .. 6 --- * ---- * --- .1 ... 1 ... 1 Multiply across and you get: -12x What's the 217???? I just do half my altitude, added to my KIAS for true. Works marvelously. 300KIAS + 120 (FL 240) = 420KTAS. TLAR Pilot Math is where it's at! 217 is the number following 216 and preceding 218. 217 is also a Centered Hexagonal Number. 1
RangerMateo Posted March 25, 2009 Author Posted March 25, 2009 2 concurs. Sorry Riddler. Try plugging that into your mission computer (or your Funk N' Wagnalls for that matter). =) I'll take this opportunity to caveat my math skillz (Yes, with a 'z') with the fact that I'm a Human Development and Family Science Major... OK, Start by inverting the last fraction and multiplying: 3x² - 27 .. 8x² ....... 6 ----------- * -------- * ---------- .... 4 ...... 9 - 3x . x² + 3x Now you can do some factoring and canceling: 3(x² - 9) .. 8x² ...... 6 ----------- * -------- * ---------- .... 4 ..... 3(3 - x) . x(x + 3) You can cancel the 4 with the 8, remove the 3's and the x's. (x² - 9) .... 2x ........ 6 ----------- * -------- * ---------- .... 1 ...... (3 - x) . (x + 3) Now x²-9 is a difference of squares which can be rewritten as (x - 3)(x + 3): (x-3)(x+3) .... 2x ........ 6 -------------- * -------- * ---------- ....... 1 ...... (3 - x) . (x + 3) Cancel the x+3: (x - 3) .. 2x .... 6 ------- * -------- * --- ...1 ... (3 - x) .. 1 Now notice if you factor out a -1, you have 3-x which will cancel: -1 .. 2x .. 6 --- * ---- * --- .1 ... 1 ... 1 Multiply across and you get: -12x 217 is the number following 216 and preceding 218. 217 is also a Centered Hexagonal Number.
sky_king Posted March 25, 2009 Posted March 25, 2009 The rough hack you are talking about goes like this. 250 IAS 14000' MSL = 14K'MSL 250 + 250*.02*14 = 250 + 70 = 320 Increase your IAS by 2% for every thousand feet for a rough hack.
Guest Safe&Clear Posted March 27, 2009 Posted March 27, 2009 Just look at your GPS display. It'll tell you your TAS and GS. And winds. And crosstrack, ETA, and nearest airport. Problem solved....
zrooster99 Posted March 27, 2009 Posted March 27, 2009 (edited) Funk N' Wagnalls My fvck'n what?!! Just arm the alt and put your bannana on your waypoint...duh! Edited March 27, 2009 by zrooster99
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