Practice question checking help

[reacher]

Hi all, I’m new here, so be gentle.

Ive got my aptitude testing (hopefully for AAAvn) in a few weeks, starting to ramp up the questions im working on as prep, but im making the required figure up and have trouble figuring out a decent and concise way to do them (pretty much essential seeing that I have a bit less than 1 min to do each in). Was hoping that I could enlist the help of you guys, many who have been around the block a few times already, in checking my answers and/or showing better/quicker ways of doing such calcs.

Many thanks

[edit] And yes i have used the search function, but found only questions relating to more basic calcs.


1. Aircraft A departs @ 1040 @ 240kts
Aircraft B departs @ 1240 @ 300kts
From same origin

How long does it take B to pass A and at what time?

Working: (working under d=st, and distance travelled have to be equal when B passes A)

480 (2hrs @ 240kts) + 240t = 300t
480 = 60t
t = 8hrs

therefore B passes A @ 2040 2400nm from orgin (long legs, I know)


2. Two AC (A and B) 800nm apart, both departing @ 0000
TAS A = 240kts
TAS B = 120kts

How far from As origin do they “meet” and how long does it take?

Dist(A) = 800 x 240 / 360 (120 + 240)

= 800 x 2/3
= 533nm

T = D/S
T = 533/240
=2 hrs and 14min



3. (these are the ones that im having trouble with)
2. Two AC (A and B) 800nm apart, A departs at 0000. B departs at 0035
TAS A = 240kts
TAS B = 120kts

How far from As origin do they “meet” and how long does it take?

Again, if you bothered this far, thanks
:D

[sycamore]

Reacher. always draw a little `scratch` diagram to help give you the picture. Q3 Stop A as B leaves.A is now 140 nm down track, distance remaining 660 nm apart; now do it as in Q2.ie 660/360 =1.833 hrs; 120 x1.833=220 nm (from B); CHECK 1.833 X 240 =440NM, PLUS 140=580 nm( fromA) . Time ==00.35 plus 1.50 ( 1h 50 min =1.833x60)=02.25 hrs.Check-2h25m =145 min, x 4nm/min(for A) =580 nm
Takes a lot longer to write it than it takes to do either mentally or using a calculator. Always check you have a `sensible` answer.
All the best and keep practising...

[TurbineTooHot]

Good luck fella, here's a few tips.

As sycamore says, if you get the chance sketch a few things down (diagrams/numbers). It really helps.

The old "two ac leave and are heading towards each other etc". Forget the two different speeds, work out a closing speed.

eg A = 240 kts B =120kts in opposite directions. Closing speed 360 kts. You can then work with one stationary and one at 360kts (6 miles a minute, get used to that).

Also don't be afraid to do things arse about face. If the question asks for distance and a time, you can work out the time first and extrapolate the distance from that, its sometimes easier.

The answer is 0225 and 580nm btw see above.

[SirToppamHat]

reacher

As you suggest, we have been here before:

Speed Time Maths (http://www.pprune.org/forums/showthread.php?s=&threadid=126284)

Good luck!

STH

[mightyai24]

Reacher,

PM me and I'll send you an excel programme I used in training to improve the spped of mental maths. Not specifically what you asked for, but speed and confidence always help!

mai24

[Onan the Clumsy]

One other point, always look for numbers that cancel out

Like 240 and 300 in the above examples both divide by 60 so kph is easy to convert into kpm

Also 240 and 120, makes an easy ratio of 2/3 to 1/3

Good luck and really practising as many of these as you can will be your best strategy.

[reacher]

Thanks all, trust me that these aren't the only ones ive been doing.... just some of the examples.

12 more days.

oh as a side note, anyone know where to DL similiar "games" that DFR used in their pilot tests....?

[wishtobflying]

reacher, see PM's please ...

SirToppamHat, the tips here are more useful than the other thread, and I've appreciated them.

Anyone have another source of sample problems to work through? Things that include variables like wind speed and direction and fuel burn would be good.

I've searched quite a bit on the 'net and found one or two, but if anyone has further suggestions ....

[SirToppamHat]

wishtobeflying

I wasn't having a dig at reacher for not finding the posting; it's just I remembered posting previously on the subject and wished to share the info there as well as the new stuff here.

Many ways to skin the cat and all that!

STH

[reacher]

Wishtobeflying and mightymia, return serve via PMs.

I gleemed what i could from the other threads, but was left unsatisfied so i started another, a little more specfic.

[wishtobflying]

Sorry STH, on re-reading, my reply did seem a little terse. Not intended that way.