View Full Version : Friday Night Trivia Smart Minds Required
ksa5223
11th Apr 2008, 05:49
http://i196.photobucket.com/albums/aa178/ksa5223/wrong.jpg
So,
1. Flight Computer, dH 10,000 (175IAS = 203TAS)
Air Specific Range is not Ground Specific Range so we should not deduct the headwind and should use the TAS
20usg x 2.72 = 54.4kg
54.4 divided by 203 = .27kg/nm
The answer is not given by the examiner, so I am confused.
Why did they mark me wrong? :mad:
Jabawocky
11th Apr 2008, 05:59
Mental maths only here.......I think its the 0.31......
Try asking someone who knows though!
J:ok:
ForkTailedDrKiller
11th Apr 2008, 06:48
An aircraft cruising at 10000ft density height in a 20 kt headwind has an indicated airspeed of 175 kts
I guess its a Bonanza, huh!
Dr :8
OZBUSDRIVER
11th Apr 2008, 07:34
ksa5223, I had to go back to make sure.
SPECIFIC AIR RANGE = FF/TAS kg/nm
So , as far as I can tell, your calcs are correct.
0.27kg/nm
Specific Ground Range takes into account W/V
using GS of 183kts gives and SGR of 0.2972kg/nm closer to 0.29 than 0.31.
What does your KDR say? Using your figures, I would take it up with your flight test ATO on the day and see what they say.
Icarus53
11th Apr 2008, 08:02
Question doesn't specify AVGAS or AVTUR. I assume the 2.72 factor you're using is USG to KG of AVGAS?
I can't remember all the numbers but using 3.8 USG/Ltr and 0.81 kg/Ltr (AVTUR) I get a conversion closer to 3, resulting in an answer closer to 0.31kg/nm.
Can't tell you how many KDRs I've had from answers that could not possibly have been wrong, but don't bother taking it up with them as I;ve never had a response. You'd like to think you get what you pay for!:ugh:
alexthepilot
11th Apr 2008, 08:34
ye if it's an ATPL examination then im guessing the conversion will be different, and thus what he said above
ksa5223
11th Apr 2008, 09:23
thanks oz
yes it is a cpl level question and it's avgas.
I think i am correct and it may well be a database error as its an online marking website :-)
Kenneth
12th Apr 2008, 09:43
And therin lies the problem with the current system..... minnimal feedback (KDR) and your left guessing why you got it wrong (if in fact you did get it wrong).