ATPL Performance and Loading
Join Date: Aug 2007
Location: Sydney
Posts: 42
Likes: 0
Received 0 Likes
on
0 Posts
Time was not an issue for me but then again time wasn't an issue for me in any of the exams. I just used a regular ruler and it worked out fine. You don't need to be too accurate. I only got 1 question on this in the exam. The question actually gives you the distances on screen so you may highlight the screen if you wish. 
Join Date: Feb 2007
Location: ˙ǝqɐq ǝɯ ʇ,uıɐ ʇɐɥʇ 'sɔıʇɐqoɹǝɐ ɹoɟ uʍop ǝpısdn ǝɯɐu ɹıǝɥʇ ʇnd ǝɯos
Age: 45
Posts: 715
Likes: 0
Received 0 Likes
on
0 Posts
hey FCB,
How do you post pictures up??
I have a couple of graphs id like to post and ask some questions about
- If the image is already somewhere on the internet just open it in another page (another tab usually doesn't work) then click, drag and drop into your text.
- If the image is not anywhere on the Internet then you've got to put it somewhere. Just get a free account at photobucket.com and scan it (or if no scanner then take a photo with your camera), upload it and then click, drag and drop (as above) from that website.
at theartistdepot.com, amazon.com or boatsafe.com would have really cared. (OK authors, consider yourselves credited). Happy plagiarising
,FRQ CB
Thread Starter
Join Date: Apr 2008
Location: Brisbane
Age: 39
Posts: 61
Likes: 0
Received 0 Likes
on
0 Posts
Thanks FCB for that.
Im having a problem comparing these 2 graphs
The above is suggesting that Vimd is also max range speed. I thought max range is 1.32Vimd.
Where as the below is suggesting Vimd is best endurance speed (which i believe is correct)
What do you think?
Join Date: May 2002
Location: Permanently lost
Posts: 1,785
Likes: 0
Received 0 Likes
on
0 Posts
I might be misunderstanding your problem, I often do but best endurance and best range are two different things.
Best endurance = Vimd
Best range = 1.32 x Vimd
The top image is misleading because of the vertical line connecting the two graphs. However, it is correct because the two graphs show different things. The top image is graphing thrust or drag and the second image is graphing power. Hence the confusion.
but best endurance and best range are two different things.Best endurance = Vimd
Best range = 1.32 x Vimd
The top image is misleading because of the vertical line connecting the two graphs. However, it is correct because the two graphs show different things. The top image is graphing thrust or drag and the second image is graphing power. Hence the confusion.
Thread Starter
Join Date: Apr 2008
Location: Brisbane
Age: 39
Posts: 61
Likes: 0
Received 0 Likes
on
0 Posts
PLovett yeh i agree with you.
I realise the lower graph in the top picture is showing power reqd
But as you say i am confused with the top picture. because its suggesting the Vimd (top graph) is also max range speed(bottom graph). Which isnt true
With the top picture. Shouldnt Vimd (top graph) line up with best endurance(bottom graph)?
I realise the lower graph in the top picture is showing power reqd
But as you say i am confused with the top picture. because its suggesting the Vimd (top graph) is also max range speed(bottom graph). Which isnt true
With the top picture. Shouldnt Vimd (top graph) line up with best endurance(bottom graph)?
Join Date: Jan 2002
Location: Australia
Posts: 54
Likes: 0
Received 0 Likes
on
0 Posts
This may help re vimd question...
http://www.pprune.org/tech-log/267271-vimd.html
See post by Oktas8 at the bottom.
It appears Vimd is approximately the best range cruise speed for a piston engine aircraft, and approximately the best endurance speed for a turbo jet aircraft.
May explain the discrepancy in graphs, one may be for piston other for jets.
http://www.pprune.org/tech-log/267271-vimd.html
See post by Oktas8 at the bottom.
It appears Vimd is approximately the best range cruise speed for a piston engine aircraft, and approximately the best endurance speed for a turbo jet aircraft.
May explain the discrepancy in graphs, one may be for piston other for jets.
Join Date: Nov 2007
Location: VXXX
Posts: 144
Likes: 0
Received 0 Likes
on
0 Posts
know your speeds
V1 Decision speed – speed to determine whether to continue or abort the takeoff following a failure of the critical engine. Failure below V1 is an abort, at or above V1 the takeoff is continued.
VMCG – minimum control speed – ground – min speed directional control using primary aerodynamic controls following failure of critical engine with max thrust set in take off config.
VMCA – Minimum control speed – air – min speed a/c can be kept within specified limits of heading and attitude following failure of critical engine in second segment config with t/o thrust applied. Defined with a rearmost CoG, within limits which gives highest value of VMCA.
VR - Speed which rotation is initiated by pilot to achieve V2 at or below 35’ with 1 engine inoperative.
VS – minimum steady flight speed / minimum speed in a stall.
VLO – speed a/c lifts off the ground.
VMIN UNSTICK – min speed a/c will lift off gnd. Done doing testing, over rotated early in take off roll, tail strike normally, held nose high attitude until lift off.
V2 – TOSS – following correct rotation and lift off procedures, allows a/c maintain gradient in climb out. Achieve by 35’.
VREF – Reference speed is the landing speed in a nominated configuration, eg VREF 30 would be the landing speed with flaps at 30°.
VMCG ≤ V1 ≤ VR
VR≥ V1 and 1.05VMCA
V2 ≥ 1.1 x VMCA and 1.2 x VS
VMCG – minimum control speed – ground – min speed directional control using primary aerodynamic controls following failure of critical engine with max thrust set in take off config.
VMCA – Minimum control speed – air – min speed a/c can be kept within specified limits of heading and attitude following failure of critical engine in second segment config with t/o thrust applied. Defined with a rearmost CoG, within limits which gives highest value of VMCA.
VR - Speed which rotation is initiated by pilot to achieve V2 at or below 35’ with 1 engine inoperative.
VS – minimum steady flight speed / minimum speed in a stall.
VLO – speed a/c lifts off the ground.
VMIN UNSTICK – min speed a/c will lift off gnd. Done doing testing, over rotated early in take off roll, tail strike normally, held nose high attitude until lift off.
V2 – TOSS – following correct rotation and lift off procedures, allows a/c maintain gradient in climb out. Achieve by 35’.
VREF – Reference speed is the landing speed in a nominated configuration, eg VREF 30 would be the landing speed with flaps at 30°.
VMCG ≤ V1 ≤ VR
VR≥ V1 and 1.05VMCA
V2 ≥ 1.1 x VMCA and 1.2 x VS
VR – such that rotation 10kts below VR will not increase the TODR
Join Date: Jul 2006
Location: Sydney
Posts: 48
Likes: 0
Received 0 Likes
on
0 Posts
W&B graphs
When i did the W&B graphs i, (and class mates), worked out a different way.
Instead of trying to find the thinnest pencil imaginable with the straightest ruler we used the following procedure:
1. At the start of the exam (or even in the 'pre-reading' time) work out how many 'mm' 'millimeters' each passenger in each section is worth. Do this by measuring say 50 passengers length and divide by 50. eg. You may end up with each passenger in 'ROWS 23-27' section is equal to 1.2mm.
2. For the actual question you need a baseline to start from. Draw a vertical line from the 'BASIC INDEX' amount. Your final calculation will be measured from this.
3. Then simply work through all the distances for each load segment. ENSURE you use a + or - depending on whether that section moves the index forward or aft (doesn't really matter which is -ive or +ive but it needs to be consistent).
4. Then just add it all up: For example you may have : + 5mm (ROW 1-6), + 3.2mm (ROW 7-12), +4.5mm (ROW 13-17), - 3.2mm (ROW 18-22) etc etc etc. You will end up with a measurement of say 23.8mm.
5. Then just measure the 23.8 mm in the '+ive' direction from you initial 'INDEX line' along the bottom of the graph (fuel area).
This way you only need to actually use the ruler for a couple of lines instead of mucking around with all the various measurements for each row. (and going cross-eyed
) And the great thing about this method is if in later questions you get the 'What's the change when moving 5 pax from ROWs 7-12 to ROWs 23-27' is you just need to make a basic summation of ' -(5 x ?? mm) + (5 x ??mm) and move your baseline that amount.
It's been a while since i looked at that exam but it gave just about everyone BIG marks...
Worked for us!
Instead of trying to find the thinnest pencil imaginable with the straightest ruler we used the following procedure:
1. At the start of the exam (or even in the 'pre-reading' time) work out how many 'mm' 'millimeters' each passenger in each section is worth. Do this by measuring say 50 passengers length and divide by 50. eg. You may end up with each passenger in 'ROWS 23-27' section is equal to 1.2mm.
2. For the actual question you need a baseline to start from. Draw a vertical line from the 'BASIC INDEX' amount. Your final calculation will be measured from this.
3. Then simply work through all the distances for each load segment. ENSURE you use a + or - depending on whether that section moves the index forward or aft (doesn't really matter which is -ive or +ive but it needs to be consistent).
4. Then just add it all up: For example you may have : + 5mm (ROW 1-6), + 3.2mm (ROW 7-12), +4.5mm (ROW 13-17), - 3.2mm (ROW 18-22) etc etc etc. You will end up with a measurement of say 23.8mm.
5. Then just measure the 23.8 mm in the '+ive' direction from you initial 'INDEX line' along the bottom of the graph (fuel area).
This way you only need to actually use the ruler for a couple of lines instead of mucking around with all the various measurements for each row. (and going cross-eyed
) And the great thing about this method is if in later questions you get the 'What's the change when moving 5 pax from ROWs 7-12 to ROWs 23-27' is you just need to make a basic summation of ' -(5 x ?? mm) + (5 x ??mm) and move your baseline that amount.It's been a while since i looked at that exam but it gave just about everyone BIG marks...
Worked for us!
Join Date: May 2002
Location: Permanently lost
Posts: 1,785
Likes: 0
Received 0 Likes
on
0 Posts
brns2,
Yep, ASL provide one, however, some have seen better days so if you have one of the same type it is worth taking it with you just in case.
I was also given some advice that when you sit down at the desk, test the calculator provided. Enter a line of "8" so that you can see if any of the elements are broken, then do a couple of simple calculations just to see that the thing is working. If you have read the thread on flight planning you will know that some people have had less than ideal calculators to work with.
Yep, ASL provide one, however, some have seen better days so if you have one of the same type it is worth taking it with you just in case.
I was also given some advice that when you sit down at the desk, test the calculator provided. Enter a line of "8" so that you can see if any of the elements are broken, then do a couple of simple calculations just to see that the thing is working. If you have read the thread on flight planning you will know that some people have had less than ideal calculators to work with.
