calculating the VDP...the easy way:)

[PC12Cowboy]

hey fellow aviators...I need an easy way to calculate the VDP for non precision approaches....Thanks

and while your at it....easy math for weight and balance shift

hmmm...I guess thats it for now...lol

 

[Monkeyfist]

approx. 300' per NM = 3 deg. path (the standard)
MDA(agl) / 350 = VDP slightly higher than 3 degrees.
You could write down the approximate VDP for MDA's of 250' and up, in increments of 25'-50'

 

[HoursHore]

Gus wears a hat. or HAT/GS. for example Hat =450 AGL w/ a 3 degree GS. 450/300= 1.5. Subtract that to the end of the Runway DME.
For Timing only approaches 10% of the timing from the FAF to the MAP. Subtract that from the total time. For example timing for 120kias is 1:48. 10% of 108 sec = 11 sec. VDP = 1:37 . This only works for 2.5 to 3.5 degree GS and is more of an educated guess to calculate required decent rate.

As for the Weight and balance questions, just ask your engineer, loadmaster or boom operator whats up with the Weight and balance, thats their area of expertise. Just kidding

 

[mattpilot]

easy math for weight and balance shift

<weight change>				<CG moves this much from current pos>
---------------------------	=   ---------------------------------
<new weight after change>		   <distance from weight change>

Is this to basic?

 

[PC12Cowboy]

Nope I need all the basic I can get
thanks my fellow aviator

 

[PC12Cowboy]

but still need an example<<<kinda slow in math

 

[minitour]

like if you've got a 2000 plane and you need to move the CG 10 inches forward, so you decide to move 200 pounds...(round numbers chosen for ease of math)

200 (Weight to move) X (You need to move it this far)
---------------------- = --------------------------------
2000# (Total Weight) 10" (Difference between the old & new CG)

-mini

*edit*
Answer: 1"

 

[mattpilot]

sure thing.... but please do me a favor - change your subtitle - i can't take this ***censored*** crap - half my screen is filled with it



Using a C172 (but still works with most airplanes - not to familiar with the big complex airliners ).

EXAMPLE#1: Say CG is 33 inch. and our weight is 2200lbs. Say we got one more pax that weighs 200lbs and we put him at station 73.

200lbs (weight change)				   <<BLANK> our answer - X multiply
-----------------------	  =		 --------------------------------
2400 (old weight + weight change)	  40 ( CG to station 73 // 73-33 = 40)
 
( 200 x 40 ) / 2400 = 3.3 inch

Our CG moves 3.3 inches. Since weight was added behind the CG, we add 3.3 to our old CG which is 36.3.


EXAMPLE #2. Since those values are outside our limits (way forward), we must shift some weight, without adding any.

We will figure out how much weight we must shift from station 37 to station 73 (front seat to rear seat) to bring our CG to station 41.

<<blank>> our answer				 4.7 [size=1](we need the CG to move from 36.3 to 41)[/size]
----------------------	  =   ---------------------------------------------
2400 (no weight change)			  36 (we move from 37 to 73)
 
We X - multiply again .......  (2400 x 4.7 ) / 36 = 313 lbs

Answer: we need to move 313 lbs from front seat to rear seat to be within limits.


Simple huh? You can use any combination... many possibilities - just follow basic rules.

 

[PC12Cowboy]

Mini...it must be snowing in oklahoma

 

[mattpilot]

Mini...it must be snowing in oklahoma

whats that supposed to mean?

 

[PC12Cowboy]

Mattpilot...there new sub title...and mini is going to my flight school in OKC

 

[minitour]

whats that supposed to mean?

I'm sure I should get it...but....can someone fill me in?

-mini

 

[mattpilot]

Mattpilot...there new sub title...and mini is going to my flight school in OKC

really? out of PWA?

I'm a spartonien out of RVS

 

[minitour]

...and mini is going to my flight school in OKC

Why the hell aren't you down at the bar w/ the rest of the instructors?

-mini

 

[mattpilot]

BTW... any of you got a 3 page paper on Hypoxia? Its due monday morning.... Only reason i'm still up is cause i'm trying to think... Can't get the first paragraph down

 

[mattpilot]

Why the hell aren't you down at the bar w/ the rest of the instructors?

-mini

Because *he* ain't worthy.


**edit OOPS - didn't see that you quoted Cowboy

 

[minitour]

BTW... any of you got a 3 page paper on Hypoxia? Its due monday morning.... Only reason i'm still up is cause i'm trying to think... Can't get the first paragraph down

It could be arranged (sp).

I did a 10 pager for a "friend" on "Aviation Safety" a while back...Got him an 18/20...

If the price is right .

-mini

 

[mattpilot]

If the price is right .

This ain't the "PRICE IS RIGHT" show...... i thought connections at flightinfo ment something?


btw.. i don't think i'd trust you with your spelling skillzzzz

 

[PC12Cowboy]

Mini got to hudsons and have a beer for me!!!......lol

 

[mattpilot]

I still don't know where you guys fly out of?

gimme names!!!!!!!!!!!!!!

 

[minitour]

This ain't the "PRICE IS RIGHT" show...... i thought connections at flightinfo ment something?


btw.. i don't think i'd trust you with your spelling skillzzzz

That's what MS Werd and spell check is for!

Mini got to hudsons and have a beer for me!!!......lol

Beer ain't ma thang...I'm more of a double whopper with cheeeeeeeeeeez man myself er... ma'self

-mini

 

[PC12Cowboy]

matt...RVS is soo far away from OUN.....but hey at least we fly every day at AIRMAN...lol

 

[minitour]

matt...RVS is soo far away from OUN.....but hey at least we fly every day ast AIRMAN...lol

I don't know about that

Instrument Program
Completion of stg 1 to stg 1 check - 2 weeks
Completion of stg 2 to stg 2 check (ITS A SIMULATOR CHECK!!) - 2 weeks
Completion of stg 3 to stg 3 check (check ride) - 3.5 weeks

Commercial Single Program
Completion of stg 1 to stg 1 check - 4.5 weeks

At least I've got all this time to study...I'm almost ready for the ATP written and about to start working on the FE written...

hmm...that brings up a neat question...

-mini

 

[PC12Cowboy]

mini...and that question is?

 

[VFR on Top]

For Timing only approaches 10% of the timing from the FAF to the MAP. Subtract that from the total time. For example timing for 120kias is 1:48. 10% of 108 sec = 11 sec. VDP = 1:37 . This only works for 2.5 to 3.5 degree GS and is more of an educated guess to calculate required decent rate.

A better one is to take 10% of the height above touchdown (HAT) at the MDA and deduct that number of seconds from the FAF-to-MAP timing. Example: FAF-to-MAP is 4.9 nm, 2:27 @ 120 kts groundspeed. HAT at the MDA is 400'. 400' x .1 = 40 (seconds). Thus, VDP = (2:27 - :40) = 1:47 from the FAF. At 120 kts groundspeed, roughly a 600 fpm descent rate is called for to maintain a 3 degree glidepath, and a descent from a HAT of 400 to the runway at that descent rate takes, magically enough, 40 seconds.

Using your formula, subtracting only 22.7 seconds--10%--from 2:27 gives you only .45 nm in the above scenario to lose 400', and you'd need almost double your descent rate to make that, assuming the MAP is at the runway threshold.

 

[minitour]

mini...and that question is?

new thread on FE/DX and "other"...sorry, guess that was kinda sh*tty...

 

[jeff333]

Look out the window. Looks good go down real easy.