Demanding DP

Let'sgoflying!

Let'sgoflying!

Touchdown! Greaser!
Joined
Feb 23, 2005
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west Texas
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Display name:
Dave Taylor
A very demanding DP

when did we start flying headings accurate to two decimals?

!FDC 5/6189 T82 ODP GILLESPIE COUNTY,
FREDERICKSBURG, TX.
TAKEOFF MINIMUMS AND (OBSTACLE) DEPARTURE PROCEDURES AMDT 1...
DEPARTURE PROCEDURE: RWY 14, CLIMB HEADING 140.73 TO 2400 BEFORE
PROCEEDING ON COURSE. RWY 32, CLIMB HEADING 320.74 TO 2400 BEFORE
PROCEEDING ON COURSE.
 
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Let'sgoflying! said:
when did we start flying headings accurate to two decimals?

!FDC 5/6189 T82 ODP GILLESPIE COUNTY,
FREDERICKSBURG, TX.
TAKEOFF MINIMUMS AND (OBSTACLE) DEPARTURE PROCEDURES AMDT 1...
DEPARTURE PROCEDURE: RWY 14, CLIMB HEADING 140.73 TO 2400 BEFORE
PROCEEDING ON COURSE. RWY 32, CLIMB HEADING 320.74 TO 2400 BEFORE
PROCEEDING ON COURSE.
Click to expand...

That's an FDC NOTAM. The charting folks should round the headings.
 
Hahaha, can anyone show me where exactly them headings are on my HSI LOL.

hsi-030p.png
 
Let'sgoflying! said:
when did we start flying headings accurate to two decimals?


DEPARTURE PROCEDURE: RWY 14, CLIMB HEADING 140.73 TO 2400 BEFORE
PROCEEDING ON COURSE. RWY 32, CLIMB HEADING 320.74 TO 2400 BEFORE
PROCEEDING ON COURSE.
Click to expand...

Yeah, and constructing runways with a sloppy .01° bend in the middle.

dtuuri
 
I bet those numbers are just the runway headings anyhow.
 
Didn't you know pts standards were actually 0.1 degrees off a heading not 10?! Lol
 
Some instruments can.

Brings up how to decimalize degrees. Is it XXX.YY..?

Or is it the degrees minutes.zz most are using.??
 
coloradobluesky said:
Some instruments can.

Brings up how to decimalize degrees. Is it XXX.YY..?

Or is it the degrees minutes.zz most are using.??
Click to expand...

I really doubt any avionics can measure or transmit heading that precisely.

ARINC-429 can only express it to 0.1 deg, for instance. And aligning a magnetometer that precisely would require heroic installation procedures. Better not over torque that bolt by 5 ft lbs....
 
JustinD said:
Didn't you know pts standards were actually 0.1 degrees off a heading not 10?! Lol
Click to expand...

But that's only for the A-ATP* ticket.


*Advanced-Airline Transport Pilot
 
MAKG1 said:
I really doubt any avionics can measure or transmit heading that precisely.

ARINC-429 can only express it to 0.1 deg, for instance. And aligning a magnetometer that precisely would require heroic installation procedures. Better not over torque that bolt by 5 ft lbs....
Click to expand...

Not to mention that at the level of tenth sit hundredths of degrees:

1) Even on autopilot it's hard for any airplane to maintain exact track with that degree of accuracy

2) The Earths magnetic field fluctuates across the surface of the earth more than that so 340.14 one day might not be the same the next day or even a few hours later.
 
rocketflyer84 said:
2) The Earths magnetic field fluctuates across the surface of the earth more than that so 340.14 one day might not be the same the next day or even a few hours later.
Click to expand...

Internally, all RNAV navigators and flight management systems use true course.

In any case, as I said before whoever wrote the NOTAM should have put the whole degree values instead of the values they use for design computations.
 
You can't demand a DP. They're there to aid ATC and if a SID doesn't help them then they're not going to approve it! Sheesh!!!!!


(....sometimes I like to just respond to thread titles without reading the OP or other posts)
 
The "fundamental theory of rounding" says you need 1/2 of the smallest adjustment you have. So if you can adjust to within 1 degree, you want 1/2 degree of precision specified. This way, you will round correctly to within your possible precision.

So if that head can be set to 1 degree, then you need to within 1/2 degree specified on the chart.
 
Cancel the thread. I was able to fly their demanding DP to, well, accuracy much greater than specified in the silly notam. Once I shut off that wildly inaccurate autopilot (only good to half a degree? I scoffed at that accuracy and did it manually).
With a little extra effort I was able to nail the altitudes to 0.05mm too.
I did get some tips from pilot Chuck Norris.
 
midlifeflyer said:
It wasn't that funny to begin with. :no:
Click to expand...
Nah. The whole thread started with a chuckle at super precise heading demands from a departure procedure. I think injecting other elements of poking fun - at society or at ourselves - are well at home here.

See what I did there?
 
ChrisK said:
Nah. The whole thread started with a chuckle at super precise heading demands from a departure procedure. I think injecting other elements of poking fun - at society or at ourselves - are well at home here.

See what I did there?
Click to expand...
Oh, the poking fun at the super-precise heading demands was funny.

But the play on the phrase "demanding DP" was only 2/3 of a pun.
 
midlifeflyer said:
Oh, the poking fun at the super-precise heading demands was funny.

But the play on the phrase "demanding DP" was only 2/3 of a pun.
Click to expand...

2/3 rounds to a descent pun.


(Oops, I did it again)
 
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