Misleading Notam

One of our local pilots misunderstood a common Notam, as shown below.
He thought the "ADD: From Shelby to RW 17: 3.52 degrees" meant add
3.52 degrees to the final approach course.

How reasonable do you think his interpretation?

(BTW, the notam just adds a descent gradient to a NP approach.)

FDC 3/0143 M01 FI/T GENERAL DEWITT SPAIN, MEMPHIS, TN. VOR RWY
16, ORIG...CHANGE ALL REFERENCES TO RWY 16/34 TO RWY 17/35.
ADD: FROM SHLBY TO RW 17: 3.52 DEGREES, TCH 31. ADD NOTE: VGSI
AND DESCENT ANGLES NOT COINCIDENT.

On 2003-12-01 09:49:46 -0800, Greg Esres said:

One of our local pilots misunderstood a common Notam, as shown below.
He thought the "ADD: From Shelby to RW 17: 3.52 degrees" meant add
3.52 degrees to the final approach course.

How reasonable do you think his interpretation?

(BTW, the notam just adds a descent gradient to a NP approach.)

I can see where one might interpret it that way. But what the "ADD" means is
that you should ADD that note to the chart. That 3.52 degrees is the "glide
path" angle from SHLBY to the missed approach point.

If there was a change to the final approach course, that would have been
explicitly stated.

Gotta agree with Larry. The whole thing smacks of vertical descent path, not
lateral alignment. Poorly written, for sure. Should at least have had
quotation marks surrounding the phrase between "From" and "degrees."

Bob Gardner

"Greg Esres" wrote in message
...
One of our local pilots misunderstood a common Notam, as shown below.
He thought the "ADD: From Shelby to RW 17: 3.52 degrees" meant add
3.52 degrees to the final approach course.

How reasonable do you think his interpretation?

(BTW, the notam just adds a descent gradient to a NP approach.)

FDC 3/0143 M01 FI/T GENERAL DEWITT SPAIN, MEMPHIS, TN. VOR RWY
16, ORIG...CHANGE ALL REFERENCES TO RWY 16/34 TO RWY 17/35.
ADD: FROM SHLBY TO RW 17: 3.52 DEGREES, TCH 31. ADD NOTE: VGSI
AND DESCENT ANGLES NOT COINCIDENT.

Hmmmm. Just how accurate is this guy's DG?

Headings in one hundredths of a degree???

--
Mike Granby, PP-ASEL,IA
Warrior N44578
http://www.mikeg.net/plane

Headings in one hundredths of a degree???

What about descent angles to within one hundredths of a degree?

"Greg Esres" wrote in message ...
Headings in one hundredths of a degree???

What about descent angles to within one hundredths of a degree?

They are consistantly listed in approach plates to that precision. Even
when they are exactly 3 degrees, the notation looks like:

GS 3.00

"Greg Esres" wrote in message
...
Headings in one hundredths of a degree???

What about descent angles to within one hundredths of a degree?

That makes more sense. A hundredth-degree change in descent angle is
(barely) perceptible on the ASI or VSI. A hundredth-degree change in
heading is not perceptible on the HI or MC.

--Gary

"Gary L. Drescher" wrote:
A hundredth-degree change in descent angle is
(barely) perceptible on the ASI or VSI.

I'd like to see a pilot or VSI which can notice the difference between
500 fpm and 502 fpm.

"Roy Smith" wrote in message ...
"Gary L. Drescher" wrote:
A hundredth-degree change in descent angle is
(barely) perceptible on the ASI or VSI.

I'd like to see a pilot or VSI which can notice the difference between
500 fpm and 502 fpm.

It's not even that much.

However, the charts always show the glideslope to the 100th. They never
show headings to that accuracy. If he'd actually looked hard at the chart
as to what they were changing, the fact that the elevation (which is depecited
on the chart in the same location) also changed would have been a big clue.

"Roy Smith" wrote in message
...
"Gary L. Drescher" wrote:
A hundredth-degree change in descent angle is
(barely) perceptible on the ASI or VSI.

I'd like to see a pilot or VSI which can notice the difference between
500 fpm and 502 fpm.

You're right, it would have been more accurate for me to say a *few*
hundredths of a degree. But that still justifies more than one decimal
place of precision. A few hundredths of a degree change of descent angle
moves the VSI needle almost as much as a one-degree heading change moves the
HI (and courses are routinely specified with single-degree precision).

--Gary