Obstacle avoidance between take-off and airway

wrote:
Well, an airport with no "triangle'T" on the chart is not going to
have published takeoff minimums.

So you are saying the answer to my question is "no".

In effect, what you are saying is that for any airport without
published takeoff minimums, departure planning must be done by VFR
sectional. To put it another way, if there is no "triangle-T" symbol
on the chart, departure planning is always "roll-your-own".

This seems odd to me, and contrary, I think, to common belief. It is
certainly contrary to my understanding of several years.


Your belief is incorrect.

Check the NACO chart legends for the Triangle T. The definition is,
"Take-off Minimums not standard and/or Departure Procedures are
published. Refer to tabulation."

If no Triange T appears on the approach charts for an airport with one
or more IAPs (i.e., and IFR airport) (use KDDC as an example) then all
runways have standard takeoff minimums and all runways have diverse
departure areas.

Perhaps you consider a diverse departure area as a "roll your own."
But, that isn't the way the system views it. It means you don't have to
follow any restriction for obstacle clearance purposes (other than no
turns below 400 feet) before proceding direct to wherever. But, even a
diverse departure area has its limits, and the next revision of the AIM
will address this. If you are making a diverse departure out of a
qualified IFR airport you need to be established on an airway or
otherwise at a 91.177 altitude within 25 miles of the airport in non-DMA
areas, and 46 miles in DMAs.

Back to Big Bear: The airport has a Triangle T of course. The
tabulation states NA for Runway 26, higher than standard for 8 (or
standard with a climb gradient) and to use the RNAV DP.

Jeppesen does a better job in that they list the takeoff minimums for
every runway at an IFR airport even when they are standard and there is
a diverse departure area.

To expand on my KDDC example a bit, every runway had an amendment to
Part 97 issued via the federal register at one time establishing only
standard takeoff minimums for all those runways.

If both standard and higher-than-standard are required than the
regualtory form will have more information on it, and that triggers the "T"

And, if an ODP is issued, that will be done as a separate, but related
action into the IFR database.

OK thanks, and I don't want to beat this to death, but I am not fully
satisfied and I hope you don't mind indulging me a question or two
more.

(1) Your answer implies that if there is no "Triangle-T", I can
depart, climb to 400 feet, level off, fly 25 miles at 400 feet, (46
miles in a DMA area) and then climb straight up to 91.77 altitude, and
I have no obstruction worries. I would appreciate if you would
confirm this.

(2)What, exactly, are the criteria for creating an ODP? I am sure
that this is not subjective. There must be a rule involving terrain
characteristics, is there not?




On Fri, 18 Jan 2008 06:59:13 -0800, Sam Spade
wrote:

wrote:
Well, an airport with no "triangle'T" on the chart is not going to
have published takeoff minimums.

So you are saying the answer to my question is "no".

In effect, what you are saying is that for any airport without
published takeoff minimums, departure planning must be done by VFR
sectional. To put it another way, if there is no "triangle-T" symbol
on the chart, departure planning is always "roll-your-own".

This seems odd to me, and contrary, I think, to common belief. It is
certainly contrary to my understanding of several years.


Your belief is incorrect.

Check the NACO chart legends for the Triangle T. The definition is,
"Take-off Minimums not standard and/or Departure Procedures are
published. Refer to tabulation."

If no Triange T appears on the approach charts for an airport with one
or more IAPs (i.e., and IFR airport) (use KDDC as an example) then all
runways have standard takeoff minimums and all runways have diverse
departure areas.

Perhaps you consider a diverse departure area as a "roll your own."
But, that isn't the way the system views it. It means you don't have to
follow any restriction for obstacle clearance purposes (other than no
turns below 400 feet) before proceding direct to wherever. But, even a
diverse departure area has its limits, and the next revision of the AIM
will address this. If you are making a diverse departure out of a
qualified IFR airport you need to be established on an airway or
otherwise at a 91.177 altitude within 25 miles of the airport in non-DMA
areas, and 46 miles in DMAs.

Back to Big Bear: The airport has a Triangle T of course. The
tabulation states NA for Runway 26, higher than standard for 8 (or
standard with a climb gradient) and to use the RNAV DP.

Jeppesen does a better job in that they list the takeoff minimums for
every runway at an IFR airport even when they are standard and there is
a diverse departure area.

wrote:
OK thanks, and I don't want to beat this to death, but I am not fully
satisfied and I hope you don't mind indulging me a question or two
more.

(1) Your answer implies that if there is no "Triangle-T", I can
depart, climb to 400 feet, level off, fly 25 miles at 400 feet, (46
miles in a DMA area) and then climb straight up to 91.77 altitude, and
I have no obstruction worries. I would appreciate if you would
confirm this.

How did you infer that out of what I said, or didn't say? The AIM is
quite explicit that,for a diverse departure area, you must climb at not
less than 200 feet per mile, from lift off until at the 91.177 altitude.

It is a 40:1 sloping surface, not a flat plane.


(2)What, exactly, are the criteria for creating an ODP? I am sure
that this is not subjective. There must be a rule involving terrain
characteristics, is there not?

I'm not teaching a TERPS course. It is all covered in Volume 4 of
TERPS, 8260.3B.

Well, with all due respct, I think we have come full circle and my
original statement is correct:

"If there is an approach chart published, but but no departure
procedure, the rule is no turns before 400' AGL, and maintain 200 FPNM
and you will be clear of obstructions."





On Fri, 18 Jan 2008 08:06:31 -0800, Sam Spade
wrote:

wrote:
OK thanks, and I don't want to beat this to death, but I am not fully
satisfied and I hope you don't mind indulging me a question or two
more.

(1) Your answer implies that if there is no "Triangle-T", I can
depart, climb to 400 feet, level off, fly 25 miles at 400 feet, (46
miles in a DMA area) and then climb straight up to 91.77 altitude, and
I have no obstruction worries. I would appreciate if you would
confirm this.

How did you infer that out of what I said, or didn't say? The AIM is
quite explicit that,for a diverse departure area, you must climb at not
less than 200 feet per mile, from lift off until at the 91.177 altitude.

It is a 40:1 sloping surface, not a flat plane.


(2)What, exactly, are the criteria for creating an ODP? I am sure
that this is not subjective. There must be a rule involving terrain
characteristics, is there not?

I'm not teaching a TERPS course. It is all covered in Volume 4 of
TERPS, 8260.3B.

I inferred it from your statement:

" It means you don't have to
follow any restriction for obstacle clearance purposes (other than no
turns below 400 feet) before proceding direct to wherever"


There is a restriction - 200FPNM.

Which is what I said in the first place .


On Fri, 18 Jan 2008 08:06:31 -0800, Sam Spade
wrote:

wrote:
OK thanks, and I don't want to beat this to death, but I am not fully
satisfied and I hope you don't mind indulging me a question or two
more.

(1) Your answer implies that if there is no "Triangle-T", I can
depart, climb to 400 feet, level off, fly 25 miles at 400 feet, (46
miles in a DMA area) and then climb straight up to 91.77 altitude, and
I have no obstruction worries. I would appreciate if you would
confirm this.

How did you infer that out of what I said, or didn't say? The AIM is
quite explicit that,for a diverse departure area, you must climb at not
less than 200 feet per mile, from lift off until at the 91.177 altitude.

It is a 40:1 sloping surface, not a flat plane.


(2)What, exactly, are the criteria for creating an ODP? I am sure
that this is not subjective. There must be a rule involving terrain
characteristics, is there not?

I'm not teaching a TERPS course. It is all covered in Volume 4 of
TERPS, 8260.3B.

wrote:
Well, with all due respct, I think we have come full circle and my
original statement is correct:

"If there is an approach chart published, but but no departure
procedure, the rule is no turns before 400' AGL, and maintain 200 FPNM
and you will be clear of obstructions."


Provided the runway has takeoff minimums and no ODP. If you made that
clear previously, I missed it.

wrote:

I inferred it from your statement:

" It means you don't have to
follow any restriction for obstacle clearance purposes (other than no
turns below 400 feet) before proceding direct to wherever"


There is a restriction - 200FPNM.

Which is what I said in the first place .

Yes you did. But, you also put words in my mouth to the contrary. ;-)

Well, you have contradicted yourself on this point, but I'm done here.

I will leave you with a challenge, however.

Name a specific airport, with an IAP, and no ODP, where an obstruction
penetrates the 200 FPNM plane within the 25(or 46)nm departure
area(starting at 400 AGL, obviously).




On Fri, 18 Jan 2008 08:46:24 -0800, Sam Spade
wrote:

wrote:
Well, with all due respct, I think we have come full circle and my
original statement is correct:

"If there is an approach chart published, but but no departure
procedure, the rule is no turns before 400' AGL, and maintain 200 FPNM
and you will be clear of obstructions."


Provided the runway has takeoff minimums and no ODP. If you made that
clear previously, I missed it.

wrote:
Well, you have contradicted yourself on this point, but I'm done here.

What point?

I will leave you with a challenge, however.

Name a specific airport, with an IAP, and no ODP, where an obstruction
penetrates the 200 FPNM plane within the 25(or 46)nm departure
area(starting at 400 AGL, obviously).

There aren't any such airports.




On Fri, 18 Jan 2008 08:46:24 -0800, Sam Spade
wrote:


wrote:

Well, with all due respct, I think we have come full circle and my
original statement is correct:

"If there is an approach chart published, but but no departure
procedure, the rule is no turns before 400' AGL, and maintain 200 FPNM
and you will be clear of obstructions."


Provided the runway has takeoff minimums and no ODP. If you made that
clear previously, I missed it.