Crossing a stepdown fix high

[David Brooks]

Is there any problem with controllers or examiners if I cross a stepdown fix
several hundred feet above the depicted altitude? I believe that, legally,
I can be at any altitude above the crossing minimum, but would this be a
bust of the PTS +/-100 tolerance, or cause a problem for ATC?

For example, take the SEA VOR 34L/R approach. Assume you are cleared for the
approach at 5000ft. Profile is 5000 at FACTS - 6nm - 3000 at MILLT - 6.7nm -
1600 at DONDO, which is the last fix before descent to the MDA. I can set up
a nice smooth descent at 300fpnm, arrive at 1600ft well before DONDO, and
avoid even thinking about a level-off by crossing MILLT something above
3200ft. Would that be a checkride ding?

-- David Brooks

[Bob Gardner]

When I was an examiner, I would have expected you to fly the approach
profile as published. Once upon a time I decided to forego the "descent and
maintain 2200 feet" on the way in to BFI's ILS 13R, thinking that I would
stay at 3000 and intercept the glideslope high....got chided by Seattle
Approach for doing so. Over the years I have learned that ATC expects you to
do the expected.

Bob Gardner

"David Brooks" > wrote in message
...
> Is there any problem with controllers or examiners if I cross a stepdown
fix
> several hundred feet above the depicted altitude? I believe that,
legally,
> I can be at any altitude above the crossing minimum, but would this be a
> bust of the PTS +/-100 tolerance, or cause a problem for ATC?
>
> For example, take the SEA VOR 34L/R approach. Assume you are cleared for
the
> approach at 5000ft. Profile is 5000 at FACTS - 6nm - 3000 at MILLT -
6.7nm -
> 1600 at DONDO, which is the last fix before descent to the MDA. I can set
up
> a nice smooth descent at 300fpnm, arrive at 1600ft well before DONDO, and
> avoid even thinking about a level-off by crossing MILLT something above
> 3200ft. Would that be a checkride ding?
>
> -- David Brooks
>
>

[Roy Smith]

David Brooks > wrote:
> Is there any problem with controllers or examiners if I cross a stepdown fix
> several hundred feet above the depicted altitude?

I doubt a controller would even notice (or care).

The examiner probably will, and might ding you on it if you didn't
explain why you were high. It sounds like you've got a perfectly good
plan, however, and I suspect most examiners would be impressed with
the level of pre-flight planning you put into this if you explained it
ahead of time. The last thing you want to do on a checkride is do
something unusual without explanation -- that leaves the examiner to
come up with his own explanation, and it might just be that you're
behind the airplane.

On the other hand, don't just cross fixes high for no good reason.
Depending on the approach, if you don't keep up (down?) with the
step-down fixes, you may find yourself having to divebomb at the end
to reach the MDA before you reach the MAP. I don't have a chart of
the approach you're talking about, but the way you describe it, it
sounds like you've already thought about that.



I believe that, legally,
>I can be at any altitude above the crossing minimum, but would this be a
>bust of the PTS +/-100 tolerance, or cause a problem for ATC?
>
>For example, take the SEA VOR 34L/R approach. Assume you are cleared for the
>approach at 5000ft. Profile is 5000 at FACTS - 6nm - 3000 at MILLT - 6.7nm -
>1600 at DONDO, which is the last fix before descent to the MDA. I can set up
>a nice smooth descent at 300fpnm, arrive at 1600ft well before DONDO, and
>avoid even thinking about a level-off by crossing MILLT something above
>3200ft. Would that be a checkride ding?

[David Megginson]

"David Brooks" > writes:

> Is there any problem with controllers or examiners if I cross a stepdown fix
> several hundred feet above the depicted altitude? I believe that, legally,
> I can be at any altitude above the crossing minimum, but would this be a
> bust of the PTS +/-100 tolerance, or cause a problem for ATC?

There's an interesting article from a 1998 Transport Canada newsletter
called "CFIT - Why are aircraft flying at minimum IFR altitudes?":

http://www.tc.gc.ca/civilaviation/ansanda/aarna/new198.htm

One of the major recommendations is that the only time a pilot should
fly at (rather than above) a minimum IFR altitude is MDA when weather
conditions require; otherwise, leave a healthy safety margin. Of
course, you'll have a hard time convincing a flight test examiner of
this, but in real life, it makes sense to me -- my plane is a lot
slower and can descend at a lot steeper angle than a big airliner, so
I don't need a long, shallow approach slope anyway.

Besides, ATC doesn't always know what approach you're flying anyway.
Are you on the ILS 25, the LOC 25, the LOC/DME 25, the NDB 25, the
NDB/DME 25, or the GPS 25? In my (so-far limited) experience,
sometimes they mention a specific approach and sometimes they do not.


All the best,


David

[David Megginson]

"Bob Gardner" > writes:

> When I was an examiner, I would have expected you to fly the approach
> profile as published. Once upon a time I decided to forego the "descent and
> maintain 2200 feet" on the way in to BFI's ILS 13R, thinking that I would
> stay at 3000 and intercept the glideslope high....got chided by Seattle
> Approach for doing so.

But in that case, if I understand correctly, you had a specific
instruction from ATC to descend to 2200 -- that's different from
step-down altitudes in a published IAP.


All the best,


David

[Paul Tomblin]

In a previous article, David Megginson > said:
>One of the major recommendations is that the only time a pilot should
>fly at (rather than above) a minimum IFR altitude is MDA when weather
>conditions require; otherwise, leave a healthy safety margin. Of
>course, you'll have a hard time convincing a flight test examiner of
>this, but in real life, it makes sense to me -- my plane is a lot
>slower and can descend at a lot steeper angle than a big airliner, so
>I don't need a long, shallow approach slope anyway.

I don't know if this would be considered "a healthy safety margin", but my
examiner said the same thing that my instructor did - that the PTS says
+100 feet/-0 feet, so you should always fly 50 feet high to give yourself
a bit of a buffer.


--
Paul Tomblin > http://xcski.com/blogs/pt/
Pascal - A programming language named after a man who would turn over in his
grave if he knew about it.

[Bob Gardner]

I didn't say it was a smart move (:-).

Bob

"David Megginson" > wrote in message
...
> "Bob Gardner" > writes:
>
> > When I was an examiner, I would have expected you to fly the approach
> > profile as published. Once upon a time I decided to forego the "descent
and
> > maintain 2200 feet" on the way in to BFI's ILS 13R, thinking that I
would
> > stay at 3000 and intercept the glideslope high....got chided by Seattle
> > Approach for doing so.
>
> But in that case, if I understand correctly, you had a specific
> instruction from ATC to descend to 2200 -- that's different from
> step-down altitudes in a published IAP.
>
>
> All the best,
>
>
> David

[Scott Lowrey]

"Roy Smith" > wrote in message
...
>
> The examiner probably will, and might ding you on it if you didn't
> explain why you were high. It sounds like you've got a perfectly good
> plan, however, and I suspect most examiners would be impressed with
> the level of pre-flight planning you put into this if you explained it
> ahead of time.

Let me guess. Rather than preflight planning, this question sprouted from
repeated attempts to pass the instrument check ride in Microsoft's Flight
Simulator! :D

Know this approach well. Must've flown in a hundred times trying to pass
that stupid "check ride". ;)

If you're flying the approach IRL, my apologies for kidding around.

-Scott

[Ron Rosenfeld]

On Thu, 16 Oct 2003 20:13:36 GMT, "Bob Gardner" > wrote:

>When I was an examiner, I would have expected you to fly the approach
>profile as published. Once upon a time I decided to forego the "descent and
>maintain 2200 feet" on the way in to BFI's ILS 13R, thinking that I would
>stay at 3000 and intercept the glideslope high....got chided by Seattle
>Approach for doing so. Over the years I have learned that ATC expects you to
>do the expected.

Bob,

Here at the other end of the country, I routinely stay at my assigned
altitude until intercepting the GP. ATC doesn't care, nor does an FAA
examiner with whom I've ridden several times.

HOWEVER, my clearance is NOT descend and maintain 2200' ... Rather, I
might be at 3000', and my clearance might be something like "maintain at or
above 1800' until established; cleared for the ILS 14 approach".

If I received a clearance that said "descend and maintain 2200', cleared
for the approach" I would treat that as an altitude assignment, and descend
to 2200' expeditiously.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

[[email protected]]

Bob Gardner wrote:

> When I was an examiner, I would have expected you to fly the approach
> profile as published. Once upon a time I decided to forego the "descent and
> maintain 2200 feet" on the way in to BFI's ILS 13R, thinking that I would
> stay at 3000 and intercept the glideslope high....got chided by Seattle
> Approach for doing so. Over the years I have learned that ATC expects you to
> do the expected.

The industry has worked hard to get away from dive-and-drive. A constant
descent profile is a lot safer, provided it doesn't bust a stepdown. If a
stepdown is mandatory it will so state on the Jepp chart, and have a line above,
as well below, the altitude on the NACO chart.

[Tim J]

Why would you want to add extra work? The approaches are published that way
for a reason. Also, another poster commented about staying at an altitude
(above the published one) until intersecting the 'GP.' I can only assume
"GP" means glide path (or glide slope). Your example was a VOR appch I
believe, but in the case of an ILS approach, it is not wise to stay above,
as you can intercept a false glideslope.

If you do the approach your way then you have to account for wind, etc to
figure out if you are at the right descent speed, etc. Just descend as
published - it is easier than figuring out a descent rate to match the winds
and airplane speed.

The bottom line is the approach is the approach - I don't think it is
intended as a "suggestion." - why stay above the heights? Wouldn't you
rather get down as fast as possible than be in the clouds? The altitudes on
the approach chart guarantee more than reasonable obstacle clearance - not
performing the approach as published would also lead me to wonder if there
are other things you would make up your own procedures for and as a DE I
would consider that a bad thing...

tim

"David Brooks" > wrote in message
...
> Is there any problem with controllers or examiners if I cross a stepdown
fix
> several hundred feet above the depicted altitude? I believe that,
legally,
> I can be at any altitude above the crossing minimum, but would this be a
> bust of the PTS +/-100 tolerance, or cause a problem for ATC?
>
> For example, take the SEA VOR 34L/R approach. Assume you are cleared for
the
> approach at 5000ft. Profile is 5000 at FACTS - 6nm - 3000 at MILLT -
6.7nm -
> 1600 at DONDO, which is the last fix before descent to the MDA. I can set
up
> a nice smooth descent at 300fpnm, arrive at 1600ft well before DONDO, and
> avoid even thinking about a level-off by crossing MILLT something above
> 3200ft. Would that be a checkride ding?
>
> -- David Brooks
>
>

[Ray Andraka]

For the VOR approaches, you probably want to get down more or less on the
steps. You'll need the time to find the airport if you do break out in many
cases. You don't however have to execute the approach as steps unless the
altitudes are depicted as mandatory altitudes (line above and below the
number). If it is a long approach, there is no need to go bombing down to the
next altitude as you cross each stepdown. Bby the same token you don't want to
be too far above the min crossing altitude when you cross it, otherwise you're
not going to have enough room to get down with a reasonable descent rate.
Ideally, you would decend at a rate that got you to the min crossing altitude as
you passed the next stepdown fix, but that usually won't happen.

Now on an ILS, you should be following the glideslope if it is working. The
stepdowns there are for a localizer only approach. Note that staying high on
the ILS until intercepting the GS will never put you in a position to get a
false GS: You'll still intersect the glideslope from underneath.

Tim J wrote:

> tim
>
> "David Brooks" > wrote in message
> ...
> > Is there any problem with controllers or examiners if I cross a stepdown
> fix
> > several hundred feet above the depicted altitude? I believe that,
> legally,
> > I can be at any altitude above the crossing minimum, but would this be a
> > bust of the PTS +/-100 tolerance, or cause a problem for ATC?
> >
> > For example, take the SEA VOR 34L/R approach. Assume you are cleared for
> the
> > approach at 5000ft. Profile is 5000 at FACTS - 6nm - 3000 at MILLT -
> 6.7nm -
> > 1600 at DONDO, which is the last fix before descent to the MDA. I can set
> up
> > a nice smooth descent at 300fpnm, arrive at 1600ft well before DONDO, and
> > avoid even thinking about a level-off by crossing MILLT something above
> > 3200ft. Would that be a checkride ding?
> >
> > -- David Brooks
> >
> >

--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759

[Ron Rosenfeld]

On Sat, 18 Oct 2003 01:36:18 GMT, "Tim J" >
wrote:

>Also, another poster commented about staying at an altitude
>(above the published one) until intersecting the 'GP.' I can only assume
>"GP" means glide path (or glide slope). Your example was a VOR appch I
>believe, but in the case of an ILS approach, it is not wise to stay above,
>as you can intercept a false glideslope.

Well of course you don't want to intercept a GP from above, but that has
nothing to do with remaining above the published GP intercept altitude
miles from the FAF where the GP will be above you.

For example, look at the ILS 14 at Nashua, NH (KASH). The GP intercept
altitude is 1800' and the precision FAF is about five miles from the
runway. It would not be unusual to be vectored to the vicinity of MUGGY at
an altitude of 3000' (or even 2500' if memory serves me) and then cleared
for the approach. At that point in space, you are well below the GP (so no
danger of intercepting a false glideslope). I would prefer to remain
straight and level until intercepting the GP, and then just do the one
reconfiguration to a descent. The alternative is more work as you
configure for a descent, level off at 1800' and reconfigure for straight
and level, and then reconfigure again for a descent just outside of CHERN.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

[[email protected]]

Tim J wrote:

>
>
> The bottom line is the approach is the approach - I don't think it is
> intended as a "suggestion." - why stay above the heights? Wouldn't you
> rather get down as fast as possible than be in the clouds? The altitudes on
> the approach chart guarantee more than reasonable obstacle clearance - not
> performing the approach as published would also lead me to wonder if there
> are other things you would make up your own procedures for and as a DE I
> would consider that a bad thing...
>
> Another "bottom line" is that the stepdown altitude in a NPA profile is a
> *minimum* altitude.

If you think in terms of getting down to a stepdown to "get out of the clouds"
that is a good way to find granite or trees instead of water vapor. This is not
just my view; the industry/government accident stats are replete.

[Steven P. McNicoll]

"David Brooks" > wrote in message
...
>
> Is there any problem with controllers or examiners if I cross a stepdown
fix
> several hundred feet above the depicted altitude? I believe that,
legally,
> I can be at any altitude above the crossing minimum, but would this be a
> bust of the PTS +/-100 tolerance, or cause a problem for ATC?
>

Assuming ATC hasn't issued an altitude restriction it's not a problem for
them, it shouldn't be a problem for an examiner as you're not wavering from
an assigned altitude.

[Steven P. McNicoll]

"Bob Gardner" > wrote in message
news:PZCjb.795942$uu5.139761@sccrnsc04...
>
> When I was an examiner, I would have expected you to fly the approach
> profile as published. Once upon a time I decided to forego the "descent
and
> maintain 2200 feet" on the way in to BFI's ILS 13R, thinking that I would
> stay at 3000 and intercept the glideslope high....got chided by Seattle
> Approach for doing so. Over the years I have learned that ATC expects you
to
> do the expected.
>

There's nothing in this scenario that suggests he was issued a hard altitude
prior to the approach clearance, it may have been at pilot's discretion.

[Steven P. McNicoll]

> wrote in message
...
>
> If you think in terms of getting down to a stepdown to "get out of the
clouds"
> that is a good way to find granite or trees instead of water vapor. This
is not
> just my view; the industry/government accident stats are replete.
>

Only if the published altitudes are wrong.

[Tim J]

That is ridiculous. If I follow the approach procedures I will stay away
from the granite. I would recommend reading TERPS. Maybe I am an idiot for
following the procedures as published, but it lets me work on the other
parts of flying and I have more time and effort left for the rest of the
work during an approach.

> wrote in message
...
>
>
> Tim J wrote:
>
> >
> >
> > The bottom line is the approach is the approach - I don't think it is
> > intended as a "suggestion." - why stay above the heights? Wouldn't you
> > rather get down as fast as possible than be in the clouds? The
altitudes on
> > the approach chart guarantee more than reasonable obstacle clearance -
not
> > performing the approach as published would also lead me to wonder if
there
> > are other things you would make up your own procedures for and as a DE I
> > would consider that a bad thing...
> >
> > Another "bottom line" is that the stepdown altitude in a NPA profile is
a
> > *minimum* altitude.
>
> If you think in terms of getting down to a stepdown to "get out of the
clouds"
> that is a good way to find granite or trees instead of water vapor. This
is not
> just my view; the industry/government accident stats are replete.
>

[[email protected]]

"Steven P. McNicoll" wrote:

> > wrote in message
> ...
> >
> > If you think in terms of getting down to a stepdown to "get out of the
> clouds"
> > that is a good way to find granite or trees instead of water vapor. This
> is not
> > just my view; the industry/government accident stats are replete.
> >
>
> Only if the published altitudes are wrong.

I guess the stats and industry/government studies are all wet then.

The published altitudes weren't wrong at KBDL when the AAL MD80 hit the trees
near the stepdown fix.

[[email protected]]

Tim J wrote:

> That is ridiculous. If I follow the approach procedures I will stay away
> from the granite. I would recommend reading TERPS. Maybe I am an idiot for
> following the procedures as published, but it lets me work on the other
> parts of flying and I have more time and effort left for the rest of the
> work during an approach.

Good idea. I'll read those TERPs.

[Tim J]

So what are you saying? The approach chart is/was wrong or the pilots made
an error?


> wrote in message
...
>
>
> "Steven P. McNicoll" wrote:
>
> > > wrote in message
> > ...
> > >
> > > If you think in terms of getting down to a stepdown to "get out of the
> > clouds"
> > > that is a good way to find granite or trees instead of water vapor.
This
> > is not
> > > just my view; the industry/government accident stats are replete.
> > >
> >
> > Only if the published altitudes are wrong.
>
> I guess the stats and industry/government studies are all wet then.
>
> The published altitudes weren't wrong at KBDL when the AAL MD80 hit the
trees
> near the stepdown fix.
>
>

[Ron Natalie]

> wrote in message ...

>
> The published altitudes weren't wrong at KBDL when the AAL MD80 hit the trees
> near the stepdown fix.
>

The hit obstacles because: They pilot descended over 300 feet below what the
altimeter would lead him to believe the MDA was, and they had a nearly hour old
altimeter setting which put them another 40 feet down. The trees were also a little
taller than the FAA had accounted for when they designed the appraoch.

They were well beyond the stepdown fix (about halfway to the runway). It's not clear
what the stepdown fix had to do with it. If they'd flown a similar apporach at an airport
with an 800 foot MDH, they'd have still hit obstacles.

The NTSB did make some comments regarding continuous descents rather than step
down fixes, but I don't think that it would have helped in this case. If you look at the
profile view actually flown (which has a 3.5 degree glideslope superimposed over it),
you find that if they had stopped at the MDA they would have gotten there only half
a mile further out than they would have done on a constant descent angle.

[Tim J]

I was just trying to point out the obstacle clearances that the approach
charts provide.

I would like to see an accident report that found that the approach chart
was incorrect and caused a crash. Does anyone have an example?

I think rather it is the (improper) execution of the approach that is the
cause of the supposed huge set of examples of crashes. If you all find it
easier to make up your own descent profiles, go right ahead. I will not try
to convince you otherwise. I will continue to fly them as published.

tim

> wrote in message
...
>
>
> Tim J wrote:
>
> > That is ridiculous. If I follow the approach procedures I will stay
away
> > from the granite. I would recommend reading TERPS. Maybe I am an idiot
for
> > following the procedures as published, but it lets me work on the other
> > parts of flying and I have more time and effort left for the rest of the
> > work during an approach.
>
> Good idea. I'll read those TERPs.
>

[Roy Smith]

In article >,
"Ron Natalie" > wrote:

> > wrote in message
> ...
>
> >
> > The published altitudes weren't wrong at KBDL when the AAL MD80 hit the
> > trees
> > near the stepdown fix.
> >
>
> The hit obstacles because: They pilot descended over 300 feet below what
> the
> altimeter would lead him to believe the MDA was, and they had a nearly hour
> old
> altimeter setting which put them another 40 feet down. The trees were also
> a little
> taller than the FAA had accounted for when they designed the appraoch.
>
> They were well beyond the stepdown fix (about halfway to the runway). It's
> not clear
> what the stepdown fix had to do with it. If they'd flown a similar apporach
> at an airport
> with an 800 foot MDH, they'd have still hit obstacles.
>
> The NTSB did make some comments regarding continuous descents rather than
> step
> down fixes, but I don't think that it would have helped in this case. If you
> look at the
> profile view actually flown (which has a 3.5 degree glideslope superimposed
> over it),
> you find that if they had stopped at the MDA they would have gotten there
> only half
> a mile further out than they would have done on a constant descent angle.
>
>
>

Not to mention that the weather was unbelievably ****ty. If I remember
the incident correctly, the storm had blown out the tower cab windows,
and the controllers had fled the building for fear of personal injury.

We're talking about

http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001207X04839&key=1

right? Unfortunately, the "full narrative available" link seems to be
stale, but http://www.ntsb.gov/publictn/1996/AAR9605.pdf is the full report.
It's kind of interesting to read.

[Greg Esres]

<<If I follow the approach procedures I will stay away from the
granite. I would recommend reading TERPS. >>

I'm certain that Airperson is far more familiar with TERPS than you
are or ever will be.

His point is that certain types of procedures lend themselves to
certain types of errors. Nonprecision approaches have a far higher
error rate than precision approaches. The weak link is the limitation
on human ability to manage complexity; the only solution is reducing
complexity, either through technology (which is what a glide slope
does) or via pilot training, such as the constant rate descent.

To comment that "if they fly the approach as published, they won't hit
anything" is a very shallow analysis. Not every CFIT deviated
intentionally from the published approach.

[Stan Gosnell]

"Tim J" > wrote in
. net:

> So what are you saying? The approach chart is/was wrong or
> the pilots made an error?

The pilots made an error. Dive and drive is dangerous. I'm in
no particular hurry to get out of the clouds - at MDA is fine.
Why would anyone be in a huge hurry to get out of the clouds?
Being in a hurry is almost always dangerous, sometimes fatal.

--
Regards,

Stan

[Stan Gosnell]

"Bob Gardner" > wrote in
news:PZCjb.795942$uu5.139761@sccrnsc04:

> When I was an examiner, I would have expected you to fly
> the approach profile as published. Once upon a time I
> decided to forego the "descent and maintain 2200 feet" on
> the way in to BFI's ILS 13R, thinking that I would stay at
> 3000 and intercept the glideslope high....got chided by
> Seattle Approach for doing so. Over the years I have
> learned that ATC expects you to do the expected.

"Descend and maintain 2200" is not the same clearance as
"Maintain at or above 2200".

--
Regards,

Stan

[David Megginson]

Greg Esres > writes:

> To comment that "if they fly the approach as published, they won't hit
> anything" is a very shallow analysis. Not every CFIT deviated
> intentionally from the published approach.

The other question is what "as published" means for an NPA -- do you
make a vertical descent at every stepdown fix? The whole point of an
NPA is that there is no vertical profile published, only a series of
minimum altitudes.


All the best,


David

[[email protected]]

Tim J wrote:

> So what are you saying? The approach chart is/was wrong or the pilots made
> an error?

The pilots made an error under lots of pressure and adverse weather conditions.
The list of fatal accident reports where stepdown fixes are busted in G/A during
IMC is a very long list indeed.

The protection offerred by dive-and-drive is substantially less than with a
constant angle or even a constant rate descent.

I guess this word hasn't gotten very far in the light aircraft world.

[[email protected]]

Tim J wrote:

> I was just trying to point out the obstacle clearances that the approach
> charts provide.
>
> I would like to see an accident report that found that the approach chart
> was incorrect and caused a crash. Does anyone have an example?
>
> I think rather it is the (improper) execution of the approach that is the
> cause of the supposed huge set of examples of crashes. If you all find it
> easier to make up your own descent profiles, go right ahead. I will not try
> to convince you otherwise. I will continue to fly them as published.

What makes you think "as published" means dive and drive any more than it means
constant angle or constant rate?

[[email protected]]

David Megginson wrote:

> Greg Esres > writes:
>
> > To comment that "if they fly the approach as published, they won't hit
> > anything" is a very shallow analysis. Not every CFIT deviated
> > intentionally from the published approach.
>
> The other question is what "as published" means for an NPA -- do you
> make a vertical descent at every stepdown fix? The whole point of an
> NPA is that there is no vertical profile published, only a series of
> minimum altitudes.

Very well stated.

[Tim J]

I was not advocating "dive and drive", whatever that means. The point I was
trying to make was that why stay above the published heights intentionally.
My comment about "get down as fast as possible" is perhaps overzealous and
was not meant to advocate go down really fast, but rather I meant get down
to the published altitude, and not stay above it purposely.

The protection is the same. If pilots can't stop a descent whether going
1000' per minute of 300' per minute is the real issue. Something else is
wrong if the "safer" rate of descent is going to save you. Correcting the
real problem is the solution, not making up rules for hiding the problem or
adding a safety net.

Busting the stepdown fixes is the problem - not the descent rate.

I will concede that the net effect of slower descent rates would be less
accidents, however I am more concerned that pilots use that as a crutch
rather than ensuring they execute approaches appropriately (not descending
below minimums).


> wrote in message
...
>
>
> Tim J wrote:
>
> > So what are you saying? The approach chart is/was wrong or the pilots
made
> > an error?
>
> The pilots made an error under lots of pressure and adverse weather
conditions.
> The list of fatal accident reports where stepdown fixes are busted in G/A
during
> IMC is a very long list indeed.
>
> The protection offerred by dive-and-drive is substantially less than with
a
> constant angle or even a constant rate descent.
>
> I guess this word hasn't gotten very far in the light aircraft world.
>

[Tim J]

Again, I am not advocating "dive and drive" - my point was that staying
above the published altitudes was questionable.

> wrote in message
...
>
>
> Tim J wrote:
>
> > I was just trying to point out the obstacle clearances that the approach
> > charts provide.
> >
> > I would like to see an accident report that found that the approach
chart
> > was incorrect and caused a crash. Does anyone have an example?
> >
> > I think rather it is the (improper) execution of the approach that is
the
> > cause of the supposed huge set of examples of crashes. If you all find
it
> > easier to make up your own descent profiles, go right ahead. I will not
try
> > to convince you otherwise. I will continue to fly them as published.
>
> What makes you think "as published" means dive and drive any more than it
means
> constant angle or constant rate?
>

[Tim J]

It really does not matter if the CFIT deviated intentionally or not. Most
likely if CFIT implies that they descended below the minimum published
altitudes for that segment.

Perhaps I am wrong (as so many of you are pointing out)
but if I make a descent rate to arrive at a step down higher than published,
it seems as though my descent rate has a good chance to not get me to the
MDA when the time is up (or distance) and I have to go missed. So
eventually I would have to do the dreaded "dive and drive" later anyway.

> wrote in message
...
>
>
> David Megginson wrote:
>
> > Greg Esres > writes:
> >
> > > To comment that "if they fly the approach as published, they won't hit
> > > anything" is a very shallow analysis. Not every CFIT deviated
> > > intentionally from the published approach.
> >
> > The other question is what "as published" means for an NPA -- do you
> > make a vertical descent at every stepdown fix? The whole point of an
> > NPA is that there is no vertical profile published, only a series of
> > minimum altitudes.
>
> Very well stated.
>

[Ray Andraka]

Do restrict your altitude to the MEAs enroute too? The stepdowns depict the
minimum altitudes for each segment of the approach. There is nothing regulatory
about flying at those minimums. What you are advocating is what others have
called 'dive and drive', ie decending quickly at each crossing then leveling at
the mda for that segment until hitting the next stepdown fix. This certainly
does increase the workload (you have less time to react to the altitude if it is
decreasing at 1000 fpm instead of 3-500 fpm), as well as the consequences for
being a little bit behind the airplane. It also gives you fewer options
(altitude) should the engine start coughing. Just from the ergonomics
standpoint, it is more stressful to you and your passengers, not to mention to
the engine (shock cooling) and airframe. Most of the time, you've got plenty of
room between the fixes to do a gentle descent and still get you at the final MDA
in plenty of time to find the airport.




--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759

[John R. Copeland]

It's probably about time for someone to bring up the Aspen approach =
again.
Be a little high and/or fast there, and you won't get down in time to =
land.
---JRC---

"Ray Andraka" > wrote in message =
...
> Do restrict your altitude to the MEAs enroute too? The stepdowns =
depict the
> minimum altitudes for each segment of the approach. There is nothing =
regulatory
> about flying at those minimums. What you are advocating is what =
others have
> called 'dive and drive', ie decending quickly at each crossing then =
leveling at
> the mda for that segment until hitting the next stepdown fix. This =
certainly
> does increase the workload (you have less time to react to the =
altitude if it is
> decreasing at 1000 fpm instead of 3-500 fpm), as well as the =
consequences for
> being a little bit behind the airplane. It also gives you fewer =
options
> (altitude) should the engine start coughing. Just from the ergonomics
> standpoint, it is more stressful to you and your passengers, not to =
mention to
> the engine (shock cooling) and airframe. Most of the time, you've got =
plenty of
> room between the fixes to do a gentle descent and still get you at the =
final MDA
> in plenty of time to find the airport.
> --
> --Ray Andraka, P.E.
>

[Stan Gosnell]

"Tim J" > wrote in
. net:

> Again, I am not advocating "dive and drive" - my point was
> that staying above the published altitudes was
> questionable.

I'm beginning to think your judgment is questionable. The
stepdown fixes give only minimum altitudes, no maximum. That
means you can't go below, but can safely and legally be above,
the altitude. There is no requirement at all to be at a
stepdown altitude immediately, unless there is a line *above*
the altitude.

--
Regards,

Stan

[Stan Gosnell]

"John R. Copeland" > wrote in
:

> It's probably about time for someone to bring up the Aspen
> approach again. Be a little high and/or fast there, and you
> won't get down in time to land. ---JRC---

I haven't flown that approach, but I've studied the approach
plate. The stepdown fixes aren't that much - you don't have to
hurry, because there isn't that much altitude change. The big
change is the final descent, after the stepdown fixes, and if
you get too low or a little off course, you'll land much more
quickly than you intended.

--
Regards,

Stan

[John R. Copeland]

"Stan Gosnell" <me@work> wrote in message =
...
> "John R. Copeland" > wrote in
> :=20
>=20
> > It's probably about time for someone to bring up the Aspen
> > approach again. Be a little high and/or fast there, and you
> > won't get down in time to land. ---JRC---
>=20
> I haven't flown that approach, but I've studied the approach=20
> plate. The stepdown fixes aren't that much - you don't have to=20
> hurry, because there isn't that much altitude change. The big=20
> change is the final descent, after the stepdown fixes, and if=20
> you get too low or a little off course, you'll land much more=20
> quickly than you intended.
>=20
> --=20
> Regards,
>=20
> Stan

Roger that, too, Stan! My wife dislikes that valley.
BTW, Aspen approach is pretty understanding if you tell them
you need to make a 360 to lose some altitude after you get the field in =
sight.
(Of course, we're talking fixed-wing performance here.)
---JRC---

[Eclipsme]

"Tim J" > wrote in message
. net...
> I was not advocating "dive and drive", whatever that means. The point I
was
> trying to make was that why stay above the published heights
intentionally.
> My comment about "get down as fast as possible" is perhaps overzealous and
> was not meant to advocate go down really fast, but rather I meant get down
> to the published altitude, and not stay above it purposely.
>
> The protection is the same. If pilots can't stop a descent whether going
> 1000' per minute of 300' per minute is the real issue. Something else is
> wrong if the "safer" rate of descent is going to save you. Correcting the
> real problem is the solution, not making up rules for hiding the problem
or
> adding a safety net.
>
> Busting the stepdown fixes is the problem - not the descent rate.
>
> I will concede that the net effect of slower descent rates would be less
> accidents, however I am more concerned that pilots use that as a crutch
> rather than ensuring they execute approaches appropriately (not descending
> below minimums).
>

Whoa! I had to get in here on this one... A crutch? Using something that
will result in less accidents is a crutch? I think NOT! A stabilized
approach will always be safer than step-downs.

Just my 2cents. I'll sit back down now.

Harvey

[Mike Rapoport]

"Tim J" > wrote in message
. net...
> Perhaps I am wrong (as so many of you are pointing out)
> but if I make a descent rate to arrive at a step down higher than
published,
> it seems as though my descent rate has a good chance to not get me to the
> MDA when the time is up (or distance) and I have to go missed. So
> eventually I would have to do the dreaded "dive and drive" later anyway.
>

As long as you are at the LAST stepdown fix at the minimium altitude and
correct airspeed then what difference does it make what altitudes you
crossed the other stepdowns?

Mike
MU-2

[Tom S.]

"Mike Rapoport" > wrote in message
nk.net...
>
> "Tim J" > wrote in message
> . net...
> > Perhaps I am wrong (as so many of you are pointing out)
> > but if I make a descent rate to arrive at a step down higher than
> published,
> > it seems as though my descent rate has a good chance to not get me to
the
> > MDA when the time is up (or distance) and I have to go missed. So
> > eventually I would have to do the dreaded "dive and drive" later anyway.
> >
>
> As long as you are at the LAST stepdown fix at the minimium altitude and
> correct airspeed then what difference does it make what altitudes you
> crossed the other stepdowns?
>

Quite -- think of what the word "minimum" means.

[Michael]

Stan Gosnell <me@work> wrote
> The pilots made an error. Dive and drive is dangerous.

So is instrument flying in general. If we all just waited for CAVU, I
bet there would be fewer accidents. Tradeoffs are made between safety
and cost/utility all the time, and dive and drive is one of them.

> I'm in
> no particular hurry to get out of the clouds - at MDA is fine.
> Why would anyone be in a huge hurry to get out of the clouds?
> Being in a hurry is almost always dangerous, sometimes fatal.

It's not about being in a hurry to get out of the clouds - it's about
reaching MDA well before reaching the MAP. In other words - it's not
about rate of descent (I couldn't care less about spending an extra
couple of minutes in the clouds) but about angle of descent (I don't
want to reach MDA only seconds before reaching the MAP). This is
simply another one of those areas where the checkride diverges from
real life.

On the checkride, as long as you reach MDA prior to the MAP, you're
good to go. In real life, you actually want to land. When ceilings
are close to MDA (or broken such that they are above MDA in places and
below in other places) and visibility is limited by haze, mist, and/or
rain (especially at night), you're going to need some time to pick the
runway out of the murk - especially if the runway environment (such as
the beacon) is not correctly depicted on the plate. Otherwise, you're
going to be shooting the missed approach not because you didn't break
out prior to MDA but because you couldn't find the runway - at all or
until it was too late to land on it using normal flight maneuvers.

In limited visibility (especially at night) finding the runway is best
accomplished while the airplane is in level flight at MDA, and
configured and trimmed to fly hands off. To get to that state, it's
necessary to descend to MDA expeditiously (dive and drive), power up
and level off, and configure the airplane - all before reaching the
MAP - so you can devote most of your time to looking out the window.
If you must rush something, you're better off rushing the relatively
straightforward descent to MDA (flown purely as an instrument
maneuver) rather than the more complex visual segment, which often
requires at least some reference to instrument for aircraft control
and at the same time requires significant 'outside' time to find the
runway.

Of course CANPA (which is what the industry is moving to) is safer -
in the sense that it allows a less competent pilot to fly the approach
without putting too much strain on his less-than-stellar skills. The
cost is increasing the probability of a missed approach when weather
is at or close to mnimums AND requiring additional equipment that the
average small airplane lacks.

An excellent article on this topic was written by John Deakin, and is
available fromm AvWeb here:
http://www.avweb.com/news/columns/182091-1.html

Michael

Please do not send email replies to this posting. They are checked
only sporadically, and are filtered heavily by Hotmail. If you need
to email me, the correct address is crw69dog and the domain name is
this old airplane dot com, but remove the numbers and format the
address in the usual way.

[Michael]

(Paul Tomblin) wrote
> I don't know if this would be considered "a healthy safety margin", but my
> examiner said the same thing that my instructor did - that the PTS says
> +100 feet/-0 feet, so you should always fly 50 feet high to give yourself
> a bit of a buffer.

This is another of those areas where training for the checkride and
training for real life are different. Sure, it works - for passing
checkrides and for those times when the the weather is significantly
above mins. But in real life, I can think of several approaches I
made where doing this would have caused me to miss.

Michael

Please do not send email replies to this posting. They are checked
only sporadically, and are filtered heavily by Hotmail. If you need
to email me, the correct address is crw69dog and the domain name is
this old airplane dot com, but remove the numbers and format the
address in the usual way.

[David Brooks]

"Mike Rapoport" > wrote in message
nk.net...
>
> "Tim J" > wrote in message
> . net...
> > Perhaps I am wrong (as so many of you are pointing out)
> > but if I make a descent rate to arrive at a step down higher than
> published,
> > it seems as though my descent rate has a good chance to not get me to
the
> > MDA when the time is up (or distance) and I have to go missed. So
> > eventually I would have to do the dreaded "dive and drive" later anyway.
> >
>
> As long as you are at the LAST stepdown fix at the minimium altitude and
> correct airspeed then what difference does it make what altitudes you
> crossed the other stepdowns?

Well, that was a given in the theoretical scenario. The smooth descent is
calculated to arrive at the last stepdown altitude well before its fix (a
couple of miles at least), not to hit it exactly. I'm not trying to avoid
that last level-off.

Someone did mention unplanned winds, and that has made me rethink the setup
a little. Given time to plan in advance, a constant-rate descent, so long as
it clears all the minimums, seems to me to be better, and nicer to your
passengers. However, factoring in actual wind seems to break the
no-math-in-the-cockpit rule. There are now multiple constraints on your
chosen descent rate, while "dive and level off" leaves more margin for
wind-induced error.

-- David Brooks

[David Megginson]

"David Brooks" > writes:

> Well, that was a given in the theoretical scenario. The smooth descent is
> calculated to arrive at the last stepdown altitude well before its fix (a
> couple of miles at least), not to hit it exactly. I'm not trying to avoid
> that last level-off.

Instead of imagining a ceiling right at MDA (or 50 feet above, so that
you have a chance of seeing the runway), let's take a more realistic
example, at least for where I live. MDA is 500 ft AGL and the ceiling
is 800 ft AGL with 1.5 SM visibility (fluctuating). You're not going
to see the runway at the FAF, five six miles back. Do you descend
fast to MDA and then level out for a few miles?


All the best,


David

[Tim J]

Thank you Michael - you seemed to have been able to state more clearly what
I was trying to say since the start of the thread...

"Michael" > wrote in message
om...
> Stan Gosnell <me@work> wrote
> > The pilots made an error. Dive and drive is dangerous.
>
> So is instrument flying in general. If we all just waited for CAVU, I
> bet there would be fewer accidents. Tradeoffs are made between safety
> and cost/utility all the time, and dive and drive is one of them.
>
> > I'm in
> > no particular hurry to get out of the clouds - at MDA is fine.
> > Why would anyone be in a huge hurry to get out of the clouds?
> > Being in a hurry is almost always dangerous, sometimes fatal.
>
> It's not about being in a hurry to get out of the clouds - it's about
> reaching MDA well before reaching the MAP. In other words - it's not
> about rate of descent (I couldn't care less about spending an extra
> couple of minutes in the clouds) but about angle of descent (I don't
> want to reach MDA only seconds before reaching the MAP). This is
> simply another one of those areas where the checkride diverges from
> real life.
>
> On the checkride, as long as you reach MDA prior to the MAP, you're
> good to go. In real life, you actually want to land. When ceilings
> are close to MDA (or broken such that they are above MDA in places and
> below in other places) and visibility is limited by haze, mist, and/or
> rain (especially at night), you're going to need some time to pick the
> runway out of the murk - especially if the runway environment (such as
> the beacon) is not correctly depicted on the plate. Otherwise, you're
> going to be shooting the missed approach not because you didn't break
> out prior to MDA but because you couldn't find the runway - at all or
> until it was too late to land on it using normal flight maneuvers.
>
> In limited visibility (especially at night) finding the runway is best
> accomplished while the airplane is in level flight at MDA, and
> configured and trimmed to fly hands off. To get to that state, it's
> necessary to descend to MDA expeditiously (dive and drive), power up
> and level off, and configure the airplane - all before reaching the
> MAP - so you can devote most of your time to looking out the window.
> If you must rush something, you're better off rushing the relatively
> straightforward descent to MDA (flown purely as an instrument
> maneuver) rather than the more complex visual segment, which often
> requires at least some reference to instrument for aircraft control
> and at the same time requires significant 'outside' time to find the
> runway.
>
> Of course CANPA (which is what the industry is moving to) is safer -
> in the sense that it allows a less competent pilot to fly the approach
> without putting too much strain on his less-than-stellar skills. The
> cost is increasing the probability of a missed approach when weather
> is at or close to mnimums AND requiring additional equipment that the
> average small airplane lacks.
>
> An excellent article on this topic was written by John Deakin, and is
> available fromm AvWeb here:
> http://www.avweb.com/news/columns/182091-1.html
>
> Michael
>
> Please do not send email replies to this posting. They are checked
> only sporadically, and are filtered heavily by Hotmail. If you need
> to email me, the correct address is crw69dog and the domain name is
> this old airplane dot com, but remove the numbers and format the
> address in the usual way.

[Stan Gosnell]

(Michael) wrote in
om:

> It's not about being in a hurry to get out of the clouds -
> it's about reaching MDA well before reaching the MAP. In
> other words - it's not about rate of descent (I couldn't
> care less about spending an extra couple of minutes in the
> clouds) but about angle of descent (I don't want to reach
> MDA only seconds before reaching the MAP). This is simply
> another one of those areas where the checkride diverges
> from real life.

We're talking about different things, I think. The OP was
talking about intermediate stepdown fixes, and so was I. IME, a
constant descent is safer than diving as quickly as possible to
an intermediate altitude, leveling off, and then diving again.
I agree you want to be at the MDA before the MAP, but it does no
real good to hit an intermediate altitude early. Even the
descent to the MDA isn't something I rush. Rushing to the MDA
can mean you see the ground far from the airport, go below the
MDA, and then encounter IMC again. I prefer to make a
stabilized descent to reach the MDA just before the MAP, and
continue the descent to landing. But if you're flying your
airplane, do it however you like. It's your life.

--
Regards,

Stan

[Michael]

Stan Gosnell <me@work> wrote
> We're talking about different things, I think. The OP was
> talking about intermediate stepdown fixes, and so was I. IME, a
> constant descent is safer than diving as quickly as possible to
> an intermediate altitude, leveling off, and then diving again.
> I agree you want to be at the MDA before the MAP, but it does no
> real good to hit an intermediate altitude early.

I can certainly agree with that.

> Even the
> descent to the MDA isn't something I rush. Rushing to the MDA
> can mean you see the ground far from the airport, go below the
> MDA, and then encounter IMC again.

That's why VDP's exist. If you descend below MDA prior to reaching
the VDP, you have only yourself to blame. If no VDP is charted, it's
easy enough to compute based on whatever descent angle you want to
fly.

> I prefer to make a
> stabilized descent to reach the MDA just before the MAP, and
> continue the descent to landing.

In other words, CANPA. Just out of curiosity, do you normally fly
with a copilot? Perhaps one whose major responsibility on the descent
is spotting the landing area?

Michael

[Steven P. McNicoll]

> wrote in message
...
>
> I guess the stats and industry/government studies are all wet then.
>

Please post the stats and industry/government studies that show aircraft
finding granite or trees at correctly published IAP altitudes.


>
> The published altitudes weren't wrong at KBDL when the AAL MD80 hit the
> trees near the stepdown fix.
>

I assume you're referring to AAL1572. The NTSB determined the probable
cause of that accident to be a descent below the MDA prior to having the
required runway visual references in sight. The impact with trees occurred
about 2.2 miles past the step-down fix.

[Steven P. McNicoll]

> wrote in message
...
>
> The pilots made an error under lots of pressure and adverse weather
> conditions. The list of fatal accident reports where stepdown fixes are
> busted in G/A during IMC is a very long list indeed.
>

Yes, the pilots made an error, but they did not find granite or trees while
getting down to a step-down fix as you stated in your previous message.
They descended below the MDA and struck trees over two miles past the
step-down fix.

[Stan Gosnell]

(Michael) wrote in
om:

> In other words, CANPA. Just out of curiosity, do you
> normally fly with a copilot? Perhaps one whose major
> responsibility on the descent is spotting the landing area?

I normally fly with a copilot, but the PNF's major
responsibility is to monitor the descent and make sure we don't
go below MDA, and generally monitor things. Spotting the
landing area is a responsibility, but not the top of the list.
Not hitting hard things at speed is the major responsibility of
both of us. If we don't land, we can try again. If we crash,
that's the end of the flight. On an ILS to minimums, he's
looking for the approach lights from about 100' above DH until
he sees something or I call out "Decide!". I still don't get in
a hurry to break out - at MAP is safer than earlier, IMO,
because it doesn't invite the temptation to get low, looking
outside. The closest I've ever been to crashing is during the
VFR sequence after breaking out.

--
Regards,

Stan