Seneca down at Avalon

"Maule Driver" wrote in message
r.com...

"Larry Dighera"
That is a tricky approach. VOR behind and above the airport.

What is it about those circumstances that causes you to characterize
the Avalon VOR/DME-B approach as tricky?

Thanks for taking the bait. On one hand, nothing is tricky about it if
flown as published (obvious and self-evident). But a bunch of folks died
here by not doing so. So what's tricky?

One way of describing what's tricky is that you can fly the approach as
published laterally, never descend below MDA, and crash.

I would not describe it that way - rather, more acurately, you fly the
approach and fail to execute the missed as published. That will get you
dead in many places and this is aout as "trickless" as they come. The
approach is named VOR/DME - so what is the trickiness?

All the information is on the approach chart. There is not much to do on
the final segment - just remain at 2100, keep a heading and then make sure
you know when to go missed. There is no timing on the approach chart and it
seems fairly clear that the approach uses DME fixes.




The fact that the MAP is a DME reading is perhaps trickier than having a
flag flip, needle spin,beacon sound, timer zero-out, or an intersection
passed. GPS helps. But such is the nature of many VOR/DME approaches.
I've *never* flown a VOR/DME approach using a DME so this is a bit of
conjecture on my part.

For those of you familiar with it, would I be right in guessing that
familiarity with VFR flight there might not make the need to climb as
obvious as it is when IMC?

I would guess the opposite. The mountain is clearly visible in VMC,
and apparently was not immediately visible when this accident
occurred.

Have you flown there? I was thinking of a place like Roanoke where it is
obvious after flying there VFR that there is a MOUNTAIN behind one of the
runways. The mountain remains in this pilot's mindseye even when in IMC.
Looking at the approach plate for AVX, it seems like the airport and the
location of the VOR are about 500' different. I'm guessing that the VOR
may
be on a highpoint. Flying there VFR I was trying to imagine whether one
would tend not to be aware that there is a critical rise in terrain in
some
directions. Especially sinced the rise is not obviously aligned with a
runway. But I've never flown there nor do I have a sectional.

So here's the trick. We're on an instructional flight, the student has
done
everything right but and is flying at MDA. We're looking for the airport
but the student has missed the DME indication for the MAP. The instructor
sees the error or not, but may decide to wait to see the student catch it
(very wrong in IMC). They proceed at MDA into the only navigational aid
on
the entire approach. The (possible) fact that in the pilots' minds eye,
they are flying to a hilltop airport surrounded by water may suggest that
flying 2100 feet above the water and 500 feet above the airport is not
going
to result in hitting terrain.

Flying it as published without error of variation would of course
eliminate
this speculation.

"Richard Hertz"
Thanks for taking the bait. On one hand, nothing is tricky about it if
flown as published (obvious and self-evident). But a bunch of folks
died
here by not doing so. So what's tricky?

One way of describing what's tricky is that you can fly the approach as
published laterally, never descend below MDA, and crash.

I would not describe it that way - rather, more acurately, you fly the
approach and fail to execute the missed as published. That will get you
dead in many places and this is aout as "trickless" as they come. The
approach is named VOR/DME - so what is the trickiness?

All the information is on the approach chart. There is not much to do on
the final segment - just remain at 2100, keep a heading and then make sure
you know when to go missed. There is no timing on the approach chart and
it
seems fairly clear that the approach uses DME fixes.

Well, I have to agree that it's all there and if you fly it as published, no
problem. But this approach seems a little different than the 'typical'
non-precision approach.

I took a quick look at the first 111 approaches inf SE 2 of 4 NC & SC. I
looked at at all non-precision, non-GPS-only approaches. There were 38 such
approaches.32 of them had a missed approach point that was over the runway.
Of the six that had MAPs short of the runway threshold, 4 of those were
TACAN (military?) only approaches. Only 2 were similiar in this way to AVX.

Nothing wrong with different. Not necessarily tricky but I can see how a
careless pilot might continue on at MDA past a MAP short of the runway while
'searching' for a view of the runway. Thinking perhaps that I can see
straight down at the MAP so I'll just proceed along another mile (45 secs)
until I see the runway below then I'll rack it around and circle to land.

I'm not saying these folks were careless, just trying to learn something
from the accident.

On second thought, I'll stick with tricky.

On Wed, 07 Jan 2004 18:25:15 GMT, "Maule Driver"
wrote in Message-Id:
m:


"Larry Dighera"
That is a tricky approach. VOR behind and above the airport.

What is it about those circumstances that causes you to characterize
the Avalon VOR/DME-B approach as tricky?

Thanks for taking the bait. On one hand, nothing is tricky about it if
flown as published (obvious and self-evident).

That's been my experience.

But a bunch of folks died here by not doing so.

I would expect that to be an issue with many IAPs.

So what's tricky?

One way of describing what's tricky is that you can fly the approach as
published laterally, never descend below MDA, and crash.

I see.

The fact that the MAP is a DME reading is perhaps trickier than having a
flag flip, needle spin,beacon sound, timer zero-out, or an intersection
passed.

I was taught to time all my approaches despite the lack of necessity
to do so on the approach plate.

GPS helps. But such is the nature of many VOR/DME approaches.
I've *never* flown a VOR/DME approach using a DME so this is a bit of
conjecture on my part.

Granted, it's convenient if ATC has radar coverage, and can call the
MAP; that's not available at AVX, IIRC. Otherwise, the pilot just
includes the DME readout in his scan.


For those of you familiar with it, would I be right in guessing that
familiarity with VFR flight there might not make the need to climb as
obvious as it is when IMC?

I would guess the opposite. The mountain is clearly visible in VMC,
and apparently was not immediately visible when this accident
occurred.

Have you flown there?

Yes.

I was thinking of a place like Roanoke where it is
obvious after flying there VFR that there is a MOUNTAIN behind one of the
runways. The mountain remains in this pilot's mindseye even when in IMC.

In the case of AVX, the mountain is a bit distant and not aligned with
the runway, so it doesn't have the same mental impact you describe.

Looking at the approach plate for AVX, it seems like the airport and the
location of the VOR are about 500' different. I'm guessing that the VOR may
be on a highpoint. Flying there VFR I was trying to imagine whether one
would tend not to be aware that there is a critical rise in terrain in some
directions. Especially sinced the rise is not obviously aligned with a
runway. But I've never flown there nor do I have a sectional.

See above.

So here's the trick. We're on an instructional flight, the student has done
everything right but and is flying at MDA. We're looking for the airport
but the student has missed the DME indication for the MAP. The instructor
sees the error or not, but may decide to wait to see the student catch it
(very wrong in IMC). They proceed at MDA into the only navigational aid on
the entire approach. The (possible) fact that in the pilots' minds eye,
they are flying to a hilltop airport surrounded by water may suggest that
flying 2100 feet above the water and 500 feet above the airport is not going
to result in hitting terrain.

Umm. I see your reasoning, but it assumes that the pilot deliberately
and/or erroneously chooses not to comply with the climb portion of the
MAP. Either case is obviously fatal.

Flying it as published without error of variation would of course eliminate
this speculation.

Flying any approach other than as published is inviting disaster, IMO.

"Larry Dighera"
Thanks for taking the bait. On one hand, nothing is tricky about it if
flown as published (obvious and self-evident).

That's been my experience.

Mine too :-)

The fact that the MAP is a DME reading is perhaps trickier than having a
flag flip, needle spin,beacon sound, timer zero-out, or an intersection
passed.

I was taught to time all my approaches despite the lack of necessity
to do so on the approach plate.

But do you do it? (no need to answer) I do remember from discussions here
about timing ILS's so that the LOC only can be flown if needed, that many
people don't. I don't time consistently. More workload and distractions
versus value of having backup information.

Granted, it's convenient if ATC has radar coverage, and can call the
MAP; that's not available at AVX, IIRC. Otherwise, the pilot just
includes the DME readout in his scan.

I didn't know that ATC does that. I've never had the MAP called for me
perhaps because I've never done a non-precision with radar coverage at the
altitude. Another gap in my experience.

For those of you familiar with it, would I be right in guessing that
familiarity with VFR flight there might not make the need to climb as
obvious as it is when IMC?

I would guess the opposite. The mountain is clearly visible in VMC,
and apparently was not immediately visible when this accident
occurred.

Have you flown there?

Yes.

I was thinking of a place like Roanoke where it is
obvious after flying there VFR that there is a MOUNTAIN behind one of the
runways. The mountain remains in this pilot's mindseye even when in IMC.

In the case of AVX, the mountain is a bit distant and not aligned with
the runway, so it doesn't have the same mental impact you describe.

That's what I was thinking. Part of our spatial awareness picture I think
includes our VFR experience at a given airport. Usually that's a good thing
as in, "don't let the controller vector me thru the final for more than 15
seconds because thar be mountains there". But here I was thinking it might
actually be deceptive as in, "as long as I don't descend below MDA, even if
I get a little sloppy out there, I won't hit anything". Clearly not the
case if you read the plate but even the graphics on the NOS plate tend to
hide the fact that the VOR is also co-located with an above MDA obstacle.

Looking at the approach plate for AVX, it seems like the airport and the
location of the VOR are about 500' different. I'm guessing that the VOR
may
be on a highpoint. Flying there VFR I was trying to imagine whether one
would tend not to be aware that there is a critical rise in terrain in
some
directions. Especially sinced the rise is not obviously aligned with a
runway. But I've never flown there nor do I have a sectional.

See above.

So here's the trick. We're on an instructional flight, the student has
done
everything right but and is flying at MDA. We're looking for the airport
but the student has missed the DME indication for the MAP. The
instructor
sees the error or not, but may decide to wait to see the student catch it
(very wrong in IMC). They proceed at MDA into the only navigational aid
on
the entire approach. The (possible) fact that in the pilots' minds eye,
they are flying to a hilltop airport surrounded by water may suggest that
flying 2100 feet above the water and 500 feet above the airport is not
going
to result in hitting terrain.

Umm. I see your reasoning, but it assumes that the pilot deliberately
and/or erroneously chooses not to comply with the climb portion of the
MAP. Either case is obviously fatal.

That's the gotcha. You could make a similar mistake at 10 different
airports and live. Here, you die.

Flying it as published without error of variation would of course
eliminate
this speculation.

Flying any approach other than as published is inviting disaster, IMO.

Yep. And I guess that is the bottom line. Almost always is in approach
accidents. Microbursts/thunderstorms being one of the very few exceptions.

I have put up a Topo image on my website which shows the terrain. The red
arrow is the VOR/DME approach path pointing away from the VOR (which is at
top of Mt Orizaba). The altitudes/distances are close to what I see on the
approach plate (see myairplane.com KAVX VOR/DME). It makes sense to turn
right to the north-west on circling (and the approach prohibits circling to
the south-east). Continuing on without climbing on the missed approach will
send you into the VOR. One has about 2.1 miles to make the climb to 3200ft
(from the airport) and about 3.2 miles from the MAP. One presumes here that
the pilot did not attempt to climb. It is unfortunate here that the the
final step down is at the same elevation as the top of the mountain give or
take 100ft.

http://snarayan.home.comcast.net/avi...x_vor_dme1.jpg


"Maule Driver" wrote in message
r.com...
That is a tricky approach. VOR behind and above the airport.

For those of you familiar with it, would I be right in guessing that
familiarity with VFR flight there might not make the need to climb as
obvious as it is when IMC?

"R. Hubbell" wrote in message
newsMLKb.102181$pY.83466@fed1read04...

I hadn't heard anything about this and was surprised when someone
asked if I had.

My condolences to the families and friends, a tragic accident.

http://ntsb.gov/ntsb/brief.asp?ev_id=20031231X02110


Seems like with 5 souls that they were probably heading out for a
buffalo burger and a visit to Avalon.

I wonder about having pax when shooting approaches. Seems like a pretty
big
distraction while learning. Do the FARs prohibit pax while IFR
training?


R. Hubbell

"R. Hubbell" wrote in message news:pMLKb.102181$pY.83466@fed1read04...

I wonder about having pax when shooting approaches. Seems like a pretty big
distraction while learning. Do the FARs prohibit pax while IFR training?

No, not at all, and in fact some viewpoints think it's a good
idea to take flight students of various flavors along, esp.
instrument students, both for learning by observation and as
an extra set of safety-pilot eyes.

Something strange about this, though -- are the TERPS really
right on this approach? Climb from 2,100 ft to 3,200 ft to
clear a 2,090 ft mountain -- shouldn't there be 2000 ft of
obstacle clearance over a mountain? Also is there an obstacle
DP for departure from that runway? Seems like going missed
after the MAP would require a non-standard climb gradient,
as would a departure?

Very sad accident

Cheers,
Sydney

"Snowbird"
Something strange about this, though -- are the TERPS really
right on this approach? Climb from 2,100 ft to 3,200 ft to
clear a 2,090 ft mountain -- shouldn't there be 2000 ft of
obstacle clearance over a mountain? Also is there an obstacle
DP for departure from that runway? Seems like going missed
after the MAP would require a non-standard climb gradient,
as would a departure?

I don't know the TERPS standards but that does seem weird. I can see where
a DP may not be required because the obstructions may not be aligned with
the runway. Can't see the 2,090 mountain on the plate. Only the 2150'
obstacle seemingly co-located with the VOR.

I get more confused the longer I look at this.

There isn't 2000' obstacle clearance on an approach. Terrain actually
slopes down from both ends of the runway. You have to screw this one up
pretty bad to hit anything.

Mike
MU-2


"Snowbird" wrote in message
m...
"R. Hubbell" wrote in message
news:pMLKb.102181$pY.83466@fed1read04...

I wonder about having pax when shooting approaches. Seems like a pretty
big
distraction while learning. Do the FARs prohibit pax while IFR
training?

No, not at all, and in fact some viewpoints think it's a good
idea to take flight students of various flavors along, esp.
instrument students, both for learning by observation and as
an extra set of safety-pilot eyes.

Something strange about this, though -- are the TERPS really
right on this approach? Climb from 2,100 ft to 3,200 ft to
clear a 2,090 ft mountain -- shouldn't there be 2000 ft of
obstacle clearance over a mountain? Also is there an obstacle
DP for departure from that runway? Seems like going missed
after the MAP would require a non-standard climb gradient,
as would a departure?

Very sad accident

Cheers,
Sydney

"Mike Rapoport" wrote in message thlink.net...
There isn't 2000' obstacle clearance on an approach. Terrain actually
slopes down from both ends of the runway. You have to screw this one up
pretty bad to hit anything.

Mike
MU-2

correct mike. flown in there many a time. IFR and VFR.

landing on 22 does present some problems to people due to the visual
as the threshold is at the top off the cliff face and there is a
slight hump to the runway.

landing on 04 tends to make people a little heavy on the breaks, due
to the over-run possibilities.





"Snowbird" wrote in message
m...
"R. Hubbell" wrote in message
news:pMLKb.102181$pY.83466@fed1read04...

I wonder about having pax when shooting approaches. Seems like a pretty
big
distraction while learning. Do the FARs prohibit pax while IFR
training?

No, not at all, and in fact some viewpoints think it's a good
idea to take flight students of various flavors along, esp.
instrument students, both for learning by observation and as
an extra set of safety-pilot eyes.

Something strange about this, though -- are the TERPS really
right on this approach? Climb from 2,100 ft to 3,200 ft to
clear a 2,090 ft mountain -- shouldn't there be 2000 ft of
obstacle clearance over a mountain? Also is there an obstacle
DP for departure from that runway? Seems like going missed
after the MAP would require a non-standard climb gradient,
as would a departure?

Very sad accident

Cheers,
Sydney

On 7 Jan 2004 12:33:57 -0800 (Snowbird) wrote:

"R. Hubbell" wrote in message news:pMLKb.102181$pY.83466@fed1read04...

I wonder about having pax when shooting approaches. Seems like a pretty big
distraction while learning. Do the FARs prohibit pax while IFR training?

No, not at all, and in fact some viewpoints think it's a good
idea to take flight students of various flavors along, esp.
instrument students, both for learning by observation and as
an extra set of safety-pilot eyes.

That makes sense.


Something strange about this, though -- are the TERPS really
right on this approach? Climb from 2,100 ft to 3,200 ft to
clear a 2,090 ft mountain -- shouldn't there be 2000 ft of
obstacle clearance over a mountain? Also is there an obstacle
DP for departure from that runway? Seems like going missed
after the MAP would require a non-standard climb gradient,
as would a departure?

Very sad accident

Yes, for sure.


R. Hubbell


Cheers,
Sydney