New Aviation Terminology

"Julian Scarfe" wrote in message
...
Not sure why there's such a strong aversion to this.

Well, for one, because nearly all fatal collisions between transport
aircraft occurred on a runway.

[...] Hence it's not unusual at a quiet controlled airport to be given
the
IFR clearance while lined up on the runway, and a take-off clearance
immediately afterwards.

I don't think anyone stipulated the "quiet controlled airport".
"Controlled" is implied, of course. But this "quiet" was never stated. In
the US, "quiet controlled airport" is either an oxymoron by definition, or a
relative term applicable to airports where there's still a fair amount of
traffic.

If the clearance were given at the hold, it could
take minutes to backtrack the runway and get airborne -- it's not unusual
to
get such a clearance a couple of minutes before the end of a flow
management
slot.

Minutes? I've never seen an airport where an airplane would take more than
ten or fifteen seconds to get lined up and take off. Not saying they don't
exist, of course, but surely it makes more sense to think about the typical
case here when talking about general procedures.

Pete

"Julian Scarfe" wrote in message
...
Not sure why there's such a strong aversion to this.


"Peter Duniho" wrote in message
...

Well, for one, because nearly all fatal collisions between transport
aircraft occurred on a runway.

That's fair enough. I think there have been at least two landing vs
position-and-hold collisions, though I don't think either of them involved
waiting for an IFR clearance -- but I take the point.

[...] Hence it's not unusual at a quiet controlled airport to be given
the
IFR clearance while lined up on the runway, and a take-off clearance
immediately afterwards.

I don't think anyone stipulated the "quiet controlled airport".
"Controlled" is implied, of course. But this "quiet" was never stated.
In
the US, "quiet controlled airport" is either an oxymoron by definition, or
a
relative term applicable to airports where there's still a fair amount of
traffic.

Well Tenerife was pretty quiet that day until the collision!

It's difficult to tell as I have limited experience of flying in the US, but
it didn't seem unusual for minutes to go by without the runway being in use.
My last flight in the US involved an unscheduled stop at PAE after a door
came open in flight. We landed on the runway and instead of asking us to
vacate we got to stop, fix the door and then backtrack on the runway to the
end. Does Paine Field count as quiet?

If the clearance were given at the hold, it could
take minutes to backtrack the runway and get airborne -- it's not
unusual
to get such a clearance a couple of minutes before the end of a flow
management slot.

Minutes? I've never seen an airport where an airplane would take more
than
ten or fifteen seconds to get lined up and take off. Not saying they
don't
exist, of course, but surely it makes more sense to think about the
typical
case here when talking about general procedures.

Again I can only think of specific cases -- I guess concrete is cheaper in
the US. :-) At my home base of Cambridge in the UK, the last paved taxiway
to/from the apron is about 2/3 of the way down the 6500 ft runway 05. Thus
the 747s that come in for maintenance end up taxying more than 4000 ft on
the runway, and they don't like doing that very quickly. It's more common
than not for them (and the rest of us for that matter) to get a clearance
while backtracking.

Julian Scarfe

"Julian Scarfe" wrote in message
...
It's difficult to tell as I have limited experience of flying in the US,
but
it didn't seem unusual for minutes to go by without the runway being in
use.
My last flight in the US involved an unscheduled stop at PAE after a door
came open in flight. We landed on the runway and instead of asking us to
vacate we got to stop, fix the door and then backtrack on the runway to
the
end. Does Paine Field count as quiet?

I'm based at Paine. It does have its quiet moments, but I wouldn't want to
sit on the runway for any extended period of time, not as a general rule.
You don't say what kind of airplane you were in, or what the nature of the
flight was. I assume that since you say you backtracked on the runway, the
airplane must've been pretty small. I personally would not have accepted
the offer to backtrack on the runway, not at Paine. Your experience is a
good example of a scenario that may or may not be entirely safe.

(That said, I'm a bit surprised you needed to backtrack on the runway
anyway. Assuming you landed on the long runway, there should have been
plenty of room for a stop-and-go. If you landed on one of the shorter ones,
the taxiway exits are close enough together that it's hardly a more
significant effort to taxi back on an actual taxiway. There's no
operational reason that justifies the reduction in safety to backtaxi on any
runway at Paine).

The bottom line IMHO is that as the pilot, it's hard to know for sure
whether current circumstances allow one to safely remain on the runway for
extended periods of time, and controllers are falliable. Aviation safety is
predicated on the idea that one makes every effort to avoid potentially
serious situations, even if those situations rarely result in a problem.

In any case, I would certainly never say that one should never wait on the
runway, but one ought to only do so when one has VERY good information with
respect to what aircraft are actually in the area, a reasonable idea of how
long the wait will be, and a good escape plan in case the wait goes longer
than expected. And one should do it only when there's a really good reason
for doing so (i.e. some benefit that justifies the risk).

Furthermore (and more relevant to your original comment) I can *easily* see
why there's such a strong aversion to this sort of thing. It's rarely an
operational necessity, and when it is, it should still only be undertaken
with the same (presumably high degree of) caution used in other areas of
flight. The aversion is quite understandable IMHO.

Pete

"Peter Duniho" wrote in message
...

I'm based at Paine. It does have its quiet moments, but I wouldn't want
to
sit on the runway for any extended period of time, not as a general rule.
You don't say what kind of airplane you were in, or what the nature of the
flight was. I assume that since you say you backtracked on the runway,
the
airplane must've been pretty small. I personally would not have accepted
the offer to backtrack on the runway, not at Paine. Your experience is a
good example of a scenario that may or may not be entirely safe.

(That said, I'm a bit surprised you needed to backtrack on the runway
anyway. Assuming you landed on the long runway, there should have been
plenty of room for a stop-and-go. If you landed on one of the shorter
ones,
the taxiway exits are close enough together that it's hardly a more
significant effort to taxi back on an actual taxiway. There's no
operational reason that justifies the reduction in safety to backtaxi on
any
runway at Paine).

It was a Seneca II. A collision would have required:

a) that a landing aircraft failed to obtain a clearance to land, and
b) that we failed to see a landing aircraft while backtracking, and
c) that the controller failed to see a landing aircraft, and
d) that the landing aircraft failed to see us, and
e) that we tried to occupy the same part of a 9000 x 150 ft runway at the
same time.

It seemed like a good bet.

The bottom line IMHO is that as the pilot, it's hard to know for sure
whether current circumstances allow one to safely remain on the runway for
extended periods of time, and controllers are falliable. Aviation safety
is
predicated on the idea that one makes every effort to avoid potentially
serious situations, even if those situations rarely result in a problem.

Given the uncertainties in estimating risks, I usually hesitate to argue
relative safety. But I have to say that if you think it's safer to give up
3000 ft of a 9000 ft runway in a light twin than to backtrack on a runway
with the controller's authorization, you either have negligible faith in the
abilities of ATC or remarkable faith in the workmanship of TCM.

In any case, I would certainly never say that one should never wait on the
runway, but one ought to only do so when one has VERY good information
with
respect to what aircraft are actually in the area, a reasonable idea of
how
long the wait will be, and a good escape plan in case the wait goes longer
than expected. And one should do it only when there's a really good
reason
for doing so (i.e. some benefit that justifies the risk).

Furthermore (and more relevant to your original comment) I can *easily*
see
why there's such a strong aversion to this sort of thing. It's rarely an
operational necessity, and when it is, it should still only be undertaken
with the same (presumably high degree of) caution used in other areas of
flight. The aversion is quite understandable IMHO.

Isn't the next logical step to outlaw position-and-hold? Why would you ever
occupy the runway without a clearance to take off?

Julian Scarfe

"Julian Scarfe" wrote in message
...
It was a Seneca II. A collision would have required:

a) that a landing aircraft failed to obtain a clearance to land, and

No. That's the whole point. A controller may well clear an airplane to
land right on top of you. You just don't know.

b) that we failed to see a landing aircraft while backtracking, and

Not hard if the airplane is behind you. Bi-directional operations at Paine
are not uncommon.

c) that the controller failed to see a landing aircraft, and

Not hard if the controller is distracted dealing with an issue elsewhere at
the airport. That said, the controller needs only to fail to see ONE of the
aircraft, either the landing one or the sitting-duck one.

d) that the landing aircraft failed to see us, and

Oddly enough, runway collisions happen. Obviously pilots of other aircraft
DO in fact find themselves not being able to see other airplanes on the
runway in time to avoid them.

e) that we tried to occupy the same part of a 9000 x 150 ft runway at the
same time.

Funny thing about coincidences. They do exist.

A common generalization made about accidents is that they usually involve a
relatively long chain of events or decisions. Alter just one, and the
entire accident never happened. Even if your chain of events is as unlikely
to occur as you think it is (and I don't agree that it is), the point is
that the chain of events CAN certainly occur.

The one element you have control over is whether you actually get onto the
runway and wait for an extended period of time. Why miss that great
opportunity to break the chain of events? It's the only one you have.

It seemed like a good bet.

I'm sure the sequence of events leading up to a great many accidents
(aircraft and otherwise) seemed like a good bet at the time.

Given the uncertainties in estimating risks, I usually hesitate to argue
relative safety. But I have to say that if you think it's safer to give
up
3000 ft of a 9000 ft runway in a light twin than to backtrack on a runway
with the controller's authorization, you either have negligible faith in
the
abilities of ATC or remarkable faith in the workmanship of TCM.

With respect to my opinion of ATC: I simply don't see the point in trusting
them when there's no real need to. I have faith in their abilities, but I
prefer to deal in things that I *know* for sure rather than trusting someone
else to do them. Too often, a person I trust lets me down. Rarely, my life
is at stake, but that is the case here.

As far as giving up 3000' of a 9000' runway: a) that's not the only
alternative to backtaxiing -- at Paine, all you have to do is get off the
runway and taxi back on the parallel taxiway; and b) frankly, AFAIK 6000' is
*plenty* of runway from which to launch a Seneca II.

I would pick option a) -- using the taxiway -- but if you are really trying
to save time and are willing to reduce your safety factor to do it, the
stop-and-go is the right solution. Backtaxiing on the runway saves you
negligible time compared to taxiing back on the taxiway, while the
stop-and-go saves you serious time.

Isn't the next logical step to outlaw position-and-hold? Why would you
ever
occupy the runway without a clearance to take off?

As I mentioned, there are times in which it's an appropriate solution. At
Paine, the most common reason that clearance is used is when the controller
is trying to get as many departures out before the next landing. Allowing
an airplane to proceed onto the runway as the preceding airplane is taking
off helps this goal. Because the takeoff is expected immediately and the
"position and holding" aircraft can see where the landing traffic is, they
can evaluate the reasonableness of the clearance. Things are happening fast
enough that ANY delay is cause for concern and the pilot can get back off
the runway.

The problem that started this discussion is one of the length of time an
aircraft is expected to sit on a runway. Five, ten, maybe even fifteen
seconds to wait for an IFR clearance seems perfectly reasonable. But
several minutes? No, not to me it doesn't.

Like I said, I'm not going to take so extreme a position as to claim that
position-and-hold is NEVER appropriate. But I certainly feel that its use
should be restricted to very narrow situations where the hazard has been
reduced to the greatest extent possible, and especially to where the pilot
doing the position and hold has first-hand knowledge regarding the safety of
the operation (as opposed to trusting ATC to take care of everything).

Finally, let me remind you that the comment to which I took issue was the
"not sure why there's such a strong aversion to this." The bottom line here
is that the reason for the aversion is clear. There are definitely safety
issues, regardless of how significant you think they are. You might as well
say "not sure why there's such a strong aversion to spiders". After all,
all but a handful of spiders are safe. Yet, no one should be surprised when
they come across another person who has a strong aversion to spiders. It's
only natural. Your apparent argument to the contrary is a bit puzzling to
me, to say the least.

Pete

I think we've passed the 80:20 point on this debate so I'll let it rest.
Needless to say I don't agree with all you say, but you've raised some point
of which awareness can only be a positive thing for me and other readers.

"Peter Duniho" wrote in message
...

The problem that started this discussion is one of the length of time an
aircraft is expected to sit on a runway. Five, ten, maybe even fifteen
seconds to wait for an IFR clearance seems perfectly reasonable. But
several minutes? No, not to me it doesn't.

No that wasn't what I intended, though I can see why you interpreted it that
way. I said it could be minutes between an aircraft receiving an IFR
clearance at the hold and being in a position to take off. In most cases I
would expect a clearance to come during the backtrack and to be available on
turnaround, within seconds. I don't think ATC would leave an aircraft
sitting there for minutes unless they anticipated a clearance from another
facility that didn't come.

Finally, let me remind you that the comment to which I took issue was the
"not sure why there's such a strong aversion to this." The bottom line
here
is that the reason for the aversion is clear. There are definitely safety
issues, regardless of how significant you think they are. You might as
well
say "not sure why there's such a strong aversion to spiders". After all,
all but a handful of spiders are safe. Yet, no one should be surprised
when
they come across another person who has a strong aversion to spiders.
It's
only natural. Your apparent argument to the contrary is a bit puzzling to
me, to say the least.

I think you do yourself no favours with that argument as fear of spiders
tends to be an irrational fear. You've eloquently outlined the hazards that
give rise to your aversion to sitting on the runway for longer than
necessary. They are quite rational, even if we disagree about the magnitude
of the risk.

Julian Scarfe

"Julian Scarfe" wrote in message
...
I think you do yourself no favours with that argument as fear of spiders
tends to be an irrational fear.

I never said the fear of spiders was entirely rational. My point is that
the fear is understandable. Likewise, whether you believe the fear of
position-and-hold is rational or not, it is certainly understandable.

Pete

I will just add one point that just occurred to me.

"Peter Duniho" wrote in message
...

a) that a landing aircraft failed to obtain a clearance to land, and

No. That's the whole point. A controller may well clear an airplane to
land right on top of you. You just don't know.

In the US ATC is permitted to anticipate separation in landing clearances:
"3-10-6. ANTICIPATING SEPARATION

Landing clearance to succeeding aircraft in a landing sequence need not be
withheld if you observe the positions of the aircraft and determine that
prescribed runway separation will exist when the aircraft cross the landing
threshold. Issue traffic information to the succeeding aircraft if not
previously reported and appropriate traffic holding in position or departing
prior to their arrival."

"American Two Forty-Five cleared to land, following United Boeing
Seven-Thirty-Seven two mile final, traffic will depart prior to your
arrival."

In the UK (and I think in the rest of Europe), such clearances are not
permitted. A landing clearance indicates that the runway *is* clear and
will remain clear of other traffic until the aircraft has vacated it.



Thus the level of confusion/incompetence/distraction required for the
controller to "clear an airplane to land right on top of you" would be very
much greater in the UK. I can imagine a scenario under the US regime where,
if the departing traffic were waiting for an IFR clearance and it were slow
to arrive, a controller might fail to resolve the unanticipated conflict.
In the UK it would require a major mistake as to fact, not just a mistaken
expectation.

"Julian Scarfe" wrote in message
...
[...]
Thus the level of confusion/incompetence/distraction required for the
controller to "clear an airplane to land right on top of you" would be
very
much greater in the UK. [...]
In the UK it would require a major mistake as to fact, not just a mistaken
expectation.

Yes, there is definitely an operational difference between landings
clearances in the US and in the UK, just as there are differences in what
qualifies an airport for a tower, and the nature of taxiways at various
airports. I do recognize that flying the US is often very different from
flying elsewhere, and my comments are specifically with respect to my own
experiences in the US. They may or may not be applicable elsewhere.

Pete