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One powerful way to reduce runway incursions is to keep airline captains focused outside
the cockpit while moving. That means minimizing attention spent inside the
cockpit such as reading charts. One dramatic improvement
with my airline was requiring the after start checklist be completed prior to
taxiing.
One area remains, though, that pilots have to look at while taxiing—the airport diagram.
For most airlines that is Jeppesen's 10-9 page. And it could use a lot of improvement.
The airline doesn't
produce these charts but, as a major customer, it should push for improvements.
The goal must be to minimize how long pilots must look at the
chart to decipher instructions. A number of visual tools can be employed that
have been incorporated in the modified
example. It's a given that pilots should try to understand taxi instructions
before moving, but sometimes instructions are given, or must be verified, while
moving.
To the right, on top, is the current FLL 10-9 page and below that is a modified
one. Look at the two diagrams and see which one is quicker to understand the
sample instructions. Remember, except for the initial call, a captain may be taxiing
the airplane while
getting instructions.
Southwest flight 1 is parked on the far east side at terminal one. A crew is getting ready to
taxi and gets this:
“Southwest 1, taxi to runway 9L via T, T5, S, hold short of taxiway Q”.
Consider also this one. The flight just landed on runway 13. The crew will
most certainly be moving when this instruction comes in.
“Southwest 1, turn left when able, left on Delta. Taxi to your gate
using Sierra, Bravo, enter the ramp at T2.”
Look at both charts to see
which are easier to use. Of the pilots I've showed these charts to the answer
has been immediately that the second one is.
The pilot is going to take much less time looking at the modified chart to
figure (or re-figure if given
new instructions while moving) his route.
Given the FAA's appropriate emphasis on minimizing runway incursions, that is an
important outcome.
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Benefits: Taxiways are much easier to find and follow.
Tower and ground frequencies are easy to find. Relevant maximum sizes for
taxiways are rapidly found or, just as important, ignored.
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Here other elements that could improve usability.
1. Increase the airport diagram size by eliminating surrounding airport
features. How many pilots use these charts to know about
items such as trees, roads, etc., near the airport? The answer is very few (none that
I've talked to). We use them to taxi. The current full chart gives up 20% of it's width to airport
surroundings—valuable chart real estate. Bordering
information may be valuable for studying the chart beforehand, but gives up
clarity in its primary function, understanding taxi routings especially in
a dimly lit cockpit.
2. Use visual icons for the most common taxiway notes. Icons can be
overused but, in this case, they can help. The max wingspan
notes are the best example since pilots will recognize quicker the need to
check if they can use a taxiway. The most common values are max
weight and max wingspan (or aircraft model). There's never a minimum
wingspan so, if the pilot sees a wing icon with 112' in it, he knows
immediately whether or not the note applies to him and can go on to read
the rest of it. Importantly, this reduces clutter, too.
3. Further reduce clutter by putting runway numbers in the runway and
terminal descriptions in the terminal using white on black.
4. Further reduce clutter by avoiding word descriptions of obvious things
wherever possible such as VOR's. Every pilot knows the standard VOR symbol
so the word "VOR" is superfluous and adds to clutter. Clarity is
improved by having secondary information, such as buildings in a
lighter shade of gray.
It's true that charts fall outside the control of the airline but we
are, after all, the customer. And we pay dearly for this service—we can
have some input. In all likelihood, Jeppesen (Boeing) wants to have a
good product but they are like any other business, not wanting to spend
money on changes unless the customer really wants them to.
Thanks for listening.
Jeff Goin
Captain, 737 |
Taxiway Design Principles
Design principles for readable taxiway
markings.
1. The letters themselves should
indicate the direction of the taxiway by their alignment. There is a
lot of value to quickly seeing that taxiway Bravo goes East/West
because of how the B's are placed. Letters should be as evenly
spaced as possible--humans pick up quickly on patterns.
2. The letter should be on
the taxiway as much as possible. It's too easy to confuse one with
another when they are off to the side, primarily when other taxiways
are nearby.
3. If the angle is less than about
30° to horizontal, then the letter should be angled with the
taxiway. This angling, on its own, helps determine quickly which
taxiway the letter applies to. Taxiways that angle more than 45°
should have their letters be aligned vertically to the page but
follow principle 1. In between those angles, other factors must be
considered—a design element that takes a good human eyeball.
4. You should not have to hunt for a
taxiway designator when clearing any runway. They should be obvious
and large.
5. Make the taxiway
letters larger. They are the most important element, we should be
able to see them clearly and quickly. Seeing the designators is much
more important than seeing the roadways that surround the airport.
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