Tricks of Sun and Storm
 Sunny summer days are often
associated with great flying, but can be tough on pilots' eyes. Sunglasses
that help cut glare in the cockpit may sometimes create another hazard,
as this air carrier Captain reports:
- While taxiing
out, after turning onto the taxiway, we noticed the cargo door light
on and company personnel on the ramp waving. We notified Ground Control,
and company personnel came to the aircraft and secured the cargo door.
This happened in part due to the annunciator light being quite dim and
in the far corner of the panel. [Since I had sunglasses on], it was
quite difficult to see.
Sunglasses are available in
a wide variety of tints, some of which may alter the color and brightness
of annunciator and warning lights. Polarized sunglasses, although effective
against reflective glare, may reveal strain patterns present in some aircraft
windshields. These patterns may visually distract pilots. Many air carrier
operations manuals specifically prohibit the use of polarized sunglasses.
Pilots should explain to their eye care providers that the sunglasses
will be used for flying, and that it is important not only to be able
to see colored warning lights and electronic displays, but to avoid visual
distortions and distractions.
Mirage
Another impediment to a pilot's
vision is the refraction of light rays on a hot day. Heat in the atmosphere
acts as a lens to create a distorted view of reality--a mirage. The mirage
may give the illusion that an object is present, when, in fact, no object
exists at close hand. The opposite situation, as reported by a general
aviation pilot, is a case in which the watery mirage effect masks a very
real hazard:
- Hot and
hazy day. Runway 06 was in use. I had the CTAF on while doing my pre-flight
checks at the approach end of runway 06. I checked both ends of the
runway, saw no traffic, made my departure call and started takeoff.
Unknown to me, an airplane had approached and landed on runway 24 while
I did my run-ups, etc. Just before rotation speed, I noticed the other
airplane on the runway. I had enough room to rotate and side-slip to
the right, and missed the other plane by a good margin. I'd heard nothing
on the radio. An airport employee said he hadn't either.
Incidents like this can be
prevented by: 1) using your radio at uncontrolled fields; 2) obtaining
airport advisory, i.e., which runway is in use; and 3) exercising great
care on hot, muggy days. Heat rising from the runway may distort your
view of objects at the other end.
Desert Storm
In the Southwestern U.S. and
some foreign locations, the approach of seasonal thunderstorms may be
signaled by dangerous emissaries--sand and dust clouds that precede the
storm front at low and high altitudes, presenting a hazard to both general
aviation and air carrier aircraft. An air carrier Captain tells a harrowing
tale of an encounter with one such dervish in Middle Eastern airspace:
- Flight approaching
[Middle Eastern] airport was cleared to descend to FL120. An area of
isolated embedded thunderstorms was being passed. Aircraft had been
slowed to turbulence penetration speed and was deviating around thunderstorms
on descent with good radar returns received. At FL180, an area of mild
precipitation showed on radar; not unlike ground clutter, it would not
contour. Rain increased in intensity followed by a very brown substance
which appeared to be wet sand. The windshields were damaged, #2 engine
flamed out, and the "pull up" [terrain warning] signal occurred
several times. The time in the heavy rain/sand was very short...but
the intensity of the deluge was considerable.
After flying through the sand cloud, the aircraft continued on and landed
uneventfully. My main concern was the lack of adequate return from a
perfectly good radar and the hazard involved in flying through wet sand.
The radome was damaged, the landing light lenses blown out, and the
windshields partly crazed over. All the static wicks were also missing.
This aircraft's Ground Proximity
Warning System (GPWS) apparently interpreted the sand cloud as terrain
and signaled a pull-up.
ASRS on the "Web"
Earlier this year, we announced
that ASRS has an Internet site. It can be reached by typing the following
address exactly as it appears:
We hope you'll visit us soon
to sample some of our aviation safety fare, including an ASRS overview,
and pilot /controller reporting forms. Also available through the Adobe
Acrobat Reader are back issues of two ASRS publications--CALLBACK from
December 1994 to the present, and Directline from Winter 1990 to the present.
Soon, you will be able to access these two publications directly in an
"html" format.
Taxi To, Not Through
ASRS frequently receives reports
of runway incursion incidents attributed to the forgetting of taxi rules,
faulty crew coordination, and unmet expectations. Our first reporter belatedly
remembered the basic rule of taxiing--proceed only as far as instructed,
and never onto the assigned takeoff runway without specific permission.
- We were
cleared to taxi to 16L. As we approached 16L, I looked for traffic,
saw none, and continued across. As the nose of the aircraft entered
the runway area, I saw a small airplane on final. It was too late to
stop, so I sped up to cross faster. The other airplane landed without
incident.
Listening to Ground earlier, I had heard him give, "Taxi 16L via...hold
short of 16L," [to another aircraft]. Because I did not get the
"hold short," I was in the mind set that I was cleared to
cross, forgetting the old basic that "taxi to" is permission
to cross all runways except the active. We get so used to being told
where to hold short that when it is not said, we forget about this exception
to the basic rule about taxiing.
Not unlike real estate, in
which the key words are "location, location, location," so it
is with taxi instructions. Controllers usually are quite explicit about
directing an aircraft where to taxi, and when. Lack of cockpit coordination
during taxi caught this flight crew off-guard, as the First Officer reports:
- After touchdown,
the Local Controller instructed us to exit runway 22 using the forward
high-speed taxiway and hold short of runway 27. I read back those instructions,
and proceeded to complete the after-landing checklist. The Captain must
not have understood our instructions to hold short, and continued to
taxi across [runway] 27. He asked me, "We were cleared to cross,
right?" and I replied, "No." Lack of proper communication
and understanding of instructions between crew members were factors
in the situation.
The Captain involved in this
same incident had expectation on his mind:
- I had been
doing this same flight for almost 2 months; runway 22 had been the runway
90% of the time, and every landing on 22 had been followed by, "Exit
the highspeed, cross 27, [contact] Ground the other side." I mistakenly
expected this, and wanted to hear it.
Confirmation between crew members
of the controller's instructions, and clarification with the controller
if necessary, might have prevented this incident. When in doubt, check
it out!
High-Speed
Taxi
Taxiway incursions are also
common, usually occurring when an aircraft taxies without clearance onto
a taxiway from a runway or ramp area. An air carrier Captain reports a
near ground collision resulting from another aircraft's apparent failure
to obtain taxi clearance.
- While we
were taxiing from the gate to taxiway A, a jet landed and exited the
runway at the intersection of A and the high-speed taxiway at a high
rate of speed directly toward our aircraft. I was forced to take evasive
action to stay safely out of his path. I queried Tower if he had cleared
the aircraft off at that exit, and he replied that he had not.
This incident was not so close
as to pose an immediate, direct hazard to my aircraft and passengers...largely
owing to the fact that my crew saw an unsafe situation rapidly developing
and took timely evasive action.
Fortunately, "see and avoid" works well on the ground, too.
A high-speed "taxi" incident of a different sort is reported
by a general aviation pilot:
- I was on
a long straight-in approach to runway 1L. At about 15 miles out, I was
asked by the Approach Controller if I had the airport in sight...and
as I got closer, he asked if I had the runway in sight. I answered yes
as I could see the right runway and what I thought was the left runway.
After I was switched to the Tower, he asked if I had the runway in sight.
I answered affirmative, as I could see the two runways I had identified
earlier. I landed on the left one. As I slowed to turn off, the Tower
told me I had landed on the taxiway.
By then it was quite clear to me, as where I turned off was at the start
of runway 1L. I should have looked at the diagram of the runways I had
with me long before I landed...
Other pilots have also reported
experiencing this embarrassment.
ASRS Recently Issued Alerts
On...
- Toe-brake failure on an
ATR-42
- Flap asymmetry control problems
on an E-120
- Loose rocks on taxiways
at a Mississippi airport
- Uncommanded spoiler deployment
on a B737-200
- Radar display strobing at
a Florida TRACON facility
April 1996 Report Intake
- Air Carrier Pilots--1872
- General Aviation Pilots--667
- Controllers--112
- Cabin/Mechanics/Military/Other--43
- TOTAL--2694
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