During the winter, flying an ILS to minimums is the easy part. Once you break out of the crud, finding and landing on a snowbound runway holds more hazard than most pilots realize.
January 31, 1996
During the winter, dozens of aircraft come to grief on ice and
snow-covered runways, sometimes after completing an otherwise
uneventful instrument approach.
These accidents are rarely fatal but they do illustrate a harsh
reality of winter flying. We worry incessantly about airframe
icing but slick runways, snowbanks and low visibility test the
limits of man and machine and very often, neither is up to the
task. A spectacular accident a few winters ago shows how condtions
can conspire to undo the best efforts of even an experienced airline
USAir Express Flight 5108, a British Aerospace Jetstream, was
on a flight from Charlotte, North Carolina to Beckley, West Virginia,
an uncontrolled airport in the southern part of the state. The
date was March 17, 1993, a few days after the infamous Storm of the
Century had dumped 31 inches of snow on the Raleigh County Airport
As secondary airports go, Raleigh County is typical. It has two
runways and four approaches, including an ILS with standard 200-and-a-half
minimums to runway 19. Following the big storm, the airport was
closed for two days but the weather had cleared enough for crews
to plow the runway. On the night of the accident, another weather
system had moved in, bringing low ceilings, freezing drizzle and
As Flight 5108 approached Beckley just after sundown, the NWS
observer on the field reported a measured 200-foot overcast, with
a mile of visibility in light drizzle, light snow and fog. Runway
19 had been plowed but a notam warned that the surface had been
cleared to only 130 feet of its 150-foot width. Two-foot high
snow berms encroached on both edges of the runway but the edge
lights were reportedly visible. The Jetstream's flight from Charlotte
was uneventful, although it overflew a scheduled stop at Bluefield,
West Virginia because the weather was below landing minimums
and because there were no passengers to drop or pick up. Flight
5108 arrived in the Beckley area just before 7 p.m. local time.
As required by the regulations, the crew checked the weather
and learned that it was above minimums, although they would have
a 7-knot tailwind.
The crew performed its in-range checklist and the Captain briefed
the approach carefully with the First Officer. Shortly after
the Jetstream turned onto the localizer, the First Officer confirmed
with the Unicom operator that the runway lights were at full
intensity. As the aircraft neared decision altitude, the FO called
off altitudes. Seven seconds after calling "one-hundred
above," the FO announced lights in sight.
First Officer: "I got the lead-in lights, continue."
Firrt Officer "There's the end of it."
First Officer: "There's the REILs."
Captain: "Taxi light's on, right?" (sound of click)
Captain: "Jeez...oh #, we've lost it...oh man, I don't believe
The next day, the NTSB accident investigator discovered that
the Jetstream had touched down on the runway, but well left
of the centerline and on the unplowed portion of the runway.
It rolled through the thick snow for 435 feet, at which point
the right gear leg sheared off and the left gear began collapsing.
The airplane then slid out onto the plowed portion of the runway
and nearly reversed direction before coming to rest atop the
snow berm along the runway edge. The crew and two passengers
escaped without serious injuries.
As wintertime runway accidents go, Flight 5108's wild ride was
unusual only in its severity. To put things in perspective, we
recently looked at several years worth of icing accident data.
The overall totals from two years-1988 and 1989-are typical.
In 1988, the NTSB's records show that there were 20 icy runway
accidents; in 1989, the total was 15. Viewed against the big
picture, runway excursions rank third behind airframe icing and
carb icing, the leading cause of icing-related accidents.
However, we suspect that the actual number of runway accidents
is much higher because many simply go unreported. We know of
incidents in which airplanes careened into runway lights or
skidded into snowbanks with only minor damage. No accident reports
Touch and Goes
If there's such a thing as a "routine" runway excursion
accident, it's probably the student pilot who suddenly finds
himself parked in a snowbank while practicing touch and goes.
Having an instructor aboard is no guarantee of a safe outcome,
either. On a dry runway, an alert instructor can correct a student's
minor squiggles with a quick stab on the rudder. When the pavement
is covered by snow or ice, a minor drift can instantly turn
into a headlong careen off the runway.
Sometimes, an instructor's attempts to salvage a landing gone
bad only makes things worse. In one accident in North Dakota,
a CFI was checking out a pilot in a Cessna 172RG. The student
was attempting a touch and go on a 2800-foot, snowcovered runway.
The trainee landed long, then caught the CFI by surprise when
he attempted takeoff with only 800 feet of runway remaining.
The instructor reacted, but too late. As the aircraft slid to
stop, it departed the left side of the runway and nosed over
in a snowbank, causing serious damage.
Earlier in the same week, a pilot attempting to land a Piper
180 at a Vermont airport had a similar run-in with a snowbank.
When he started to slide after touching down, he tried to go
around. The left main was sheared off by a high snow pile and
the pilot returned to land on the right main, significantly damaging
the left wing.
If the 1988-89 winter seasons are an accurate indication, the
majority of slick runway accidents occur at uncontrolled fields.
No surprise there. Outlying airports tend to have narrower,
shorter runways and runway lighting tends to be minimal or non-existent.
More important, as the crew of Flight 5108 discovered, a major
storm can overwhelm the snow removal capabilities of small airports.
Give It A Try?
Knowing this, you'd think that pilots would give small, snow-covered
airports a wide berth and most probably do. But there are always
a few who are willing to tempt fate by landing or taking off
on short, snow or slush-covered runways. That's exactly what
the pilot of a Cessna 182 did at small Wisconsin airport. He
elected to land on a 2500-foot snow-covered grass strip but
wound up nosed over off the end of the runway. He told accident
investigators that he flew the approach fast and touched down
long, virtually assuring that he would have insufficient distance
With their wider runways and superior snow removal, towered
airports-especially air carrier airports-have fewer runway excursion
incidents. However, as in the case of Flight 5108, the most
damaging runway excursions seem to involve faster, heavier aircraft,
whether at towered airports or not. The NTSB's records contain
numerous accidents in which relatively fast airplanes (medium
twins and up) complete an instrument approach only to touchdown
in a snowbank or careen out of control off the end of the runway.
Even if the crew is acutely aware of the hazards and prepared
to counter them, suprises may yet lurk upon touchdown. Two accidents
illustrate the point.
In the first, an MU-2 on a cargo flight into Spokane, Washington
had completed an ILS just after dawn. Spokane is a towered field
and even though the runway had been plowed, it was still covered
by 2 inches of ice and snow, some of which had been heaped up
on the left side of the runway, burying the lights. The pilot
said he thought he had landed on the centerline but the aircraft
drifted left and went out of control in a snowbank.
In the second accident, the crew of a Lear 25 was inbound to Bend,
Oregon, an uncontrolled airport. The weather was clear but the
crew suspected the runway might be icy. Before landing, the crew
made a low pass to examine the surface and, seeing no evidence
of ice or snow, they returned for landing.
On rollout, some 2000 feet beyond the landing threshold, the Lear
began to skid. The aircraft was equipped with a drag chute but
it was inoperative. Unable to stop, the Lear overran the 5000-foot
runway, struck a fence and came to rest in a ditch. A post-accident
inspection revealed that the last half of the runway was coated
by black ice, which is all but invisible.
Avoid the Hazard
From the warm comfort of an armchair, it's great sport to second-guess
any pilot who comes to rest in a snow-filled ditch or tears off
out of control, chopping off edge lights like so many bowling
pins. After all, isn't the hazard obvious and anyway, why not
just cancel the flight entirely or land somewhere else? The hazard
is obvious. But most experienced snowbelt pilots will tell you
that judging the degree to which a snowy runway will affect aircraft
control is next to impossible. Then there's the challenge of actually
seeing the runway on a snowy, gray day or at night.
In the case of Flight 5108, the Captain was no newcomer. He had
more than 12,000 hours, some of it flown in snowy West Virginia.
As we said, no cause has been deter mined but judging from the
NTSB factual report and CVR recording, the crew carried out the
flight professionally and with all due care and yet were caught
completely by surprise when the aircraft wound up in the
The all-time, bulletproof option is to just bag the entire flight.
For-hire crews have that option, but it's not always easy to exercise
it; there's enormous pressure (often unspoken) to deliver the
paying passengers. The pressure is less for Part 91 pilots but
it's still there. One go/no-go test is this: how important is
the trip compared to the prospect of ending it nosed over in a
snow drift? A variation of this is IFR contributor Bob Gardner's
all-purpose test: How will I look in the accident report?
Still want to go? Stack the odds in your favor by flying into
an air carrier airport or one that has known snow-removal capability.
A long drive to the destination is better than a short skid into
the runway lights. Avoid short, narrow paved runways and turf
strips. Even if the runway and taxiways are dry, snowberms can
do massive damage to wings and landing gear.
If you must use a small airport, try to arrive in daylight and
don't rely on notams for field conditions. Call ahead for a detailed
report on conditions, including lights. Is the runway plowed to
its full width and length? Is the asphalt dry or covered by thin,
patchy snow? Has it been sanded? Are lights on both sides of the
runway visible? Be extremely cautious when a sub-freezing dusk
follows a warm day; the meltwater from plowed snow can freeze
into sheets of ice. If possible, have a vehicle check the runway
before takeoff or landing.
Stick to Daylight
Clearly, the accident record and common sense suggest that the
risk goes way up at night, in low visibility or in a crosswind
or downwind landing. If you attempt an approach in any of these
conditions (or all three), the risk is much higher. Again, the
long, wide and well lighted runways at air carrier airports are
the best option.
When approaching at night in the snow, it may be better to leave
the landing light off until just before touchdown. The reflection
off airborne snow can be mesmerizing and will make it harder to
see the runway. When operating on snowy and icy surfaces, slow
is better and that applies equally to landing and taxiing. Those
slow, short-field techniques you learned as a student but probably
haven't used much since are suitable for landing on slippery surfaces.
One fact of winter flying is that the same conditions that put
ice on the runway may put ice on the airframe. In that case, a
slow approach won't do. You'll have to keep the speed up, land
without flaps and take your chances .
Another technique-a low-level drag before actually landing- isn't
a bad idea, either. Although it didn't help that Lear crew in
Oregon, dragging the field may reveal snow or slush that's too
deep to chance. Or maybe it'll scare you into landing elsewhere.
On a dry runway, touching down in a slight crab is sloppy technique
but no big deal; once the tires grab, the aircraft cocks itself
straight. Try that on a slick runway and you'll all but guarantee
a skid. If that happens, regain control with vigorous rudder input
and judicious power. In a twin, differential power may be more
effective than rudder. Don't try to steer with brakes; they'll
probably be useless.
Salvaging a skid by attempting an immediate takeoff would appear
to be chancy, too, according to the accident record. On a slippery
runway, the tires lack the traction to counteract torque and P-factor
so unless you're quick on the rudder, firewalling it could worsen
the skid. And if you don't get airborne before hitting the snowbanks,
you'll do more damage because you'll be going faster. A slow-speed
slide into snow might be more acceptable.
The only good thing about snow on runways is that it eventually
melts, sometimes in a matter of hours. Waiting for that to happen
seems a small price to pay to avoid the ignominy of a surprise
sleigh ride through the airport boondocks.