LOSS OF ACFT CTL. ACFT DAMAGED WHEN NOSEWHEEL COLLAPSES AFTER STRIKING SNOW BERM. TKOF ABORTED PROC.

Narrative

TKOF WAS SCHEDULED FOR A BUSINESS TRIP TO LITTLE ROCK; AR; WITH 2 PLTS AND 4 PAX. OVERNIGHT APPROX 4 INCHES OF LAKE EFFECT SNOW HAD FALLEN. THE RWY WAS PLOWED THE PREVIOUS DAY. A CAR WAS DRIVEN ON THE RWY TO DETERMINE THE EFFECT THE NEW SNOW WOULD HAVE ON THE TKOF PERFORMANCE OF THE PLANE; AND IT WAS DETERMINED BY THE PLTS THAT THE NEW SNOW WOULD HAVE NO ADVERSE EFFECT. THIS DECISION WAS LATER VERIFIED BY A TAXI TEST. AT XX35 AM THE TKOF WAS INITIATED ON RWY 2. ACCELERATION WAS NORMAL. AFTER ABOUT 1500 FT AND ACCELERATING THROUGH 80 KTS; THE L MAIN GEAR SEEMED TO ENCOUNTER A SNOW DRIFT AND ACCELERATION DIMINISHED SOMEWHAT. THIS DRIFT WAS APPARENTLY CONCEALED BY THE NEW SNOW WHICH CAUSED THE ENTIRE RWY AND THE SURROUNDING AREA TO APPEAR UNIFORM. THE ONLY CONTRAST BEING THE RWY LIGHTS AND THEY WERE PARTIALLY BURIED BY PREVIOUS SNOW PLOWING. AT THE FIRST INDICATION THAT THE TKOF WAS NOT PROCEEDING NORMALLY; THE DECISION WAS MADE TO ABORT. PWR WAS REDUCED TO IDLE AND; AS THE PLANE SLOWED; THE L TURNING TENDENCY INCREASED UNTIL NORMAL CTL INPUTS WERE NO LONGER EFFECTIVE. AT THIS POINT; THE NOSEWHEEL STRUCK THE ACCUMULATED SNOW ALONG THE EDGE OF THE RWY AND COLLAPSED; CAUSING THE PROPS TO STRIKE THE GND. THE PLANE THEN CAME TO A STOP AND ALL OCCUPANTS EXITED THROUGH THE PAX DOOR WITH NO INJURIES. THE SOUTH BEND; IN; FLT STANDARDS DISTRICT OFFICE WAS NOTIFIED AND 2 INSPECTORS RESPONDED; AND AFTER INSPECTION OF THE ACFT; DETERMINED THAT WHAT HAD HAPPENED BE DECLARED AN INCIDENT. THE POINT I WOULD LIKE TO MAKE BY DESCRIBING THIS INCIDENT IS THE ILLUSION CREATED BY THE NEW SNOW COVER. THOSE OF US WHO OPERATE ROUTINELY FROM SMALL ARPTS ON THE LEE SIDE OF A LARGE BODY OF WATER ARE CERTAINLY AWARE OF MOST OF THE PROBS CAUSED BY LAKE EFFECT SNOW; BUT IN THIS CASE; THE COMBINATION OF THE NEW SNOW COVER; POOR EARLY MORNING LIGHT AND THE FACT THAT THERE WAS NOT A SINGLE TRACK OR ANYTHING OF CONTRAST ON THE RWY OR THE SURROUNDING AREA EXCEPT THE TRACKS WE MADE IN CHKING THE RWY. IT WAS FELT THAT THE RWY LIGHTS WOULD GIVE ADEQUATE CTRLINE GUIDANCE DURING TKOF; BUT LACK OF DEFINITION; THE RWY BEING PHYSICALLY NARROWED BY PREVIOUS PLOWINGS MADE TRACKING THE CTRLINE ALMOST IMPOSSIBLE. THERE WERE NO VISUAL CLUES AS TO VARIOUS SNOW DEPTH EITHER ON OR ADJACENT TO THE RWY. IN MY 40 PLUS YRS OF FLYING; I HAVE EXPERIENCED THIS CONDITION ONLY 1 OTHER TIME AND THAT WAS DURING A LNDG AT MEIGS FIELD ON CHICAGO'S LAKE FRONT. THE ILLUSION IS VERY SIMILAR TO A GLASSY WATER LNDG IN A FLOAT PLANE. THE CONCLUSIONS TO BE DRAWN HERE ARE; OF COURSE; TO NEVER TAKE ANYTHING FOR GRANTED; ESPECIALLY THE FIRST TKOF OF THE DAY FROM A SMALL ARPT; AND THE EXISTENCE OF THE OPTICAL ILLUSION CAUSED BY TRACKLESS PRISTINE SNOW. ALSO; THAT THE EFFECT OF THE ILLUSION IS MUCH MORE DECEPTIVE AS TKOF SPD INCREASES.