Narrative:

I departed the cumberland airport, cumberland, md, with a student and his wife on a VFR night training flight to the nemacolin airport in farmington, PA. The WX was 25000' scattered, visibility greater than 10 mi and the surface winds were calm. There was a full moon but it had barely risen and the conditions at the time of the incident were essentially those of a moonless night. The en route portion of the flight went west/O incident and I descended from 4500' to 4000' MSL as I sighted the airport and descended to 3000' MSL (1000' AGL) and entered a left downwind for runway 23. As I turned left base I began a descent to 2500' MSL and turned final at that altitude. I had turned on the landing light but found it too distracting at that point so I turned it off again. I began a normal descent with the runway environment in sight. On short final, just as I was reaching to turn on the landing light, there was a thump and the aircraft yawed slightly to the left as the wings struck the tops of the trees. The aircraft was landed west/O further incident and taxied to parking. Inspection revealed that the left wing sustained leading edge damage on the outer two panels and that the right wing also sustained some leading edge damage, though less than the left. There was no indication before impact that the aircraft was below the glide path and my student who was observing saw nothing out of the ordinary. There was no VASI in operation and with the moon low on the horizon the tree line was not visible. I feel that the following factors were contributors in varying degrees to the incident. Fatigue. I had flown a four hour cross-country earlier in the day with a student pilot who had had some problems, including a blown tire on takeoff. Visibility. As I discussed with my student en route, this airport presented some real hazards (which I why I elected to make the landing). It is located in the country and had no lights other than the runway lights which makes judging height and descent rate very difficult it was a real black hole. In addition the runway was narrow, sloped uphill and had a displaced threshold. Airport information. The nemacolin airport is private and while I knew the field elevation and runway length, I did not have exact figures on the width, slope, or the threshold displacement which turned out to be extreme in each case. I was essentially a victim of the optical illusion created by a long, narrow runway that sloped uphill complicated by a significant displaced threshold. It is ironic that I hit the trees as I was consciously aware of the illusion problem and trying to correct for it. The final vision factor was the gap in the tree line along the runway axis that allowed for an unobstructed view with no indication that the tree line was so close. In conclusion, I must admit that the major cause of the problem was the lack of specific knowledge of the displaced threshold. I aimed farther down the runway but obviously not far enough. The second factor was a lack of any kind of VASI. I feel that any airport, public or private which has such a potentially dangerous landing environment should have some kind of VASI, even if it is a simple panel display. I will also never turn final west/O my landing light on throughout the final approach.

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Original NASA ASRS Text

Title: PLT OF SMA ON APCH DESCENDING ON FINAL ALIGNED WITH RWY OF UNCONTROLLED ARPT HIT TREE TOPS. WAS ABLE TO CONTINUE APCH AND LNDG. ACFT DAMAGED. NIGHT APCH AND LNDG.

Narrative: I DEPARTED THE CUMBERLAND ARPT, CUMBERLAND, MD, WITH A STUDENT AND HIS WIFE ON A VFR NIGHT TRNING FLT TO THE NEMACOLIN ARPT IN FARMINGTON, PA. THE WX WAS 25000' SCATTERED, VISIBILITY GREATER THAN 10 MI AND THE SURFACE WINDS WERE CALM. THERE WAS A FULL MOON BUT IT HAD BARELY RISEN AND THE CONDITIONS AT THE TIME OF THE INCIDENT WERE ESSENTIALLY THOSE OF A MOONLESS NIGHT. THE ENRTE PORTION OF THE FLT WENT W/O INCIDENT AND I DSNDED FROM 4500' TO 4000' MSL AS I SIGHTED THE ARPT AND DSNDED TO 3000' MSL (1000' AGL) AND ENTERED A L DOWNWIND FOR RWY 23. AS I TURNED L BASE I BEGAN A DSNT TO 2500' MSL AND TURNED FINAL AT THAT ALT. I HAD TURNED ON THE LNDG LIGHT BUT FOUND IT TOO DISTRACTING AT THAT POINT SO I TURNED IT OFF AGAIN. I BEGAN A NORMAL DSNT WITH THE RWY ENVIRONMENT IN SIGHT. ON SHORT FINAL, JUST AS I WAS REACHING TO TURN ON THE LNDG LIGHT, THERE WAS A THUMP AND THE ACFT YAWED SLIGHTLY TO THE L AS THE WINGS STRUCK THE TOPS OF THE TREES. THE ACFT WAS LANDED W/O FURTHER INCIDENT AND TAXIED TO PARKING. INSPECTION REVEALED THAT THE L WING SUSTAINED LEADING EDGE DAMAGE ON THE OUTER TWO PANELS AND THAT THE R WING ALSO SUSTAINED SOME LEADING EDGE DAMAGE, THOUGH LESS THAN THE L. THERE WAS NO INDICATION BEFORE IMPACT THAT THE ACFT WAS BELOW THE GLIDE PATH AND MY STUDENT WHO WAS OBSERVING SAW NOTHING OUT OF THE ORDINARY. THERE WAS NO VASI IN OPERATION AND WITH THE MOON LOW ON THE HORIZON THE TREE LINE WAS NOT VISIBLE. I FEEL THAT THE FOLLOWING FACTORS WERE CONTRIBUTORS IN VARYING DEGS TO THE INCIDENT. FATIGUE. I HAD FLOWN A FOUR HR CROSS-COUNTRY EARLIER IN THE DAY WITH A STUDENT PLT WHO HAD HAD SOME PROBS, INCLUDING A BLOWN TIRE ON TKOF. VISIBILITY. AS I DISCUSSED WITH MY STUDENT ENRTE, THIS ARPT PRESENTED SOME REAL HAZARDS (WHICH I WHY I ELECTED TO MAKE THE LNDG). IT IS LOCATED IN THE COUNTRY AND HAD NO LIGHTS OTHER THAN THE RWY LIGHTS WHICH MAKES JUDGING HEIGHT AND DSNT RATE VERY DIFFICULT IT WAS A REAL BLACK HOLE. IN ADDITION THE RWY WAS NARROW, SLOPED UPHILL AND HAD A DISPLACED THRESHOLD. ARPT INFO. THE NEMACOLIN ARPT IS PRIVATE AND WHILE I KNEW THE FIELD ELEVATION AND RWY LENGTH, I DID NOT HAVE EXACT FIGURES ON THE WIDTH, SLOPE, OR THE THRESHOLD DISPLACEMENT WHICH TURNED OUT TO BE EXTREME IN EACH CASE. I WAS ESSENTIALLY A VICTIM OF THE OPTICAL ILLUSION CREATED BY A LONG, NARROW RWY THAT SLOPED UPHILL COMPLICATED BY A SIGNIFICANT DISPLACED THRESHOLD. IT IS IRONIC THAT I HIT THE TREES AS I WAS CONSCIOUSLY AWARE OF THE ILLUSION PROB AND TRYING TO CORRECT FOR IT. THE FINAL VISION FACTOR WAS THE GAP IN THE TREE LINE ALONG THE RWY AXIS THAT ALLOWED FOR AN UNOBSTRUCTED VIEW WITH NO INDICATION THAT THE TREE LINE WAS SO CLOSE. IN CONCLUSION, I MUST ADMIT THAT THE MAJOR CAUSE OF THE PROB WAS THE LACK OF SPECIFIC KNOWLEDGE OF THE DISPLACED THRESHOLD. I AIMED FARTHER DOWN THE RWY BUT OBVIOUSLY NOT FAR ENOUGH. THE SEC FACTOR WAS A LACK OF ANY KIND OF VASI. I FEEL THAT ANY ARPT, PUBLIC OR PRIVATE WHICH HAS SUCH A POTENTIALLY DANGEROUS LNDG ENVIRONMENT SHOULD HAVE SOME KIND OF VASI, EVEN IF IT IS A SIMPLE PANEL DISPLAY. I WILL ALSO NEVER TURN FINAL W/O MY LNDG LIGHT ON THROUGHOUT THE FINAL APCH.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.