Douglas DC-3 accident at Lebanon, New Hampshire, 31 May 1955 (N19942)

Accident narrative

On May 31, 1955, at 1826, Northeast Airlines Flight 568, a Douglas DC-3 (N19942), overshot the runway while landing at Lebanon Airport in Lebanon, New Hampshire. The aircraft struck a drainage ditch and was substantially damaged. None of the 12 passengers or three crew members were injured.

**The flight** Flight 568 originated at La Guardia Airport in New York, destined for Lebanon with a scheduled stop at Keene, New Hampshire. The aircraft departed at 1612 under Visual Flight Rules (VFR). The crew consisted of Captain Parker F. Schofield, who had 9,878 total pilot hours with 7,699 in the DC-3; First Officer C. Peter Blouin, who had 457 hours in the DC-3; and Stewardess Sybil Walker.

Near Greenfield, Massachusetts, the crew observed a thunderstorm ahead and received an Instrument Flight Rules (IFR) clearance to Keene. The flight was cleared via Blue Airway 5 to the Lebanon radio beacon at 6,000 feet, later revised to 5,000 feet. The crew overflew Keene due to thunderstorms and poor radio reception. Upon finding a 5,000-foot ceiling at Lebanon, they canceled their IFR clearance and proceeded VFR for landing.

Northeast Operations relayed a 1807 special weather observation for Lebanon, reporting a partially obscured sky, 800 scattered clouds, an estimated 3,000-foot overcast ceiling, two miles of visibility in light rainshowers and fog, and calm winds.

**The approach and landing** Captain Schofield circled the airport to the left to approach runway 18. On the base leg, the landing gear and full wing flaps were extended, remaining down throughout the approach and landing roll. The aircraft crossed the airport boundary at a reported 90 knots and touched down on the wet runway 900 feet from the approach end.

The captain applied steady braking, followed by intermittent "pumping," but failed to stop the aircraft. It rolled off the end of the runway, struck a drainage ditch, and came to rest on its fuselage underside 57 feet from the runway end. Because of the rain, the crew kept the passengers inside the aircraft until cars arrived.

**What the investigation found** Lebanon Airport's runway 18 is 4,000 feet long, surfaced with coarse bituminous material containing small depressions where rain collects. An airport rule required landings to the south when the wind was calm.

Tire marks showed the aircraft touched down on its main gear 900 feet from the threshold, with the tail wheel off the runway surface. The captain stated the aircraft was in a three-point position as it left the runway. He told investigators he did not consider a go-around because of rising terrain and low clouds south of the airport. He unlocked the tail wheel to attempt a groundloop but decided against it due to the aircraft's speed and the associated hazard. Hoping to clear the ditch, he applied power before leaving the runway and cut the ignition switches as the aircraft went off the end. The landing gear struck the far side of the 30-foot-wide ditch three feet below its top.

Examination of the wreckage revealed no pre-impact mechanical failures or malfunctions in the aircraft or its braking system. The tires were inflated and showed no scuff marks. The aircraft's gross weight was 21,998 pounds, which was 3,348 pounds under the allowable limit and properly distributed.

Witnesses stated the approach appeared slightly high and fast. The Board noted that an approach speed of 90 knots and a touchdown 900 feet past the threshold would normally be safe on a dry 4,000-foot runway, but was a marginal operation on a wet surface. The Board concluded that keeping the tail in the air for 3,000 feet required a somewhat excessive touchdown speed. The fact that the landing gear struck the top half of the far bank of the ditch indicated the aircraft still had considerable speed when it ran off the runway. High speed and momentum in the landing roll would retard the dissipation of wing lift, adversely affecting braking action.

The crew reported seeing indications on the trees of an overriding tailwind after the accident. However, weather analysis indicated only a very light northwest breeze above the surface, increasing to 6 to 8 knots at 400 feet. The Board found it extremely unlikely that a strong wind could have existed within 500 feet of the surface while the surface wind remained calm.

**Probable cause** The Board determined that the probable cause of this accident was "an approach too high and too fast under the existing calm wind and wet runway condition and the subsequent ineffective braking action."