Background
The flight departed from Wilmington, Delaware, en route to Rutland, Vermont. The pilot diverted to Binghamton after receiving the Albany weather and learning that the Rutland weather was not available. After landing, the pilot told flight service station personnel that he had phoned Rutland and was told the weather was good.
Flight Sequence
Before continuing the flight, the pilot obtained two weather briefings and was advised of flight precautions for icing and turbulence, as well as pilot reports concerning icing. He filed a flight plan and continued to Rutland. While approaching Rutland at 6,000 feet, the pilot reported moderate icing. He requested clearance to climb and was cleared to 8,000 feet, but had difficulty climbing. He then requested and received vectors to Burlington, which had a 3,500-foot overcast and good visibility.
While en route to Burlington, the pilot was unable to maintain a minimum safe altitude of 5,500 feet and declared an emergency. After descending below clouds, he reported that ice was coming off the aircraft. He reported the runway in sight and was cleared to land.
Witness Observations
Witnesses reported that on final approach, the aircraft lost 150 to 200 feet, then regained some altitude several times. During the third loss of altitude, it hit the ground in a flat attitude and slid approximately 300 feet onto the runway.
Aircraft Details
The aircraft was not equipped for flight in known icing conditions. The pitot heat switch was found in the off position. A DC-9 crew reported a 15-knot loss of speed on final approach.