On January 8, 1999, a Cessna 310R (registration N31UV) was involved in an aviation accident near Allentown, PA. Investigators recorded the probable cause as: The pilot's failure to ensure complete removal of ice from the right wing's outboard section, which contributed to a hard landing due to early power reduction in the flare. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot diverted to a nearby airport following an incomplete deicing cycle that left four inches of ice on the right wing's outboard section, resulting in a hard landing during the flare phase.
What happened
The pilot was operating the aircraft when ice began to accumulate on the wings. To address this, the pilot activated the airplane's deicing boots. However, the system failed to completely clear the right wing; specifically, the outboard three-foot section remained covered in ice. Approximately four inches of ice were later observed on the outboard leading edge of the right wing by ground personnel.
Due to the situation, the pilot decided to divert to a nearby airport. Upon arrival, an Instrument Landing System (ILS) approach was executed. During the final phase of the landing, the pilot reduced power early while in the flare. This premature reduction of thrust resulted in the airplane making a hard landing upon touchdown.
The investigation
Ground personnel examined the aircraft after the incident and observed about four inches of ice on the outboard leading edge of the right wing. This confirmed that the deicing boots did not fully clear the specified section during operation.
Probable cause
The pilot's failure to ensure complete removal of ice from the right wing's outboard section, which contributed to a hard landing due to early power reduction in the flare.