Aviation Accident Summaries

Aviation Accident Summary IAD04IA032

Fryeburg, ME, USA

Aircraft #1

N4674L

Aviat A-1A

Analysis

According to the pilot, while cruising at 700-800 feet agl, the airplane's engine began running roughly, and experienced a loss of power. The pilot enriched the mixture, then applied carburetor heat, which made the engine run rougher, so he removed it. The engine continued to lose power until level flight could no longer be maintained. The pilot opted to land in a farmer's field; however, irrigation equipment was present, so he landed on a beach along a river. The airplane touched down fast, and subsequently floated. Nearing the end of the beach, the pilot attempted to abort the landing. When the pilot advanced the throttle, the engine responded with "about 15 percent power." The wheels of the airplane contacted the water, and the airplane nosed over, and came to rest upside down in the river. Prior to the incident, the pilot had contacted the state division of aeronautics regarding the legality of landing on sandbars in that river. Ambient temperature/dewpoint conditions at the time were favorable for moderate carburetor icing at cruise power, and serious carburetor icing at glide power.

Factual Information

On July 16, 2004, at 1057 eastern daylight time, an Aviat A-1A, N4674L, sustained minor damage during a forced landing near Fryeburg, Maine. The certificated commercial pilot was not injured. Visual meteorological conditions prevailed, and no flight plan had been filed. The local personal flight, which departed Laconia Municipal Airport (LCI), Laconia, New Hampshire, about 0915, was conducted under 14 CFR Part 91. According to the pilot's written statement, dated July 23, 2004, he was about 1 hour 15 minutes into a "scenic flight," when the "engine began running roughly with reduction/loss in power (induction icing?), making level flight impossible." The pilot then attempted an "emergency-precautionary landing" on a river beach. A go-around was attempted, "but [the] engine responded with very little power." In an interview on August 25, 2004, the pilot stated that he was taking pictures of the Saco River, between 700 and 800 feet above ground level (agl). The propeller control was set at 1,800 rpm, and the throttle was set at 17 to 18 inches of manifold pressure. The engine began to run "roughly," so the pilot enriched the mixture and applied carburetor heat. However, the carburetor heat made the engine run rougher, so the pilot removed it. The engine continued to lose power until level flight became impossible. The pilot initially chose to land in a farmer's field, but upon closer inspection, decided not to due to the presence of irrigation equipment. The pilot then decided to land on a beach in the Saco River. During the landing, the airplane touched down once; however, its airspeed was fast, so the pilot applied elevator backpressure. The airplane floated until it reached the end of the beach, at which time, the pilot tried to abort the landing. When the pilot applied full throttle, the engine responded with "about 15 percent power." The wheels of the airplane subsequently contacted the water, the airplane nosed over, and came to rest upside down in the river. Prior to the accident, on June 23, 2004, the pilot sent an e-mail to the New Hampshire Division of Aeronautics, inquiring as to the legality of landing on sandbars in New Hampshire rivers, and listed the Saco River as an example. The weather reported at Eastern Slopes Regional Airport (IZG), Fryeburg, Maine, about 3 nautical miles southeast, at 1054, included calm winds, 10 statute miles visibility, a few clouds at 3,600 feet, an overcast ceiling at 5,500 feet, temperature 72 degrees Fahrenheit, dew point 63 degrees Fahrenheit, and a barometric pressure of 29.63 inches of mercury. A carburetor probability icing chart indicated that the ambient conditions were favorable for moderate carburetor icing at cruise power, and serious carburetor icing at glide power.

Probable Cause and Findings

The pilot's improper use of carburetor heat, which resulted in a loss of engine power. A factor was the lack of suitable terrain for the forced landing.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports