Aviation Accident Summaries

Aviation Accident Summary CHI98LA034

ULYSSES, KS, USA

Aircraft #1

N9404W

PIPER PA-28-235

Analysis

The pilot encountered freezing rain during a night cross-country flight at 5,000 feet above mean sea level (msl). He said his windshield had iced up during the flight. According to the pilot, he began a descent to prepare for a landing as he neared his destination. During the descent, the pilot noted his altimeter did not move below 4,000 feet msl. The pilot continued the descent until colliding with the ground. He said the altimeter indication went to 3,000 feet msl when the airplane collided with the ground. The accident site's terrain elevation was about 3,000 feet msl. The pilot said he did not turn on the pitot heat during the flight. The altimeter static port was on the aft side of the pitot-tube. During an altimeter bench-check, the altimeter functioned normally except it indicated between 50 and 120 feet low at various altitudes. There was no indication of sticking or rough operation at any altitude tested. The pilot did not obtain a weather briefing before departing on the accident flight.

Factual Information

On November 11, 1997, at 2100 central standard time (cst), a Piper PA-28-235, N9404W, piloted by a private pilot, was destroyed during a collision with the ground while in a descent. The 14 CFR Part 91 personal flight was not operating on a flight plan. The pilot stated visual meteorological conditions prevailed at the time of the accident. He said he was piloting the airplane on a night cross country flight in freezing rain under an overcast ceiling that was about 5,000 feet above mean sea level (msl). The pilot reported minor injuries. The flight departed Montezuma, Kansas, about 2030 cst. The pilot said his airplane's "Windshield picked up ice..." during the flight. He said he began to descend "...to 3,500 feet msl to prepare for landing..." as the airplane neared its destination. According to the pilot, N9404W's altimeter "...stayed at 4,000 feet when he passed that level." He continued, "The airplane felt like it was going down but [the] altimeter stayed at 4,000 feet. I hit the ground and the altimeter went to 3,000 feet." He said, "I did not know I was that close to the ground." The accident site's terrain elevation was about 3,000 feet msl. During an interview the pilot said the airplane's windshield was covered with ice. He said the static port was covered with ice due to the freezing rain. The pilot said he did not obtain a weather briefing because the weather was good at his departure point. The accident airplane's pitot-static system ports are on a single assembly located on the left wing. The pitot-tube is an electrically heated unit. The static port is located on the aft side of the pitot tube. The pilot stated he did not have the pitot heat "ON." N9404W's altimeter had been checked on November 30, 1994. The altimeter was functionally checked on November 19, 1997. The altimeter was tested in a climb of 1,500 feet per minute (fpm) to an altitude of 11,000 feet. The examination revealed it functioned normally except it indicated about 120 feet low. During the altimeter's descent check, it was tested at a rate of 1,500 fpm between 11,000 feet to 6,000 feet. Once at 6,000 feet its descent rate was reduced to 300 fpm until it showed 1,000 feet. The altimeter functioned normally in the descent except it indicated 50 to 80 feet low. There was no indication of sticking or rough operation at any altitude tested.

Probable Cause and Findings

the pilot's continued flight into adverse weather conditions, his failure to activate the pitot heat system, and his failure to maintain clearance from the terrain. Factors associated with this accident were: the pilot did not obtain a preflight weather briefing, the adverse weather (icing) condition, and accumulation of ice on the windshield.

 

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