Dodge City, KS, USA
N108L
BEECH V35
The pilot stated that the pitot heat system was working during preflight. He obtained a full weather briefing from flight service, and checked the weather via the internet before departing. While airborne at 6,000 feet to 6,500 feet mean sea level he encountered instrument meteorological conditions and turned on the pitot heat. Sometime later, the airplane encountered moderate icing conditions. The airspeed indicator stopped working and the pilot diverted from his route of flight to an alternate airport. While over the runway on landing approach, the airplane stalled and landed hard, substantially damaging the airplane. Ice was found at the impact site, on the airplanes surfaces, and in the pitot tube. Inspection of the pitot tube revealed the pitot heat was not functioning at the pitot tube. On the day of the accident there were two AIRMETs for moderate icing in effect for the pilot’s route of flight and altitude. The pilot could not recall being informed of the icing conditions during his weather briefing and his briefing from flight service could not be located.
On December 6, 2009, at 1415 central standard time, a Beech V35 airplane, N108L, was substantially damaged during landing at Dodge City Regional Airport (DDC), Dodge City, Kansas. Instrument meteorological conditions prevailed. The commercial pilot and passenger were not injured. The personal flight was being conducted under the provisions of Title 14 Code of Federal Regulations Part 91 with an Instrument Flight Rules (IFR) flight plan. The cross-country flight originated at the Anoka County-Blaine Airport (ANE), Minneapolis, Minnesota, and was en route to Dalhart Municipal Airport (DHT), Dalhart, Texas. The pilot obtained a telephone weather brief from flight service, filed an IFR flight plan, and checked the weather on the internet prior to departing ANE. The pilot stated that during preflight inspection the pitot heat was checked and was working. The pilot departed ANE under visual flight rules and climbed to 6,500 feet mean sea level (MSL). After about one and a half hours of flight the pilot encountered IFR conditions, obtained an IFR clearance, and descended to 6,000 feet MSL. The pilot reported the airspeed indicator stopped working so he elected to divert to DDC, which was the nearest airport with an ILS approach. While over the runway on landing approach the airplane “fell straight down” and landed hard. There are three types of AIRMETs for different weather conditions, each represented by a phonetic letter. AIRMETs ZULU (Z) indicate widespread areas of moderate icing. There were two AIRMET ZULU’s in effect for the pilot’s intended route of flight from 0845 to 1500. One indicated moderate ice below 15,000 feet MSL, and the other indicated moderate ice below 10,000 feet MSL. On the Safety Board Form 6120.1, Accident/Incident Report, the pilot marked Automated Report as his source of weather information, Telephone/Computer as the method of briefing, and Full for briefing type/completeness. The pilot noted on the Safety Board Form 6120.1 that an Airmen's Meteorological Information (AIRMET) for instrument meteorological conditions (IFR) was in effect at the time of the accident and he told the investigator he could not recall being briefed on the icing conditions. Investigators were unable to obtain a copy of the actual briefing provided to the pilot to verify what he had been briefed. Beechcraft Bonanza V35, V35A (D-7977 thru D-9068) and V35B (D-9069 thru D-9947) Pilot’s Operating Handbook (POH/AFM, P/N 35-590118-31B4) states: • Section II – Limitations, Page 2-12 WARNING FLIGHT IN ICING CONDITIONS IS PROHIBITED • Section IV – Normal Procedures, Page 4-20 ICING CONDITIONS Flight in Icing Conditions Is Prohibited • Section X – Safety Information, Page 10-6 Don’t fly in possible icing conditions Examination of the airplane revealed all three landing gear collapsed, both wing spars bent, and the left main gear penetrated the top of the left wing. Ice was found on the surfaces of the airplane and on the ground near the impact point. Initial post accident inspection of the pitot heat system showed the pitot heat switch was in the on position and ice was found in the pitot tube. Power was applied to the airplane, but no heat was detected at the pitot tube. The pitot tube was removed from the airplane by investigators and electrical power was applied directly to the unit. No heat was detected from the pitot tube. The airspeed indicator was examined and found to work normally. An examination of the remaining systems revealed no anomalies.
The failure of the pitot heat system in icing conditions resulting in an inoperative airspeed indicator which led to an inadvertant stall while on final approach. Contributing to the accident was the pilot's decision to fly into known icing conditions.
Source: NTSB Aviation Accident Database
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