# NTSB CHI98LA098: Cessna 402B, N108RS, Mason City, IA, February 27, 1998 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: February 27, 1998, 17:35 local (23:35 UTC) - Place: Mason City, IA - Coordinates: 43.149635, -93.189147 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=43.1496&lon=-93.1891&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report June 26, 1998 - Report: Approved by Office Director - NTSB case key (mKey): 10832 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI98LA098 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/10832/pdf - Page: https://openairdocs.org/ntsb/CHI98LA098 ## Probable cause the accumulation of airframe ice during flight, and failure of the pilot to attain a proper flare for landing. Factors relating to the accident were: the adverse weather (icing) condition; and the pilot's limited forward visibility, due to ice on the windshield and the light condition at dusk. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, approach - weather condition - icing conditions (contributing factor) - miscellaneous,airframe - ice (cause) - window,flight compartment window/windshield - ice (contributing factor) - Hard landing, landing - flare/touchdown - light condition - dusk (contributing factor) - visual/aural perception, pilot in command (contributing factor) - weather condition - tailwind - flare - not attained, pilot in command (cause) - Gear collapsed, landing - flare/touchdown - landing gear,tire - separation - landing gear - overload ## Analysis The pilot said the airplane encountered freezing rain that was changing to snow as the airplane broke out of the clouds at 600-feet above ground level during an ILS approach. He said the airplane had about 3/8 to 1/2-inch of ice on its airframe. According to the pilot, the airplane touched down on its left main landing gear, as he landed at dusk with a 10-knot left quartering tailwind. He said the left main gear tire rolled off its wheel as the nose gear and right main landing gear contacted the runway. Both the right main and nose landing gear collapsed. The pilot said he landed in a slight crab at touchdown on the ice-covered runway. The pilot said the windshield was ice covered with a clear area of about 8-inches by 11-inches through which he could see. ## Factual narrative On February 27, 1998, at 1735 central standard time (cst), a Cessna 402B, N108RS, piloted by a commercial pilot, was substantially damaged during a hard landing on runway 35 (6,501' X 150' ice coated asphalt) at the Mason City Municipal Airport, Mason City, Iowa. The 14 CR Part 91 positioning flight was operating on an IFR flight plan. Visual meteorological conditions prevailed at the time of the accident. The pilot reported minor injuries. The flight departed Denison, Iowa, at 1700 cst. The pilot stated he landed the airplane "...on the left main tire first." He said the left tire rolled off the wheel's rim on touchdown. The pilot continued, "[The] nosewheel hit along with the right main collapsing both a nose wheel and right main. Airplane came to stop, just on the left side of runway." During the telephone interview with the pilot it was revealed that runway 35 was ice covered. The pilot said he landed N108RS with a 10-knot, left quartering, tailwind. He said the airplane had about 3/8 to 1/2-inch of ice on its airframe. As the airplane exited the overcast at 600-feet above ground level, the pilot said it encountered freezing rain that was transitioning to snow. The pilot said he had been using the airplane's alcohol windshield deice system to keep the windshield free of ice. He said that he had an opening about 8-inches by 11-inches to look through during the landing flare and touchdown. He said the airplane's left main landing gear tire "struck" the runway and rolled off the wheel's rim. He said the airplane yawed to the left as the nose gear and right main landing gear touched down followed by a collapse of both assemblies. The pilot said the airplane was in a "slight" crab at touchdown. ## Aircraft - Registration: [N108RS](https://openairdocs.org/deregistered/N108RS-2016-09-01), registration cancelled 2016-09-01, S/N 402B-0440, built 1973 (OpenAirDocs) - Reported make and model: Cessna 402B - Registry model: [Cessna 402B](https://openairdocs.org/model/cessna-402b) (registry code 207590P) (OpenAirDocs) - Registry engine: [Continental TSIO-520 series](https://openairdocs.org/engine/continental-tsio-520-series) (registry code 17040, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 0440 - Airframe hours: 4984 - Engines: Continental TSIO-520-E 300 horsepower reciprocating - Damage: Substantial damage - Flight: Positioning, Part 91 - Registered owner: Dwyer Aircraft Sales, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, November 26, 1997, 73 hours before - Departed: DNS, DENISON, IA - Destination: MCW - Flight plan: IFR - Airport: MCW, Mason City Municipal, runway 35, 6,501 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 31; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 1,744 total, 218 in this make and model, 1,433 as pilot in command, 31 in the last 90 days, 17 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Dusk - Wind: 230° at 14 knots - Visibility: 5 statute miles - Lowest ceiling: 1,200 ft overcast - Temperature: 36 °F, dew point 34 °F - Altimeter: 29.00 inHg - Observed at: MCW, 1 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19980227006219A](https://openairdocs.org/incident/19980227006219A), Feb 27, 1998: Cessna 402B, Mason City, IA, Substantial damage. Became loaded with ice during IFR flight. Hard side load impact on landing collapsed the gear. Crosswind a factor. (.4) the pilot said the airplane encountered… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.