# NTSB CHI94LA045: Cessna 210B, N9684X, Dubuque, IA, December 6, 1993 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: December 5, 1993, 19:57 local (Dec 6, 1993, 01:57 UTC) - Place: Dubuque, IA - Coordinates: 42.499095, -90.69049 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=42.4991&lon=-90.6905&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious, 1 minor - Status: Completed, report December 19, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 9436 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI94LA045 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9436/pdf - Page: https://openairdocs.org/ntsb/CHI94LA045 ## Probable cause FLIGHT BY THE PILOT INTO KNOWN ICING CONDITIONS, WHICH RESULTED IN AIRFRAME ICING AND AN INABILITY OF THE AIRCRAFT TO MAINTAIN ALTITUDE ON THE ILS GLIDEPATH, ONCE THE LANDING GEAR WAS LOWERED. THE WEATHER CONDITIONS WERE RELATED FACTORS. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with terrain/water, approach - faf/outer marker to threshold (ifr) - flight into known adverse weather - performed, pilot in command (cause) - weather condition - low ceiling (contributing factor) - weather condition - fog (contributing factor) - weather condition - rain (contributing factor) - weather condition - icing conditions (contributing factor) - airframe - ice (cause) - proper glidepath - not possible, pilot in command ## Analysis THE PILOT RECEIVED A FULL WEATHER BRIEFING APPROXIMATELY FIVE AND A HALF HOURS BEFORE DEPARTURE, WHICH INCLUDED AN AIRMET FOR ICING CONDITIONS IN THE AREA. THIRTY MINUTES BEFORE TAKEOFF, HE RECEIVED A WEATHER UPDATE AND WAS GIVEN FOUR PIREPS ABOUT MODERATE TO SEVERE ICING CONDITIONS ALONG HIS ROUTE OF FLIGHT. HE REPORTED HEAVY ICING CONDITIONS DURING CRUISE AND EVENTUALLY ADVISED AIR TRAFFIC CONTROL THAT HE WAS UNABLE TO MAINTAIN ALTITUDE. THE PILOT WAS THEN CLEARED FOR THE ILS APPROACH. HE REPORTED THE AIRPLANE HAD TWO INCHES OF ICE ACCUMULATION AND WAS ACCUMULATING MORE. AFTER EXTENDING THE LANDING GEAR AT APPROXIMATELY 800 FEET AGL, THE PILOT WAS UNABLE TO MAINTAIN ALTITUDE ON THE ILS GLIDEPATH AND LANDED SHORT OF THE RUNWAY. ## Factual narrative On December 5, 1993, at 1957 central standard time, a Cessna 210B, N9684X, sustained substantial damage when it landed short of runway 31 at Dubuque Municipal Airport, Dubuque, Iowa. The pilot received serious injuries, and his sole passenger received minor injuries. An IFR flight plan was filed, and instrument meteorological conditions prevailed at the time. A weather observation from Dubuque Municipal Airport was taken three minutes after the time of the accident. The observation reported a measured ceiling of 200 overcast, two miles visibility with fog, temperature 37 degrees, and dewpoint 37 degrees. According to the FAA, approximately five and a half hours before departure, the pilot received a full weather briefing and was given an Airmet for icing conditions in the area. Thirty minutes before takeoff, the pilot received an update on the weather conditions. At this time the pilot was given four Pireps for moderate to severe icing conditions which existed in the area of his destination. In a written statement provided to the NTSB, the pilot says he was experiencing heavy icing conditions and eventually advised air traffic control that he was unable to maintain altitude. Air traffic control then cleared the pilot for the ILS approach at Dubuque Municipal Airport. At approximately 3,300 feet, the pilot reported the airplane had two inches of ice accumulation. At 800 feet AGL, he lowered the landing gear and was unable to maintain the glideslope. The airplane landed short of the runway. ## Aircraft - Registration: [N9684X](https://openairdocs.org/deregistered/N9684X-2012-11-26), registration cancelled 2012-11-26, S/N 21057984, built 1962 (OpenAirDocs) - Reported make and model: CESSNA 210B - Registry model: [Cessna 210B](https://openairdocs.org/model/cessna-210b) (registry code 2073410) (OpenAirDocs) - Registry engine: [Continental I0-470 series](https://openairdocs.org/engine/continental-i0-470-series) (registry code 17027, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 210-57984 - Airframe hours: 3967 - Engines: CONTINENTAL IO-470-S 260 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Perry J. Walton - Registered owner: Perry J. Walton - Airworthiness certificate: Standard, Normal - Last inspection: Annual, September 14, 1993, 90 hours before - Departed: PWK, WHEELING, IL - Destination: DBQ - Flight plan: IFR - Airport: DBQ, Dubque Municipal, runway 31, 6,498 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 18,000 total, 40 in this make and model, 108 in the last 90 days, 29 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Instrument (IMC), Night/dark - Wind: 160° at 8 knots - Visibility: 2 statute miles - Lowest ceiling: 200 ft overcast - Temperature: 37 °F, dew point 34 °F - Altimeter: 29.00 inHg - Observed at: DBQ, 1 nm away ## Other investigations on N9684X (1) 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. - [NTSB MKC69D0275](https://openairdocs.org/ntsb/MKC69D0275), Dec 4, 1968: Cessna 210 (N9684X), Watertown, SD, substantial damage 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.