# NTSB DEN04CA067: Cessna 172N, N5048E, Lyons, CO, April 24, 2004 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: April 24, 2004, 11:40 local (17:40 UTC) - Place: Lyons, CO - Coordinates: 40.224998, -105.26667 - Nearby events: https://openairdocs.org/map.md?lat=40.2250&lon=-105.2667&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report July 29, 2004 - Report: Approved by Office Director - Parties: FAA FSDO - NTSB case key (mKey): 59109 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN04CA067 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/59109/pdf - Page: https://openairdocs.org/ntsb/DEN04CA067 ## Probable cause a loss of engine power due to carburetor icing. Contributing factors were weather conditions conducive to carburetor icing and unsuitable terrain available on which to make a forced landing and the road sign. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - nonmechanical, descent - weather condition - carburetor icing conditions (contributing factor) - carburetor heat control - activated - Forced landing, emergency descent/landing - emergency procedure - attempted, pilot in command(cfi) - On ground/water collision with object, landing - roll - unsuitable terrain or takeoff/landing/taxi area - encountered (contributing factor) - object - sign (contributing factor) - terrain condition - roadway/highway ## Analysis According to the flight instructor, they were practicing engine failure procedures (with the use of carburetor heat) when the engine lost power. During the landing roll, the airplane struck a street sign, substantially damaging the airplane. The engine was run by an Airframe and Powerplant mechanic on April 24, 2004. The engine started without hesitation and a carburetor heat check and magneto check were performed with no anomalies. The fuel tanks were reported to be "half full." The temperature was 45 degrees Fahrenheit (F), and the dewpoint was 33 degrees F. According to the Carburetor Icing Chart, the conditions were conducive for "serious icing at cruise power." ## Factual narrative On April 24, 2004, at approximately 1140 mountain daylight time, a Cessna 172N, N5048E, was substantially damaged when it struck a sign during a forced landing near Lyons, Colorado. The commercial flight instructor and pilot receiving instruction were not injured. Visual meteorological conditions prevailed. No flight plan had been filed for the local flight being conducted under the provisions of Title 14 CFR Part 91. The flight had departed Vance Brand Airport, Longmont, Colorado, at approximately 1050. According to the flight instructor, they were practicing engine failure procedures (with the use of carburetor heat) when the engine lost power. He made a forced landing on a road near Lyons, Colorado. During the landing roll, the airplane struck a street sign. The right auxiliary wing spar was bent, the right leading edge was crushed, and the left horizontal stabilizer was crushed. The engine was run by an Airframe and Powerplant mechanic on April 24, 2004. The engine started without hesitation and a carburetor heat check and magneto check were performed with no anomalies. The fuel tanks were reported to be "half full." The Fort Collins Loveland METAR (Routine Aviation Weather) taken at 1055 reported the temperature as 45 degrees Fahrenheit (F), and the dewpoint as 33 degrees F. According to the Carburetor Icing Chart, the conditions were conducive for "serious icing at cruise power." ## Aircraft - Registration: [N5048E](https://openairdocs.org/deregistered/N5048E-2011-08-04), registration cancelled 2011-08-04, S/N 17271699, built 1978 (OpenAirDocs) - Reported make and model: Cessna 172N - Registry model: [Cessna 172N](https://openairdocs.org/model/cessna-172n) (registry code 2072434) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17271699 - Airframe hours: 8004 - Engines: Lycoming O-320-H2AD 160 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Air West Flight Center Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 20, 2004, 10 hours before - Departed: 2V2, LONGMONT, CO ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 43; injuries: none; commercial, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; last flight review September 11, 2003; seat: rear; flight hours: 1,196 total, 178 in this make and model, 1,114 as pilot in command, 39 in the last 90 days, 9 in the last 30 days, 1 in the last 24 hours - Student pilot; age 17; injuries: none; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 12 total, 7 in this make and model, 11 in the last 90 days, 5 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 45 °F, dew point 34 °F - Altimeter: 29.97 inHg - Observed at: FNL, 170 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 20040424009199A](https://openairdocs.org/incident/20040424009199A), Apr 24, 2004: Cessna 172N, Lyons, CO, Substantial damage. (-23) Aircraft departed longmont vance brand airport (2V2) on a training flight with an instructor and student on board. The student pilot under direction of… 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.