DEN05LA013

NTSB accident investigation · Cessna 170A · Glenwood Spring, CO · October 23, 2004

Accident · Serious injuriesLimited investigationFinal report
Date
October 23, 2004, 11:05 local (17:05 UTC)
Place
Glenwood Spring, CO
Injuries
1 serious
Damage
Substantial damage
Phase of flight
Approach
Aircraft
N9176ACessna 170A
Weather
Visual (VMC) · Day
Status
Completed · report March 30, 2005
Report
Approved by Office Director
Parties
FAA Flight Standards District Office, Teledyne Continental Motors, Inc., Cessna Aircraft Company
FAA report
20041023026839A
Case key
60429

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

the pilot's failure to use carburetor heat which resulted in the formation of carburetor ice and the loss of engine power. Related factors were conditions conducive for carburetor icing and the lack of suitable terrain for a forced landing.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of engine power(partial) - nonmechanicalApproach - vfr pattern - final approach
Carburetor heat - not usedPilot in commandCause
Fuel system,carburetor - iceCause
Weather condition - carburetor icing conditionsFactor
Forced landingDescent - emergency
In flight collision with objectEmergency descent/landing
Object - residence
Terrain condition - none suitableFactor
In flight collision with terrain/waterDescent - uncontrolled
Terrain condition - ground

Analysis

Prior to the accident, the pilot had been flying for approximately 1 hour. He stated that he descended from approximately 8,500 feet msl at an engine power setting of 2,200 rpm, without carburetor heat. This descent lasted approximately 20 to 30 minutes as he flew from west to east, approximately 60 miles. The pilot entered the traffic pattern at approximately 7,000 feet msl. He applied carburetor heat, enrichened the mixture "somewhat", and reduced power to approximately 1,500 to 1,700 rpm, "prepatory for landing." The aviation routine weather report (METAR) reported the temperature as 34 degrees Fahrenheit (F) and the dewpoint as 31 degrees F. According to the carburetor icing chart, conditions were conducive for "serious icing at cruise power."According to the pilot, he was on final approach when he "decided [the] aircraft [was] too high" and added throttle to initiate a go-around. The engine did not respond to the application of throttle. The airplane impacted the roof of a townhouse, slid down and subsequently impacted the side of an adjacent townhouse causing substantial damage to the airplane.

Factual narrative

On October 23, 2004, at approximately 1105 mountain daylight time, a Cessna 170A, N9176A, piloted by a private pilot, was substantially damaged when it impacted the roof of a townhouse while maneuvering near Glenwood Springs, Colorado. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under the provisions of Title 14 CFR Part 91 without a flight plan. The pilot sustained serious injuries. The local flight originated at approximately 1000.

Prior to the accident, the pilot had been flying for approximately 1 hour. He stated that he descended from approximately 8,500 feet msl at an engine power setting of 2,200 rpm, without carburetor heat. This descent lasted approximately 20 to 30 minutes as he flew from west to east, approximately 60 miles. The pilot entered the traffic pattern at approximately 7,000 feet msl. He applied carburetor heat, enrichened the mixture "somewhat," and reduced power to approximately 1,500 to 1,700 rpm, "prepatory for landing."

According to the accident report submitted by the pilot, he was on final approach for runway 32 when he "decided [the] aircraft [was] too high" and added throttle to initiate a go-around. The engine did not respond to the application of throttle. In a phone conversation with the pilot, he stated that the engine did not cough or sputter and the propeller was still spinning. According to a witness who observed the airplane prior to the accident, the engine sounded as if it was running with "landing power." The pilot reversed course to avoid flying over the city of Glenwood Springs. He was unable to maintain altitude and the airplane impacted the roof of a townhouse, slid down the roof and subsequently impacted the side of an adjacent townhouse. The airplane came to rest on the ground between the two town homes. The engine, propeller and cowling were crushed aft and the left wing was crushed aft.

On November 4, 2004, the engine was inspected and run by a representative of Teledyne Continental Motors under the auspices of the National Transportation Safety Board. No anomalies were noted that would have precluded the engine from producing power.

The aviation routine weather report (METAR) at Rifle, Colorado, reported the temperature as 34 degrees Fahrenheit (F) and the dewpoint as 31 degrees F. According to the carburetor icing chart, conditions were conducive for "serious icing at cruise power."

Aircraft

Registration
N9176A
Reported as
Cessna 170A
Category
Airplane
Serial number
18937
Airframe hours
3,896
Engine
Teledyne Continental C-145-2, 145 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Standard, Normal
Last inspection
Annual · January 12, 2004 · 41 hours before
Departed
GWS · Glenwood Spring, CO
Airport
GWS · Glenwood Springs Muni

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
69
Injuries
Serious
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, Valid Medical--w/ waivers/lim
Last flight review
August 19, 2004
Seat
Left
Flight hours
624 total · 215 in this make and model · 21 in the last 90 days · 12 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
None
Temperature
34 °F, dew point 30 °F
Altimeter
30.12 inHg
Observed at
RIL, 19 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.