Aviation Accident Summaries

Aviation Accident Summary WPR12LA418

Nampa, ID, USA

Aircraft #1

N90RW

CESSNA 180

Analysis

The pilot receiving instruction reported that after he conducted a thorough preflight inspection, he and the flight instructor briefed a soft field takeoff; the pilot lowered the flaps to 20 degrees, positioned the airplane onto the runway, and started to take off. During the initial climb, when the airplane was about 30 feet above the ground, the pilot noticed that the airplane had a slight bank to the right. He glanced at the airspeed indicator, and he believed it read either 70 or 90 mph. He attempted to correct for the right bank; however, the airplane did not respond. The instructor took over the flight controls and immediately added full left rudder and aileron. The airplane initially started to bank toward the left before it rolled into a steep right bank of about 60 degrees and impacted terrain. Witnesses reported that the airplane appeared to be climbing normally, and then it seemed to “sink” and slow; the right wing lowered about 10 degrees before it dropped another 50 degrees, and subsequently impacted terrain. Postaccident examination of the wreckage revealed no anomalies with the airframe that would have precluded normal operations. The reason for the uncommanded bank could not be determined.

Factual Information

HISTORY OF FLIGHT On September 13, 2012 about 1833 mountain daylight time, a Cessna 180, N90RW, impacted terrain shortly after takeoff from Nampa Municipal Airport (MAN), Nampa, Idaho. The certified flight instructor (CFI) was seriously injured, and the private pilot receiving instruction sustained minor injuries. The airplane sustained substantial damage to the wings, fuselage, and empennage. The airplane was registered to the private pilot and operated as an instructional flight under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the local flight. The pilot reported that after he conducted a thorough preflight inspection, the CFI and he started the airplane and taxied to runway 29. They conducted a run-up, and they verified the control yoke movements with its respective control surfaces. The pilot reported that both the CFI and he conducted this check individually, and neither pilot noted anything abnormal with the flight controls. After the control check, the CFI instructed the pilot to conduct a soft field takeoff using 20 degrees of flap. The pilot lowered the flaps, positioned the airplane onto the runway, and started the takeoff roll. After liftoff, he lowered the nose of the airplane to gain speed and get a better reference to the airport, and then noticed a slight bank to the right. He glanced at the airspeed indicator and he believed it read either 70 or 90 mph; he could not get an accurate read because the sun was in his eyes and there was a lot of glare on the instrument panel. The pilot attempted to correct for the bank by turning the control yoke to the left, however, the airplane continued to bank to the right. The CFI took over the flight controls and attempted to correct the bank; however, the airplane continued to bank further and impacted the ground, between the taxiway and the departure runway, and came to rest inverted. The pilot reported that he did not hear the stall warning horn during the accident sequence. The CFI reported that during the shallow initial climb, about 30-50 feet above the ground, the pilot commented on the airplane not responding to control inputs. When he took over the flight controls from the pilot, he immediately added full left rudder and aileron. The airplane initially started to respond to the left before it went into an about 60 degree bank to the right. The airplane started to lose altitude and it descended into terrain. The CFI reported that he vaguely recalls telling the pilot to raise the flaps; however, he does not remember for sure, nor does he remember if the pilot retracted them or not. Witnesses reported that they watched the airplane conduct a run-up and pretakeoff check that lasted for about 10 minutes. They observed the airplane enter the runway area and proceed about 900 feet down the runway relatively slowly, with the flaps partially extended. About 1,000 feet down the runway, the witnesses heard a smooth application of takeoff power, and shortly thereafter the airplane became airborne. The airplane appeared to climb normally before it seemed to “sink” and slow. The right wing lowered slightly (about 10 degrees) for a few seconds, and with the airplane still appearing to be flying slowly, the right wing dropped about 50 more degrees, and the airplane assumed a nose down attitude. The airplane descended until it impacted terrain. PERSONNEL INFORMATION At the time of the accident, the pilot, age 52, held a private pilot certificate with airplane single engine land privileges. His certificate was issued on January 25, 2007. His most recent Federal Aviation Administration (FAA) third-class airman medical certificate was issued on August 2, 2012 with the restriction that he must have glasses available for near vision. According to the pilot, he had 433 total flight hours; this was his first flight in the accident airplane make and model. At the time of the accident, the certified flight instructor, age 54, held an airline transport pilot certificate, with flight instructor ratings for airplane single- and multi-engine land as well as instrument airplane. His most recent FAA second-class medical was issued on October 2, 2011 with no limitations. According to the CFI, he had 14,500 total flight hours, 250 of which were in the accident airplane make and model. AIRCRAFT INFORMATION The accident airplane, a tailwheel equipped Cessna 180, serial number 30195, was manufactured in 1953 and was equipped with a Continental Motors O-470R engine. The airplane was purchased by the pilot in November 2011; however, the airplane was disassembled and underwent major repairs due to an accident by the previous owner. Review of the airplane’s maintenance records revealed that the following repairs and modifications were made to the airplane just prior to the accident flight: the fuselage boot cowl and landing gear box areas were repaired, new shoulder harnesses and lap belt assemblies were installed, and a new instrument panel was installed. “A portion of the aileron control system” had been removed and replaced with a “later style aileron control system;” this included the aileron control yoke being changed from a “T yoke” configuration to a “U yoke” configuration, and the installation of new left and right aileron direct control cables. The airplane also underwent an annual inspection on August 6, 2012; at that time, the airplane had a total time of 3,800 hours. According to the maintenance records and maintenance personnel, they conducted ground runs and taxi tests of the airplane; however, it was never test flown. METEOROLOGICAL INFORMATION At 1835, the weather reporting station located at MAN reported Wind from 350 degrees at 3 knots, 10 statute miles of visibility, clear skies, temperature 27 degrees Celsius (C), dewpoint -3 degrees C, and an altimeter setting of 30.23 inches of mercury. AIRPORT INFORMATION According to the FAA Airport/Facility Directory, runway 11/29 was 5,000 feet long by 75 feet wide. The runway surface was asphalt, and both the pilot and the CFI reported that the runway conditions were dry at the time of the accident. The airport field elevation was 2,537 feet. WRECKAGE AND IMPACT Postaccident examination of the airframe by representatives of the FAA and Cessna Aircraft Company revealed no anomalies with the airframe that would have precluded normal operation. The airplane was found with the aft fuselage separated about 5 feet forward of the horizontal stabilizer, and only remained attached by the control cables. The right wing was separated and was found underneath the left side of the inverted aircraft; the left wing remained attached to the fuselage. Flight control cable continuity was established from the respective controls within the cockpit to all flight control surfaces. The aileron and flap control cables were fracture separated, consistent with overload. The aileron control cable routing and rigging was also examined, and no anomalies were noted. The flaps and flap handle were in the up position. The fuel tank caps were in place and secured; the tanks contained an undetermined amount of fuel. The pitot tube and static port openings were examined and unobstructed; the stall warning switch tab on the leading edge of the wing moved freely. The stall warning switch, horn, and light were tested and were operational. The stall warning horn and light assembly were mounted to the glove box; the light was not visible to the occupants with the glove box door in the closed position. The cockpit throttle, mixture, and propeller controls were in the full forward position. The fuel selector handle and valve were in the ‘both’ position. The control yoke for the right seat, where the CFI was sitting, was found deflected fully aft, and bent approximately 90 degrees horizontally to the right, resting against the instrument panel. The firewall fuel strainer was examined and was clear of debris. ADDITIONAL INFORMATION A representative from the Cessna Aircraft Company reported that for the 1953 Cessna 180, if the flaps are positioned at 20 degrees, the airplane will stall at 55 mph with a 0 degree bank, 59 mph with a 30 degree bank, and 78 mph with a 60 degree bank. If the flaps are retracted, then the airplane’s stalling speed is 60 mph with a 0 degree bank, 64 mph with a 30 degree bank, and 85 mph with a 60 degree bank.

Probable Cause and Findings

An uncommanded bank after takeoff followed by an aerodynamic stall. The reason for the uncommanded bank could not be determined because postaccident examination did not reveal any anomalies that would have precluded normal operation.

 

Source: NTSB Aviation Accident Database

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