Aviation Accident Summaries

Aviation Accident Summary WPR21LA068

Ogden, UT, USA

Aircraft #1

N577CP

Cirrus Design Corp. SR22

Analysis

The pilot reported that during takeoff on runway 17, the engine ran smoothly, and the airplane became airborne “in the usual spot.” During the initial climb, the pilot noticed a loss of power that prevented the airplane from continuing to climb, and he initiated a right turn to land on runway 3. During the landing roll, he realized the airplane would not stop with maximum braking. The pilot added that he tried to pull the parachute handle, but it did not activate during the accident sequence. The pilot further stated that he used his right hand to pull the handle as he was flying with this left and could not recall how much force he was able to pull the handle with. The airplane exited the right side of the runway and came to rest upright beyond the departure end of the runway. Examination of the airframe parachute system revealed no evidence of a mechanical failure or malfunction that would have precluded normal operation. It’s likely that the parachute did not deploy due to the pilot not exerting enough force on the deployment handle. Recorded data from the avionics display showed that during takeoff, the manifold pressure had increased to 34.81 inches, and decreased to 25.55 inches about 7 seconds later. The engine rpm reduced from about 2,650 to about 2,478. The data showed that rpm remained about 2,600, with manifold pressure around 25 inches, throughout the duration of the flight until power was reduced for landing. Postaccident examination of the engine revealed that the sensing line from the left intercooler to the pressure controller was hand tight at the control unit. The right-side turbocharger shaft nut was found in the inlet of the turbine along with significant damage to the turbine inlet housing. Examination of the induction system revealed that one of the induction tubes and clamp were crushed, and the remainder were intact. The increase in manifold pressure during takeoff most likely was the result of the loose sensing line between the left intercooler and pressure controller. Furthermore, while it is possible that a loose induction tube clamp would result in a decrease in manifold pressure, it could not be determined due to post impact damage sustained to the induction system. The right-side turbocharger shaft nut found loose was most likely a result of impact damage to the turbocharger from the accident sequence.

Factual Information

On December 10, 2020, about 1547 mountain standard time, a Cirrus Design Corp. SR22, N577CP, was substantially damaged when it was involved in an accident at the Ogden Hinkley Airport (OGD), Ogden, Utah. The pilot was seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that during takeoff on runway 17, the engine ran smoothly, and the airplane became airborne “in the usual spot.” During the initial climb, he noticed a loss of power that prevented the airplane from continuing to climb so he lowered the nose to “keep up my airspeed” as he initiated a right turn to land on runway 3. The pilot stated that he landed on runway 3 and realized the airplane would not stop with maximum braking. Subsequently the airplane exited the right side of the runway and came to rest upright beyond the departure end of the runway. Postaccident examination of the airplane revealed the airplane sustained structural damage to the left wing and fuselage. The pilot added that he tried to pull the parachute handle, but it did not activate during the accident sequence. The pilot further stated that he used his right hand to pull the handle as he was flying with this left and could not recall how much force he was able to pull the handle with. He added that his goal was to get down as quick as he could, and he knew the [para]chute wouldn’t give the normal sway down but was “hoping for some drag.” Recorded data was recovered from the onboard avionics display units. The data (see figure 1) showed that the engine power increased around 1545:07. During this time, the left and right turbine inlet temperatures (TIT) began to differentiate, with the right TIT temperatures remaining higher than the left. About 21 seconds later, the manifold pressure had increased to 34.8 inches and an rpm of 2,652.3. About 7 seconds later, the manifold pressure decreased to 25.55 inches and the rpm reduced to 2,478.2. The data showed that the airplane established a positive rate of climb at 1545:37 and entered a right turn 12 seconds later. The airplane continued the right turn and reached a maximum GPS altitude of 4,695 ft mean sea level, before a descent began at 1546:35, while west of runway 17/35 and north of runway 3/21. The data showed that the airplane aligned with runway 3 and touched down about 2,423 ft from the departure end of the runway, at a groundspeed of about 121.84 knots. Throughout the recorded data, engine rpm remained around 2,600, with manifold pressure at about 25 inches, until about 18 seconds before touchdown. The airplane’s avionics features a Crew Alert System (CAS), which under certain conditions, would trigger a warning message. A Cirrus Aircraft representative reported that once the manifold pressure exceeded 34 inches, a CAS warning message “manifold pressure” would be displayed and accompanied by an audible double chime that repeats until acknowledged by the pilot by pressing the warning soft key. The recorded data showed that the CAS warning message criteria was met about 10 seconds before takeoff. The pilot reported that he did not recall any audible chimes or tones. Figure 1: Plotted avionics display data. The Cirrus Airframe Parachute System (CAPS) handle was out of the handle holder. The handle holder mounting bracket was bent downward about 90°. The CAPS system was not activated. The CAPS activation switch was not triggered. With the rocket removed, the activation handle was actuated, and activation cable continuity was established to the igniter switch. The igniter switch circuit continuity was operationally tested. No evidence of any preexisting malfunction that would have precluded normal operation of the CAPS was found. The pilot operating handbook (POH) states in part that pulling the activation handle will activate the rocket and initiate the CAPS deployment sequence. The POH further states to activate the rocket, pull the activation handle from its receptacle…clasp both hands around the activation handle and pull straight down with a strong, steady, and continuous force until the rocket activates. Additionally, the POH references that 45 lbs of force, or greater, may be required to activate the rocket. Examination of the engine revealed that the sensing line from the left intercooler to the pressure controller was hand tight at the control unit. The No. 1 cylinder spark plug, and No. 4 cylinder spark plug ignition lead were also found hand tight. The right-side turbocharger shaft nut was found in the inlet of the turbine. Significant damage to the turbine inlet housing was observed. Further examination of the induction system revealed that one of the induction tubes and clamp were crushed, consistent with impact. The remainder of the induction tubes were intact and undamaged. Review of the airframe and engine maintenance logbooks revealed that the most recent annual inspection was completed 2 days prior to the accident. The entry stated that the Tornado Alley Turbocharger System Inspection for continued airworthiness was complied with. The Tornado Alley Turbo, Inc., 22-6460004 Continued Airworthiness manual, revision a, states in part that “manifold pressure is high and stays high after engine is warm,” the “absolute pressure control sensing line is broken or loose.” A representative from Tornado Alley Turbo, Inc., reported that pressure outside of the induction tubes is about 5 inches lower than inside, and if the clamps on the couplings are not secure, there is enough of a differential in pressure to produce an air leak at the coupling.

Probable Cause and Findings

The partial loss of engine power for reasons that cannot be determined due to lack of available evidence.

 

Source: NTSB Aviation Accident Database

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