N800RW

HISTORY OF FLIGHT On November 16, 2012, about 0726 mountain standard time, a Cirrus Aircraft SR22, N800RW, was substantially damaged when the airplane descended to the ground under parachute near Show Low, Arizona, after the engine experienced a complete loss of oil pressure during cruise flight. The pilot/owner received minor injuries. The personal flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and the flight was operating on a Federal Aviation Administration (FAA) instrument flight rules (IFR) flight plan.

According to the pilot, he departed Animas Airpark (00C), Durango, Colorado, about 0600, with an intended destination of Nogales International Airport (OLS), Nogales, Arizona. About 2 hours after takeoff, while in cruise flight at 12,000 feet above mean sea level, air traffic control (ATC) cleared the flight to 14,000 feet for terrain clearance purposes. Just before the airplane reached the new assigned altitude, the pilot heard a loud "pop." About 4 minutes later, he received an oil pressure annunciation on the primary flight display. At that time, the indicated oil pressure was about 47 pounds per square inch (psi), which was at the bottom of the normal range. Within 1 minute the pilot saw the oil pressure had decreased to 0 psi, so he shut down the engine, and advised ATC. He asked for vectors to the nearest airport, was advised that Show Low Regional Airport (SOW), Show Low, was the closest, and then turned towards SOW. During the descent, about the same time that ATC advised him that radar contact had been lost, the pilot recognized that he would be unable to reach SOW. He then advised ATC that he would deploy the ballistic parachute when he was over terrain that appeared suitable for a parachute landing. The pilot estimated that he deployed the parachute between 1,000 and 2,000 feet above ground level. The airplane impacted in a field while it was swinging towards the left under the parachute, bounced at least one time, and came to rest upright. The pilot shut down the airplane and exited. He contacted assistance via his satellite telephone. The pilot and airplane were located about 2 hours after the landing, aided by his re-inflation of the parachute and use of his personal mobile (not satellite) telephone.

PERSONNEL INFORMATION

The pilot held a private pilot certificate with airplane single- and multi-engine, and instrument airplane ratings. He had approximately 1,661 total hours of flight experience, including approximately 1,140 hours in the accident airplane make and model. His most recent flight review was completed in December 2011, and his most recent FAA third-class medical certificate was issued in January 2011.

AIRCRAFT INFORMATION

FAA records indicated that the airplane was manufactured in 2005, and was purchased new by the pilot. The airplane was equipped with the standard Cirrus Airframe Parachute System (CAPS) and a Continental Motors IO-550 series engine. In February 2009 a Forced Aeromotive Technologies (FAT) supercharger was installed in accordance with supplemental type certificate (STC) SA10925SC.

The most recent annual inspection was completed in July 2012, and the airplane had accumulated about 60 hours in service since that inspection. At the time of the accident, the airplane and engine each had a total time (TT) in service of about 1,150 hours.

METEOROLOGICAL INFORMATION

The 0735 automated weather observation at SOW, located about 8 miles north of the landing site, included calm winds, visibility 10 miles, clear skies, temperature 1 degree C, dew point -5 degrees C, and an altimeter setting of 30.25 inches of mercury.

WRECKAGE AND IMPACT INFORMATION

The landing site was in remote territory. According to the pilot, after he exited the airplane, he photo-documented the scene. The right main landing gear was fracture-separated from the airplane, and the nose and left main landing gear remained attached but were displaced up and right. Propeller damage was minor, consistent with it not rotating during the impact sequence. The airplane was otherwise intact, except for the normal disruptions caused by the parachute deployment. Shortly after the pilot documented the scene, the wind inflated the parachute, and dragged the airplane about 100 feet across the terrain. The pilot left the scene to obtain assistance, and on his return with first responders, discovered that the airplane had then been dragged further by the parachute, and had been inverted, before the parachute deflated and ceased dragging the airplane. The responding law enforcement agency personnel cut the parachute bridle straps to prevent further movement of the airplane. FAA personnel responded to the scene, but NTSB personnel did not.

The responding FAA inspectors reported that the exterior surfaces of the left side and aft lower fuselage exhibited significant oil streaking. While the airplane was still inverted, the inspectors decowled the engine, and observed a significant amount of engine oil had been deposited inside the cowling and engine compartment. They observed that the oil line that supplied engine oil to the supercharger bearing for lubrication had fracture-separated from the supercharger at the nipple fitting. FAA personnel removed several avionics units for possible data download by the NTSB recorders laboratory. The airplane was recovered and transported to a secure location for detailed examination. The downloaded data corroborated the information provided by the pilot.

ADDITIONAL INFORMATION

Supercharger Design and Installation Information

The supercharger was mounted to the aft section of the engine, and was driven via a belt by a pulley mounted to an engine accessory drive. The supercharger bearings were lubricated by pressurized engine oil, which was sprayed into the supercharger via a nozzle. The nozzle connected to the engine oil system via a series of fittings and a flexible hose. The nozzle was provided as part of the STC, and threaded directly into the supercharger body. A standard AN816-6-2D aluminum nipple fitting installed into the nozzle, and an MS27226 fitting with a B-nut was used to attach the flexible oil line to the nipple.

According to the STC holder, in order to attain a leak-proof joint from the oil line to the supercharger without damaging the supercharger, nozzle, or AN816 nipple, two wrenches had to be used concurrently to properly attach and secure the oil line to the supercharger. This requirement was explicitly specified in the supercharger installation instructions. However, those instructions did not specify the installation torque values for any of those components.

The STC instructions for continued airworthiness (ICA) required that the oil nozzle be removed and cleaned in conjunction with every annual inspection. However, the ICA did not contain any information regarding the need to use two wrenches, and did not specify the installation torque values for the nozzle, AN816 nipple, or oil line B-nut fitting.

Review of the STC installation and ICA documentation that was current at the time of the accident revealed that neither document set contained any guidance regarding the use of sealant for the nozzle, nipple, or oil line B-nut.

Supercharger Maintenance Information

The supercharger was installed when the airplane had a TT of 674 hours. According to the maintenance records, a new supercharger "drive seal" was installed, and the oil nozzle was "cleaned, resealed, and torqued" by Arapahoe Aero on 7/11/12. That activity was accomplished in conjunction with the airplane's most recent annual inspection. At that time, the airplane had a TT of about 1,090 hours.

The most recent recorded maintenance regarding or affecting the supercharger was conducted by an aircraft mechanic on 10/03/2012. That mechanic was not associated with Arapahoe Aero. The maintenance records entry cited the removal and reinstallation of the "Forced Airmotive compressor after factory repair." At that time, the airplane had a TT of about 1,125 hours, which was about 451 hours since the initial installation of the supercharger.

According to the mechanic who conducted that activity, he had removed and reinstalled FAT superchargers four or five times previously. He had worked with FAT maintenance personnel several times on the accident airplane, and had received guidance from FAT for performing supercharger removal & installation. The mechanic was aware of the need to use two wrenches while tightening the oil line (a flexible hose) fitting to the nozzle.

The mechanic also stated that he had not been involved in annual inspections of the accident airplane subsequent to the supercharger installation, and had not ever performed the repetitive nozzle cleaning required during an annual inspection. Regarding his actions to remove the supercharger, the mechanic stated that he removed the oil line B-nut from the AN816 nipple that was installed in the oil nozzle. He reported that the nipple fitting and oil nozzle stayed in the compressor when it was sent to FAT for repair, and that the repaired supercharger was provided to him with the oil nozzle already installed in the supercharger. He stated that when he reinstalled the oil line B-nut onto the nipple, he used a wrench to hold the oil nozzle in place, and another to secure and torque the joint. The mechanic also stated that he did not apply any sealant or RTV(room temperature vulcanization) silicone to the oil nozzle or the nipple.

The AN816-6-2D nipple that connected the flexible oil line to the supercharger nozzle was aluminum, and consisted of two male ends with different, incompatible thread types. The end that threaded into the oil nozzle was a tapered pipe thread, while the end that threaded into the oil line was non-tapered. Examination revealed that the nipple had fractured on the section that threaded into the nozzle, and that a fractu...