ERA09FA497

The pilot's failure to maintain adequate main rotor rpm, for undetermined reasons.

The Federal Aviation Administration (FAA) Flight Standards District Office (FSDO) inspector arranged to conduct a flight as pilot in command (PIC) of the helicopter as part of his participation in the FAA's internal flight currency and proficiency program, informally referred to as the "4040 program." The PIC and the FSDO manager agreed that the flight could also serve as a familiarization flight for a newly-hired, pilot-rated FSDO inspector. Shortly after takeoff, the PIC informed an air traffic controller that he had changed his plans, and he was cleared as requested to a nearby airport. The helicopter was observed to hover, land, and lift off for a circuit of the traffic pattern. It landed again, and began a second circuit. While on the downwind leg, the helicopter entered a descent that had a rate of approximately 2,400 feet per minute and subsequently impacted trees, terrain, and a house in a residential neighborhood. The PIC held multiple certificates and ratings, and the vast majority of his experience was in fixed-wing aircraft. He had about 140 hours of helicopter experience, and about 60 hours in Robinson helicopters. The second pilot held multiple certificates and ratings, and had over 4,000 hours of helicopter flight experience. His most recent helicopter piloting experience was about 9 years prior to the accident. Due to certain flight and operational characteristics, the FAA mandated Robinson-specific training for pilots, via Special Federal Aviation Regulation (SFAR) 73. The accident flight was the second pilot's first flight in a Robinson helicopter, and no records of any Robinson-specific training or endorsements, including those required by SFAR 73, were located for him. The final trajectory of the helicopter was consistent with a main rotor stall that developed when the helicopter was on the downwind leg. Post-accident examination and testing of the helicopter and components, including a full-power run of the engine, did not reveal any evidence of pre-impact failures or malfunctions. The helicopter manufacturer published notices for pilots that stated that main rotor stall due to low rotor rpm could occur rapidly, and at any airspeed, and could make "recovery virtually impossible." Other guidance noted that appropriate pilot response to an impending stall in an airplane was the opposite of the appropriate response for the helicopter, and could result in, or aggravate, rotor stall. The reason for the decay of the main rotor rpm could not be definitively determined.

HISTORY OF FLIGHT On September 1, 2009, about 1425 central daylight time, a Robinson R44 Raven I helicopter, N33PX, was substantially damaged when it struck trees, terrain and a house near Jackson/Hawkins Field (HKS), Jackson, Mississippi. The pilot in command (PIC) was seriously injured, and the second pilot was fatally injured. The combination currency flight for the PIC and familiarization flight for the second pilot was operated under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed. According to recorded air traffic control (ATC) voice and radar information, the helicopter first contacted Jackson Approach about 1404, when it was still on the ground at Flowood Industrial STOLport (MS90), Flowood, Mississippi. The approach controller instructed the helicopter to contact approach once it was airborne, and assigned it a discrete transponder code. Shortly thereafter, the helicopter reported that it was airborne and northbound. The helicopter target was acquired by the ATC radar facility located at Jackson-Evers Airport (JAN), Jackson, Mississippi. The first radar return associated with the helicopter appeared at 1405:55, when the helicopter was at a radar-indicated altitude of 300 feet above mean seal level (msl), and 2,400 feet north of MS90. Shortly after that, the helicopter contacted approach control again, advised that there was a change of plans, and requested to proceed to HKS for practice at "Area 1." "Area 1" was the designation for a helicopter practice area at HKS, which was located in the grassy area to the east of runway 16/34, and to the north of runway 11/29. The radar data ground track showed the helicopter turn from a northerly heading to a south-southwesterly heading, at an altitude of 700 feet msl. When the helicopter was approximately 4 miles southeast of HKS, Jackson Approach informed the helicopter that radar services were terminated, and instructed it to contact HKS air traffic control tower (ATCT). The helicopter contacted HKS ATCT, requested approval for hover practice, and the request was approved by HKS ATCT. The radar ground track showed that the helicopter turned to the northwest and headed for the southeast corner of Area 1. As the helicopter descended towards HKS, it temporarily disappeared below Jackson Approach radar coverage; the last return acquired during this approach was at 1411:20, and an altitude of 400 feet. According to the ATCT local controller, the helicopter practiced hovering for a short time, and then landed in Area 1. The helicopter then requested "right closed traffic" for Area 1, and was cleared "for the option" by the ATCT controller. The helicopter's radar return was re-acquired at 1420:22, at an altitude of 500 feet. The helicopter flew the downwind leg at an altitude of 900 feet msl, and a lateral offset of approximately 3,800 feet to the east of Area 1. The helicopter made another approach to Area 1, and the last radar return for this approach was acquired at 1422:53, with an indicated altitude of 400 feet msl. The local controller reported that the helicopter conducted a "touch and go," and began another circuit of the traffic pattern. The helicopter re-appeared on radar at 1424:08, at an altitude of 600 feet. Radar returns indicated that the helicopter made an immediate right turn for a second downwind leg that was offset approximately 1,700 feet east of Area 1. The local controller again cleared the helicopter for the option. The local controller then communicated with an aircraft waiting to depart runway 34, and when she tried to visually locate the helicopter to ensure traffic separation, she did not see it. She made several calls to the helicopter, but it did not respond. The last three radar returns from the helicopter were at 1424:37.220, 1424:41.840 and 1424:46.550. The radar return altitudes were 1,000, 800, and 600 feet, respectively. The last recorded radar return was located 700 feet northwest of the accident site. Two pilots from the Mississippi Department of Public Safety (DPS) were standing outside a hangar on the west side of HKS, and one of them saw the helicopter make an approach to Area 1. He then watched it taxi to the north, taxi back to the south, and then climb out to the north for a circuit of the traffic pattern. When the helicopter was on the downwind leg approximately due east of his position, the DPS pilot saw it begin "falling rapidly," and he pointed it out to the other DPS pilot. The other DPS pilot, who had flown Robinson helicopters, initially responded that the high descent rate was not unusual for Robinson helicopters, but as he watched it, he agreed that the descent rate did seem high. After the helicopter had descended a few hundred feet, the two DPS pilots observed it enter a right bank of about 15 degrees. Both DPS pilots stated that prior to the bank, the helicopter's pitch attitude was approximately level. Both pilots watched the helicopter disappear behind the treeline to the east. They realized that the helicopter had likely crashed, and in response, began preparing their helicopter for flight. Another witness was walking down his driveway to meet the postman, when his attention was drawn to the helicopter by its noise, which he described as repeated "clup" sounds. The witness saw the helicopter descend rapidly towards him from the north, strike a tree, and enter "into a spin." It then struck a second tree and "fell into the house," disappearing from view behind the house across the street from the witness. The witness crossed the street and went around the right (east) side of the house to the helicopter, where he saw a person in the left front seat. The postman went around the west side of the house to the helicopter, and noticed that there was another person in the helicopter as well. Both witnesses used their mobile telephones to summon assistance. PERSONNEL INFORMATION Both occupants of the helicopter were inspectors from the Jackson, Mississippi, FAA Flight Standards District Office (FSDO). The PIC was seated in the right seat, and the second pilot was seated in the left seat for the flight. Pilot in Command (PIC) According to FAA information, as of the date of the accident, the PIC was employed by the FAA for about 3 years. He held multiple certificates and ratings, including commercial pilot and flight instructor certificates with rotorcraft-helicopter ratings. According to information compiled from the PIC's personal logbook and FAA records, as of the date of the accident, he had approximately 22,000 total hours of flight experience. This included approximately 221 total hours of helicopter experience, which included approximately 6 hours of R22 experience, and 81 hours of R44 experience. The records indicated that 27.9 of those hours were accrued without a check- or safety-pilot on board. The balance of his helicopter experience was primarily in Bell 206 and Schweizer 300 series helicopters. His most recent FAA second-class medical certificate was issued in April 2009. The PIC's logbook indicated that his initial helicopter flight occurred in April, 2006, in an R44. His first recorded solo flight in a helicopter was conducted on November 7, 2007, in a Schweizer 300 helicopter. The PIC successfully completed his flight test for a commercial helicopter certificate on November 15, 2007. At that time he had 99 total hours of helicopter flight experience, including 39 hours of dual, and no solo, flight experience in Robinson helicopters. On January 22, 2008 the PIC successfully completed his flight test for a helicopter instructor rating. At that time he had 138 total hours of helicopter flight experience, including 60 hours of dual, and no solo, flight experience in Robinson helicopters. Both the commercial- and instructor- flight tests were conducted in a Schweizer 300 helicopter. The most recent R44 entries in