Accidents: June 2012

 - June 2, 2012, 12:55 AM

Preliminary Report: Cause of Turboprop Ditching Still Unknown

Hawker Beechcraft King Air C90GTx, 17 nm north of Aruba, April 3, 2012– A new King Air C90GTx, on a delivery flight from the Hawker Beechcraft factory in Wichita to Hato International Airport, Willemstad, Curacao, via Fort Lauderdale Executive Airport (FXE), ditched in the sea 17 nm north of Aruba. Both pilots were rescued unharmed. Approximately 100 nm short of the destination, the pilots reported less fuel on board than anticipated. The flight-plan distance from FXE to Curacao is approximately 1,054 nm. The HBC website shows the King Air C90GTx’s range as 1,289 nm.

Preliminary Report: Air Ambulance Turboprop Crashes in Virgin Islands

Paye, St. Maarten, Virgin Islands, May 5, 2012–A Piper Cheyenne III operating as an air ambulance flight crashed near St. Maarten in the northeast Caribbean, killing all four people aboard. The aircraft crashed four minutes after departure from L’Esperance Airport in St. Martin, the French territory that shares the island with Dutch St. Maarten. A single pilot flew the Cheyenne, and a doctor and a nurse were in the cabin with the passenger being transported to Martinique. The company had reportedly already replaced another charter aircraft with the accident airplane due to mechanical issues.

Preliminary Report: Turboprop Hits High Terrain

Dornier Do-228, Jomson, Nepal, May 14, 2012–Fifteen of the 21 people aboard an Agni-Air Dornier Do-228 were killed when the 19-seat turboprop struck the side of a hill near Jomson Airport, Nepal. The aircraft was returning to Pokhara Airport after being unable to land at Jomson at the time of the accident. Jomson’s 2,000-foot-long STOL runway sits at the 8,800-feet level in rugged territory. This is the second Agni-Air Do-228 fatal accident in less than two years. The other Do-228 crashed in August 2010 near Makwanpur, killing all 14 people aboard.

Preliminary Report: Helicopter Hits Phoenix Home

Hughes 269C, Phoenix, May 2, 2012–A Hughes 269C operated by Canyon State Aero of Mesa was substantially damaged during a Part 91 VMC photo flight after it collided with a home near Phoenix. The commercial pilot sustained serious injuries, and the passenger sustained minor injuries. The helicopter departed Deer Valley Airport (DVT), Phoenix, at about 10:30 a.m. local time. A witness reported the helicopter appeared to be flying erratically before it hit the roof of a house and a brick wall. The helicopter came to rest upright in the back yard of an adjoining house. An FAA aviation safety inspector who examined the wreckage at the accident site reported that the helicopter had sustained extensive structural damage.

Preliminary Report: United Nations Turboprop Crashes in South Sudan

Cessna 208B Grand Caravan, Yambio Airfield, South Sudan, May 2, 2012–A Cessna 208B Grand Caravan was substantially damaged during a landing accident at Yambio Airfield, South Sudan. The aircraft hit a drainage channel on landing, then flipped over and came to rest upside down. One of the pilots and a passenger were injured, but reports suggested none of the injuries was life threatening. The Cessna was being operated on a United Nations flight from Juba to Yambio.

Preliminary Report: Twin Turboprop Crashes in Brazil

Hawker Beechcraft King Air C90A, Jundiaí, Brazil, April 20, 2012–A Brazilian-registered King Air C90A was destroyed when it hit the ground shortly after takeoff from Comandante Rolim Adolfo Amaro State Airport (SBJD), Jundiaí, Brazil. The pilot was killed. Visual conditions existed at the time of the accident.

Preliminary Report: Helicopter Damaged during Positioning Flight

Bell 407, Aberdeen, S.D., April 14, 2012–A Bell 407 operated under Part 91 by Med-Trans of Tucson, Ariz., sustained substantial damage during a forced landing near Aberdeen, S.D. The commercial pilot, the only occupant, sustained minor injuries. The positioning flight, conducted in visual conditions, originated from Aberdeen Regional Airport at approximately 2:50 a.m. local time. A statement from the pilot said that while en route to his destination, the helicopter began an uncommanded left yaw, accompanied by a low howling sound. The pilot elected to conduct a precautionary landing. The helicopter touched down hard, and the main rotor blades severed the helicopter’s tail boom.

Preliminary Report: Turboprop’s Wing Separates in Takeoff Accident

Bombardier Dash 8-311Q, Kigoma Airport, Tanzania, April 9, 2012–A Dash 8-300Q suffered substantial damage in a takeoff accident at Kigoma Airport , Tanzania. There were no fatalities. The airplane was operating a flight from Kigoma to Tabora and Dar Es Salaam. Initial reports say that after the airplane overran the runway on takeoff its right main landing gear struck a muddy pothole, causing the right wing to separate inboard of the number-two engine. The engine twisted upside down and to the side, causing the front of the powerplant to penetrate the fuselage at the under-wing emergency exit.

Preliminary Report: Turboprop Lands with Nose Gear Retracted

Bombardier DHC-8-402, Houston, April 7, 2012–A Colgan Air Q400, operating under Part 121 as United Express 4915, landed during daylight with the nose gear retracted on Runway 9 at George Bush Intercontinental/Houston Airport (IAH). The crew had previously declared an emergency, reporting that the nose gear would not come down. After flying past the control tower for a visual check, the crew elected to land with the nose gear retracted. No injuries were reported to the 31 passengers and four crewmembers on board. The aircraft, however, received substantial damage.

Final Report: Helicopter Substantially Damaged on Training Flight

Eurocopter AS350B3, Jacksonville, Fla., Jan. 7, 2011–A Department of Homeland Security (DHS) AStar being operated on a Part 91 VFR training flight by U.S. Customs and Border Patrol (CBP) was damaged during a practice approach to Runway 25 at Herlong Airport in Jacksonville. The NTSB attributed the accident to the CFI’s improper decision to attempt hover flight without hydraulic power and his subsequent loss of control.

The flight had departed from Jacksonville Naval Air Station. The CFI on board was instructing the commercial pilot in daylight maneuvers designed to simulate total hydraulic failure.

Wind at the airport was reported as light and variable at six knots for the flight. During an approach intended to transition into a hover, the commercial pilot began to lose directional control as the helicopter approached to within five feet of the surface. The student asked the flight instructor to assume control, which he did. The helicopter, however, entered multiple revolutions, climbs and descents and eventually came in contact with the ground, spun and rolled over. The fuselage, tail rotor and main rotor drive systems were substantially damaged. The helicopter came to rest about 290 feet south of Runway 25.

Post-accident examination of the helicopter did not reveal any pre-impact mechanical malfunctions, nor did either pilot report any mechanical abnormalities. According to the helicopter manufacturer’s flight manual training supplement, hovering without hydraulic power is not an approved procedure. The manual stated, in part: “Caution: Do not attempt to carry out hover flight or any low-speed maneuver without hydraulic pressure assistance. The intensity and direction of the control feedback forces will change rapidly. This will result in excessive pilot workload, poor aircraft control and possible loss of control.”

The CFI reported 2,782 hours of total helicopter flight experience, which included 580 hours in make and model, while the commercial pilot reported 1,154 hours of total helicopter flight experience, which included 12 hours in make and model.

Final Report: Bird Strike Results in Engine Recertification

Hawker Beechcraft BE-400A, Sugar Land, Texas, July 31, 2009–The pilot of a Beechjet 400A reported seeing a small flock of birds, including a heron, cross the aircraft’s departure flight path as the aircraft approached rotation speed at Sugar Land Airport near Houston. The crew of the Part 91 flight reported that immediately after the birds passed, the number-two engine lost power. The crew rejected the takeoff and brought the aircraft to a stop on the runway with no injuries to any of the eight people on board. While damage to the airframe was minor, a post-flight inspection revealed that all but one of the right engine’s fan blades were fractured. The inlet duct had also separated and was hanging by a bleed air duct. Bird snards from a 1.5- to two-pound juvenile yellow-crowned night heron were found on the runway and in the right engine. A bird’s head and wing were later found on the departure runway. A USDA wildlife biologist also removed bird snards from the engine inlet.

Examination of the Pratt & Whitney Canada JT15D-5 revealed the spinner had separated during the bird strike and entered the engine, resulting in the separation of the fan blades and subsequent failure of the engine. Although standards in place at the time of the Beechjet’s certification tested the engine for bird ingestion with a four-pound goose, the tests were conducted without the spinner installed on the front of the fan. The standards “demonstrated freedom from explosion, disintegration or uncontrollable fire.” AC-33-1B further stated that it would be acceptable if the engine required shutdown. Engine certification requirements were later updated to require testing of the spinner as an “associated component.”

The JT15D-5 is a dual-spool turbofan featuring a one-stage fan, a one-stage axial flow booster and a one-stage centrifugal-flow high-pressure compressor (HPC). The engine also employs a reverse-flow annular combustor, a one-stage high-pressure turbine that drives the HPC, and a two-stage low-pressure turbine that drives the fan and booster stages. After the incident, the right engine was removed and sent to Pratt & Whiney Canada for teardown and examination under the supervision of an NTSB inspector.

The examination revealed that although all but one of the fan blades fractured adjacent to the root platform, there were no penetrations through the fan case. The spinner was missing from the engine, but investigators found scoring marks the approximate size and shape of the spinner on the inside of the inlet duct. Metallurgical examination of the shaft, which secures the spinner, showed the failure to be a rotational bending type of fracture. Metallurgical examination of the fan blades identified several with surface traces of the alloy used in the spinner.

In response to concerns about the engine’s spinner, Pratt & Whitney Canada released a report written during engine certification in which a four-pound snow goose was shot at 299.2 knots into a JT15D-5 operating at maximum cruise power. The report stated the snow goose struck the fan rotor at the outer diameter of the nose cone and the inner ends of the fan blades. All of the fan blades remained intact, but five of the 47 blades were noticeably bent and the leading-edge tip corner was bent on 13 other fan blades. The nose cone had several indentations; the tips of all 38 fan core stators were bent; and eight of the fan core stators were severely bent. The containment case remained intact.

The NTSB determined the probable cause of this incident was the failure of the spinner following an unavoidable bird strike. Contributing to the incident were the inadequate engine bird strike certification requirements in place at the time the engine was certified.

Final Report: Helicopter Engine Failed during Power Line Patrol

McDonnell Douglas MD-369E, Acworth, Ga., Aug. 12, 2009– The NTSB determined the probable cause of the helicopter’s hard landing to be the loss of engine power due to fatigue failure of a third-stage turbine wheel airfoil.

At about 10:00 a.m. EDT, the pilot of a McDonnell Douglas 369E on a VFR Part 91 aerial power line observation flight heard a loud bang and a braking noise, quickly followed by both aural engine out warnings and caution lights. The pilot chose to execute an emergency autorotation but landed hard, hitting a runoff ditch behind some homes, substantially damaging the rotorcraft. There was no post-crash fire. The commercial pilot received minor injuries, but the passenger was seriously injured.

An examination of the engine’s turbine section revealed rub marks throughout the turbine section consistent with an out-of-balance condition caused by a third-stage turbine blade separation. The third-stage wheel blade fractured under fatigue near the root of the airfoil and no anomalies were found at the fatigue origin. The crack propagation is estimated to be greater than 2,000 cycles. Investigators found no additional cracks on the other third-stage wheel airfoils.

The helicopter’s logbooks revealed 3,820 hours on the engine and 4,257 on the airframe. The rotorcraft had received a 100-hour inspection at 3,809.6 hours and all operating parameters appeared normal. The hot section and turbine inspections were completed on Feb. 21, 2008, at 2,958 hours. The third-stage turbine wheel was overhauled on Feb. 3, 2004, at 1,210.6 hours and 1,633.0 cycles and was due to be replaced at 4,710.6 hours. At the time of the accident the wheel had 2,609.7 hours and 2,412.0 cycles.