# NTSB ANC06LA064: Robinson R44, N688JK, Skwentna, AK, May 30, 2006 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 29, 2006, 19:20 local (May 30, 2006, 03:20 UTC) - Place: Skwentna, AK - Coordinates: 62.122222, -151.235549 - Nearby events: https://openairdocs.org/map.md?lat=62.1222&lon=-151.2355&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report February 26, 2007 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: FAA, Anchorage Flight Standards District Office - NTSB case key (mKey): 63778 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC06LA064 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/63778/pdf - Page: https://openairdocs.org/ntsb/ANC06LA064 ## Probable cause The pilot's improper rigging of the external sling load, which allowed the suspended load/cargo cable to entangle and disable the tail rotor control, resulting in a loss of control during cruise and an in-flight collision with terrain. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Cargo shift, cruise - loading of cargo - improper, pilot in command (cause) - external load cable/hook - entangled (cause) - Rotor failure/malfunction, cruise - rotor system,tail rotor blade - snagged (contributing factor) - Loss of control - in flight, cruise - rotorcraft flight control,tail rotor control - inoperative - Forced landing, descent - emergency - In flight collision with terrain/water, descent - emergency - terrain condition - ground ## Analysis The commercial certificated helicopter pilot was transporting an external sling load and a passenger from a remote off-airport site on a Title 14, CFR Part 135 on-demand air taxi flight. He stated that after lifting a relatively light load on a short sling line, he transitioned to cruise flight. Shortly after entering cruise flight, he said he inadvertently allowed the cargo and sling line to strike the tail rotor blades. The cargo/cable disabled the tail rotor, and the pilot was unable to maintain control of the helicopter. The helicopter subsequently collided with terrain during the ensuing forced landing. The pilot indicated that there were no preimpact mechanical problems with the helicopter. ## Factual narrative On May 29, 2006, about 1920 Alaska daylight time, a skid-equipped Robinson R44 helicopter, N688JK, operated by Ace Flyers, dba JayHawk Air, Anchorage, Alaska, had a loss of tail rotor effectiveness during an emergency landing, and sustained substantial damage when it collided with terrain, about 17 miles north-northwest of Skwentna, Alaska. The commercial certificated pilot and the sole passenger reported no injuries. The local flight was operating in day visual meteorological conditions as an on-demand, Title 14, CFR Part 135 air taxi flight when the accident occurred. During a telephone conversation with the NTSB investigator-in-charge (IIC) on May 30, the pilot reported that he was repositioning the passenger and a wire mesh cage from a remote drilling site near Sable Creek to a site nearby on the Kahiltna River. The pilot related that the wire cage was slung underneath the helicopter on a line about 18 feet long. He stated that about a minute after liftoff from the 1,200 feet msl site, following the transition to cruise flight, he looked outside the helicopter to try and see how the load was positioned. He said he could not visually acquire the load, and he suddenly heard an unusual noise and felt a shudder/vibration. He immediately jettisoned the load, and sought an emergency landing site close by. The landing site was a clear area in alder brush, on about a 15 degree slope. The pilot reported that the helicopter continued to vibrate and make unusual sounds as he came to a 2 foot hover over the landing site. When he increased the main rotor pitch with the collective control, the pilot said he stepped on the tail rotor control pedals, but there was "no pedal" and no response from the tail rotor. The helicopter quickly started to rotate, and immediately rolled onto its side as it touched the ground. The pilot stated that it was likely that the load on the tether line somehow struck or interfered with the tail rotor, although he could not see any damage to the tail rotor after landing. In his written statement to the NTSB, the pilot wrote in the section titled: Recommendation (How Could This Accident Have Been Prevented), "Pilot Error--I allowed a light load to catch the tip of the tail rotors." ## Aircraft - Registration: [N688JK](https://openairdocs.org/deregistered/N688JK-2017-07-06), registration cancelled 2017-07-06, S/N 10106, built 2003 (OpenAirDocs) - Reported make and model: Robinson R44 - Registry model: [Robinson Helicopter R44 II](https://openairdocs.org/model/robinson-helicopter-r44-ii) (registry code 7640122) (OpenAirDocs) - Registry engine: [Lycoming 0-540 series](https://openairdocs.org/engine/lycoming-0-540-series) (registry code 41532, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 45012 - Engines: Lycoming IO-540AE4/5 205 horsepower reciprocating - Damage: Substantial damage - Flight: Part 135 - Registered owner: Ace Flyers - Airworthiness certificate: Standard, Normal - Departed: Skwentna, AK - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 61; injuries: none; commercial; airplane ratings: single-engine sea, single-engine land; medical: class 2, with waivers/limitations; last flight review May 1, 2006; seat: right; flight hours: 8,500 total, 50 in this make and model, 8,440 as pilot in command, 100 in the last 90 days, 50 in the last 30 days, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 100 statute miles - Lowest ceiling: none - Temperature: 64 °F ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20060529012089A](https://openairdocs.org/incident/20060529012089A), May 29, 2006: Robsin R44RAVENII, Skwentna, AK, Substantial damage. (-23) Pilot departed with sling and empty steel cage on hook. While in transition one and a half minutes into the flight he felt a shudder in the tail rotor… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.