# NTSB ANC03LA070: Helio H-391B, N17081, Big Lake, AK, July 7, 2003 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 7, 2003, 14:50 local (22:50 UTC) - Place: Big Lake, AK - Coordinates: 61.533332, -149.816665 - Nearby events: https://openairdocs.org/map.md?lat=61.5333&lon=-149.8167&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report September 1, 2004 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: FAA-AL-ANC FSDO 03 - NTSB case key (mKey): 57448 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC03LA070 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/57448/pdf - Page: https://openairdocs.org/ntsb/ANC03LA070 ## Probable cause A loss of engine power for an undetermined reason during takeoff initial climb, which resulted in an in-flight collision with trees. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, takeoff - initial climb - reason for occurrence undetermined (cause) - lack of certification, pilot in command - Forced landing, descent - emergency - In flight collision with object, emergency landing after takeoff - object - tree(s) ## Analysis The private certificated pilot landed a float-equipped airplane on a lake near his cabin. The pilot did not hold a seaplane rating. The pilot said he then began a takeoff toward the south, with about 5,000 feet of available space. During the initial climb, the oil pressure decreased to about 60 psi, and the engine rpm decreased to 3400 rpm. The airplane climbed to about 150 feet and the bottom of the floats struck several tree tops. The airplane then descended to the ground and received damage to the wings and fuselage. The pilot said the wind was from the southwest about 3 knots, and the temperature was about 74 degrees. A postaccident examination of the engine did not reveal any evidence of a mechanical malfunction. ## Factual narrative On July 7, 2003, about 1450 Alaska daylight time, a float-equipped Helio H-391B airplane, N17081, sustained substantial damage when it collided with several trees during takeoff and initial climb at Big Lake, Alaska. The airplane was being operated as a visual flight rules (VFR) local area personal flight under Title 14, CFR Part 91, when the accident occurred. The airplane was operated by the pilot. The private certificated pilot, and the sole passenger, were not injured. Visual meteorological conditions prevailed. No flight plan was filed, nor was one required. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on July 9, the pilot reported that he departed Finger Lake in Wasilla, Alaska, and planned to do a touch and go at Big Lake. He said that during the departure from Finger Lake, he noticed the engine oil pressure flicker, and decrease to about 65 psi, which is near the low end of the normal operating range. He proceeded to Big Lake and landed near Crocker Island where he has a cabin. The pilot said he then began a takeoff toward the south, with about 5,000 feet of available space. During the initial climb, the oil pressure decreased to about 60 psi, and the engine rpm decreased to 3400 rpm. The airplane climbed to about 150 feet, and the bottom of the floats struck several tree tops at the south end of the lake. The airplane then descended to the ground and received damage to the wings and fuselage. The pilot said the wind was from the southwest about 3 knots, and the temperature was about 74 degrees. The pilot did not hold a seaplane rating. Following recovery of the airplane, the NTSB IIC examined the airplane on July 10. The throttle, propeller, and mixture controls were full forward at the instrument panel, and each control operated its respective component. The carburetor heat control was in the off position. The air intake was unobstructed. The engine contained 10 quarts of oil. The oil screen was free of contaminants. The crankshaft rotated when the propeller was turned by hand. Gear train continuity was established, and thumb compression in each cylinder was noted when the crankshaft was rotated by hand. The magnetos produced spark at all terminals upon hand rotation. The sparks plugs were dry and had a gray appearance. The engine fuel strainer contained clean, blue-colored fuel, and the screen was free of contaminants. ## Aircraft - Registration: N17081 (not matched to a registry record) - Reported make and model: Helio H-391B - Category: Airplane - Serial number: 068 - Airframe hours: 2240 - Engines: LYCOMING GO-435 260 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Joseph P. Caterinichio - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 31, 2002, 60 hours before - Departed: BIG LAKE, AK ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 62; injuries: none; private; airplane ratings: single-engine land; medical: class 3, expired; seat: left; flight hours: 2,000 total, 150 in this make and model, 2,000 as pilot in command, 20 in the last 90 days, 6 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 215° at 3 knots - Visibility: 30 statute miles - Lowest ceiling: none - Temperature: 73 °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 20030707037119A](https://openairdocs.org/incident/20030707037119A), Jul 7, 2003: Helio H391B, Big Lake, AK, Substantial damage. (-23) Pilot stated that the aircraft seemed sluggish on take off, and at about fifty feet he noticed a loss in manifold pressure. A gradual left turn was made… 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.