# NTSB IAD97LA070: Mbb BK-117-A1, N122LF, Kane, PA, April 30, 1997 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: April 30, 1997, 18:10 local (22:10 UTC) - Place: Kane, PA - Coordinates: 41.659091, -78.800651 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.6591&lon=-78.8007&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed, report September 28, 1999 - Report: Approved by Office Director - NTSB case key (mKey): 28190 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=IAD97LA070 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/28190/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=28190 - Page: https://openairdocs.org/ntsb/IAD97LA070 ## Probable cause The pilot's decision to perform a low airspeed vertical descent with a tailwind, which resulted in settling with power. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, landing - weather condition - tailwind - airspeed - low, pilot in command (cause) - in-flight planning/decision - improper, pilot in command (cause) - settling with power - inadvertent, pilot in command - Hard landing, landing ## Analysis After a 30 minute flight to his destination, the pilot found the hospital helipad, which was about a 200 square foot area, with 40 foot high wires on the north side, and 35 to 50 feet high trees surrounding the rest of the area. A windsock indicated about 3 to 5 knots winds from the west/southwest. During the approach from the southwest, the pilot descended vertically to the helipad. The pilot attempted to stop the rate of descent with the airspeed below 10 knots. The helicopter shuttered with the application of additional power. The helicopter yawed right, and 'the additional collective pitch seemed to have no effect on slowing the rate of descent, the rate of descent seemed to increase at this point.' The pilot determined that he did not have sufficient space to fly out of the area and at impact, all remaining collective pitch had been applied. No master caution or annunciator panel lights were noticed, nor was any audio tones heard. A helicopter aerodynamics manual described conditions conducive to settling with power, which included a vertical or near vertical descent of at least 300 feet per minute, engine power between 20 and 100 percent, during downwind steep approaches. ## Factual narrative On April 30, 1997, about 1810 eastern daylight time, a MBB (Messerschmitt) BK117-A1, N122LF, was substantially damaged as it impacted the ground during landing at Kane Hospital, Kane, Pennsylvania. The certificated airline transport pilot, a passenger observer in the cockpit, and the two medical personnel in the cabin area, were not injured. The helicopter, owned by the Geisinger Medical Center of Danville, Pennsylvania, was operated by Keystone Helicopter Corporation of West Chester, Pennsylvania. Visual meteorological conditions prevailed, and a company visual flight rules flight plan was filed for the positioning flight conducted under 14 CFR Part 91. The flight originated from the Bellefont Airport (N96), Bellefont, Pennsylvania, about 1727. The pilot reported that the helicopter performed a normal takeoff and a uneventful 30 minute flight en route to Kane, Pennsylvania. He stated that upon his arrival, he circled the town looking for the hospital. On the second pass, the pilot identified the hospital. He described the helipad as small, located in a clear area which was about 60 to 75 yards square. Wires, about 40 feet high, were on the north side of the clearing, and trees, varying from 35 feet to 50 feet in height, surrounded the rest of the area. The pilot reported that the windsock indicated about 3 to 5 knots from the west/southwest. He stated that his approach path to the helipad was based on the lowest obstacles surrounding the helipad, which was from the southwest. The pilot decided to descend vertically to the helipad. He slowed his airspeed below 10 knots and attempted to stop his descent rate at 50 feet agl. He stated that the helicopter shuttered with the application of additional power at about effective translational lift (ETL). The helicopter yawed right, and the pilot stated that "the additional collective pitch seemed to have no effect on slowing the rate of descent, the rate of descent seemed to increase at this point." The pilot stated that a "fly away" was not possible due to the proximity of the trees and wires, so he announced to the crew, "We're settling in guys!" The pilot reported that he did not recall any master caution or annunciator panel lights illuminating nor any audio tones because he was focused outside the cockpit. He stated that he continued to pull collective pitch, and at the time of touchdown, all remaining collective pitch was applied. With about 2 to 3 knots of forward airspeed, the helicopter impacted the ground and rotated to the right. The pilot recalled reducing the collective immediately to arrest the yaw rate. The helicopter stopped after completing a 180 degree turn. A Federal Aviation Administration (FAA) Inspector conducted a preliminary examination of the wreckage. The main rotor blades were damaged, the landing skids were bowed out, the helicopter was resting on the rear fuselage, and the tailboom was separated and lying on the ground next to the right side of the helicopter. The Inspector reported that he was able to verify control continuity of the cyclic and the collective and "found no reason that the anti-torque system should not have worked." The wreckage was transported to Keystone Helicopter Corporation in West Chester, Pennsylvania. Representatives from the helicopter and engine manufacturers, the operator, the Federal Aviation Administration, and the Investigator in Charge from the National Transportation Safety Board met to examine the wreckage on May 13, 1997. Rigging for flight controls and power train were verified and no anomalies noted. Fuel samples were taken from five drain areas, with the aft right sample rust orange in color, and the others yellow. The samples were sent to the AlliedSignal Chemistry Lab for testing. The aft right sample was found to contain red dyed (high sulfur) diesel fuel. The differences noted were in viscosity, color, and freezing point. Only the freezing point did not meet Jet A specifications of -40 degrees Fahrenheit. The sample was determined to have a -31 degrees Fahrenheit freezing point. Both engines were removed and placed in a test cell on May 14, 1997. It was noted after the removal of the left engine that a bolt was missing from the plenum. A test run was completed with the bolt out, and then with the bolt replaced. The engines were determined capable of producing their assigned horsepower. The fuel filters were removed from both engines after the testing. Both filters had accumulated debris which consisted of dirt, fibers, a black 'rubber-like' compound and a trace of metallics. A U.S. Army manual, FM 1-203 Fundamentals of Flight, stated under the topic, Settling With Power: "Settling with power is a condition of powered flight in which the helicopter settles in its own downwash...Conditions conducive to settling with power are a vertical or near vertical descent of at least 300 feet per minute and low forward speed. The rotor system must also be using some of the available engine power (from 20 to 100 percent) with insufficient power available to retard the sink rate. These conditions can occur during downwind approaches...[and] steep approaches..." ## Aircraft - Registration: [N122LF](https://openairdocs.org/deregistered/N122LF-1997-12-04), registration cancelled 1997-12-04, S/N S7002 (OpenAirDocs) - Reported make and model: Mbb BK-117-A1 - Registry model: [Messerschmitt BK 117](https://openairdocs.org/model/messerschmitt-bk-117) (registry code 5626010) (OpenAirDocs) - Category: Helicopter - Serial number: 7002 - Airframe hours: 5570 - Engines: Lycoming LTS101-650 650 horsepower turbo shaft - Damage: Substantial damage - Flight: Positioning, Part 91 - Operator: Keystone Helicopters - Registered owner: Geisinger Medical Center - Airworthiness certificate: Standard, Normal - Last inspection: Continuous airworthiness, April 21, 1997, 62 hours before - Departed: N96, BELLEFONT, PA - Destination: NONE - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 36; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane, helicopter; medical: class 1, valid medical--no waivers/lim.; seat: right; flight hours: 4,600 total, 190 in this make and model, 4,250 as pilot in command, 100 in the last 90 days, 36 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 11 knots, gusting 16 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 66 °F, dew point 27 °F - Altimeter: 29.00 inHg - Observed at: BFD, 13 nm away ## 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 19970430007149A](https://openairdocs.org/incident/19970430007149A), Apr 30, 1997: Bolkms BK117A1, Kane, PA, Substantial damage. Helicopter was on a life flight when it crashed on landing at hospital. ## Docket (6 files) The files NTSB released with the investigation on March 19, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=28190. 1.3 MB in all. - Supplement s (item 1, PDF, 1 page, 82 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13443738&FileExtension=pdf&FileName=Supplement%20S-Master-Rel.pdf - Pilot-operator aircraft accident report NTSB form 61201-2 (item 2, PDF, 6 pages, 499 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13444688&FileExtension=pdf&FileName=Pilot-Operator%20Aircraft%20Accident%20Report%20NTSB%20Form%2061201-2-Master-Rel.pdf - FAA accident investigation record-inspectors statements (item 3, PDF, 4 pages, 226 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13444420&FileExtension=pdf&FileName=FAA%20Accident%20Investigation%20Record-Inspectors%20Statements-Master-Rel.pdf - Pilot's statement and diagram of the landing area (item 4, PDF, 2 pages, 303 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13443741&FileExtension=pdf&FileName=Pilot%27s%20Statement%20and%20Diagram%20of%20the%20Landing%20Area-Master-Rel.pdf - Statement of party representatives to NTSB investigation (item 5, PDF, 2 pages, 142 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13443438&FileExtension=pdf&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Master-Rel.pdf - Release of aircraft wreckage NTSB form 612015 (item 6, PDF, 1 page, 50 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13444793&FileExtension=pdf&FileName=Release%20of%20Aircraft%20Wreckage%20%20NTSB%20Form%20612015-Master-Rel.pdf 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.