# NTSB CHI93LA320: Bell 47-G5, N1347X, Schaumburg, IL, August 12, 1993 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: August 12, 1993, 12:30 local (17:30 UTC) - Place: Schaumburg, IL - Coordinates: 42.009948, -88.10009 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=42.0099&lon=-88.1001&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report August 17, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 9279 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI93LA320 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9279/pdf - Page: https://openairdocs.org/ntsb/CHI93LA320 ## Probable cause the pilot's improper autorotation techniques. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Hard landing, landing - flare/touchdown - precautionary landing - performed, pilot in command - autorotation - improper, pilot in command (cause) ## Analysis The aerial application helicopter took off with full fuel (55 gal.), and a full spray load (50 gal.). Witnesses reported the helicopter used the entire runway to get airborne. The helicopter was leveled off at 500 feet agl. The pilot stated he heard a loud bang and felt vibrations shortly after level off. He entered an autorotation. He said he flared the helicopter at 50 feet, but could not slow the rate of descent. The helicopter made a hard landing in a residential area. Post-landing investigation of the helicopter flight controls revealed no malfunction. A test run of the engine was performed without any problems. ## Factual narrative On August 12, 1993, at 1230 central daylight time, a Bell 47-G5 helicopter, N1347X, operated by Clarke Environmental Mosquito Control, Inc., Roselle, Illinois, sustained substantial damage from a hard autorotative landing near Schaumburg, Illinois. The commercial pilot received minor injuries. The aerial application flight originated at the Schaumburg Air Park at 1225. No flight plan was filed, and visual meteorological conditions prevailed at the time. The helicopter was serviced at the Schaumburg Air Park before takeoff. The load was 50 gallons of spray mixture, and 55 gallons of fuel. Witnesses at the airport said the helicopter used the entire runway to become airborne. The pilot reported he leveled off at 500 feet above ground level. After levelling off he heard a loud bang behind him, and the helicopter began to vibrate. The pilot said he entered an autorotation and picked out a landing site to his right. He flared the helicopter at 50 feet, and stated he felt no response when he raised the collective. The helicopter landed hard. The helicopter was examined by an FAA Airworthiness Inspector. The inspector reported the flight control system was functional. The engine was examined, and a functional test run was performed. The inspector noted no problems with the engine. ## Aircraft - Registration: [N1347X](https://openairdocs.org/aircraft/N1347X), registered now, S/N 7829, built 1966 (OpenAirDocs) - Reported make and model: BELL 47-G5 - Registry model: [Bell 47G-5](https://openairdocs.org/model/bell-47g-5) (registry code 1181032) (OpenAirDocs) - Registry engine: [Lycoming VO-435 series](https://openairdocs.org/engine/lycoming-vo-435-series) (registry code 41525, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 47-65 - Engines: LYCOMING VO-435-B1A 260 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Clarke Mosquito Control - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 29, 1993, 11 hours before ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 40; commercial; instrument ratings: helicopter; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 1,800 total, 250 in this make and model, 1,600 as pilot in command, 200 in the last 90 days, 50 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 6 knots - Visibility: 4 statute miles - Lowest ceiling: 5,000 ft broken - Temperature: 79 °F, dew point 72 °F - Altimeter: 29.00 inHg - Observed at: ORD, 9 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 19930812029229A](https://openairdocs.org/incident/19930812029229A), Aug 12, 1993: Bell 47G5, Schaumburg, IL, Substantial damage. Overloaded on departure. Loud bang. Autorotated. Made hard landing in residential area. No anomalies. Gross weight. 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.