# NTSB FTW96LA271: Boeing 737-201, N207AU, Granite, CO, June 22, 1996 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: June 22, 1996, 15:45 local (21:45 UTC) - Place: Granite, CO - Location: 39.0436° N, 106.2634° W: Placed by OpenAirDocs: center of Granite, CO, within about 6 miles (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=39.0436&lon=-106.2634&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious, 2 minor, 95 uninjured - Status: Completed, report December 23, 1996 - Report: Approved by Office Director - NTSB case key (mKey): 19879 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW96LA271 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/19879/pdf - Page: https://openairdocs.org/ntsb/FTW96LA271 ## Probable cause An encounter with clear air turbulence. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, descent - normal - in-flight weather advisories - issued, atc personnel(dep/apch) - seat belt sign - selected, copilot/second pilot - passenger briefing - issued, copilot/second pilot - weather condition - turbulence,clear air (cause) ## Analysis The crew had been forewarned to expect severe turbulence on descent into the Denver area. The 'Fasten Seat Belts' sign was turned on, and flight attendants were instructed to make sure everyone was seated with their seat belts fastened. An elderly woman got up and walked towards the aft lavatory. Light turbulence was encountered as a flight attendant attempted to seat the passenger in a jump seat. Before seat belts could be fastened, the airplane encountered severe turbulence. The passenger and flight attendant were thrown around the cabin, sustaining a serious injury and minor injury, respectively. Another flight attendant and a passenger also sustained minor injuries. ## Factual narrative On June 22, 1996, approximately 1545 mountain daylight time, a Boeing 737-201, N207AU, operated by Frontier Airlines, Inc., as flight 328, in scheduled domestic passenger service, was not damaged when it encountered severe turbulence during descent over Granite, Colorado. One passenger received serious injuries, and one passenger and two flight attendants received minor injuries. There were no injuries to the airline transport-rated captain and first officer, and the other flight attendant and 91 passengers. Visual meteorological conditions prevailed, and an IFR flight plan had been filed. The flight was being conducted under Title 14 CFR 121, and originated in Albuquerque, New Mexico, on June 22, 1996, at 1505. According to the captain, he had begun the descent from FL290 into Denver and had been forewarned of reported turbulence. The "Fasten Seat Belts" sign was turned on, and flight attendants were instructed to be seated and to fasten their seat belts. An elderly woman got up and walked towards the aft lavatory. The airplane began to encounter light turbulence and a flight attendant attempted to seat the passenger in a flight attendant jump seat. Before her seat belt could be fastened, the airplane encountered severe turbulence and the passenger sustained a serious back injury. The flight attendant struck her head against the cabin ceiling, then struck her hip against the galley. At that time, the airplane was at FL240. Written statements were submitted by the three cabin crew members that corroborated the captain's report. The digital flight data recorder (DFDR) was removed from the airplane and sent to NTSB headquarters in Washington, D.C. for examination. According to the Flight Data Recorder Specialist's Report, the airplane was on a magnetic heading of 325 degrees, at 280 knots, and in a shallow descent from 29,000 feet when the DFDR recorded "violent vertical acceleration oscillations" that lasted approximately 150 seconds. Oscillation magnitudes ranged from +2.0 g's to -0.5 g's. ## Aircraft - Registration: [N207AU](https://openairdocs.org/deregistered/N207AU-2000-02-03), registration cancelled 2000-02-03, S/N 19423 (OpenAirDocs) - Reported make and model: Boeing 737-201 - Registry model: [Boeing 737-201](https://openairdocs.org/model/boeing-737-201) (registry code 1384454) (OpenAirDocs) - Category: Airplane - Serial number: 19423 - Airframe hours: 83 - Engines: P&W JT8D-9A 14500 lbs thrust turbo jet - Damage: No damage - Flight: Part 121 - Operator: Frontier Airlines - Registered owner: Usair, Inc. - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, June 22, 1996, 9 hours before - Departed: ABQ, ALBUQUERQUE, NM - Destination: DEN, DENVER, CO - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; flight engineer, commercial, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 21,230 total, 893 in this make and model, 180 in the last 90 days, 60 in the last 30 days, 9 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 300° at 20 knots, gusting 26 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 70 °F, dew point 46 °F - Altimeter: 29.00 inHg - Observed at: DEN, 109 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 19960622046049A](https://openairdocs.org/incident/19960622046049A), Jun 22, 1996: Boeing 737201, Granite, CO. (.4)The crew had been forewarned to expect severe turbulence on descent into the denver area. The 'fasten seat belts' sign was turned on, and flight attendants… 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.