|
| Title: | In-flight upset, Northwest Airlines, Inc., Boeing 727-251, N274US, Near Thiells, New York, December 1, 1974 |
| Micro summary: | Following a high-altitude stall, this Boeing 727 crashed. |
| Event Time: | 1974-12-01 at 1926 EST |
| File Name: | 1974-12-01-US.pdf |
| Publishing Agency: | National Transportation Safety Board (NTSB) |
| Publishing Country: | USA |
| Report number: | NTSB-AAR-75-13 |
| Pages: | 35 |
| Site of event: | 3.2 nmi west of Thiells, NY |
| Latitude/Longitude: | N41°12'53" W74°5'40" |
| Departure: | John F. Kennedy International Airport, Jamaica, New York, USA |
| Destination: | Buffalo Niagara International Airport, Cheektowaga, New York, USA |
| Airplane Type(s): | Boeing 727-251 |
| Flight Phase: | Climb |
| Registration(s): | N274US |
| Operator(s): | Northwest Airlines |
| Type of flight: | Ferry |
| Occupants: | 3 |
| Fatalities: | 3 |
| Serious Injuries: | 0 |
| Minor/Non-Injured: | 0 |
| Other Injuries: | 0 |
| Executive Summary: | About 1926 EST on December 1, 1974, Northwest Airlines Flight 6231, a Boeing 727-251, crashed about 3.2 mi west of Thiells, New York. Flight 6231 was a ferry flight to Buffalo, New York. The accident occurred about 12 minutes after the flight had departed John F. Kennedy International Airport, Jamaica, New York. Three crewmembers, the only persons aboard the aircraft, died in the crash. The aircraft was destroyed. The aircraft stalled at 24,800 feet m.s.l. and entered an uncontrolled, spiralling descent to the ground. Throughout the stall and descent the flightcrew did not recognize the actual condition of the aircraft and did not take the correct measures necessary to return the aircraft to level flight. Near 3,500 feet m.s.l. , a large portion of the left horizontal stabilizer separated from the aircraft, which made control of the aircraft impossible. The National Transportation Safety Board determines that the probable cause of this accident was the loss of control of the aircraft. because the flightcrew failed to recognize and correct the aircraft's high-angle-ofattack, low-speed stall and its descending spiral. The stall was precipitated by the flightcrew's improper reaction to erroneous airspeed and Mach indications which had resulted from a blockage of the pitot heads by atmospheric icing. Contrary to standard operational procedures, the flightcrew had not activated the pitot head heaters. |
| Learning Keywords: | Operations - Icing |
| Operations - Upset in-flight (extreme attitudes, stall, spin) | |
| Systems - Flight Instruments | |
| Systems - Pitot/Static System | |
| Consequence - Hull Loss |
Accident Reports on DVD, Copyright © 2006 by Flight Simulation Systems, LLC. All Rights Reserved. All referenced trademarks are the property of their respective owners.www.fss.aero