1994 — Oct 31, American Eagle Flight 4148 Crashes, Icing, near Roselawn, IN — 68
— 68 Aviation Safety Network. “Accident Description, American Eagle…Flight 4184.”
— 68 Hubert, Ronan. “Crash of an ATR72-212 in Chicago: 68 killed.” BAAA, Geneva, SUI.[1]
— 68 NationMaster.com. American Eagle Flight 4184.
— 68 NTSB, AAR, In-Flight Icing Encounter and Loss of Control…Flight 4184, 1996, p. vii.
— 68 WTHR 13, Indianapolis. “Victims of 1994 Roselawn…crash remembered…” 10-30-2014.
Narrative Information
NTSB Executive Summary: “On October 31, 1994, at 1559 Central Standard Time, an Avions de Transport Regional, model 72-212 (ATR 72), registration number N401AM, leased to and operated by Simmons Airlines, Incorporated, and doing business as American Eagle flight 4184, crashed during a rapid descent after an uncommanded roll excursion. The airplane was in a holding pattern and was descending to a newly assigned altitude of 8,000 feet when the initial roll excursion occurred. The airplane was destroyed by impact forces; and the captain, first officer, 2 flight attendants and 64 passengers received fatal injuries. Flight 4184 was a regularly scheduled passenger flight being conducted under 14 Code of Federal Regulations, Part 121; and an instrument flight rules flight plan had been filed.
“The National Transportation Safety Board determines that the probable causes of this accident were the loss of control, attributed to a sudden and unexpected aileron hinge moment reversal that occurred after a ridge of ice accreted beyond the deice boots because: 1) ATR failed to completely disclose to operators, and incorporate in the ATR 72 airplane flight manual, flightcrew operating manual and flightcrew training programs, adequate information concerning previously known effects of freezing precipitation on the stability and control characteristics, autopilot and related operational procedures when the ATR 72 was operated in such conditions; 2) the French Directorate General for Civil Aviation’s inadequate oversight of the ATR 42 and 72, and its failure to take the necessary corrective action to ensure continued airworthiness in icing conditions; and 3) the French Directorate General for Civil Aviation’s failure to provide the
Federal Aviation Administration with timely airworthiness information developed from previous ATR incidents and accidents in icing conditions, as specified under the Bilateral Airworthiness Agreement and Annex 8 of the International Civil Aviation Organization.
“Contributing to the accident were: 1) the Federal Aviation Administration’s failure to ensure that aircraft icing certification requirements, operational requirements for flight into icing conditions, and Federal Aviation Administration published aircraft icing information adequately accounted for the hazards that can result from flight in freezing rain and other icing conditions not specified in 14 Code of Federal Regulations, Part 25, Appendix C; and 2) the Federal Aviation Administration’s inadequate oversight of the ATR 42 and 72 to ensure continued airworthiness in icing conditions.
“The safety issues in this report focused on communicating hazardous weather information to flightcrews, Federal regulations regarding aircraft icing and icing certification requirements, the monitoring of aircraft airworthiness, and flightcrew training for unusual events/attitudes.
“Safety recommendations concerning these issues were addressed to the Federal Aviation Administration, the National Oceanic and Atmospheric Administration, and AMR Eagle. Also, as a result of this accident, on November 7, 1994, the Safety Board issued five safety recommendations to the Federal Aviation Administration regarding the flight characteristics and performance of ATR 42 and ATR 72 airplanes in icing conditions. In addition, on November 6, 1995, the Safety Board issued four safety recommendations to the Federal Aviation Administration concerning the Air Traffic Control System Command Center. In accordance with Annex 13 to the Convention on International Civil Aviation, the Bureau Enquetes-Accidents provided comments on the Safety Board’s draft of the accident report that are contained in Volume II of this report.” (NTSB. AAR. Flight 4184, pp. vii-viii.)
“Survival Aspects
“The accident was not survivable because the impact forces exceeded human tolerances, and no occupiable space remained intact. The Newton County Coroner’s Office investigative report stated that the occupants sustained fatal injuries due to, “multiple anatomical separations secondary to velocity impact of aircraft accident.”.” (NTSB. AAR. Flight 4184, p. 73.)
NTSB: “The French Bureau Enquetes-Accidents strongly disagreed with the NTSB report, with what it claimed was a virtual exclusion of the investigative phase of the NTSB investigation, and offered its own 341 page report containing the following substitute Probable Cause statement:
The Probable Cause of this accident is the loss of control of the aircraft by the flight crew, caused by the accretion of a ridge of ice aft of the de-icing boots, upstream of the ailerons, due to a prolonged operation of Flight 4184 in a freezing drizzle environment, well beyond the aircraft’s certification envelope, close to VFE, and utilizing a 15 degree flap holding configuration not provided for by the Aircraft Operating Manuals, which led to a sudden roll upset following an unexpected Aileron Hinge Moment Reversal when the crew retracted the flaps during the descent.
The contributing factors to this highly unusual chain of events are:
- The failure of the flight crew to comply with basic procedures, to exercise proper situational awareness, cockpit resource management, and sterile cockpit procedures, in a
known icing environment, which prevented them from exiting these conditions prior to the ice-induced roll event, and their lack of appropriate control inputs to recover the aircraft when the event occurred:
- The insufficient recognition, by Airworthiness Authorities and the aviation industry worldwide, of freezing drizzle characteristics and their potential effect on aircraft performance and controllability;
- The failure of Western Airworthiness Authorities to ensure that aircraft icing certification conditions adequately account for the hazards that can result from flight in conditions outside 14 CFR Part 25, Appendix C, and to adequately account for such hazards in their published aircraft icing information;
- The lack of anticipation by the Manufacturer as well as by Airworthiness and Investigative Authorities in Europe and in the USA, prior to the post accident Edwards AFB testing program, that the ice-induced Aileron Hinge moment reversal phenomenon could occur.
- The ATC’s improper release, control, and monitoring of Flight 4184. (NTSB. Flight 4184, Vol. II, p. 10.)
“The NTSB’s record in this investigation clearly shows that this flight crew had entered icing conditions, and yet failed to comply with mandatory requirements pertaining to such conditions contained in the applicable flight manuals, Federal Aviation Regulations, and explicit company policies, which, if followed, would have prevented this accident….
“Thus, the BEA strenuously disagrees with the current Analysis, Findings, and Probable Cause Statement sections, which ignore, or address in a very shallow fashion, very important issues in this accident, and only addresses in an excessive mode the aircraft and the manufacturer’s and Airworthiness Authorities’ responses to certain prior incidents. This excessive approach is simply no supported by the NTSB’s own record of investigation.” (NTSB. Flight 4184, Vol. II, 11.)
“The NTSB knows of the extensive wind tunnel testing, high speed taxi tests, flight testing, and considerable efforts spent by the manufacturer after Roselawn for the first-ever USAF tanker freezing drizzle/rain testing program for civil or military aircraft at Edwards AFB. The NTSB knows from its own involvement in the testing that the phenomenon of an “ice-induced aileron hinge moment reversal” and its associated flow separation behind the boots at low Angle of Attack was discovered for the very first time as a result of this exhaustive post-Roselawn investigation.” (NTSB. Flight 4184, Vol. II, 15.)
ASN: This was the first loss of an ATR-72 and, as of February 2008, the worst. At the time it was the 35th worst aviation accident in the US, and, as of Feb 2008 the 42nd worst. (Aviation Safety Network, Accident Description, American Eagle/Simmons Airlines Flight 4184)
Sources
Aviation Safety Network. Accident Description. American Eagle/Simmons Airlines Flight 4184. Accessed 12/19/2008 at: http://aviation-safety.net/database/record.php?id=19941031-1
Hubert, Ronan. “Crash of an ATR72-212 in Chicago: 68 killed.” Bureau of Aircraft Accidents Archives, Geneva, Switzerland. Accessed 2-26-2016 at: http://www.baaa-acro.com/1994/archives/crash-of-an-atr72-in-chicago-68-killed/
National Transportation Safety Board. Aircraft Accident Report. In-Flight Icing Encounter and Loss of Control, Simmons Airlines, d.b.a. American Eagle Flight 4184, Avions de Transport Regional (ATR) Model 72-212, N401AM, Roselawn, Indiana, October 31, 1994 (NTSB/AAR-96/01; NTIS PB96-910401). Washington, DC: NTSB, adopted July 9, 1996, 340 pages. Accessed at: http://www.ntsb.gov/Publictn/1996/aar9601.pdf
National Transportation Safety Board. Aircraft Accident Report. In-Flight Icing Encounter and Loss of Control, Simmons Airlines, d.b.a. American Eagle Flight 4184, Avions de Transport Regional (ATR) Model 72-212, N401AM, Roselawn, Indiana, October 31, 1994. Volume II: Response of Bureau Enquetes-Accidents to Safety Board’s Draft Report (NTSB/AAR-96/02; NTIS PB96-910402). Washington, DC: NTSB, adopted July 9, 1996, Notation 6486C, 341 pages. Accessed at: http://www.ntsb.gov/publictn/1996/AAR9602.pdf
WTHR 13, Indianapolis (David MacAnally). “Victims of 1994 Roselawn plane crash remembered on 20th anniversary.” 10-30-2014, updated 10-31-2014. Accessed 2-26-2016 at: http://www.wthr.com/story/27167731/2014/10/30/dedication-set-at-memorial-of-1994-plane-crash
[1] While the plane’s destination was Chicago, the crash was near Roselawn, Indiana.