PB96-910402 NTSB/AAR-96/02 DCA95MA001 NATIONAL TRANSPORTATION SAFETY BOARD WASHINGTON, D.C. 20594 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 I TO SAFETY BOARD’S DRAFT REPORT / I 6486C The National Transportation Safety Board is an independent Federal agency dedicated to promoting aviation, railroad, highway, marine, pipeline, and hazardous materials safety. Established in 1967, the agency is mandated by Congress through the Independent Safety Board Act of 1974 to investigate transportation accidents, determine the probable causes of the accidents, issue safety recommendations, study transportation safety issues, and evaluate the safety effectiveness of government agencies involved in transportation. The Safety Board makes public its actions and decisions through accident reports, safety studies, special investigation reports, safety recommendations, and statistical reviews. Information about available publications may be obtained by contacting: National Transportation Safety Board Public Inquiries Section, RE-51 490 L’Enfant Plaza, S.W. Washington, D.C. 20594 (202)382-6735 (800)877-6799 Safety Board publications may be purchased, by individual copy or by subscription, from: National Technical Information Service 5285 Port Royal Road Springfield, Virginia 22161 (703)487-4600 NTSB/AAR-96/02 PB96-910402 NATIONAL TRANSPORTATION SAFETY BOARD WASHINGTON, D.C. 20594 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 Adopted: July 9, 1996 Notation 6486C ● Abstract: Volume II contains the comments of the Bureau Enquetes-Accidents on the Safety Board’s draft of the accident report. The comments are provided in accordance with Annex 13 to the Convention on International Civil Aviation. Volume I of this report explains the crash of American Eagle flight 4184, an ATR 72 airplane during a rapid descent after an uncommanded roll excursion. The safety issues discussed in the report focused on communicating hazardous weather information to flightcrews, Federal regulations on 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. MINISTERE DE L’AMENAGEMENT DU TERRITOIRE, DE L'EQUIPEMENT ET DES TRANSPORTS SECRETARIAT D’ETAT AUX TRANSPORTS INSPECTION GENERALE DE L’AVIATION CIVIL Le Bourget. le 13 mai 1996. ET DE LA METEOROLOGIE BUREAU ENQUÊTES-ACCIDENTS j ‘1 ;:,, COMMENTS OF THE BUREAU ENQUETES ACCIDENTS (FRANCE) ON THE NATIONAL TRANSPORTATION SAFETY BOARD DRAFT FINAL REPORT ON THE ACCIDENT OF SIMMONS AIRLINES FLIGHT 4184 AT ROSELAWN, INDIANA ON OCTOBER 31, 1994 --------------------------------- SUBMITTED PURSUANT TO ANNEX 13 TO THE CONVENTION ON INTERNATIONAL CIVIL AVIATION Bâtiment 153- Aéroport du Bourget -93352 LE BOURGET cedex Téléphone (33.1) 49 92 72 00 / Télécopie (33.1) 49 92 72 03 INTRODUCTION 6 EXECUTIVE SUMMARY 7 1. FACTUAL INFORMATION 23 1.1. History of the flight 23 1.2. Personnel information 47 1.2.1 the Captain 47 1.2.2 the First Officer 47 1.3. Airplane information 48 1.3.1. ATR 72 icing certification 48 1.3.2. ATR72 Anti-icing Advisory System 62 1.3.3. ATR 72 stick pusher Stall Protection System 66 1.4. ATR 72 icing operating procedures 68 1.4.1. AFM/FCOM and Manufacturer information 68 1.4.2. AMR EAGLE / SIMMONS, Flight Manual and other pertinent documentation 77 1.5. ATR Flight Training 83 1.5.1. ATR Training Center 83 1.5.2. AMR EAGLE Training Centers 89 1.6. Meteorological information 90 1.7. Flight recorders 98 1.7.1. CVR 98 1.7.2. DFDR 99 1.8. Tests and research 101 1.8.1. previous ATR 42 incidents 102 1.8.2. post flight 4184 accident actions 120 1.8.3. Bilateral Airworthiness Agreement (BAA] 126 1.8.4. certification process between FAA, and DGAC under the BAA 127 1.8.5. Continuing Airworthiness information exchanged between FAA and DGAC under the BAA, and - knowledge of the NTSB regarding icing related incidents addressed in the NTSB’s Report 129 1.9. Air Traffic Control 136 1.10. Additional information worldwide fleet icing events 141 1.11. Additional pertinent documentation 148 1.12. Additional comments to NTSB factual section 154 2 ANALYSIS 173 2.1. Meteorological factors 174 2.2. History flight 176 2.2.1. Holding technique 176 2.2.2. Analysis of holding pattern sequences 177 2.2.3. Flight crew performance 180 2.2.4. Capacity of aircraft recovery 208 2.2.5. Crew response to roll upset 217 3 I 2.3. Previous ATR icing incidents and adequacy of DGAC/ATR actions 218 2.3.1. Mosinee incident 218 2.3.2. Air Mauritius and Ryan air incidents 224 2.3.3. Newark incident 226 2.3.4. Burlington incident 228 2.3.5. Conclusion 230 2.4. Air Traffic Control 233 2.5. The DGAC’s continuing airworthiness monitoring under the bilateral airworthiness agreement 236 2.6. ATR operations in icing conditions 244 2.6.1. Certification 244 2.6.2. Flight characteristics 247 2.7. ATR dissemination of ice related information 250 2.7.1. The NTSB Report misrepresents facts and ATR knowledge 250 2.7.2. ATR dissemination of icing information 255 2.7.3. ATR training for unusual attitudes 257 3. CONCLUSION 258 3.1. BEA findings 258 3.2. Probable cause 266 4 I 4. RECOMMENDATIONS 268 4.1. Flight crew performance - sterile cockpit 268 4.2. Pre-flight and in-flight weather information 269 4.3. Pireps 269 4.4. Aircraft certification - freezing drizzle / rain 270 4.5. Certification and continuing airworthiness under the BAA 271 4.6. ATR 272 4.7. AMR EAGLE 273 5. APPENDICES 274 5 INTRODUCTION The BEA appreciates the invitation extended to it by the NTSB, as required by Annex 13 to the Convention on International Civil Aviation, to comment on the draft accident investigation Final Report. This will serve as the BEA’s comments on that draft Final Report. We understand that the Board, as required by Section 6.9 of Annex 13, will either amend the draft Final Report to include the substance of these comments, or append these comments to the Final Report. However the BEA wishes to express its disappointement about its absolute non participation to the investigation phase related to analysis, findings, causes and safety recommendations, despite the initial commitment from the NTSB and despite its repeated efforts to provide the NTSB investigators with relevant views and documentation. This presently leads to a major disagreement between two Investigative Authorities on facts, analysis and on the accident causes, and, moreover, to the risk that the safety recommendations will not be properly taken into account by all the parties of the aviation community worldwide, because they will be based . on an arguable report. EXECUTIVE SUMMARY General The BEA strongly disagrees with substantial portions of the Factual, and with the Analysis, Conclusions, and Probable Cause sections of the report. In the BEA's view, except for the Recommendations section, the present report is incomplete, inaccurate,and unbalanced, It appears to have been influenced by an a priori belief on the probable cause of this accident The BEA strongly believes that today one-sided approach is detrimental to the cause of international aviation safety. The Factual section selectively reports the facts of this accident. Some relevant facts are omitted and some other which are included are simply not accurate or their presentation is misleading. The BEA regrets it, since it had already advised the NTSB of a number of significant omissions, inaccuracies, and misrepresentations through his three sets of comments to the earlier drafts of this section, and since it was agreed that many of these errors would be rectified. The Analysis and Conclusions sections are hampered by the incomplete and inaccurate Factual section. “Many of the issues which are discussed are addressed in an incorrect or incomplete manner. Those sections also regrettably omit any discussion of several highly relevant issues for safety and for the understanding of this accident and fail to address a true combination of factors which has caused it. They clearly are inconsistent with the safety recommendations which follow. 7 Given the facts of this accident, the current Probable Cause statement, which ignores critical causal factors, is unbalanced, not correct, and detrimental to the public concern for safety. Accordingly, the BEA considers that the report requires substantial reworking. Acknowledging the necessity, for achieving true aviation safety to take into consideration all relevant aspects of the aviation system, outside any national consideration or any a priori sharing of blame or liability, it has expended significant efforts to prepare in these comments such a substantial reworking of all or part of the quoted sections, to assist the NTSB in making the necessary revision and facilitate the inclusion of the comments. Probable Cause Statement This accident was caused by a combination of factors, as reflected in the following BEA-proposed 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.