Spanair Flight JK5022 Accident involving aircraft McDonnell Douglas DC-9-82 (MD-82), registration EC-HFP, operated by Spanair, at Madrid-Barajas airport on 20 August 2008 ESASI, Amsterdam 19-20 April 2012
SUMMARY 1. History of the flight 2. The relevant data 3. Investigation challenges 4. Design aspects. Take Off Warning System (TOWS) 5. Overview of maintenance factors analysis 6. Overview of operational factor analysis
HISTORY OF THE FLIGHT (4/4) G:\ESASI\Spanair 5022.avi
THE RELEVANT DATA The physical evidences. Flaps/slats Wing control surfaces and associated elements. Flaps/slats Flaps/slats control lever Slats indication lights DFDR data CVR data The TOWS failure CVR data
WING CONTROLSURFACES AND ASSOCIATED ELEMENTS FLAPS/SLATS Several flap actuators were recovered. Each was extended by a different amount. In the case of the right outboard flap, its inboard actuator was extended five inches and the central actuator 1.1 inches. The flaps were easily extended and retracted, making it impossible to determine the position they had on the aircraft.
WING CONTROLSURFACES AND ASSOCIATED ELEMENTS FLAPS/SLATS SLATS DRUM ACTUATORS The part of the piston that was extended was not covered in soot. The actuators were not blocked and could be moved freely. TRACKS FOR THE NOS. 0 AND 1 SLATS PANELS ON THE LEFT SIDE. They were found locked in the fully retracted position.
FLAPS/SLATS CONTROL LEVER THE LEFT STUB ON THE FLAPS LEVER WAS CONSIDERABLY DEFORMED. THE SLOT CORRESPONDING TO THE UP/RET POSITION ON THE FIXED FLAPS GUIDE HAS A MARK THAT CORRESPONDS TO THE DAMAGE MADE BY THE LEVER STUB.
FLAPS/SLATS CONTROL LEVER & SLATS INDICATION LIGHTS Take off condition- CG/flaps selection indication panel Flaps/Slats control lever Slats indication lights
DFDR DATA FLAPS DEFLECTION Second taxi and take off was with flap setting 0º. Flaps sensors send info directly FDAU Slats sensors send info to DFGC and then to FDAU. A problem in bus connecting DFGC and FDAU prevented to record Slat parameter in DFDR. Flap sensor Slat sensor DFGC FDAU Flight Data Acquisition Unit DFDR Flight Data Recorder
CVR DATA TOWS Throughout the takeoff run and until the end of the CVR recording, no sounds were recorded coming from the Takeoff Warning System (TOWS).
FINDINGS 1. Flaps and slats remain retracted during take off which it is a non approved configuration. 2. Crew did not actuate flap/slat control lever. 3. TOWS failed to provide a warning to the crew of the improper aircraft configuration.
INVESTIGATION CHALLENGES WHY 1 did not TOWS work? DESIGN ASPECTS 2 did not crew select and verify flap/slat position in spite of having procedures and checklists intended to? OPERATION ASPECTS AND 3 Were there any previous conditions that might have prevented the accident? MAINTENANCE ASPECTS
DESIGN ASPECTS. TOWS FAILURE The relationship between the TOWS and the RAT probe. The R2-5 relay R2 5 Relay AC Power K 33 Breaker Coil Ground Flight Switches Landing Gear Section A TOWS Section B Section C Heater Section D Ram Air Temperature (RAT) Probe AC Power Z 29 Breaker Thrust Rating Panel (TRP) 13
DESIGN ASPECTS. TOWS FAILURE The R2-5 relay Comparison between the recovered relay R2-5 and a new one of the same model Flight condition Ground condition R2-5 operation diagram 14
DESING ASPECTS. TOWS FAILURE. THE R2-5 RELAY. High RAT probe temperature. Cases involving other MD operators Data from five MD-80 operators Sampling of over 100 airplanes spanning 15 years Cases compiled by Boeing (2000-2008) REPLACEMENT R2-5 RELAY (80%)
DESING ASPECTS. TOWS FAILURE. R2-5 RELAY INSPECTION. Comparison between the recovered relay R2-5 and a new one of the same model Functional test of R2-5 relay Reference to Leach and Boeing specifications The results did not reveal any defect CT scan Performed at ZEISS facilities in Aalen (Germany) No abnormalities found in internal components in this exam
DESING ASPECTS. TOWS FAILURE. R2-5 RELAY TEARDOWN.
Design aspects. Conclusions R2-5 findings Given the importance of the R2-5 relay to the operation of the TOWS, an evaluation should be conducted of the relay s operating conditions, its real service life, its reliability and its failure modes. Specific maintenance instructions should be defined for this component based on the findings of said evaluation.
Design aspects. Conclusions TOWS in airplanes of the MD-82 generation TOWS design should be reviewed in MD-82 generation airplanes. The goal of this review should be to require that the TOWS comply with the applicable requirements for critical systems classified as essential in CS 25.1309 and FAR 25.1309. 19
Design aspects. Conclusions Certification of TOWS systems Regulations CS-25 and FAR 25 should be revised to add a requirement that ensures that TOWS are not disabled by a single failure or that they provide the crew with a clear and unequivocal warning when the system fails. Guidelines and the clarifying material for the CS-25 and FAR-25 regulations should consider the human errors associated with faults in takeoff configurations when analytically justifying the safety of the TOWS, and to analyze whether the assumptions used when evaluating these systems during their certification are consistent with existing operational experience and with the lessons learned from accidents and incidents. 20
Overview of maintenance factors analysis Local conditions There was another airplane ready for replacement of aircraft if deemed necessary. Self-induced pressure for mechanic: People on board waiting to departure after a delay. High temperatures inside the cabin. Ground assistance and flight crew waiting for a decision from maintenance (replace or not the aircraft). The MEL was available on board
Overview of maintenance factors analysis Individual actions AMM was not consulted Maintenance personnel performed an incomplete analysis of the RAT probe heater malfunction on the ground. Maintenance personnel actuation analysis 1. To place more importance on the most immediate information available 2. To adopt only a few theories 3. Once a theory is adopted, they tend to look for evidence to support it and reject information contrary to it. Tunnel vision phenomenon
Overview of maintenance factors analysis MINIMUM EQUIPMENT LIST (MEL) CONCERNS Go straight to MEL looking for alleviation is not restricted by rules but is not in line with good maintenance practices. MEL is used As first option to try to dispatch an aircraft in detriment of a troubleshooting and/or malfunction correction. Under conditions of dispatch pressure and few time to make a decision.
Maintenance aspects. Conclusions MMEL should be modified in items that may be related to RAT probe heating on the ground so that said items include maintenance (M) and/or operating (O) instructions to check the TOWS. Troubleshooting contained in AMM only consider the case in which the heating system does not supply heat to the RAT probe in flight.
Overview of operational factors analysis According to factual information: 1. CHECKLISTS. Spanair checklists didn t require TOWS to be checked prior to every flight. 2. CRM. There were several deviation from the SOP s. 3. STALL RECOVERY PROCEDURE. Crew didn t identify aircraft stall.
Overview of operational factors analysis SOP s. CHECKLISTS (1/6) 1. There were differences between Boeing FCOM and Spanair OM. 2. Nobody (authority, operator, audits) noticed those differences, so the TOWS wasn t checked prior every flight according to Spanair procedures.
Overview of operational factors analysis SOP s. CHECKLISTS (2/6) 1. National authorities in Europe only accept the checklists. They aren t required to approve them. It isn t clear how in-depth it should be the assessment to accept checklists (there aren t guides). 2. It is not required the operators to have a procedure for controlling the changes in checklists. There aren t any guidance material for the preparation or modification of checklists.
Overview of operational factors analysis SOP s. CHECKLISTS (3/6) The Spanair checklists didn t follow the best criteria related to the design of checklist. 14.12.08 After start checklist The item to check the flaps/slats was omitted. We can hear on the CVR Ask for taxi.. when first officer is about to read the item 9, the last one.
Overview of operational factors analysis SOP s. CHECKLISTS (4/6) 14:22:06 Takeoff Imminent checklist Final items reading by the first officer: FINAL ITEMS, WE HAVE, SORRY ELEVEN ALIGNED EIGHT, ELEVEN STOWED
Overview of operational factors analysis SOP s. CHECKLISTS (5/6) 1. Best criteria to design and modify checklists should be known by everybody. 2. Regulation and guidelines should be developed for both, European authorities and operators, related to the design and maintenance of checklists.
Operational aspects. Conclusions. SOP s. CHECKLISTS (6/6) Guidance material should be drawing up for the preparation, evaluation and modification of checklists associated with normal, abnormal and emergency procedures that is based on the criteria that govern safety management systems.
Overview of operational factors analysis CREW RESOURCE MANAGEMENT (1/3) The circumstances of the accident revealed the existence of several factors potentially related to knowledge and training deficiencies resulting in human errors: stress induced by operational pressures, hurry-up, lack of coordination among crew members, lack of assertiveness, channelized attention, expectation bias, procedural adherence
Overview of operational factors analysis CREW RESOURCE MANAGEMENT (2/3) 1. Captain and first officer received initial and recurring CRM training according to regulation. 2. Line Checks by the authority and operational assessments didn t reveal any weaknesses related to CRM. 3. There is a mismatch between the improper CRM observed in the accident and the efforts expended in the area of CRM. We should ask: 4. Proper training for inspectors.
Operational aspects. Conclusions. CREW RESOURCE MANAGEMENT (3/3) Research or studies should be conducted aimed to assess how the requirements involving crew resource management (CRM) in the European Union are applied and their effectiveness. The results of these studies should reveal the weaknesses that exist in this area and yield proposals for correcting them. Regulatory initiatives should be undertaken intended to require commercial public transport operators to implement a program of line operations safety audits (LOSA), as part of their accident prevention and flight safety programs.
Overview of operational factors analysis STALL RECOVERY PROCEDURE (1/3) Just after take off, the stick shaker and stall aural warning activated. The crew didn t recognized the stall condition. So, they didn t apply the stall recovery procedure, although the stall recovery procedure didn t include the flap/slat lever check.
Overview of operational factors analysis STALL RECOVERY PROCEDURE (2/3) 1. The need to train takeoff stalls has emerged as a constant from most significant accidents related to improper takeoff configuration. 2. Include a check of flap/slat lever in the stall recovery procedure is key for an effective recovery. 3. Simulator are capable of emulating stall conditions.
Operational aspects. Conclusions. STALL RECOVERY PROCEDURE (3/3) Takeoff stall recovery should be part of initial and recurring training programs of pilots. The stall recovery procedure in the (AFM) of large transport airplanes should include a check of the flap/slat lever and its adjustment. Requirements should be established for flight simulators so as to allow simulator training to cover sustained takeoff stalls that reproduce situations that exceed those included in the flight envelope.
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