Accident and Serious Incident Reports: WX

Accident and Serious Incident Reports: WX

Definition

Reports relating to accidents and serious incidents which involved weather or related atmospheric conditions as a significant causal factor.

The reports are grouped together below in subcategories. Weather related events are mostly related to the occurrence or risk of a loss of control because of the effects of significant in flight icing or in flight turbulence. The turbulence case can involve en route or low level flight, the latter especially in respect of approach and landing. Many adverse weather events are associated with Cumulonimbus (Cb) cloud or phenomena associated with them such as the occurrence of HailMicrobursts or Tornados.

In-Flight Airframe Icing

On 14 November 2016, an ATR72-600 crew lost control at FL150 in severe icing conditions. Uncontrolled rolls and a 1,500 feet height loss followed during an apparent stall. After recovery, the Captain announced to the alarmed passengers that he had regained control and the flight was completed without further event. The Investigation found that the crew had been aware that they had encountered severe icing rather than the forecast moderate icing but had attempted to continue to climb which took the aircraft outside its performance limitations. The recovery from the stall was non-optimal and two key memory actions were overlooked.

In the early hours of 24 July 2014, a Boeing MD 83 being operated for Air Algérie by Spanish ACMI operator Swiftair crashed in northern Mali whilst en route from Ouagadougou, Burkina Faso to Algiers and in the vicinity of severe convective actvity associated with the ICTZ. Initial findings of the continuing Investigation include that after indications of brief but concurrent instability in the function of both engines, the thrust to both simultaneously reduced to near idle and control of the aircraft was lost. High speed terrain impact followed and the aircraft was destroyed and all 116 occupants killed.

On 9 September 2017, an ATR 72-500 crew temporarily lost control of their aircraft when it stalled whilst climbing in light to moderate icing conditions after violation of applicable guidance. Recovery was then delayed because the correct stall recovery procedure was not followed. A MAYDAY declaration due to a perception of continuing control problems was followed by a comprehensively unstabilised ILS approach to Madrid. The Investigation concluded that the stall and its sequel were attributable to deficient flight management and inappropriate use of automation. The operator involved was recommended to implement corrective actions to improve the competence of its crews.

On 11 January 2017, control of a Cessna Citation 560 departing Oslo on a short positioning flight was lost control during flap retraction when a violent nose-down manoeuvre occurred. The First Officer took control when the Captain did not react and recovered with a 6 g pullout which left only 170 feet of ground clearance. A MAYDAY - subsequently cancelled when control was regained - was declared and the intended flight was then completed without further event. The Investigation concluded that tailplane stall after the aircraft was not de-iced prior to departure was the probable cause of the upset.

On 15 February 2013, an Embraer EMB-500 Phenom 100 crew lost control of their aircraft shortly before touchdown at Berlin Schönefeld when it stalled and crash-landed. The Investigation was not completed for almost six years but concluded that the stall was a result of ice accretion during an approach in icing conditions without activation of the airframe de icing system. It found poor crew awareness of both the ice and stall protection systems and, suspecting that this may be true of other type-rated pilots, accordingly made Safety Recommendations to key regulatory authorities concerning the type rating syllabus.

On 5 June 2017, a Saab 340B encountered an unexpected short period of severe in-cloud turbulence and icing soon after climbing through FL 100 on departure from Edinburgh and a temporary but constrained loss of pitch control occurred during which three successive Angle of Attack-triggered stick shaker activations occurred before the severity of the turbulence reduced and the intended climb could be resumed. The Investigation found that the crew had not responded to the problem in accordance with prescribed procedures and that at no time during the episode had they set Maximum Continuous Power to aid prompt and effective recovery.

On 13 December 2017, control of an ATR 42-300 was lost just after it became airborne at night from Fond-du-Lac and it was destroyed by the subsequent terrain impact. Ten occupants sustained serious injuries from which one later died and all others sustained minor injuries. The Investigation found that the accident was primarily attributable to pre-takeoff ice contamination of the airframe with an inappropriate pilot response then preventing an achievable recovery. It was found that significant airframe ice accretion had gone undetected during an inadequate pre-flight inspection and that there was a more widespread failure to recognise airframe icing risk.

On 21 December 2015, a Boeing 787-8 at FL400 in the vicinity of convective weather conducive to ice crystal icing penetrated an area which included maximum intensity weather radar returns. A very short period of erratic airspeed indications followed and the FCS reverted to Secondary Mode requiring manual flying. Since this Mode remained 'latched' and could therefore only be reset on the ground, it was decided that an en route diversion was appropriate and this was accomplished without further event. Boeing subsequently modified the FCS software to reduce the chances of reversion to Secondary Mode in short-duration unreliable airspeed events.

On 20 October 2013, a Boeing 757-200 Co-Pilot believed his aircraft was at risk of stalling when he saw a sudden low airspeed indication on his display during a night descent and reacted by increasing thrust and making abrupt pitch-down inputs. Other airspeed indications remained unaffected. The Captain took control and recovery to normal flight followed. The excursion involved a significant Vmo exceedance, damage to and consequent failure of one of the hydraulic systems and passengers and cabin crew injuries. The false airspeed reading was attributed by the Investigation to transient Ice Crystal Icing affecting one of the pitot probes.

On 3 October 2014, the crew of a Saab 340 in the cruise at FL150 in day IMC did not recognise that severe icing conditions had been encountered early enough to make a fully-controlled exit from them and although recovery from the subsequent stall was successful, it was achieved in a non-standard manner. The Investigation concluded that although both mountain wave effects and severe icing had contributed to the incident, the latter had been the main cause. Both crew understanding of airframe icing risk and supporting Operator and Manufacturer documentation on the subject were considered deficient.

In-Flight Icing - Piston Engine

On 1 August 2002, a Cessna 404, en-route at FL130 over Greenland, experienced sudden power loss on both engines, probably as a result of ice in the induction systems, leading to loss of control. The crew regained control at 3000 feet.

On 9th October 2003, a Cessna 172, suffered loss of power and made a forced landing after experiencing Carburettor Icing, over Toronto, Canada

In-Flight Icing - Turbine Engine

On 13 January 1982, an Air Florida Boeing 737-200 took off in daylight from runway 36 at Washington National in moderate snow but then stalled before hitting a bridge and vehicles and continuing into the river below after just one minute of flight killing most of the occupants and some people on the ground. The accident was attributed entirely to a combination of the actions and inactions of the crew in relation to the prevailing adverse weather conditions and, crucially, to the failure to select engine anti ice on which led to over reading of actual engine thrust.

On 4 June 2002, the crew of an MD82 in the cruise at FL330 with AP and A/T engaged failed to notice progressive loss of airspeed and concurrent increase in pitch attitude as both engines rolled back to thrust levels which could not sustain level flight. The aircraft stalled and a recovery was accomplished with significant altitude necessary before engine thrust was restored and a diversion made. The Investigation attributed the engine rollback to ice crystal icing obstructing the engine inlet pressure sensors following crew failure to use the engine anti-icing as prescribed. Two Safety Recommendations were made.

On 25 August 2010, a Boeing 757-200 being operated by UK airline Astraeus on a passenger flight from Freetown Sierra Leone to London Heathrow was in the cruise at night in IMC at FL370 when vibration levels on both engines increased. When the prescribed ice shedding drill was followed, one engine malfunctioned and vibration on the other remained abnormally high and so a MAYDAY was declared and a diversion to Nouakchott, Mauritania was made without further event. None of the 103 occupants were injured and there was no engine damage.

On 11 August 1991, an British Aerospace ATP, during climb to flight level (FL) 160 in icing conditions, experienced a significant degradation of performance due to propeller icing accompanied by severe vibration that rendered the electronic flight instruments partially unreadable. As the aircraft descended below cloud, control was regained and the flight continued uneventfully.

On 5 January 2004, a Fokker 70, operated by Austrian Airlines, carried out a forced landing in a field 2.5 nm short of Munich Runway 26L following loss of thrust from both engines due to icing.

On 13 January 2000, a Shorts SD3-60 suffered a double engine failure on approach to Marsa Brega, Libya, attributed to failure to use engine anti-icing during flight in icing conditions. The aircraft ditched into the sea and was destroyed by impact forces.

En Route In-Cloud Air Turbulence

On 16 January 2020 an Airbus A380 in the cruise at FL 400 in an area of correctly forecast convective turbulence encountered severe turbulence not anticipated by the crew who had not put on the seatbelt signs or alerted the cabin crew in time for the cabin to be secured. An unsecured passenger was seriously injured and several other passengers and an unsecured member of cabin crew were lifted off their feet but managed to avoid injury. The Investigation concluded that the flight crew had not made full use of the capabilities of the available on board weather radar equipment.

On 15 August 2019, a Boeing 787 descending towards destination Beijing received ATC approval for convective weather avoidance but this was then modified with both a new track requirement and a request to descend which diminished its effectiveness. A very brief encounter with violent turbulence followed but as the seat belt signs had not been proactively switched on, the cabin was not secured and two passengers sustained serious injuries and two cabin crew sustained minor injuries. The Investigation noted that weather deviation requests could usefully be accompanied by an indication of how long they were required for.

On 27 February 2012, the crew of an Airbus A330 en route at night and crossing the East African coast at FL360 encountered sudden violent turbulence as they flew into a convective cell not seen on their weather radar and briefly lost control as their aircraft climbed 2000 feet with resultant minor injuries to two occupants. The Investigation concluded that the isolated and rapidly developing cell had not been detected because of crew failure to make proper use of their weather radar, but noted that activation of flight envelope protection and subsequent crew action to recover control had been appropriate.

On 17 October 2011, a Singapore Airlines Boeing 777-300 in the cruise at night with a Training Captain in command made what turned out to be an insufficient deviation around a potential source of turbulence and, with the seat belt signs remaining off, a number of cabin crew and passenger injuries were sustained during sudden brief but severe turbulence encounter. The Operator subsequently introduced enhanced pilot training to support more effective weather avoidance and better use of the various types of weather radar fitted to aircraft in their 777 fleet.

On 18 October 2011, an Etihad Boeing 777-300 encountered severe turbulence westbound over the Bay of Bengal because of a late track deviation whilst the aircraft commander was briefly absent from the flight deck. Two occupants, one a member of the cabin crew and the other a passenger, sustained severe injuries and 12 other occupants sustained minor injuries. The subsequent Investigation noted that the severe weather encountered was evident well in advance and could have been avoided. The low level of experience in role and on aircraft type of the operating crew was noted.

On 19 April 2018, a Boeing 787-8 suddenly encountered a short period of severe turbulence as it climbed from FL160 towards clearance limit FL 190 during a weather avoidance manoeuvre which had taken it close to the Amritsar overhead and resulted in a level bust of 600 feet, passenger injuries and minor damage to cabin fittings. The Investigation found that the flight had departed during a period of adverse convective weather after the crew had failed to download a pre flight met briefing or obtain and review available weather updates.

On 5 June 2017, a Saab 340B encountered an unexpected short period of severe in-cloud turbulence and icing soon after climbing through FL 100 on departure from Edinburgh and a temporary but constrained loss of pitch control occurred during which three successive Angle of Attack-triggered stick shaker activations occurred before the severity of the turbulence reduced and the intended climb could be resumed. The Investigation found that the crew had not responded to the problem in accordance with prescribed procedures and that at no time during the episode had they set Maximum Continuous Power to aid prompt and effective recovery.

On 5 September 2014, the crew of an Embraer 145 encountered a more continuous area of convective activity en-route than expected. When it became impossible to see a way to continue through it, the aircraft commander requested, received and actioned flight path advice from the Company flight-following function. This led to the penetration of a mature thunderstorm and several minutes of severe turbulence with aircraft control lost and only regained upon exit from the storm. The Investigation found that the weather avoidance advice was based on an inappropriate source and that following it was an inappropriate command decision.

On 3 February 2013, an Airbus A340 crew in the cruise in equatorial latitudes at FL350 in IMC failed to use their weather radar properly and entered an area of ice crystal icing outside the prevailing icing envelope. A short period of unreliable airspeed indications on displays dependent on the left side pitot probes followed with a brief excursion above FL350 and reversion to Alternate Law. Excessive vibration on the left engine then began and a diversion was made. The engine remained in use and was subsequently found undamaged with the fault attributed to ice/water ingress due to seal failure.

On 20 April 2012, the crew of a Boeing 737-200 encountered negative wind shear during an ILS final approach at night in lMC and failed to respond with the appropriate recovery actions. The aircraft impacted the ground approximately 4 nm from the threshold of the intended landing runway. The Investigation attributed the accident to the decision to continue to destination in the presence of adverse convective weather and generally ineffective flight deck management and noted that neither pilot had received training specific to the semi-automated variant of the 200 series 737 being flown and had no comparable prior experience.

Hail Damage

On 9 June 2006, an Airbus 321-100, operated by Asiana Airlines, encountered a thunderstorm accompanied by Hail around 20 miles southeast of Anyang VOR at an altitude of 11,500 ft, while descending for an approach to Gimpo Airport. The radome was detached and the cockpit windshield was cracked due to impact with Hail.

On 26th May 2003, a British Midland A321 suffered severe damage from hail en route near Vienna.

Volcanic Ash Effects

On 24 June 1982, a Boeing 747-200 had just passed Jakarta at FL370 in night VMC when it unknowingly entered an ash cloud from a recently begun new eruption of nearby Mount Galunggung which the crew were unaware of. All engines failed in quick succession and a MAYDAY was declared. Involuntary descent began and a provisional diversion back to Jakarta, which would necessitate successful engine restarts to clear mountainous terrain en-route was commenced. Once clear of cloud with three successful engines restarts and level at FL120, the diversion plan was confirmed and completed with a visual approach from the overhead. 

On 15 December 1989, a Boeing 747-400 positioning for a planned en-route stop at Anchorage with crew awareness of a significant volcanic eruption in progress some 150 nm upwind entered volcanic ash during descent north northeast of the airport. When an attempt to climb out of the ash using full thrust was made, all engines failed. After repeated and eventually successful engine restart attempts as a 13,000 feet loss of altitude occurred, the fight was completed. The Report of the comprehensive NTSB Investigation remains unpublished with only a brief factual report containing neither Safety Recommendations nor Safety Actions issued.

Sand/Dust Storm

none on SKYbrary

Fog

On 5 August 2019, a Cessa 560XLS touched down in runway undershot at Aarhus whilst making a night ILS approach there and damage sustained when it collided with parts of the ILS LOC antenna caused a fuel leak which after injury-free evacuation of the occupants then ignited destroying most of the aircraft. The Investigation attributed the accident to the Captain’s decision to intentionally fly below the ILS glideslope in order to touch down at the threshold and to the disabling of the EGWPS alerting function in the presence of a steep authority gradient, procedural non-compliance and poor CRM.

On 2 March 2018, a Cessna 525A touched down at Bern aligned with the left hand edge of the runway and then left it completely before re-entering it after a little over 300 metres and completing the landing roll without further event. Damage to the aircraft and six runway edge and taxi lights was subsequently found. The Investigation noted that the crew stated that they had retained full visual contact with the runway during final approach and that the recorded braking action was good. It was not possible to establish why neither pilot had been aware of the misalignment.

On 19 July 2017, an Airbus A319 crew ignored the prescribed non-precision approach procedure for which they were cleared at Rio de Janeiro Galeão in favour of an unstabilised “dive and drive” technique in which descent was then continued for almost 200 feet below the applicable MDA and led to an EGPWS terrain proximity warning as a go around was finally commenced in IMC with a minimum recorded terrain clearance of 162 feet. The Investigation noted the comprehensive fight crew non-compliance with a series of applicable SOPs and an operational context which was conducive to this although not explicitly causal.

On 29 March 2016, an Antonov AN-26B which had just taken off from Cox s Bazar reported failure of the left engine and requested an immediate return. After twice attempting to position for a landing, first in the reciprocal runway direction then in the takeoff direction with both attempts being discontinued, control was subsequently lost during further manoeuvring and the aircraft crashed. The Investigation found that the engine malfunction occurred before the aircraft became airborne so that the takeoff could have been rejected and also that loss of control was attributable to insufficient airspeed during a low height left turn.

On 18 June 2013, a Boeing 737-800 crew en route to Adelaide encountered un-forecast below-minima weather conditions on arrival there and decided to divert to their designated alternate, Mildura, approximately 220nm away where both the weather report and forecast were much better. However, on arrival there, an un-forecast rapid deterioration to thick fog had occurred with insufficient fuel to go anywhere else. The only available approach was flown, but despite exceeding the minimum altitude by 260 feet, no visual reference was obtained. A further approach with the reported overcast 100 feet agl and visibility 200 metres was continued to a landing.

On 18 June 2013, a Boeing 737-800 crew en route to Adelaide learned that un-forecast below-minima weather had developed there and decided to divert to their designated alternate, Mildura, approximately 220nm away where both the weather report and forecast were much better. However, on arrival at Mildura, an un-forecast rapid deterioration to thick fog had occurred with insufficient fuel to divert elsewhere. The only available approach was flown to a successful landing achieved after exceeding the minimum altitude by 240 feet to gain sight of the runway. An observation immediately afterwards gave visibility 900 metres in fog with cloudbase 100 feet.

On 7 December 1983, a Boeing 727-200 taking off from Madrid in thick fog collided at high speed with a Douglas DC-9 which had not followed its departure taxi clearance to the beginning of the same runway. The DC-9 crew did not advise ATC of their uncertain location until asked for their position after non-receipt of an expected position report. The Investigation concluded that flight deck coordination on the DC-9 had been deficient and noted that gross error checks using the aircraft compasses had not been conducted. The airport was without any surface movement radar.

On 3 December 1990 a Douglas DC9-10 flight crew taxiing for departure at Detroit in thick fog got lost and ended up stopped to one side of an active runway where, shortly after reporting their position, their aircraft was hit by a departing Boeing 727-200 and destroyed by the impact and subsequent fire. The Investigation concluded that the DC9 crew had failed to communicate positional uncertainty quickly enough but that their difficulties had been compounded by deficiencies in both the standard of air traffic service and airport surface markings, signage and lighting undetected by safety regulator oversight.

On 5 January 2014, a Boeing 737-800 operating a domestic flight into Dehli diverted to Jaipur due to destination visibility being below approach minima but had to break off the approach there when the aircraft ahead was substantially damaged during landing, blocking the only runway. There was just enough fuel to return to Dehli as a MAYDAY flight and successfully land below applicable minima and with minimal fuel remaining. The Investigation found that a different alternate with better weather conditions would have been more appropriate and that the aircraft operator had failed to provide sufficient ground-based support to the flight.

On 5 January 2014, an Airbus A320 was unable to land at Delhi due to visibility below crew minima and during subsequent diversion to Jaipur, visibility there began to deteriorate rapidly. A Cat I ILS approach was continued below minima without any visual reference because there were no other alternates within the then-prevailing fuel endurance. The landing which followed was made in almost zero visibility and the aircraft sustained substantial damage after touching down to the left of the runway. The Investigation found that the other possible alternate on departure from Delhi had materially better weather but had been ignored.

Clear Air Turbulence

On 12 October 2019, an ATR 42-500 on which Captain upgrade line training was being conducted encountered mild clear air turbulence soon after descent began and despite setting flight idle power, a concurrent speed increase led to concern at a possible VMO exceedence. An abrupt and ultimately simultaneous manual increase in pitch attitude followed leading to serious injury to the unsecured cabin crew which rendered them unfit to work. The Investigation found that the upset - a change in pitch from -2.3° to +6.3°in one second - was almost entirely due to pitch input from both pilots rather than turbulence.

On 17 January 2021, a Boeing 777-300 which had just begun descent into Beirut encountered unexpected moderate to severe clear air turbulence which resulted in one major and several minor injuries to unsecured occupants including cabin crew. The Investigation found that the flight crew had acted in accordance with all applicable procedures on the basis of information available to them but noted that the operator’s flight watch system had failed to generate and communicate a message about a relevant SIGMET until after the severe turbulence episode due to a data processing issue not identified as representing an operational safety risk.

On 13 September 2017, the airspeed of a Boeing 737-800 unexpectedly increased during an intentionally high speed descent and the Captain’s overspeed prevention response, which followed his taking over control without following the applicable procedure, was inappropriate and led directly to cabin crew injuries, one of which was serious. The Investigation found that the speed increase had been the result of a sudden decrease in tailwind component associated with windshear and noted that despite moderate clear air turbulence being forecast for the area, this had not resulted in the seat belt signs being on or any consequent cabin crew briefing.

On 10 July 2019 an Airbus A380 in the cruise at night at FL 400 encountered unexpectedly severe turbulence approximately 13 hours into the 17 hour flight and 27 occupants were injured as a result, one seriously. The detailed Investigation concluded that the turbulence had occurred in clear air in the vicinity of a significant area of convective turbulence and a jet stream. A series of findings were related to both better detection of turbulence risks and ways to minimise injuries if unexpectedly encountered with particular reference to the aircraft type and operator but with wider relevance.

On 13 February 2019, a Boeing 737-800 en-route over the southern Adriatic Sea unexpectedly encountered severe clear air turbulence and two unsecured cabin crew and some unsecured passengers were thrown against the cabin structure and sustained minor injuries. The Investigation found that the Captain had conducted the crew pre-flight briefing prior to issue of the significant weather chart applicable to their flight by which time severe turbulence due to mountain waves at right angles to an established jetstream not shown on the earlier chart used for the briefing was expected at a particular point on their route.

On 2 February 2020, an Airbus A380 in the cruise at night at FL 330 encountered unforecast clear air turbulence with the seatbelt signs off and one unsecured passenger in a standard toilet compartment sustained a serious injury as a result. The Investigation noted that relevant airline policies and crew training had been in place but also observed a marked difference in the availability of handholds in toilet compartments provided for passengers with disabilities or other special needs and those in all other such compartments and made a corresponding safety recommendation to standardise and placard handhold provision in all toilet compartments.

On 21 August 2019, an Airbus A340-600 encountered sudden-onset moderate to severe clear air turbulence whilst in the cruise at FL 360 over northern Turkey which resulted in a serious passenger injury. The Investigation found that the flight was above and in the vicinity of convective clouds exhibiting considerable vertical development but noted that neither the en-route forecast nor current alerting had given any indication that significant turbulence was likely to be encountered. It was noted the operator s flight crew had not been permitted to upload weather data in flight but since this event, that restriction had been removed.

On 24 June 2018, a Boeing 777-300 was briefly subjected to unexpected and severe Clear Air Turbulence (CAT) whilst level at FL300 which resulted in a serious injury to one of the cabin crew as they cleared up after in-flight service. The Investigation concluded that the turbulence had occurred because of the proximity of the aircraft to a strong jet stream and that the forecast available at pre-flight briefing had underestimated the strength of the associated vertical wind shear.

On 2 September 2013, an Airbus A330-200 crossing the ITCZ at FL400 at night encountered sudden severe turbulence unanticipated by the crew resulting in serious injuries to a few cabin crew / passengers and minor injuries to twelve others. An en route diversion to Fortaleza was made. The Investigation found that the origin of the turbulence was severe convective weather and failure to detect it in an area where it had been forecasted indicated that it was probably associated with sub-optimal use of the on-board weather radar with the severity of the encounter possibly aggravated by inappropriate contrary control inputs.

On 30 December 2015, a Boeing 777-300 making an eastbound Pacific crossing en-route to Toronto encountered forecast moderate to severe clear air turbulence associated with a jet stream over mountainous terrain. Some passengers remained unsecured and were injured, one seriously and the flight diverted to Calgary. The Investigation found that crew action had mitigated the injury risk but that more could have been achieved. It was also found that the pilots had not been in possession of all relevant information and that failure of part of the air conditioning system during the turbulence was due to an improperly installed clamp.

Precipitation-limited In Flight Vision

On 15 August 2015, an Airbus A321 on approach to Charlotte commenced a go around but following a temporary loss of control as it did so then struck approach and runway lighting and the undershoot area sustaining a tail strike before climbing away. The Investigation noted that the 2.1g impact caused substantial structural damage to the aircraft and attributed the loss of control to a small microburst and the crew’s failure to follow appropriate and recommended risk mitigations despite clear evidence of risk given by the aircraft when it went around and available visually.

On 20 June 2019, an Airbus A320 about to touchdown at night at Calicut drifted to the right once over the runway when the rain intensity suddenly increased and briefly left the runway before regaining it and completing the landing and taxi in. Runway edge lighting and the two main gear tyres were damaged. The Investigation attributed the excursion to loss of enough visual reference to maintain the centreline until touchdown followed by late recognition of the deviation and delayed response to it. The visibility reduction was considered to have created circumstances in which a go-around would have been advisable.

On 13 January 1982, an Air Florida Boeing 737-200 took off in daylight from runway 36 at Washington National in moderate snow but then stalled before hitting a bridge and vehicles and continuing into the river below after just one minute of flight killing most of the occupants and some people on the ground. The accident was attributed entirely to a combination of the actions and inactions of the crew in relation to the prevailing adverse weather conditions and, crucially, to the failure to select engine anti ice on which led to over reading of actual engine thrust.

On 29 October 2006, an ADC Airlines Boeing 737-200 encountered wind shear almost immediately taking off from Abuja into adverse weather associated with a very rapidly developing convective storm. Unseen from the apron or ATC TWR it stalled, crashed and burned after just over one minute airborne killing 96 of the 105 occupants. The Investigation concluded that loss of control during the wind shear encounter was not inevitable but was a consequence of inappropriate crew response. Concerns about the quality of crew training and competency validation were also raised.

On 24 November 1998, a KLM uk Fokker 100 overran runway 20 at Southampton after a late and fast daylight touchdown in rain was followed by poor braking. The Investigation found that the assessment of the runway as ‘wet’ passed by ATC prior the incident was correct but that sudden heavy rain shortly before the aircraft landed had caused a rapid deterioration to somewhere between ‘Wet’ and ‘Flooded’. Slow drainage of water from the runway was subsequently identified and the runway was grooved.

On 16 August 2018, a Boeing 737-800 made a stabilised approach to Manila during a thunderstorm with intermittent heavy rain but the crew lost adequate visual reference as they arrived over the runway. After a drift sideways across the 60 metre-wide landing runway, a veer off occurred and was immediately followed by a damaging collision with obstructions not compliant with prevailing airport safety standards. The Investigation found that the Captain had ignored go around calls from the First Officer and determined that the corresponding aircraft operator procedures were inadequate as well as faulting significant omissions in the Captain s approach brief.

On 20 February 2018, a Boeing MD-83 attempting a night landing at Port Harcourt during a thunderstorm and heavy rain touched down well beyond the touchdown zone and departed the side of the runway near its end before continuing 300 metres beyond it. The Investigation found that a soft touchdown had occurred with 80% of the runway behind the aircraft and a communications failure on short final meant a wind velocity change just before landing leading to a tailwind component of almost 20 knots was unknown to the crew who had not recognised the need for a go around.

On 28 September 2018, a Boeing 737-800 was flown into the sea short of the intended landing runway at Chuuk during a non-precision approach which was continued below MDA without having obtained the required visual reference. The Investigation found that the Captain s approach had become unstable soon after autopilot disconnection and an excessive rate of descent had taken the aircraft below the indicated glideslope and below MDA despite multiple EGPWS Sink Rate aural Alerts and a visual-only PULL UP Warning with impact following 22 seconds after passing MDA. The absence of an aural PULL UP Warning was considered significant.

On 8 April 2015, an Airbus A320 crew lost their previously-acquired and required visual reference for the intended landing runway at Brasilia but continued descent in heavy rain and delayed beginning a go around until the aircraft was only 40 feet above the runway threshold but had not reached it. A premature touchdown prior to the runway then occurred and the aircraft travelled over 30 metres on the ground before becoming airborne again. The Investigation was unable to establish any explanation for the failure to begin a go around once sufficient visual reference was no longer available.

On 6 December 2016, a Boeing 737-800 approaching Darwin at night in the vicinity of thunderstorm activity suddenly encountered very heavy rain just before landing which degraded previously good visual reference. After drifting right of centreline just before and after touchdown, the right main gear left the runway for 400 metres before regaining. The landing and taxi-in was subsequently completed. The Investigation attributed the excursion to difficulty in discerning lateral drift during the landing flare to an abnormally wide runway with no centreline lighting in poor night visibility and noted similar previous outcomes had been consistently associated with this context.

Strong Surface Winds

On 7 August 2020, a Boeing 737-800 making its second attempt to land at Calicut off a night ILS approach with a significant tailwind component became unstabilised and touched down approximately half way down the 2,700 metre-long wet table top runway and departed the end of it at 85 knots before continuing through the RESA and a fence and then dropping sharply onto a road. This caused the fuselage to separate into three pieces with 97 of the 190 occupants including both pilots being fatally or seriously injured and 34 others sustaining minor injuries. Significant fuel spillage occurred but there was no fire.

On 9 January 2020, a Fokker 100 overran the landing runway at Newman. The Investigation found that a stabilised approach had preceded a correctly-positioned touchdown and attributed the overrun to a combination of the approach speed required by the prevailing crosswind and runway surface conditions. It was noted that whilst the aircraft operator did not permit contaminated runway operations, they had not provided their pilots with any guidance as to when contamination might exist and also that advisory material published by the safety regulator did not cover the risk of reduced braking performance during landings in moderate or heavy rainfall.

On 17 September 2020, a Bombardier Global 6000 which had completed a circling approach to land at Biggin Hill in day VMC touched down with an inappropriate pitch and roll attitude which caused the right wingtip to contact the runway surface. The Investigation found that the landing technique just before touchdown was not in accordance with the manufacturer’s crosswind landing technique although the roll rate achieved could not be accounted for by the roll control input alone and was probably increased by localised wind velocity variations despite the absence of any such variations being reported by ATC.

On 9 February 2020, the tail strike prevention system on a Boeing 787-9 was annunciated during takeoff from London Heathrow in gusting crosswind conditions. Permission to hold at 6000 feet to conduct the response procedure was given and since this procedure did not permit pressurisation, an overweight return to land followed. The Investigation found that although the tail strike protection system had returned the pitch rate to the correct one after an exceedence just before commencing rotation, lateral control inputs then resulted in a decrease in lift resulting in the tail contact angle being reached whilst still on the runway.

On 9 February 2020, a Boeing 737-800 rejected its takeoff from East Midlands from a speed above V1 after encountering windshear in limiting weather conditions and was brought to a stop with 600 metres of runway remaining. The Investigation found that the Captain had assigned the takeoff to his First Officer but had taken control after deciding that a rejected takeoff was appropriate even though unequivocal QRH guidance that high speed rejected takeoffs should not be made due to windshear existed. Boeing analysis found that successful outcomes during takeoff windshear events have historically been more likely when takeoff is continued.

On 16 January 2018, a McDonnell Douglas MD-82 attempting to land at Tarbes was subject to gross mishandling by the crew and the approach became unstable. A subsequent low level go-around attempt was then made without setting sufficient thrust which resulted in sustained and close proximity to terrain at an airspeed close to stall entry before the required thrust was eventually applied. The Investigation was hindered by non-reporting of the event but was able to conclude that multiple pilot errors in a context of poor crew coordination during the approach had caused confusion when the go around was initiated.

On 14 September 2010, the crew of a Sichuan Airlines Airbus A319 continued an ILS approach into Wuxi despite awareness of adverse convective weather conditions at the airport. Their inattention to automation management then led to a low energy warning and the inappropriate response to this led to the activation of flight envelope protection quickly followed by a stall warning. Inappropriate response to this was followed by loss of control and a full stall and high rate of descent from which recovery was finally achieved less than 900 feet agl.

On 29 October 2006, an ADC Airlines Boeing 737-200 encountered wind shear almost immediately taking off from Abuja into adverse weather associated with a very rapidly developing convective storm. Unseen from the apron or ATC TWR it stalled, crashed and burned after just over one minute airborne killing 96 of the 105 occupants. The Investigation concluded that loss of control during the wind shear encounter was not inevitable but was a consequence of inappropriate crew response. Concerns about the quality of crew training and competency validation were also raised.

On 1 September 2018, a Boeing 737-800, making its second night approach to Sochi beneath a large convective storm with low level windshear reported, floated almost halfway along the wet runway before overrunning it by approximately 400 metres and breaching the perimeter fence before stopping. A small fire did not prevent all occupants from safely evacuating. The Investigation attributed the accident to crew disregard of a number of windshear warnings and a subsequent encounter with horizontal windshear resulting in a late touchdown and noted that the first approach had meant that the crew had been poorly prepared for the second.

On 17 October 2019, a Saab 2000 overran the Unalaska runway after touchdown following difficulty braking and exited the airport perimeter before finally coming to rest on shoreline rocks. The Investigation attributed the poor braking to incorrect brake system wiring originating during maintenance some 2½ years earlier but noted the touchdown occurred with crew awareness that the prevailing tailwind component was well in excess of the permitted limits with no reason not to use the into-wind runway and attributed this to plan continuation bias. The aircraft operator’s failure to apply their specifically-applicable airport qualification requirements to the Captain was noted.

Lightning Damage

On 22 February 2008, a Eurocopter AS332 L2 Super Puma flying from an offshore oil platform to Aberdeen was struck by lightning. There was no apparent consequence and so, although this event required a landing as soon as possible, the commander decided to continue the remaining 165nm to the planned destination which was achieved uneventfully. Main rotor blade damage including some beyond repairable limits was subsequently discovered. The Investigation noted evidence indicating that this helicopter type had a relatively high propensity to sustain lightning strikes but noted that, despite the risk of damage, there was currently no adverse safety trend.

On 5 May 2019, a Sukhoi RRJ-95B making a manually-flown return to Moscow Sheremetyevo after a lightning strike caused a major electrical systems failure soon after departure made a mismanaged landing which featured a sequence of three hard bounces of increasing severity. The third of these occurred with the landing gear already collapsed and structural damage and a consequential fuel-fed fire followed as the aircraft veered off the runway at speed. The subsequent evacuation was only partly successful and 41 of the 73 occupants died and 3 sustained serious injury. An Interim Report has been published.

On 26 November 2014, an Airbus A330-200 was struck by lightning just after arriving at its allocated stand following a one hour post-landing delay after suspension of ramp operations due to an overhead thunderstorm. Adjacent ground services operatives were subject to electrical discharge from the strike and one who was connected to the aircraft flight deck intercom was rendered unconscious. The Investigation found that the equipment and procedures for mitigation of risk from lightning strikes were not wholly effective and also that perceived operational pressure had contributed to a resumption of ground operations which hindsight indicated had been premature.

On 25 September 2001, an Embraer 145 in descent to Manchester sustained a low power lightning strike which was followed, within a few seconds, by the left engine stopping without failure annunciation. A successful single engine landing followed. The Investigation concluded that the cause of failure of the FADEC-controlled AE3007 engine (which has no surge recovery logic) was the aero-thermal effects of the strike to which all aircraft with relatively small diameter fuselages and close mounted engines are vulnerable. It was considered that there was a risk of simultaneous double engine flameout in such circumstances which was impossible to quantify.

On 15 December 2014, the Captain of a Saab 2000 lost control of his serviceable aircraft after a lightning strike when he attempted to control the aircraft manually without first disconnecting the autopilot and despite the annunciation of a series of related alerts. The aircraft descended from 4,000 feet to 1,100 feet at up to 9,500 fpm and 80 knots above Vmo. A fortuitous transient data transmission fault caused autopilot disconnection making it possible to respond to EGPWS 'SINK RATE' and 'PULL UP' Warnings. The Investigation concluded that limitations on autopilot disconnection by pilot override were contrary to the type certification of most other transport aircraft.

On 14th September 1999, a Britannia Airways Boeing 757 crash landed and departed the runway after a continued unstabilised approach in bad weather to Girona airport, Spain.

On 4 December 2003, the crew of a Dornier 228 approaching Bodø lost control of their aircraft after a lightning strike which temporarily blinded both pilots and damaged the aircraft such that the elevator was uncontrollable. After regaining partial pitch control using pitch trim, a second attempt at a landing resulted in a semi-controlled crash which seriously injured both pilots and damaged the aircraft beyond repair. The Investigation concluded that the energy in the lightning had probably exceeded certification resilience requirements and that up to 30% of the bonding wiring in the tail may have been defective before lightning struck.

Low Level Windshear

On 9 February 2020, a Boeing 737-800 rejected its takeoff from East Midlands from a speed above V1 after encountering windshear in limiting weather conditions and was brought to a stop with 600 metres of runway remaining. The Investigation found that the Captain had assigned the takeoff to his First Officer but had taken control after deciding that a rejected takeoff was appropriate even though unequivocal QRH guidance that high speed rejected takeoffs should not be made due to windshear existed. Boeing analysis found that successful outcomes during takeoff windshear events have historically been more likely when takeoff is continued.

On 15 August 2015, an Airbus A321 on approach to Charlotte commenced a go around but following a temporary loss of control as it did so then struck approach and runway lighting and the undershoot area sustaining a tail strike before climbing away. The Investigation noted that the 2.1g impact caused substantial structural damage to the aircraft and attributed the loss of control to a small microburst and the crew’s failure to follow appropriate and recommended risk mitigations despite clear evidence of risk given by the aircraft when it went around and available visually.

On 19 August 2017, an Airbus A340-300 encountered significant unforecast windshear on rotation for a maximum weight rated-thrust night takeoff from Bogotá and was unable to begin its climb for a further 800 metres during which angle of attack flight envelope protection was briefly activated. The Investigation noted the absence of a windshear detection system and any data on the prevalence of windshear at the airport as well as the failure of ATC to relay in English reports of conditions from departing aircraft received in Spanish. The aircraft operator subsequently elected to restrict maximum permitted takeoff weights from the airport.

On 4 August 2018, a Junkers Ju-52 making a low level sightseeing flight through the Swiss Alps crashed killing all 20 occupants after control was lost when it stalled after encountering unexceptional windshear. The Investigation found that the pilots had created the conditions which led to the stall and then been unable to recover from it and concluded that the accident was a direct consequence of their risky behaviour. It found that such behaviour was common at the operator, that the operator was being managed without any regard to operational risk and that safety regulatory oversight had been systemically deficient.

On 14 September 2010, the crew of a Sichuan Airlines Airbus A319 continued an ILS approach into Wuxi despite awareness of adverse convective weather conditions at the airport. Their inattention to automation management then led to a low energy warning and the inappropriate response to this led to the activation of flight envelope protection quickly followed by a stall warning. Inappropriate response to this was followed by loss of control and a full stall and high rate of descent from which recovery was finally achieved less than 900 feet agl.

On 29 October 2006, an ADC Airlines Boeing 737-200 encountered wind shear almost immediately taking off from Abuja into adverse weather associated with a very rapidly developing convective storm. Unseen from the apron or ATC TWR it stalled, crashed and burned after just over one minute airborne killing 96 of the 105 occupants. The Investigation concluded that loss of control during the wind shear encounter was not inevitable but was a consequence of inappropriate crew response. Concerns about the quality of crew training and competency validation were also raised.

On 23 December 2011, an Austrian Airlines Airbus A321 sustained a tail strike at Manchester as the main landing gear contacted the runway during a night go around initiated at a very low height after handling difficulties in the prevailing wind shear. The remainder of the go around and subsequent approach in similar conditions was uneventful and the earlier tail strike was considered to have been the inevitable consequence of initiating a go around so close to the ground after first reducing thrust to idle. Damage to the aircraft rendered it unfit for further flight until repaired but was relatively minor.

On 1 September 2018, a Boeing 737-800, making its second night approach to Sochi beneath a large convective storm with low level windshear reported, floated almost halfway along the wet runway before overrunning it by approximately 400 metres and breaching the perimeter fence before stopping. A small fire did not prevent all occupants from safely evacuating. The Investigation attributed the accident to crew disregard of a number of windshear warnings and a subsequent encounter with horizontal windshear resulting in a late touchdown and noted that the first approach had meant that the crew had been poorly prepared for the second.

On 27 May 2018, four losses of separation on final approach during use of dependent parallel landing runways occurred within 30 minutes at Madrid following a non-scheduled weather-induced runway configuration change. This continuing situation was then resolved by reverting to a single landing runway. The Investigation attributed these events to “the complex operational situation” which had prevailed following a delayed decision to change runway configuration after seven consecutive go-arounds in 10 minutes using the previous standard runway configuration. The absence of sufficient present weather information for the wider Madrid area to adequately inform ATC tactical strategy was assessed as contributory.

On 20 February 2018, a Boeing MD-83 attempting a night landing at Port Harcourt during a thunderstorm and heavy rain touched down well beyond the touchdown zone and departed the side of the runway near its end before continuing 300 metres beyond it. The Investigation found that a soft touchdown had occurred with 80% of the runway behind the aircraft and a communications failure on short final meant a wind velocity change just before landing leading to a tailwind component of almost 20 knots was unknown to the crew who had not recognised the need for a go around.

In Flight Icing - Turboprop Engine

none on SKYbrary

In Flight Icing - Jet Engine

none on SKYbrary

Mountain Wave/Rotor Conditions

none on SKYbrary

Triggered Lightning Strike

none on SKYbrary

Layer Cloud Airframe Icing

On 9 February 2020, a Boeing 737-800 rejected its takeoff from East Midlands from a speed above V1 after encountering windshear in limiting weather conditions and was brought to a stop with 600 metres of runway remaining. The Investigation found that the Captain had assigned the takeoff to his First Officer but had taken control after deciding that a rejected takeoff was appropriate even though unequivocal QRH guidance that high speed rejected takeoffs should not be made due to windshear existed. Boeing analysis found that successful outcomes during takeoff windshear events have historically been more likely when takeoff is continued.

On 15 August 2015, an Airbus A321 on approach to Charlotte commenced a go around but following a temporary loss of control as it did so then struck approach and runway lighting and the undershoot area sustaining a tail strike before climbing away. The Investigation noted that the 2.1g impact caused substantial structural damage to the aircraft and attributed the loss of control to a small microburst and the crew’s failure to follow appropriate and recommended risk mitigations despite clear evidence of risk given by the aircraft when it went around and available visually.

On 19 August 2017, an Airbus A340-300 encountered significant unforecast windshear on rotation for a maximum weight rated-thrust night takeoff from Bogotá and was unable to begin its climb for a further 800 metres during which angle of attack flight envelope protection was briefly activated. The Investigation noted the absence of a windshear detection system and any data on the prevalence of windshear at the airport as well as the failure of ATC to relay in English reports of conditions from departing aircraft received in Spanish. The aircraft operator subsequently elected to restrict maximum permitted takeoff weights from the airport.

On 4 August 2018, a Junkers Ju-52 making a low level sightseeing flight through the Swiss Alps crashed killing all 20 occupants after control was lost when it stalled after encountering unexceptional windshear. The Investigation found that the pilots had created the conditions which led to the stall and then been unable to recover from it and concluded that the accident was a direct consequence of their risky behaviour. It found that such behaviour was common at the operator, that the operator was being managed without any regard to operational risk and that safety regulatory oversight had been systemically deficient.

On 14 September 2010, the crew of a Sichuan Airlines Airbus A319 continued an ILS approach into Wuxi despite awareness of adverse convective weather conditions at the airport. Their inattention to automation management then led to a low energy warning and the inappropriate response to this led to the activation of flight envelope protection quickly followed by a stall warning. Inappropriate response to this was followed by loss of control and a full stall and high rate of descent from which recovery was finally achieved less than 900 feet agl.

On 29 October 2006, an ADC Airlines Boeing 737-200 encountered wind shear almost immediately taking off from Abuja into adverse weather associated with a very rapidly developing convective storm. Unseen from the apron or ATC TWR it stalled, crashed and burned after just over one minute airborne killing 96 of the 105 occupants. The Investigation concluded that loss of control during the wind shear encounter was not inevitable but was a consequence of inappropriate crew response. Concerns about the quality of crew training and competency validation were also raised.

On 23 December 2011, an Austrian Airlines Airbus A321 sustained a tail strike at Manchester as the main landing gear contacted the runway during a night go around initiated at a very low height after handling difficulties in the prevailing wind shear. The remainder of the go around and subsequent approach in similar conditions was uneventful and the earlier tail strike was considered to have been the inevitable consequence of initiating a go around so close to the ground after first reducing thrust to idle. Damage to the aircraft rendered it unfit for further flight until repaired but was relatively minor.

On 1 September 2018, a Boeing 737-800, making its second night approach to Sochi beneath a large convective storm with low level windshear reported, floated almost halfway along the wet runway before overrunning it by approximately 400 metres and breaching the perimeter fence before stopping. A small fire did not prevent all occupants from safely evacuating. The Investigation attributed the accident to crew disregard of a number of windshear warnings and a subsequent encounter with horizontal windshear resulting in a late touchdown and noted that the first approach had meant that the crew had been poorly prepared for the second.

On 27 May 2018, four losses of separation on final approach during use of dependent parallel landing runways occurred within 30 minutes at Madrid following a non-scheduled weather-induced runway configuration change. This continuing situation was then resolved by reverting to a single landing runway. The Investigation attributed these events to “the complex operational situation” which had prevailed following a delayed decision to change runway configuration after seven consecutive go-arounds in 10 minutes using the previous standard runway configuration. The absence of sufficient present weather information for the wider Madrid area to adequately inform ATC tactical strategy was assessed as contributory.

On 20 February 2018, a Boeing MD-83 attempting a night landing at Port Harcourt during a thunderstorm and heavy rain touched down well beyond the touchdown zone and departed the side of the runway near its end before continuing 300 metres beyond it. The Investigation found that a soft touchdown had occurred with 80% of the runway behind the aircraft and a communications failure on short final meant a wind velocity change just before landing leading to a tailwind component of almost 20 knots was unknown to the crew who had not recognised the need for a go around.

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