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|Category:||Loss of Control|
|Content source:||Flight Safety Foundation|
Note: A number of SKYbrary articles cover different aspects of a go-around in detail, these can be found in the Related Articles section below. The review here is intended to compliment these articles and aims to provide an overview of the subject beyond “how to” fly a go-around. Pilots should recognise the priority of their own Company procedures as detailed in the applicable Operations Manuals and, where applicable as part of approved operational-use documentation, the relevant Aircraft Flight Manual (AFM).
A Safety Manoeuvre
A Go-Around is performed for safety reasons e.g. failure to acquire / loss of the required visual reference for a landing, sudden change in wind velocity detrimental to continuing an approach, evidence or advice of a runway incursion and where an approach is unstabilised. One of the largest contributing factors to fatal accidents overall and to all runway excursion accidents, is the failure to successfully execute a go-around or and/or a failure to make a timely decision to go-around.
However the go-around manoeuvre itself, and subsequent flight management, will introduce new risks, as shown in the example accidents highlighted below.
For a majority of pilots a go-around will be a rare event. Current training for go-arounds may fail to cover their execution adequately, especially in respect of the form in which they are most likely to be encountered - with all engines functioning. The effect of this can lead to pilots being unprepared even if they have made the decision to go-around. This is particularly true where the onset of the circumstances which have created the need for a go around have not been anticipated. If, because of this, one or both pilots are “startled”, the consequences can include:
- contributing to a delay in initiating the necessary action as well as in making the decision which can complicate the manoeuvre and increase risk
- contributing to a failure by the PF to apply the trained SOP aircraft handling / management as prescribed, especially in sequence and to ineffective cross-monitoring by the PM,
At the initiation of any go around manoeuvre, especially one near to or even in contact with the runway, workload is significantly increased so that they are likely to be functioning much nearer their mental capacity than during the approach phase. Notwithstanding their need to communicate with aircraft making a go around to assure traffic separation, Air Traffic Control, need to recognise that this is a time to keep communication to a minimum commensurate with safety. The only additional communication which will be helpful to pilots beyond instructions essential for separation are those which simplify the go around being flown - for example by increasing the stop altitude or issuing a radar heading in place of a complex tracking sequence. The message is that ATC can make an important contribution to go-around safety.
Although increased crew cooperation, task-sharing, cross-monitoring and situational awareness are all required at this time, there is a risk that one or both pilots can become fixated on a single issue, especially airspeed, at the expense of aircraft pitch attitude. If this happens, then a number of effects may follow:
- attention may narrow and instrument scanning may cease,
- overall situational awareness may decrease
- effective communication between pilots diminishes and standard callouts may be omitted.
In effect CRM breaks down.
Such a 'tunnel vision' effect is often a consequence of somatogravic illusion which arises when the effects of acceleration and pitch change are unconsciously confused. Loss of Control from which recovery is not attempted until it can no longer be achieved before ground impact is a real risk which is exacerbated if pilots are overloaded.
'Aviate, Navigate, Communicate' was an early mantra summing up relative pilot priorities as flying became a more complicated activity than simply keeping control of the aeroplane which has absolutely survived the test of time and still underlies the more recent concept of Crew Resource Management (CRM). Effective CRM has particular relevance to the safe conduct of a go-around and must its facilitation must underlie the construction of effective go-around training regimes if they are to succeed.
CRM and SOPs
Communication and coordination between pilots can suffer during a go-around, and cross-monitoring tasks can be completely overlooked. Sufficiently detailed discussion about a potential go-around, the technique to be adopted and the corresponding FMS use required, the expected aircraft performance and the applicable missed approach procedure needs to take place as part of the Descent Checks to ensure that task delegation and cross-monitoring expectations are clear.
Although it has not found widespread favour, some operators, notably British Airways, use the Monitored Approach as a universal SOPs in order to better prepare both pilots for the eventual 'go-around' or 'continue-towards-a-landing' decision. This method requires one pilot to act as PF for the approach and to remain in that role and fly a go around if, at or prior to DA/MDA, a call of 'land' or equivalent is not made. Most operators, however, maintain the designated PF in that role throughout. The available evidence neither supports or contradicts this. What is important is that the appreciation of the effect of different levels of pilot experience on teamwork in the flight deck. Positive / assertive behaviour and communication must displace any tendency of either pilot to make assumptions, automatically accept non compliance or have inappropriate levels of confidence in the judgement or capabilities of their colleague. Any need for an unplanned late change of PF during approach or go around should be a rare and exceptional event.
If a breakdown in CRM occurs, then it is likely that situational awareness between pilots will become degraded. If both pilots fail to maintain effective flight instrument scanning during the initiation and execution of a go around, in particular focussing on pitch attitude, then an incipient upset will not be detected and the risk that they will be unable to avoid the trap presented by a somatogravic illusion to which they may be exposed during acceleration and/or rapid pitch change.
Pitch, Power, Performance
Crew mishandling of Pitch, Power and Performance is a leading factor in fatal go-around accidents.
The essential actions are
- Establish and maintain the prescribed Pitch Attitude ensuring that essential configuration changes in landing gear status, speedbrake status and wing configuration have been made.
- Set and confirm the appropriate Power/Thrust.
- Confirm that the expected Climb Performance has been achieved
Since it is quite likely that pilots flying large commercial aircraft will be utilising some element of automation, it is particularly important that they fully understand the way in which the auto-throttle system works and at all times remain cognisant of autopilot status, and monitor Flight Management System selections. Where use of a Take-off / Go-around (TO/GA) Mode is involved, there must be a complete understanding of its performance and limitations.
When executing a go-around it is also likely that pitch response with all engines functioning will be amplified due to the relatively low gross weight towards the end of a flight and the high thrust available from modern aircraft engines. This is especially true for aircraft with under-wing mounted engines. Some attention is beginning to be given to the problems which may follow the use of TOGA thrust but unless there are applicable SOPs which provide a clear option to apply less than this thrust when initiating a go around, it must be used initially, with a recognition that subsequent reduction may be necessary.
When go-arounds are initiated from very low levels (below 200ft) and speeds, it is desirable to minimise height loss as the momentum and flight vector of the aircraft change in response to new power and flight control inputs. The directly commanded change in pitch attitude will be assisted by the application of increased thrust and in many cases by a requirement to retract one stage of flap too. The combined effect may be a risk of excessive pitch attitude, particularly of the application of thrust is other than gentle-progressive and some forward pitch control input may be necessary to counteract this.
The majority of modern transport aircraft have trimmable horizontal stabilisers and it is possible that during low speed on an approach pitch trim can reach, or approach , the limits of available travel. As a result, if a go-around is then initiated, there may not be enough direct pitch control available to counter the pitch-up caused by a large increase in thrust and the trimmable horizontal stabiliser, with its much greater surface area compared with the that of an elevator, may provide the necessary pitch-down input. It is important that pilots remain aware of how pitch trim has been used during an approach and what control remains available both in autoflight or manually if a go around is then executed. An example of an accident which indicated the importance of this awareness was the loss of a China Airlines A300 in the vicinity of Nagoya Airport, Japan in 1994.
Completing a go-around safely
The avoidance of a level bust at the conclusion of a missed approach is extremely important since if no further climb clearance has been received, the restriction is likely to be in place because of the need to avoid conflict with other aircraft flying above. The same is true of specified tracks and any radar headings, although these may also be linked to the avoidance of obstacles and terrain - or the requirements of noise abatement.
Throughout any missed approach, pilots need to maintain their concentration and manage the go around flight phase with effective task-sharing and cross-monitoring. There could be a temptation to relax after an initially sudden and intense period of activity!
Missed Approach Risks
A missed approach may encounter risks that were not present on the approach which preceded it such as:
- loss of separation
- unexpected wake turbulence
- Controlled Flight Into Terrain (CFIT)
- adverse weather
- loss of control especially in dark night or IMC where spatial disorientation is most likely
- reduced fuel endurance
The 2013 Go-Around Safety Forum - Findings and Conclusions
The Findings and Conclusions from the June 2013 Go-Around Safety Forum held in Brussels contain many useful ideas which might inform a review of the relevant Strategies by the various stakeholders.
Strategies relevant to the Safe Execution of Go-Arounds
The Forum resulted in the definition of a total of eight strategies covering the issues involved in go-around safety. Three of these covered the safe execution of go arounds:
- Strategy 4 – Ensure that go-around training and awareness appropriately reflect different risk execution scenarios.
- Strategy 5 – Review go-around policy, procedures and documentation to maximise their effectiveness, clarity and understanding..
- Strategy 6 – Ensure that low relevant experience of one or both crew does not prejudice the effectiveness of cross monitoring during approach, landing and go-around.
Conclusions relevant to Air Operators
Forum Conclusions relevant to the various strategies were not used to develop specific Recommendations but those below which are relevant to the safe execution of go arounds should nevertheless provide useful starting points for aircraft operators who seek opportunities to support the safe go-around execution by their pilots:
Related Accidents and Incidents
A list of 66 independently investigated accidents and incidents involving go-arounds can be found in the annex to the this Study presented by Captain Ed Pooley at the Go-Around Safety Forum in Brussels 2013. Some of these are listed here:
- A320, vicinity Bahrain Airport, Kingdom of Bahrain, 2000: On 23 August 2000, an Airbus A320-200 being operated by Gulf Air on a scheduled passenger flight from Cairo to Bahrain commenced a night go around in VMC after its non precision approach to runway 12 at destination became unstable but then failed to establish a normal climb before descending at speed into the sea 3 miles from the airport. The aircraft was destroyed and all 143 occupants were killed.
- B752, vicinity Gardermoen Oslo Norway, 2002: On 22 of January 2002, a Boeing 757-200 operated by Icelandair commenced an unstabilised approach to Oslo Gardermoen airport in instrument meteorological conditions (IMC) and in the presence of a strong tail wind. The result was a near loss of control and low altitude go-around with exceedance of speed limits and g-values exerted on the airframe.
- CRJ1, vicinity Brest France, 2003: On 22 June 2003, a Bombardier CRJ100 being operated by Brit Air flew an inaccurate and unstabilised ILS approach to runway 26L at destination at night and in IMC and impacted terrain following an unsuccessful attempt at a go-around. The accident site was 2,150 meters from the runway threshold and 450 meters from the extended runway centreline. The aircraft struck several obstacles and caught fire. One of the 24 occupants died and four others were injured.
- B733, vicinity Bournemouth UK, 2007: On 23 September 2007, the pilots of a Thomsonfly Boeing 737-300 almost lost control of their aircraft after initiating a go around from an unstable low airspeed and low thrust condition reached progressively but unnoticed during an approach to Bournemouth at night. Mismanagement of the aircraft during the go around was attributed to a lack of adequate understanding of the aircraft pitch control system and led to extreme pitch and an aerodynamic stall but the crew subsequently recovered control of the aircraft and an uneventful second approach and normal landing followed.
- A332, vicinity Tripoli Libya, 2010: On 12 May 2010, an Afriqiyah Airways Airbus A330 making a daylight go around from a discontinued non precision approach at Tripoli, after visual reference was not obtained at MDA, did not sustain the initially established IMC climb and, following flight crew control inputs attributed to the effects of somatogravic illusion and poor CRM, descended rapidly into the ground with a high vertical and forward speed, The aircraft was destroyed by impact forces and the consequent fire and all but one of the 104 occupants were killed.
- Flying a Manual Go-around
- Go-around from Low Airspeed/Low Thrust
- Take-off / Go-around (TO/GA) Mode
- Go-around - Transition to Instrument Flying
- Rejected Landings
- Missed Approach
- Go-around Decision Making
- ATM Contribution to Go-around Safety
- Go-around Training
- Stabilised Approach
- Go-Around Decision-Making and Execution Project, Tzvetomir Blajev, Capt William Curtis (Flight Safety Foundation), March 2017.
- Go-Around Safety Forum, Brussels 2013: Findings and Conclusions.
- Go-Around Safety Forum, Brussels 2013: Presentations.
- Go-Around Safety Forum, Brussels 2013: Videos of Presentations.
- Airplane State Awareness During Go-Around (ASAGA). Presentation by G. Adam & J. Condette, French Bureau d’Enquêtes et D’Analyses pour la sécurité de l’aviation civile.
- Why Some Go-Arounds Go Wrong. Presentation by Capt. Alex Fisher Guild of Air Pilots and Air Navigators (GAPAN) 2013.
- Go-Around Accident and Incident Report Review. Presentation by Capt. Ed Pooley, The Air Safety Consultancy & FSF European Advisory Committee ,2013.
- The Study of Accidents and Serious Incidents Involving a Go-Around. Capt. Ed Pooley, The Air Safety Consultancy, 2013.
- FSF ALAR Briefing Note 6.2 - Manual Go-Around.
- Airbus Briefing Note – Being Prepared for Go-Around.
- FSF Safety Digest – Killers in Aviation: Facts about approach and landing and CFIT accidents.
- Go-Around Decision and maneuver: How to Make it Safer. Capt. Bertrand de Courville, Air France.
- Study on Aeroplane State Awareness during Go-Around - an English translation of a Study by the BEA France based on the results of completed investigations conducted by the BEA or by other non-French investigation authorities. The Appendices are not included as they have not been translated into English.
- Do you really understand how your trim works? Many do not, and why it matters. - A paper written by Captain Alex Fisher for GAPAN. The paper was presented at the Go-Around Safety Forum (GASF) in Brussels in 2013.
- "Pilot Decision Making and Go-Arounds"; Capt Michael Gillen. Presentation to IASS2016.
- "Operational and Training Considerations for Safe Go-Around Procedures"; Captain Bryan Burks. Presentation to IASS2016.
- ^ FSF Safety Digest - Killers in Aviation: Facts about approach and landing and CFIT accidents
- ^ Go-Around Safety Forum. 2013. Brussels. Findings and Conclusions.
- ^ FSF ALAR Briefing Note 6.1: Being Prepared to Go Around.
- ^ a b Airplane State Awareness during Go-Around. Presentation by G. Adam & J. Condette. 2013. Brussels. Cite error: Invalid
<ref>tag; name "ASAGA" defined multiple times with different content
- ^ The Study of Accidents & Serious Incidents Involving Go-Around. Capt. Ed Pooley. The Air Safety Consultancy 2013.
- ^ Go-Around Decision and Maneuver: How to Make it Safer. Capt. Bertrand de Courville. Air France.
- ^ Go-Around Accident and Incident Report Review. Presentation by Capt. Ed Pooley, The Air Safety Consultancy 2013
- ^ a b Why Some Go-Arounds Go Wrong. Presentation by Capt. Alex Fisher, Guild of Air Pilots and Air Navigators (GAPAN) 2013 Cite error: Invalid
<ref>tag; name "Fisher" defined multiple times with different content
- ^ A306, vicinity Nagoya Japan, 1994
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