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Interruption or Distraction
From SKYbrary Wiki
| Article Information | ||
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| Category: | Human Behaviour | 
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| Content source: | SKYbrary | 
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| Content control: | EUROCONTROL | 
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Contents |
Description
Pilots and ATCOs perform lengthy and complex procedures in the course of their duties. An interruption breaks the thread of these procedures and can have undesirable consequences. Distractions can make it difficult for the pilot or ATCO to concentrate on the task in hand.
Types of Interruption
Interruption on the flight deck may result from causes within the aircraft, e.g. the occupant(s) of (the) flight deck supernumary crew seat (s), the activation of an caution or warning, the activation of a cabin crew call alert, unexpected information from ATC or the operating Company.
Interruption may also occur in the control room, e.g due to a telephone call, a message from a colleague or detection of a potential airspace infringement or level bust.
Types of Distraction
Examples of circumstances where distraction may occur on the flight deck include non-relevant conversation, equipment malfunction and adverse weather.
For the ATCO, distraction may result from extraneous noise, e.g. loud conversation between colleagues, or from an uncomfortable or inconvenient position.
Effects
On the flight deck, the interruption of a procedure may result in missing a vital checklist action or failing to follow correctly a prescribed procedure.
In the control room, interruption may cause an ATCO to fail to take an intended action.
Distraction on the flight deck or in the control room may make it difficult for the pilot or ATCO to concentrate on his/her task, possibly resulting in error or omission.
Defences
Well designed and diligently applied SOPs should minimise the prevalence of, or significant effect from, interruptions and distractions. For example, the sterile flight deck procedure implemented by many airlines below FL100 reduces distractions and interruptions during a period which can be expected to result in relatively high-workload situations during most flights. However, these same arrangements are often not applied to critical elements of the pre flight process. As an example, departure performance calculations made by the crew prior to engine start are done at a time when the risk of interruption or distraction within, or external to, the crew is routinely high.
Typical Scenarios
- A flight deck checklist is interrupted by an interphone call from the cabin crew; the checklist is subsequently resumed but an important action is omitted.
- A discussion of non-relevant matters is carried out on the flight deck and none of the crew members present notice that they have entered an active runway without clearance.
- Cross checking of take off performance calculations being made in the flight deck prior to engine start is interrupted by the arrival of the dispatcher.
- An ATCO misses an important message due to a radio playing in the control room.
Contributory Factors
- Equipment malfunction or failure;
- Controller Position Design;
- Poor TRM;
- Inadequate SOPs.
Solutions
- Review and if necessary improve SOPs;
- Insist that SOPs are followed;
- Review and if necessary improve the design of the ATCO’s position;
- Review and if necessary improve CRM and TRM training provisions.
Accidents & Incidents
Events on the SKYbrary Accident and Incident Database where the Official Investigation included reference to Distraction as an element in causation:
- CRJ2, Dubai UAE, 2011 (RE HF) (On 9 May 2011, a Bombardier CRJ 200 being operated by Gama Aviation on a positioning flight from Dubai to Dammam Saudi Arabia with just the flight crew and one cabin crew on board inadvertently attempted to take off at night in normal visibility aligned along the right hand edge of runway 30 for which take off clearance had been given. The error was not detected until a collision with a lighting installation after which a high speed rejected take off was made. There were no injuries but damage was caused to the right hand wing by impact with the fixed lighting which was also damaged.)
- B737, Chicago Midway IL, USA 2011 (RE HF) (On 26 April 2011 a Southwest Boeing 737-700 was assessed as likely not to stop before the end of landing runway 13C at alternate Chicago Midway in daylight and was intentionally steered to the grass to the lef of the runway near the end, despite the presence of a EMAS. The subsequent investigation determined that the poor deceleration was a direct consequence of a delay in the deployment of both speed brakes and thrust reverser. It was noted that the crew had failed to execute the ‘Before Landing’ Checklist which includes verification of speed brake arming.)
- B763, en route North Bay Canada, 2009 (LOC HF AW LOS) (On 19 June 2009 a Boeing 767-300 being operated by Polish carrier LOT on a scheduled passenger flight from Chicago O’Hare to Warsaw was in the cruise at FL330 feet in night IMC when one of the air speed indicators suddenly displayed a false high reading, which triggered an over speed warning. The flight crew response was based on the presumption that the speed increase was real and thrust was reduced and the aircraft put into a climb. A stall warning followed and descent was then made.)
- P46T, vicinity Son Bonet Palma de Mallorca Spain, 2002 (HF AI CFIT) (On 19 December 2002, a Piper PA-46 Malibu, after takeoff from Son Bonet Aerodrome, penetrated the control zone (CTR) of Palma de Mallorca tower. The pilot was instructed to leave the CTR and the aircraft headed towards mountainous terrain to the north of the island where the flight conditions were below the VFR minimum. In level flight the aircraft impacted terrain at an altitude of 2000 ft killing all three occupants.)
- CRJ9, Whitehorse YK Canada, 2009 (RI HF) (On 6 March 2009, a Bombardier CRJ 705 being operated by Air Canada Jazz on a daylight scheduled domestic passenger flight from Vancouver BC to Whitehorse landed on runway 31L without clearance and after overflying two snow sweepers operating on the same runway. There was no contact between the aircraft and the vehicles or any abrupt avoidance manoeuvre and none of the 58 aircraft occupants or those in the vehicles were injured.)
- … further results
Related OGHFA Articles
- Managing Interruptions and Distractions (OGHFA BN)
- Attention and Vigilance (OGHFA BN)
- Discipline (OGHFA BN)