SUMMARIES OF REPORTS PUBLISHED IN THE FIRST SIX MONTHS OF 2009
These are short summaries of some interim or final accident reports published in the first six months of 2009. The accidents may have occurred in previous years.
Aeroflot-Nord Boeing 737-550
Spatial disorientation of the pilots, particularly the captain, was one of the factors that led to the loss of an Aeroflot-Nord Boeing 737-550 that crashed on approach to Perm on 14 September 2008, killing all 88 people on board, according to the CIS accident investigator MAK.
Poor training of the crew was also cited, and the investigator associated the disorientation with the different logic employed in the attitude director indicators in the 737 compared with the Tupolev Tu-134 that the crew used to fly before converting to the 737.
Aeroflot-Nord was also criticised for failing to supervise the crew's duty and rest times, probably leaving them fatigued, and for its low standard of maintenance demonstrated by the fact that the crew had to set the two power levers to different positions on the throttle quadrant to obtain the same power.
In an initial statement on the loss of an Airbus A320 during a post-maintenance test flight out of Perpignan in southern France on 27 November 2008, the French investigator BEA has commented on the lack of regulations and guidance applying to non-revenue flights like acceptance checks.
The agency comments that there is no guidance about constraints that should be applied, nor about the skills that would be required by the crew operating the flight. This, says the BEA, can lead to the "improvisation" of test routines, and to crews carrying them out during inappropriate flight phases.
EasyJet Boeing 737-700
Meanwhile the UK Air Accidents Investigation Branch, commenting about a serious incident that occurred during an EasyJet Boeing 737-700 post-maintenance test flight, noted that an informal verbal debrief - rather than a written one - by the crew to the maintenance organisation about a pitch trim imbalance led to the elevator balance tabs being adjusted in the wrong direction, making the problem worse.
In the subsequent test flight the crew partially lost control of the aircraft during a manual reversion check with the hydraulic power to the control actuators switched off, but managed to regain control when it was restored.
The UK Civil Aviation Authority has since said it intends to publish an airworthiness communication "relating to the co-ordination between operators and maintenance organisations surrounding the conduct of maintenance check flights".
Spanair Boeing MD-82
A study by NASA Ames of data from the USA's aviation safety reporting system (ASRS) has revealed that since 2000 there have been 55 take-offs made successfully - but unintentionally - with the aircraft not correctly configured for take-off.
As in the case of the Spanair Boeing MD-82 crash at Madrid, Spain on 20 August last year, the crews took off without setting the flaps, but unlike Spanair they got away with it.
The study found that constant interruptions during the period from pushback to lining up for take-off mean that the crews cannot perform their pre-take-off tasks in a "linear" fashion.
The study observes that multi-tasking at this stage of the flight is probably inevitable for pilots, but that distractions and interruptions should be recognised by crews as a hazard in their own right.
One-Two-Go Boeing MD-82
Thailand's department of civil aviation reports that crew fatigue, poor training and inadequate crew resource management were the reasons for the 16 September 2007 One-Two-Go Boeing MD-82 accident during a landing in stormy weather at Phuket airport, Thailand. The aircraft ran off the runway and was severely damaged. The airline was grounded and ordered to improve its safety management, but it is flying again now.
Thomsonfly Boeing 737-300
A Thomsonfly Boeing 737-300 crew on approach to Bournemouth airport, UK on 23 September 2007 let the aircraft's speed fall to 20kt (37km/h) below reference airspeed following an uncommanded disconnect of the autothrottle.
When the captain noticed the low speed he initiated go-around just before the stall warning stickshaker operated, but the combination of high nose-up trim and the sudden dramatic increase in power from the low-slung engines led to a strong pitch-up moment that the elevator alone could not overcome.
The aircraft reached a maximum nose-up pitch of 44e_SDgr before the captain recovered control and landed the aircraft safely.
The UK Air Accidents Investigation Branch has recommended that Boeing, the US Federal Aviation Administration and the European Aviation Safety Agency consider devising a better means of alerting crews to autothrottle disconnect.
They also recommend that crews should be made more aware of the possible need to apply pitch trim to back up elevator forces in circumstances like this.
The Boeing 737-800
The Italian investigator ANSV reports that a Ryanair captain whose baby son had just died was not in a fit state to command his aircraft. The captain had not declared his personal circumstances to Ryanair.
The Boeing 737-800, inbound to Rome Ciampino in September 2005 in a region dotted with convective storms that day, made unstabilised approaches first to Ciampino, then to Fiumicino, and finally landed safely at Pescara.
It was only intervention by the relatively inexperienced co-pilot that caused a dangerous approach to Fiumicino to be abandoned.
Air Tahoma Convair 580
An Air Tahoma Convair 580 that crashed shortly after take-off from Columbus, Ohio, USA on 1 September 2008 had its elevator trim cables reversed during maintenance, according to the US National Transportation Safety Board.
When the crew tried to trim the aircraft in the nose-up sense shortly after take-off, the nose dipped and the pilots could not hold it up. All three crew died when the aircraft crashed in a field. The maintenance task had not been correctly signed off.
The US Federal Aviation Administration revoked Air Tahoma's operating certificate.