High blood pressure
11 August 2003
25 February 2002
31 October 2005
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15 September 2011
Instances of deep vein thrombosis (DVT) have made headlines for several years now. A number of airline passengers have complained that they sustained blood clots, usually in the deep veins of one of their legs, arising out of a long haul flight. In some cases, that blood clot has become dislodged and complications, which in some cases proved fatal, have ensued. The most serious complication is when a blockage is caused in the lungs and a pulmonary embolism is caused. This can result in respiratory failure.
The possibility that long periods of immobility causes DVT has also been reported on for many years. However, today's relative accessibility to air travel means that any health issue affecting even a very small number of passengers becomes a matter of public interest and concern, both to the travelling public and to airlines. Few things are taken more seriously in the travel business than the health and safety of passengers.
The legal focus on DVT in aviation, though, is as a liability issue between passengers and airlines. In that regard, the Warsaw Convention provisions govern. The convention recently had to be interpreted by the Court of Appeal in the Deep Vein Thrombosis and Air Travel Group Litigation. Judgment was given on 2 July 2003. The convention holds that air carriers are liable for bodily injury to a passenger if there has been an accident on board, or in any of the operations of embarking or disembarking from an aircraft - but there must be an 'accident' for the airline to be liable.
The question, therefore, is whether DVT is in fact the personal, particular and peculiar reaction of the passenger to the normal and expected conditions of carriage by air, or whether it is caused by accident.
Certain facts potentially relevant to DVT cases were agreed as a factual matrix by the parties before the Court of Appeal, purely for the determination of whether they were capable of constituting such an 'accident'.
The claimant was assumed to have suffered symptomatic DVT caused by a usual flight on which nothing untoward occurred. The court decided the case on the footing that the typical and usual features of air travel included passengers sitting in cramped positions with insufficient space provided by airlines. Other variables considered were air pressure, levels of oxygen and cabin temperature.
Moreover, it was agreed for these purposes only that both claimants were correct in their assertion that airlines knew, or ought to have known, that passengers would be at an increased risk of suffering DVT, over and above that incurred in everyday life, and that the airlines did not give any warning as to the risk assumed or any advice as to how to minimise such risks.
The claimants' appeal failed; the airlines' argument that the factual matrix was not capable of constituting an 'accident' was accepted. The Court of Appeal, with the Master of the Rolls giving the leading judgment, applied a decision of the US Supreme Court in Air France v Saks, which, for the purpose of the Warsaw Convention, holds that an accident is "an unusual or unexpected event or happening external to the passenger".
The claimants' argument, resting on a failure by the airlines to warn and/or to advise on steps to minimise the risk, simply could not be categorised as an event. The flight, the permanent features of an aircraft and the conditions ordinarily applying were also not capable of amounting to an event. Also, as the specimen matrix was based on
the typical procedures of the airline industry as a whole, at the material time they could not be said to have been "unexpected or unusual". Therefore, the factual matrix was not capable of being an 'accident'.
The Master of the Rolls also quoted the passage of Lord Justice Mustill when deciding the insurance case of Axa Re v Field as to the meaning of an 'event'.
This decision of the English Court of Appeal comes at a stage when various other courts around the world, particularly in Australia and the US, are also considering DVT claims. This usually comes about by way of preliminary motions to dismiss or to hear preliminary issues with the attendant burdens upon the party - the airline - so applying. An important case on appeal in that regard - Povey v British Airways, Qantas & anor - was also heard in Australia on 28 July - judgment was reserved in this case.
The Warsaw Convention is, of course, a private international law convention designed to strike a balance between the interests of passengers and those of carriers and to promote uniformity around the world.
The Court of Appeal decision in England will be applauded for its clarity and reasoning and be of considerable assistance, sometimes as a persuasive authority, in other jurisdictions, both with regard to DVT and other allegations of harm when arising out of circumstances not founded in an accident. It should have the effect of discouraging claims against airlines for injury in the form of DVT or its complications in the absence of what can be objectively viewed as an accident. The passenger will also need to be able to prove that an injury was in fact caused by the accident on board a particular flight.
In the UK, the Warsaw Convention provides the sole and exclusive cause of action in relation to the matters with which it deals (see Sidhu v British Airways); and so unless a passenger can bring a claim within its provisions, there is no claim at law against an airline even though an injury may have been sustained.
That is not invariably the interpretation given to the convention, although it is the position in the UK and US. The convention is, however, not applicable to aviation industry participants other than airlines, or what may be termed the 'servants or agents' of airlines. In the US, product manufacturers have been joined as defendants to DVT claims and in Australia the Civil Aviation Safety Authority has been sued.
There is no scope for the introduction of new liability rules if they conflict with the Warsaw Convention rules. However, reported remarks of the claimants' legal team that the above judgment amounted to a "licence to kill" for airlines are entirely misplaced. Later this year a new convention, the Montreal Convention 1999, will come into force in place of the Warsaw Convention, in relation to flights between states which are party to the new convention. However, the liability provisions relevant to DVT are unchanged.
Nicholas Hughes is head of the aerospace department at Barlow Lyde & Gilbert