Air travel is one of the greatest inventions of the modern era, rightly occupying a vital part of human civilization with a cumulative interlace and exchange of rights and responsibilities. However, as is usual with every sphere of human civilization, this invention presents a unique potpourri of criminal and civil liabilities to both the carriers and passengers alike. Liabilities in international carriage of passengers and goods by air are generally governed by conventions, 1 crafted majorly to promote the aviation industry, achieve uniformity and limit the liability of carriers for passenger injuries and deaths. 2 One of the grey areas in the allocation and limitation of liability is the one manifested in Deep Vein Thrombosis (DVT) claims. Increased awareness about the causes and implications of DVT has led to a surge in law suits and claims against air carriers in international carriage of goods and passengers. While this trend is longstanding in more established jurisdictions, 3 the concept of aviation litigation in general and DVT in particular is just catching on in Nigeria. Perhaps, this accounts for the scanty state of jurisprudence and case law on the discourse.

Courts in advanced jurisdictions have examined DVT cases and arrived at opposing decisions although a vast majority of these decisions were carrier-friendly. From the restrictive approach in Saks, 4 to the expansive approach in Wallace's case, 5 the passengers seem to be at the receiving end of most of the decisions. Although, passengers have always maintained that failure to warn of the risk is a ground to make the carriers liable since they prioritize economic benefits over human lives, this contention has been rejected by courts in Australia, 6 Canada, 7 Germany and even the USA. Thus, while DVT decisions in more advanced jurisdictions may appear to predominantly favour the carriers due to the predominant carrier leaning and sympathy,decisions by Nigerian courts may be expected to follow the country's general leaning as a passenger nation. This piece aims at examining DVT, its relationship with air travel, the liability of carriers and the attitude of the courts as well as project the likely disposition in Nigeria while proffering workable recommendations.


Also known as the economy class syndrome, 8 DVT is a grievous medical condition in which blood clots are formed in a deep vein thereby circumventing the free flow of blood and resulting into swelling in the affected areas. 9 The swelling naturally dissolves but where it does not, the blood clot travels to the brain, lungs or artery causing great danger to, and in extreme cases, the death of the passenger. 10 The general sentiment behind most DVT claim is rooted in the firm belief that the carriers know better but choose to subject the unfortunate passengers to cramping in.

A Critical Appraisal of the Liability of Airlines for Deep Vein Thrombosis (DVT)Claims.

the desire to extract optimal benefits. 11 Although underlying health conditions often compound the risks of developing DVT, it is believed that the carriers knowing that passengers are at a higher risk of developing DVT on board a long-haul flight over and above that expected in their normal everyday life, should create better conditions to alleviate these risks. Thus, while airlines across the world have been subject of claims for their aggravation of these existing conditions, the failure of airlines to warn passengers seem to be the predominant basis advanced so far for the liability of the carriers.

In response to the widespread acceptance of its liability for failure to warn, some carriers have put in place measures to address these shortcomings by a combination of educative and preventive steps as symbolized by pre-take off announcements and issuance of compression stockings. Nevertheless, the individual response has done little or nothing to tilt the scale of expectation one way or the other as different jurisdictions appear to have evolved along the line of their sympathy and allegiance to the major actors (passengers/carriers).


The liability of carriers for death, injury, delay, loss of baggage, etc of passengers is regulated by the Warsaw Convention 1929 and subsequently other conventions such as the Montreal Convention (For the Unification of Certain Rules for International Carriageby Air) 1999 which has been domesticated 12 in Nigeria by virtue of Section 48 of the Civil Aviation Act 2006 thereby making it the applicable law in Nigeria with respect to international carriage by air. In most jurisdictions, 13 decisions absolving air carriers from liabilities for DVT are hinged on the somewhat ambivalent logic that it does not constitute "an air accident". Perhaps, a good starting point therefore is to examine the term "accident" under the authorities so as to avail us a clear background as to the rationale for the judicial divergence on the subject matter. Also, although Nigerian courts are yet to decide cases on DVT claims, the position in more advanced countries shall be explored vis-a-vis our own laws and disposition on the subject matter.

Article 17 of the Montreal Convention which is in pari materia the Warsaw Convention imposes liability on the carrier for:

"damage sustained in case of death or bodily injury of a passenger upon condition only that the accident which caused the death or injury took place on board the aircraft or in the course of any of the operations of embarking or disembarking"

The import of this is that carriers are liable for deaths, harm or injuries to passengers on board an aircraft which occurred on the aircraft or in the normal course of embarking and disembarking. The term accident although not defined under the Warsaw and Montreal Conventions was defined under the Chicago Convention 1944 14 as follows:

"An accident is "an occurrence associated with the operation of an aircraft ... in which a person is fatally or seriously injured as a result of being in the aircraft ... or direct exposure to jet blast, except when the injuries are from natural causes, self-inflicted or inflicted by other persons . . . ."

The above definition was adopted in the Nigerian case of Harka Air Services v Keazor 15 by Adekeye J.S.C thus:

"Under the Aviation Law, an aircraft accident is an occurrence associated with the operation of an aircraft which takes place between the time any person boards the aircraft with the intention of flight until such time as all such persons have disembarked in which (a) a person suffers a fatal or serious injury as a result of being in the aircraft,.............."

Although this Nigerian case was not based on the Warsaw or Montreal Convention as it did not relate to international carriage, it is not unexpected that the court would adopt this conventional definition to rule in favour of a plaintiff making claims on the basis of the convention. However, it is doubtful that the court would come to the same conclusion 16 in a DVT claim based on accident unless the plaintiff is able to prove negligence or recklessness on the part of the carrier.

A more precise definition for a DVT scenario was offered by the US Supreme Court when it defined an accident as "an unexpected or unusual event or happening that is external to the passenger". 17 The court went further by holding that for an injury or harm to be said to be caused by accident, the event or happening that caused the passenger's injury must be abnormal, "unexpected or unusual". In other words, the event must be external to the passenger and not the passenger 's own internal reaction to the usual, normal and expected operation of the aircraft. 18 Applying the logic of the above definition to a DVT scenario, one can safely argue that a DVT injury does not constitute an accident as to make the carrier liable under the Conventions. This position was maintained in the case of Saks v Air France. 19 In that case, Mrs. Saks boarded a flight from Paris to Los Angeles and as the flight was about to descend, she felt a severe pressure and pain in her left ear which continued after the jetliner landed. She consulted a doctor shortly afterwards and was diagnosed with permanent deafness in her left ear. In an action against the airline, the court held that there was no accident as the injury sustained was the passenger's own internal reaction to the usual, normal and expected operation of the aircraft. Applying the reasoning in Saks v. Air France, it would appear that no DVT claim would generally succeed on the ground of a cramped-up seat, failure to warn or to provide the necessary socks if the airline can prove that its in-flight and operating conditions was not unusual, abnormal or unexpected. This reasoning is not only extreme but clearly defeats the purpose for which the liability regime under Article 17 was conceived. In the case of Wallace v Korean Airline, 20 Mrs. Wallace boarded a flight from Seoul, Korea to Los Angeles, California but about 3 hours into the trip, she fell asleep only to wake up later to realize the passenger sitting next to her had unbuckled her belt, unbuttoned and unzipped her shorts, and placed his hand in her underwear to fondle her genitals. The Second Circuit Court overturning the decision of the US District Court held that the act of sexual predation was an Article 17 accident, whether or not it is a natural incident of air travel. A paradigm shift however came in the popular case of Husain v Olympic Airways, 21 where the court extended the definition of accident to situations where the carrier failed to protect a passenger against the harmful conduct of a co-passenger. In that case, a man who died after a severe asthma attack following repeated requests from his wife to the cabin crew to relocate him far from the smoking section was held to amount to an Article 17 accident and was affirmed by the second circuit. The decision in the above case implies that despite the definition given in Saks v Air France, 22 the court may, in deserving circumstances be open to expand the definition of accident to include injuries due to co-passengers, sexual assaults by co-passengers, 23 etc. It would appear that the deciding factor in the above case was the involvement or what could be termed negligence of the cabin crew to provide the alternative seat to the deceased. As plausible as the rationale behind this decision is, it is yet to be seen how the ratio is adapted to a DVT case. 24 Applying the logic in this case to a DVT claim, the court would impute a DVT liability to a no accident scenario under Saks where for instance, such passenger requests for a compression stocking or more comfortable seat where he can move his legs and the crew fail to provide that despite its availability. 25 Put in the Nigerian context, courts in Nigeria are also likely to adopt the same approach where negligence on the part of the carrier is glaring. 26 This position is equally provided for by the provision of Article 25 (1) of the Warsaw Convention 27 thus: 

The carrier shall not be entitled to avail himself of the provisions of this Convention which exclude or limit his liability, if the damage is caused by his willful misconduct or by such default on his part as, in accordance with the law of the Court seized of the case, is considered to be equivalent to willful misconduct. The import of the above is that the carrier will be liable without monetary limitation where the damage to a passenger is due to willful misconduct on his part or that of his crew or agent acting within the scope of his employment. 28 Applying this to a DVT case, where negligence or willful misconduct on the part of the carrier can be proved, it not only makes the carrier liable but also prohibits it from enjoying the limited liability provisions under the conventions. Thus, a well-crafted DVT case on negligence and/or willful misconduct of the carrier may present the passenger with a double victory scenario. 29

It is worthy of note that the U.S supreme court in the Saks' case adopted a restrictive approach to the definition of accident by confining itself to the drafter's intent and did not want to explore an expansive approach to same. Attempts to explore the latter approach is what birthed decisions such as that in Wallace v Korean Airline 30 and Husain v Olympic Airways. 31 In the same vein, some courts have adopted the restrictive approach in the Saks case and arrived at differing positions. For instance, a claim against a carrier for injury suffered from an unprovoked punch from a copassenger was dismissed for not constituting an accident. 32 The court equally dismissed a claim against British Airways by a passenger for injuries sustained after being punched in the face by a copassenger as the plane taxied to the gate upon landing. 33 Building on the expansive approach as established in the Wallace and Hussain's case, the court has ground to hold a carrier liable for injury suffered by a passenger in the hands of a co-passenger during the course of a flight in circumstances where the act of the co-passenger was caused by the direct act of the carrier or its employee. Applying that to a DVT case, it is safe to argue that the court would arrive at a similar decision because the circumstance is such that the carrier is directly involved in the act. For instance, in the case of Tsevas v Delta Airlines, 34 a claim by a female passenger against an intoxicated male passenger sitting next to her who had grabbed, kissed and fondled her was held to be an accident under Article 17. The decision of the court was influenced by the fact that the crew continued to serve the man alcoholic beverages despite the woman's complaint that he is intoxicated as well as the crew's refusal to move the woman to another seat. 35 It would appear that the same position is likely to be maintained if these were DVT cases before a Nigerian court.


Unlike the case in other advanced jurisdictions, 36 there is no known decision on DVT liability in Nigeria yet. In majority of the cases in other jurisdictions, the courts have based their decisions to exclude the carriers from liability on the absence of issues of material fact. 37 Some of these cases would be examined viz-a-viz Article 17 of the Warsaw and Montreal Conventions:

In the case of Deep Vein Thrombosis and Air Travel Litigation, 38 24 (Twenty-four) passengers in a group action sued 18 (eighteen) airline companies for having suffered DVT while onboard the carriers' 'respective airlines'. The passengers had argued that the airlines had complete control over the conditions which had caused their injury, namely the cramped seating arrangements in the aircraft. The court in interpretingwhether or not it amounts to an Article 17 accident dismissed the action stating that for the purpose of Article 17, accident requires an unexpected or unusual event or happening that was external to the passengers. While the decision in the above case represents the present position in the UK, DVT claims against carriers appear to take a different direction in the United States. Forinstance, in the case of Blansett v. Continental Airlines, 39 the court denied the carrier's motion to dismiss the claim for failure to warn of the risk of developing DVT whilst aboard the airline. Similarly in Miller v Continental Airline Inc, 40 where one Debra Miller had suffered a near-fatal heart attack and had open-heart surgery to remove a blood clot after traveling on a flight from Paris, France to San Francisco, California, the court defined "accident" as the airline&# 39;s failure to warn passengers about the risk of DVT, adding that there were unexpected or unusual events or happenings external to the passenger. 41 In these cases, the courts in the United States refused the carrier's motion to dismiss based on failure to warn. The tide seems to be turning and airlines may soon be faced with a variety of suits arising from injuries sustained from DVT while onboard an aircraft. This is because a carrier should or ought to have known, prior to a flight that by virtue of carriage by air, passengers would be at an increased risk of suffering DVT over and above that incurred in everyday life. In light of the above, carriers are advised to warn as to the DVT risks associated with air travel or proffer advice on how to minimize any such risk, at any time before or during the flight.


DVT is yet to be a subject of judicial interpretation in Nigeria. However, the Nigerian courts have on countless times been faced with matters bordering on interpretation of the Montreal and Warsaw conventions ranging from denied boarding in Virgin Atlantic Airways v. Amaran 42 to emotional stress and inconvenience in British Airways v.Atoyebi. 43 A careful examination of majority of these cases including cases involving domestic flights reveals that the Nigerian courts are more disposed to remedy wrongful treatment of passengers. 44 However, the question that needs to be answered is whether the courts would maintain the same position when presented with a DVT case especially in the light of the peculiarity of the individual cases and the courts' apparent reluctance to classify DVT as an aircraft accident as to make them rule in favour of the passenger. Therefore, for a claimant to emerge successful, he must choose between the near impossible and unsuccessful route of establishing the chain of causation and the relatively untested yet, plausible route of negligence. Discussing further on failure of a carrier to warn passengers on the risk of DVT, there is no established standard of prescribed warning or any custom of carriers issuing such warnings. Arguably, carriers can spin this lacuna and consolidate it with a narrative of pre-existing condition to deny liability. While the presence of pre-existing condition could serve as a good defence, the same could also be gainfully explored to great advantage by a prudent claimant. This is because while this defence may avail a carrier in an Article 17 claim, it would not appear to foreclose a claim in tort on the ground of inherent nature of the sickness that is solely aggravated by the flight condition. This is hinged on the "eggshell skull rule" 45 which presupposes that a person takes his victim as he finds him. Thus, in a scenario where Mr. XYZ is very tall and would be easily prone to develop DVT unlike Mr. ABC who is short and would sit comfortably with little or nodiscomfort despite the cramped sitting arrangement, it is believed that Mr. XYZ should have a greater chance of getting a ruling in his favour because of the peculiarities of his physique (his height). In such a situation, the defence could argue that he should have bought a business class ticket or more comfortable seat to avert such occurrence rather than expect the airline to change their entire sitting arrangement or limit the number of seats to cater for his peculiarity. From the passenger's perspective, one could also argue that a prudent person would request for a more convenient seat whilst aboard the aircraft knowing fully well that there is one 46 . Failure to grant the request would amount to the carrier shooting itself in the legs as a successful claim could be established following that logic. 47 In the light of the above, it stands to reason that sooner or later, a DVT case would be tabled before a Nigerian court to at least provide a reference point to develop our case law and jurisprudence on the subject.


Generally speaking, there is no consensus on the liability of carriers for DVT especially in the light of the highly controversial definition of "accident" given in Saks v Air France which ushered in a pattern of carrier-friendly decisions across different jurisdictions. Heralding the truth of the restrictive approach in Saks' case, the courts are increasingly embracing the attitude to rebuff attempts to stretch the definition of accident to cover failure to warn. When the issue of failure to warn came up in Australia, 48 the court held that it does not amount to an air accident under the Warsaw Convention. This line of decision has been upheld across different jurisdictions and the same position was upheld when a Canadian court was faced with interpretation of the same issue. 49 Nigerian courts in applying Article 17 are not likely to depart significantly from this reasoning. However, a well-crafted case in tort especially in negligence may offer the necessary reprieve in this respect. Thus, from the carrier's perspective, it is imperative to put in place measures that do not only pass the Article 17 test but also puts the carrier above board in its tortious liability estimation. While an airline may get away with the traditional defence in a cramped seating arrangement, it would be difficult for the same carrier where it fails to meet the specific needs of the passenger. To this end, it is imperative for each airline to have standard operating procedure/manual for dealing with this class of passenger and to educate its key personnel responsible for applying and administering same.


1. Notable ones include the Warsaw Convention, 1929 and the Montreal Convention 1999. Others include The Hague Protocol 1955, the Guadalajara Convention 1961, the Guatemala City Protocol 1971, The Chicago Convention 1944, etc.

2. Prior to the Conventions, the earliest being the War saw Convention 1929, carriers were potentially liable without monetary limits for all passenger claims arising from injuries, deaths or baggage loss.

3. This includes countries like the United States of America (USA), United Kingdom (UK), Canada, Australia, Germany, etc.

4. Saks v Air France 470 U.S. 392, 105 S.Ct. 1338, 84 L.ED.2d 289 (1985).

5. Wallace v Korean Airline No 98 Civ. 1039, 1999 WL 187213, at 4-5 (S.D.N.Y. 1999). See also Deep Vein Thrombosis and Air Travel litigation (2006) Lloyd's Rep. Plus 17.

6. See Van Luin v. KLM Airline (10377/01 NSW Dist. Ct.)

7. See McDonald v. Korean Air & China Travel Inc No. 01-330373, 18 September 2002.

8. This is because it is prone to affect passengers in the economy class of an aircraft more where there is the least space allocation per passenger with their legs being immobilized due to absence of leg room. Note however that this does not preclude passengers in business class from developing DVT.

9. deep-vein-thrombosis/symptoms-causes/syc-203 52557 (accessed on June 5, 2021 at 10:15 am)

10. When it travels to the brain, it can lead to stroke but if it remains lodged in the leg, serious damage may occur and can result in tissue damage, ulcerations, skin lesions, or in serious cases removal of the leg.

11. DVT is popularly associated with long-haul flights where passengers are unable to move their legs and this school of thought believes that with better spacing between the seats and better engagement with the carriers, the cases will not be as rampant.

12. Note also that the Warsaw Convention has been domesticated in Nigeria by the Carriage by Air (Colonies, Protectorates and Trust Territories) Order 1958, as amended by the Hague Protocol. Thus, both the Montreal and Warsaw Conventions still applies in Nigeria. This position has been affirmed by the courts in plethora of cases: Akinjoku v. Lufthansa German Airlines & Anor (2018) LPELR-46729 (CA);Ibidapo v. Lufthansa Airlines (1997) LPELR1397 (SC); Virgin Airways v. Amaran (2018) LPELR- 44785 (CA); Cameroon Airlines v. Otutuizu (2011) LPELR- 827 (SC), etc.

13. Including the UK, USA, Canada, Germany, Australia, etc.

14. This is also known as The Convention on International Civil Aviation.

15. (2011) LPELR (SC) 13.

16. In that case, the plaintiff suffered injuries and loss of items due to the crash-landing of the defendant airline. This was due to a bad weather condition that had forced all other major airlines to cancel their flights for the period but due to the defendant's own negligence, carelessness and recklessness, they continued the journey despite all odds which eventually caught fire and got the passengers scampering for safety.

17. See the case of Saks v. Air France 470 U.S. 392, 105 S.Ct. 1338, 84 L. Ed.2d 289 (1985).

18. The U.S Supreme Court relied on the French meaning of accident which means "an unexpected, unusual and unintended event" in that case to give its description of the term. This is as a result of the fact that the original text of the Warsaw Convention was drafted in French.

19. Supra.

20. No. 98 Civ. 1039, 1999 WL 187213, at *4-5 (S.D.N.Y. Apr. 6, 1999)

21. 316 F.3d 829 (9th Cir. 2002), cert. granted, 123.

22. Supra.

23. See Walllace v Korean Airline (Supra).

24. It is important to note that the court found that the flight attendant's excuse of non-availability of alternative seats was untrue. However, the decision might have tilted in the opposing direction if actually there was no available seat at the time thereby making it impossible for the carrier to provide the remedy sought.

25. The carrier might however not be liable in cases where the passenger fails to make a request or requested comfort is not available on the aircraft.

26. See Harka Air Services v Keazor (Supra).

27. Similar provision is contained under Article 22 (5) of the Montreal Convention.

28. See Hermano v. United Airlines, 1999 WL 1269187 (N.D. Cal. Dec 21, 1999). See also Koirala v. Thai Airways Int'l 126 F.3d 1205, 1209 (9 th Cir. 1997).

29. It is a double win in the sense that firstly, the passenger is able to push a successful case and secondly, he is able to bypass the monetary imitation provisions of the Convention.

30. Supra.

31. Supra. See also Wallace v Korean Air (Supra).

32. See Stone v. Continental Airlines 905 F. Supp. 823 (D. Haw. 1995).

33. Price v. British Airways, 1992 WL 170679 (S.D.N.Y.).

34. Inc.,1997 WL 767278 (N.D. Ill. 1997).

35. See also the case of Langadinos v. American Airlines, 199 F.3d 68 (1st Cir. 2000).

36. Countries like United States of America, United Kingdom, Canada, Germany, Australia, etc fall under this category.

37. An example is the case of Scherer v. Pan American World Airways, Inc., 387 N.Y.S. 2d 580 (1st Dep't 1976) where the court dismissed a DVT claim on grounds that there must be bodily injury for it to come under the purview of Article 17. See also Toteja v. British Airways, 1999 WL 1425399 (D. Md. July 20, 1999); Margrave v. Brit- ish Airways, 643 F. Supp. 510, 512 (S.D.N.Y. 1986).

38. [2006] Lloyd's Rep. Plus 17.

39. 246 F. Supp. 2d 596 (S.D. Tex. 2002).

40. 260 F. Supp. 2d 931 (N.D. Cal. 2003).

41. See also Wylie v. American Airlines, Inc., 260 F. Supp. 2d 931 (N.D. Cal. 2003).

42. (2018) LPELR 44785 (CA). See also Emirates Airline v Ngonadi (2013) LPELR 22053 (CA); Emirate Airline v Mekwunye (2014) LPELR 22685 (CA).

43. (2014) LPELR 23120 (SC).

44. This is because Nigeria is essentially a passenger state thus it leaves one to wonder the position the courts would take when faced with a DVT claim.

45. The principle is to the effect that the Defendant in a matter must take full responsibility for all the damages that they caused to the victim, regardless of the fact that the particular Plaintiff was more susceptible than a normal person may have been.

46. Note that it might be difficult where it appears there is honestly no such seats available as the relief sought in that kind of situation would have become impossible for the carrier to carry out.

47. The same would apply in the case of an excessively obese patient.

48. See the decision of the District court of New South Wales in the case of Van Luin v. KLM Airline (Supra).

49. See the decision of the Ontario superior court of justice in the case of McDonald v. Korean Air & ChinaTravel Inc (Supra).

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.