Applicable Law

The District Court of Frankfurt/Main recently ruled on an airline's liability for deep vein thrombosis (DVT) developed by a passenger on an intercontinental flight.(1) The court rejected the claim, ruling that health problems incurred on a long-haul flight are part of the general risk of life. The court stated that the plaintiff did not submit sufficient statistical data confirming a link between in-flight conditions and DVT and therefore, regarding DVT, no special contractual duties of the airline company could be determined.


The plaintiff, born in 1946 and 1.8 metres tall, flew economy class from Frankfurt to Cape Town and back within nine days. The gap between the rows of seats in the aircraft, a Boeing 747-400, was 81 centimetres. The plaintiff argued that he had developed DVT (also known as 'economy-class syndrome' or 'traveller's thrombosis') followed by a pulmonary embolism on both flights. Allegedly, he was still suffering from the consequences of the pulmonary embolism and was still dependent on medication. In his opinion, the cramped seating position in the aircraft due to unreasonably dense seating arrangements was responsible for his health problems. In addition, he alleged that the carrier did not properly inform passengers of the risks resulting from long-haul flights under these conditions. He claimed Dm15,000 (€7,669) in compensation for pain and suffering.

Applicable Law

The air carrier's liability for DVT could theoretically arise from two sources of law. One is the Warsaw Convention,(2) which contains uniform liability provisions for international flights between signatory states. Since in the present case the plaintiff's DVT had undisputedly occurred on such an international flight, claims under the Warsaw Convention had to be considered first. Theoretically, liability could also be based on German law if it was applicable besides the Warsaw Convention.

Warsaw Convention
Article 17 of the Warsaw Convention provides:

"The carrier shall be liable for damage sustained in the event of the death or wounding of a passenger, or any other bodily injury suffered by a passenger, if the accident which caused the damage so sustained took place on board the aircraft or in the course of the operations of embarking or disembarking."

The keyword of this provision is 'accident'. In various signatory states, courts have regularly held that an 'accident'(3) within the meaning of Article 17 requires "an unexpected and/or unusual event or happening that is external to the passenger", and that it cannot be considered an accident where the "injury indisputably results from the passenger's own personal reaction to the usual, normal and expected operation of the aircraft".(4) According to this strict interpretation, in-flight DVT cannot be regarded as an accident, as it does not result from an external impact on the passenger, but is rather caused by an internal physiological process.(5) Although this strict definition has been modified under different aspects in recent decisions - putting emphasis on the characteristic risks inherent in air travel(6) or focusing on the local aspects of the incident(7) - the requirement of an external cause has not yet been discarded.

Following these precedents, the district court denied a claim under the Warsaw Convention.

Applicability of national law
Pursuant to its Article 24, the Warsaw Convention generally excludes all claims brought under national law. The district court obviously presumed that this is only true when damages are actually granted in accordance with the convention and therefore did not elaborate as to what extent the Warsaw Convention in fact excludes the applicability of national law.

Courts of various other jurisdictions have held that Article 24 already applies once a claim falls within the convention's scope of application.(8) In other words, national law is excluded if the contract of carriage is subject to the Warsaw Convention. This opinion corresponds with the purpose of the Warsaw Convention to provide uniform conditions for compensation claims. A strict exclusion of any claims given under national law is essential from this point of view. In Germany, this question has not yet been clarified by a superior court. The court dealing with the pending appeal will have the chance to do so.

Claims under German law
Assuming that national law was not excluded by the Warsaw Convention, the district court went on to examine whether a compensation claim could be brought under German law.

Sections 44 and following of the German Air Traffic Act contain special liability provisions, but these only cover national flights (Section 51).

In addition, the airline's liability cannot be based on the German Product Liability Act, which provides in Section 1 for a manufacturer's liability for damages resulting from a defective product he has produced and/or distributed. The airline cannot be considered to be the aircraft's manufacturer or distributor within the meaning of Section 4 of the Product Liability Act. Even though the airline is usually responsible for the seating arrangements on board, it is not involved in the manufacturing process itself and does not distribute the aircraft.

Therefore, a claim under German law could only be based on the general provisions of the German Civil Code. Contractual claims as well as claims given under tort law should be considered.

Contractual liability
A claim for damages might follow on from a violation of contractual duties.(9)

Under the contract of carriage, the airline is obliged to take all reasonable steps in order to protect the passengers from suffering injury while on board (general duty of care). It would be a breach of the contractual duties if the seating arrangements on the aircraft were suitable to cause harm to the passengers' health.

In order to succeed in a claim, a passenger would first have to establish a causal link between the seating arrangements and DVT. This might be done on a statistical basis by showing that the seating arrangements (in economy class) significantly increase the risk of DVT. So far, reliable data on this question is not available.(10) In its decision, the district court also expressly denied the existence of a causal link. Referring to the medical studies available, the court stated that the DVT risk on board an aircraft is not significantly higher than in any other situation involving periods of prolonged sitting.

However, even if a general link between DVT and long-haul flights could be established on a statistical basis, the passenger would still have to prove that in his particular case the DVT was in fact caused by the airline's violation of duty. Evidence must be presented on an entirely individual basis.(11) In order to do so, a passenger is required to prove that he would not have developed DVT had he not been on a long-haul flight. Possible alternative causes of DVT must be excluded. Since it is generally accepted that there are various personal predispositions which significantly increase the risk of developing DVT (eg, stress, cardiac insufficiency or smoking)(12), a claimant will usually face serious problems in presenting such evidence.

In addition, liability for violation of contractual duties is fault-based. Therefore, a passenger would also have to prove that the airline had acted negligently when providing economy class seats for long-haul flights. Again, this will be difficult as long as the airline has complied with internationally accepted seating standards (gaps of at least 76 centimetres).

Alternatively, a claim for contractual damages could be based on a violation of the duty to provide information. Even if the airline is not obliged to provide greater gaps between the rows of seats, it might still be obliged to inform its passengers of the risk of DVT. The extent to which information must be provided is determined according to the requirements of an average passenger. Since the risks arising from periods of prolonged sitting - not just in an aircraft - are generally known, it will be difficult for a passenger to establish fault on part of the airline concerning its duty to inform. This is especially true if the airline, as is usually the case, screened a video clip suggesting exercises and frequent movement during the flight.

The action was dismissed since the plaintiff had not even presented sufficient evidence to prove a violation of contractual duties.

Liability in tort
While compensation for personal or material damages might be sought under contract law as well as under tort law, claims for pain and suffering can only be based on tort (Sections 847 and 253 of the German Civil Code). Since the plaintiff had only claimed compensation for pain and suffering, the district court could (and should) have focused on tort claims.

To found a tort claim pursuant to Section 823(1) of the German Civil Code, a passenger would be required to establish - on an individual basis - a causal link between the conditions on the aircraft and his DVT, as well as negligence. As a result of the current public awareness of DVT, it is unlikely that such claims will be successful.


The district court's conclusion that the defendant was not liable for the plaintiff's DVT was correct. Nevertheless, the court missed an opportunity to point out that it will not be sufficient for a passenger to establish a statistical link between flight conditions and DVT. A claimant will have to prove a causal link between the air travel and DVT in his individual case. This requires proof that no innate predisposition was responsible for the DVT.

It will be difficult for passengers to succeed with claims of this type, even if the German courts continue to apply national law in DVT cases.

For further information on this topic please contact Detlef Hass or Ina Brock at Lovells by telephone (+49 89 290 120) or by fax (+49 89 290 12 222) or by email ([email protected] or [email protected]).


(1) District Court of Frankfurt/Main, October 29 2001, 221 O 54/01 (appeal pending) VersR 2001, 1575.

(2) Convention for the Unification of Certain Rules Relating to International Carriage by Air, signed at Warsaw on October 12 1929.

(3) German Civil Code, VersR 1982, 243.

(4) Air France v Saks, 470 US 392 [1985].

(5) Kahlert/Hast, "Die haftungsrechtlichen Folgen des so genannten 'Economy-Class-Syndroms'", VersR 2001, 559; Mühlbauer, "Nochmals: Die haftungsrechtlichen Folgen des so genannten 'Economy-Class-Syndroms'", VersR 2001, 1480 (1481).

(6) Morris v KLM Royal Dutch Airlines, 3 All ER 126 [2001].

(7) Baratt v Trinidad & Tobago (BWIA International) Airways Corp, 1990 WL 127590 [1990].

(8) El Al Israel Airlines, Ltd v Tsui Yuan Tseng, 535 US 155 [1999]; Sidhu v British Airways PLC, 1 All ER 193 [1997].

(9) At the time of the decision, such claims would have been based on case law, while as from January 1 2002 they are provided for in Section 280(1) of the German Civil Code.

(10) House of Lords, Session 1999-2000, Science and Technology Committee Publications - Fifth Report, Chapter 6; Mühlbauer, VersR 2001, 1480 (1481, n 8).

(11) OLG Frankfurt, 25 W 23/00, dated March 16 2001.

(12) Supra, n 10.