Lufthansa Technik AG v Astronics Advanced Electronic Systems & Anor

Permission to amend a statement of case is discretionary. A proposed amendment must have a real prospect of success and must be coherent and properly particularised. Where an amendment is made shortly before a substantial trial, the applicant must explain the delay and demonstrate why justice requires it. The court must consider the additional disclosure, evidence, cost and pressure that the amendment would create, together with the risk to the trial date. A party is generally entitled to prepare for the pleaded case and need not divert its trial preparation to meet an unpermitted draft amendment. Amendments which introduce a substantial new case and threaten the trial fixture should ordinarily be refused. A discrete amendment may nevertheless be allowed where it can be addressed fairly before trial and brings the pleadings into line with existing expert evidence.

The Defendants applied in two patent infringement account proceedings for permission to re-re-amend their defences and to rely on a notice of experiments. The proposed amendments concerned certification, power management as the alleged technical barrier to market entry, the location of supply, alternative designs and the Intellicabin outlet.

The application was made less than 11 weeks before a 15-day trial. Lufthansa objected on grounds of lateness, prejudice, the need for further disclosure and expert evidence, and the risk that the trial would have to be vacated. The central issue was whether the court should exercise its discretion under CPR Part 17 to permit the amendments at that stage.

1. Applicable principles. Under Civil Procedure Rules 1998, Part 17, an amendment must have a real prospect of success. It must also be coherent, properly particularised and supported by evidence establishing a sufficiently arguable factual basis. In deciding whether to permit a late amendment, the court applies the overriding objective and balances the applicant’s prejudice against prejudice to the opposing party and other court users.
2. Lateness is relative. An amendment is late where it could have been advanced earlier, duplicates work or requires significant litigation steps to be revisited. It is very late where permission threatens the trial date. Parties have a legitimate expectation that trial fixtures will be maintained. The applicant must provide a good explanation for delay.
3. A responding party is not obliged to divert itself from trial preparation to meet a contested amendment for which permission has not been granted. The court must assess the position at the hearing of the amendment application, not by assuming that the opposing party should have prepared for the draft pleading when it was first served.
4. The proposed certification amendment was incoherent because it assumed a causal case which Lufthansa did not advance. The power-management amendment introduced a substantial new causation case, rather than merely clarifying the existing apportionment case. It required materially different disclosure and evidence, including investigation of the GD AES Patents, and there was no realistic timetable preserving the trial. Permission was refused.
5. The amendments concerning the location of supply and secondary components were refused. After the withdrawal of the proposed counterfactual cases, their remaining wording was unexplained and risked leaving those cases open indirectly.
6. Permission was granted for the amendment concerning plug detectors positioned at the side of plug holes. The issue was discrete and had already been addressed in the existing alternative-design evidence. Permission was also granted for the Intellicabin amendment because Lufthansa could address that discrete issue before trial and it brought the pleadings into line with expert evidence.
7. The Defendants were permitted to rely on the notice of experiments, subject to directions agreed by the parties, and time was extended for two expert reports. Costs and any application for permission to appeal were reserved.