At present nine Harrier aircraft are being modified at Warton. Three aircraft have already completed their modification. The 12 Harrier aircraft are being upgraded for a total cost of some £33 million (VAT exclusive).
Planned upgrades to bring all Tranche 1 Typhoon aircraft to the same standard are included in the production contract price. The majority of this work is likely to be carried out at BAE Warton. Subsequent upgrades have yet to be defined and costed.