Joint Strike Fighters (JSF) are unable to fly properly in hot weather because designers of the F-35 Lightning II JSF want it to be 'stealthy' so it won't show up on enemy radar.
The knowledge gained from Initial Operational Test and Evaluation (IOT&E) programmeon the three JSF purchased by the MOD will be fundamental for us tofully understand the aircraft in areas such as operational andtechnical capability. We will make a decision about the furtherpurchaseof the JSF when the evaluation of the IOT&E has been completed.
Two of the JSF IOT&E aircraft will be delivered in 2011 and one in 2012.
Due to past experience we were aware of the potential issues associated with thermal management on a fifth-generation stealth platform. Therefore, in 2000 prior to the contract award, a realistic but demanding requirement for the aircraft to operate in hot conditions, and within a range of realistic operational scenarios, was set.
While meeting this requirement is a demanding task for Team JSF,design work to date together with the experience from flight tests hasindicated that the thermal management system is working to predictionsand is meeting the requirement with margin to spare.
Consequently thermal management is not currently considered to be a programme risk.
Defence Secretary John Hutton said:
"The Joint Strike Fighter will form an essential part of our Future Combat Air Capability. By purchasing three aircraft for testing, we will secure access to the development of the programme.Working alongside their US colleagues, our pilots will gain anunrivalled understanding of this awesome aircraft and its capabilities.This is a vitalprogramme for UK Defence both for the military and for industry, with over 100 UK companies involved in the programme."