HX Challenge completed successfully Press release The HX Challenge has been completed successfully. Finnish Air Force HX Fighter Programme Director, Colonel Juha-Pekka Keränen analyses the testing and evaluation event in this article. Finnish Air Force HX Fighter Programme Director, Colonel Juha-Pekka Keränen. Photo: Finnish Defence Forces. The HX Challenge was defined in the Request for Quotations (RFQ) as one out of the three opportunities for the candidates to demonstrate their capabilities and the validity of the information presented in their responses to the RFQ. For us working in the HX Fighter Programme, the HX Challenge was perhaps the most important of these three opportunities because the event was entirely in our own control and we were able to provide a fair and balanced testing environment in Finland for all the five categories of operations itemised in the RFQ.