The Daily Mail offered the film as a FREE DVD a few years ago. Copies are still available from various eBay vendors – prices from around 49p, 50p and 99p (various P&P charges). Other former FREE DVDs include:

The Way to the Stars
Reach for the Sky
The Dambusters
Angles One Five

The Way to the Stars (aka Johnny in the Clouds in the US) is my personal favourite, there’s less action than the others but it is very moving and has a powerful sense of place and time.