That is a perfect Biggles joke! This one is a lot of fun, full of adventure and drama and the dangers of flying a plane belonging to the enemy in wartime - I think every possible flying-the-enemy's-plane mishap that you can ever think of happens to Biggles and co eventually. Also this is another great Bertie book, though he is absolutely batshit in the best way, you can see why he's the one who ends up living with Biggles and Algy and Ginger afterwards. And the moment where Biggles is consoling the dying gunner is heartbreaking.