I discovered Joe Poyer's novels back in 1994 while hunting through a second-hand bookshop. It was North Cape that caught my attention: a (literally) Cold War thriller about an advanced US spy plane that is shot down. It crashes in Norway and the pilot has to escape on foot. Not a million miles away from (and pre-dating) Firefox and Firefox Down by Craig Thomas, two of my favourite thrillers.
About the same time I found Vengeance 10, a novel about Germany's WW2 rocket program and Tunnel War, a thriller about a fictional channel tunnel being built in 1911. All three of those books were very well written and enjoyable so I decided to track down his others.