This past summer at the Duxford air show in England I came upon a P-51 Mustang that was being worked on and thus not flying that day. Stopping at the explanatory display, I was astonished to read that for this iconic airplane only 120 days had passed from design to production.  Could this be true?

Research uncovered surprises. In 1940 British industry was running flat out producing Spitfires and Hurricanes to keep the German Luftwaffe at bay. In April the British turned to the Americans, asking North American Aviation to build Curtis P-40 Warhawks for the Royal Air Force.  North American told the British that instead of the slower Warhawk they could build a faster more maneuverable plane from scratch. Thus began in Inglewood, CA the four-month sprint creating the Mustang, arguably the most successful Allied fighter plane in the Second World War.

There’s more.  When the first Mustangs arrived in England they didn’t fly as high and far as anticipated.  Aviation engineers said the problem was the underpowered Allison engine. They suggested that the mighty Rolls-Royce Merlin engine that powered both the Lancaster heavy bomber and the Spitfire fighter be put into the Mustang.  

P-51D Mustang, Imperial War Museum, Duxford

The result was a game changer. Powered by the Merlin 61, the P-51D Mustang could fly faster than anything the Germans had, 430 mph at 30,000 feet with a range of 1,000 miles. With external fuel tanks Mustangs could accompany B-17 and B-24 bombers from East Anglia all the way to Berlin and back. It is reported that when German air marshal Hermann Goering saw Mustangs over Berlin he said the war was lost.  

The US Army Air Force took note. Merlin engines were built in Detroit by the Packard car company. Mustang production was expanded, 8,000 were ultimately built. 

As to the Merlin engine, some historians say it is the engine that won the war. I first heard of the Merlin when Air Wisconsin captain James Clark told me during a long flight delay in Omaha in April that he loves the—thump, thump, thump of the Merlin engine starting up and then the unique whine when it’s running . He was referring to the Merlin-powered planes he’s observed at the Oshkosh, WI Fly-In that attracts thousands every July.

Readers will enjoy the video accessible from the link below.  Produced by the Imperial War Museum in Duxford, it chronicles in detail the story of the Mustang, the American fighter-bomber developed for the Royal Air Force, its first user. In the air war against Nazi Germany 30,000 Americans and 50,000 Britons lost their lives.  #

https://www.iwm.org.uk/history/how-the-p-51-mustang-became-a-legend