[Llarry]

In 1940, the U.S, Navy directed Grumman Aircraft to modify an F4F Wildcat to incorporate folding wings. This was a high-priority project to enable more fighters to be assigned to carriers. In April of 1941, the first folding-wing Wildcat was completed.

At about the same time, two additional .50 caliber machine guns were added to the wing armament -- located farther out than the four original guns -- and various armor and combat survivability measures were added. The Navy ordered resulting 436 F4F-4s in June of 1941 and by the end of the year, F4F-4s were rolling out of the Grumman factory.

The additions added almost 700 pounds to the empty weight of the F4F and the pilots were less than thrilled. Performance suffered by comparison to the older F4F-3. But the changes were exactly what was needed to give the F4F-4 the edge in combat against the Japanese A6M Zero carrier fighter. The F4Fs could dish out punishment in combat and also take hits without being downed.

Innovation in tactics did the rest. Previously the Navy and Marines had used three-plane sections. As a result, often only the section leader was firing, while his two wingmen were concentrating on keeping up. In 1942, the four-plane division was adopted, along with what was called "beam defense." Two planes more or less abreast, with wide spacing so that if an enemy got on the tail of one, the other had room to turn in and shoot the enemy down. Two of these sections made a division and likewise if one section was threatened, the other could get the Japanese fighters off their tails.

The first blood for the new F4F-4s came in June of 1942 at the Battle of Midway. Carrier COs loved their new, larger fighter squadrons (with 27 F4F-4s) and wanted even more F4Fs. Fighter squadrons were enlarged to 36 planes after Midway; now they could both escort friendlies to attack the enemy AND save some fighters to protect the carrier from enemy attack.

Here's a new F4F-4 on a carrier deck getting its guns test-fired. Each wing has two .50s further in and the third .50 out a bit. The covers for the ammunition boxes are open in this photo.

The F4F-4 was outclassed in many respects by Japanese fighters, and yet amassed a good record -- winning more than it lost. It also bought time -- time that was critical for development of the new generation of fighters that were coming: The Vought F4U Corsair and the Grumman F6F Hellcat.