[4][5] From an early age, "Red Mike" (a nickname he gained because of his red-blond hair)[5] demonstrated an interest in aviation, and in his 20 June 1911 high school salutatory[5] address at Huntington High School, Grumman predicted that "[t]he final perfection of the aeroplane will be one of the greatest triumphs that man has ever gained over nature.

[4][5][8] Although Grumman applied for flight training, he failed a medical evaluation when the examining board incorrectly diagnosed flat feet.

[5][9] After the completion of the course, Grumman's first posting, along with a promotion to lieutenant, was at the League Island Naval Yard as an acceptance test pilot for Curtiss- and Navy-built flying boats.

After a reduction in rank to ensign in the peacetime U.S. Navy, Grumman resigned his Naval commission in October 1920, becoming a test pilot flying various types of Loening amphibians while doing some design and development on these aircraft.

Unwilling to leave Long Island to continue working for Keystone, Grumman joined fellow Loening employees Jake Swirbul and William Schwendler in resolving that their best option was to quit and form their own company.

The first project of the new company involved Grumman and Swirbul, as president and vice-president, on hands and knees, sorting out and matching nuts and bolts, prior to assembling Loening floats.

[15] The innovative, manually operated landing gear which progressed from a heavy and unreliable design to a more sturdy version helped his company win contracts from the U.S. Navy.

"[17] He single-handedly invented the famous "Sto-Wing" wing-panel folding system that revolutionized carrier aircraft storage and handling, pioneered on the F4F-4 Wildcat subtype.

[20] Despite his innate shyness, Grumman's management style included a "hands-on" approach where he could talk comfortably with both executives and factory floor workers.

Seeking out company test pilot Selden "Connie" Converse, he asked for a check out in a "hot ship": the front line F6F Hellcat.

After a 10-minute cockpit check, Grumman waved Converse away, started the engine and was soon taxiing down the runway and into the air on a half-hour joy ride.

[5] Like its competitors, Grumman Aircraft Engineering Corporation experienced severe postwar downsizing, dropping from 20,500 to 5,400 employees immediately after the cessation of hostilities.

It was an extremely hard decision because the company had been careful to cultivate a positive workplace culture;[25] when a canvass was made of employees who wanted to "move on" at war's end, only 126 came forward.

However, Grumman personally retained as many veteran employees as possible, calling back the most proficient and experienced "hands", predominantly those who had 10 years of service.

[5] Building with the core group, Swirbul and Grumman restructured the company, first solidifying its long-term contracts with the U.S. Navy, beginning a continuous line of new combat aircraft.

[30] With Swirbul's death on 28 June 1960, Grumman lost not only a close friend but his "right hand" during a time when he was faced with critical decisions as to the company's future.

Although his role as chairman became reduced, Grumman's counsel was paramount and when the Gulfstream project was launched, two models of a high-wing and low-wing configuration were set up outside his office.

[citation needed] In 1953, Grumman was elected to the board of trustees of his alma mater, Cornell University, and donated $110,000 for a new squash building[38] which now bears his name, as does an office and lab space on the campus.