September 1 in American history

The chines running along the SR-71's nose were not part of the original A-3 concept at all. CIA-affiliated researcher Frank Rodgers found that a sphere's cross-section scattered radar poorly, and Lockheed stretched that idea into flattened fuselage edges to shrink the plane's radar signature. Wind-tunnel work then revealed a bonus nobody designed for: the chines threw off vortices that generated extra lift, letting engineers reduce the wings' angle of incidence, cut drag, and even raise the aircraft's fuel-carrying weight. The same vortices made the plane resist stalling at landing speed. A feature meant only to hide the jet from radar ended up reshaping how it flew, letting designers scrap the canard foreplanes they had originally planned to add.

At one point 80 percent of the titanium delivered to Skunk Works was rejected for metallurgical contamination. Lockheed also learned the hard way that ordinary tap water would corrode welded titanium because of its chlorine content, so crews had to wash parts with distilled water, and cadmium-plated tools were banned outright because they caused the same corrosion. To keep costs down, engineers used a more workable titanium alloy that softened at lower temperatures, which meant inventing new fabrication methods from scratch. Fuselage panels were built to fit only loosely on the ground, since the airframe would expand several inches once heated in flight. Those improvised techniques later spread into manufacturing for other aircraft entirely.

Air Force crews called it an 'unstart.' If the terminal shock wave inside an engine inlet snapped forward past the cowl, the afterburner would often blow out and the sudden mismatched thrust between the two engines could yaw the jet violently sideways. The whiplash sometimes slammed pilots' helmets into the canopy and triggered loud banging as the opposite engine suffered a 'sympathetic stall.' Early on, crews had to manually unstart both inlets and restart them together to regain control. NASA's Dryden center eventually traced part of the problem to nose-chine vortices disrupting airflow into the engines, and by 1980 a new digital system, DAFICS, replaced the analog controls and largely eliminated the violent unstarts.

Thomas Gage and George Washington served together in 1755 at the disastrous Battle of the Monongahela, where Gage briefly took command of the shattered 44th Regiment after Braddock fell mortally wounded and Washington organized the retreat. The two men kept up a cordial relationship for several years afterward, but the two men drifted apart as the crisis deepened. By 1770, Washington was openly condemning Gage's methods of enforcing British authority in Massachusetts. By 1775 Gage was the Crown's enforcer in Massachusetts and Washington was commanding the army raised against him. Their shared battlefield experience never translated into political sympathy once Gage took up the governorship.

In 1759, General Amherst ordered Gage to seize Fort La Galette on Lake Ontario and push on toward Montreal if possible. Gage arrived at Oswego, weighed the unknown French strength near the fort and at Montreal, and decided against attacking at all, sending Amherst a letter explaining his reasoning. Amherst was furious at the inaction, and though no formal censure followed, Gage's troops were pointedly placed in the rear during the 1760 Montreal campaign. The episode showed a pattern of caution under uncertainty, the same caution Gage displayed toward provincial arms caches after the Powder Alarm rattled him fifteen years later.

Gage attempted to purchase the cooperation of Massachusetts political leaders directly, targeting both Samuel Adams and Benjamin Church. Adams refused every overture and remained an implacable opponent. Church, however, took the money and secretly fed Gage intelligence on rebel activities while posing as a trusted Patriot insider. The arrangement gave Gage a covert channel into the opposition's planning long before shots were fired at Lexington. Church's double game was exposed later in the war, but in the tense months of 1774 it gave the governor a rare edge: real information from inside a movement that otherwise gave him almost nothing but rumor and defiance.