Iran and ensuing blockade in the Strait of Hormuz, a critical shipping lane, has spiked oil prices and sent governments scrabbling for their reserves. How high will prices go, and how bad could it get? On Friday night, United Airlines CEO Scott Kirby published a memo to his employees that demonstrates his very fuel-dependent business is prepping for a very long fallout. “Our plans assume oil goes to $175/barrel and doesn’t get back down to $100/barrel until the end of 2027,” he wrote. Jet fuel accounts for between a quarter and a third of airlines’ operating costs. Prices have doubled from $70 a barrel since the war started four weeks ago, threatening to seriously cut into airlines’ profitability. Kirby said that his airline has a strategy: United will cut some 5 percent of its planned flight schedule during the second and third quarters of this year, with trims coming especially in “off peak periods” like redeyes and less popular travel days: Tuesdays, Wednesdays, and Saturdays.…