Passengers may be surprised to learn that a bright, scorching summer day can delay or even cancel a flight. Yet extreme heat can create serious challenges for aviation. High temperatures reduce aircraft performance, potentially leading to delays, weight limits, additional fuel stops and, in certain situations, cancellations. According to Embry-Riddle Aeronautical University professor Cary Grant, who flew for United Airlines for decades, a very hot day can disrupt operations much like snow or

DUBAI, United Arab Emirates (AP) — Iran’s currency sank to an unprecedented low Monday as Washington prepared to unveil new sanctions described as an “economic D-Day,” intensifying pressure on an economy already damaged by earlier restrictions and a U.S. naval blockade. The rial fell to 2.02 million against the U.S. dollar when trading began on unofficial currency markets. Iran’s Central Bank maintained an official rate of roughly 1.5 million rials per dollar, although most Iranians rely on the