According to reports, the Federal Aviation Administration has approved a regulation that requires operators of older US-registered Boeing 737s to install new warning systems within three years that will warn pilots of pressurization problems onboard. The warning systems are in response to a 2005 crash of a Helios Airways Boeing 737-300 that was flying from Cypress to Greece. That crash occurred when the aircraft had climbed to its cruising level without automatic cabin pressurization. Without the cabin pressurized the human…