Certain COVID-19 Vaccines Require A Temperature Of -70°C (-94°F) For Proper Preservation

Noting that dry ice is widely used in aviation to keep perishable goods cold as they traverse the supply chain, the FAA has published a SAFO (Safety Alert for Operators) to urge caution in flying larger amount of freight using this cooling system. When properly vented and shipped in small quantities, dry ice poses little risk to aircraft occupants. However, when a large amount of dry ice is involved, sublimation can cause serious risks. The sublimation of dry ice occurs when it passes directly from a solid state to a gaseous state at temperatures higher than -78° C (-108.4°F), under normal atmospheric pressure.

AD 2020-21-16 Requires Repetitive Ultrasonic Inspections Of The Upper Wing Skin

The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes. This AD was prompted by a determination that the upper wing skin at engine nacelle points may be subject to undetected cracking. This AD requires repetitive ultrasonic inspections of the upper wing skin at certain engine strut positions for cracking; repetitive detailed and ultrasonic inspections of the strut lower spar fitting, diagonal brace strut end clevis, and diagonal brace wing attach end clevis for cracking; repetitive detailed inspections o