A Hot Topic: Innovative Aircraft Temperature Controls
Pharmaceuticals and biotechnological products are often produced in one region of the world and sold in another.
As these products move across continents by ocean or air, their quality depends on the reliability of the selected shipping company and mode of transport. An international flight may last up to 14 hours or more (including ground time at transit points), and many shippers are unclear about the environmental conditions shipments may experience during a long-haul flight. Thermal mapping recommendations are typically made with refrigerated storage areas in mind. Aircraft manufacturers are known to test temperatures on empty cargo holds, but data remains too often proprietary and undisclosed to customers.
FedEx Express took a scientific approach towards aircraft thermal mapping about two years ago. The key component of this scientific approach was the systematic collection and analysis of collected temperature data, which allowed for the development of control protocols and specialized software. The research was performed by the Life Sciences and Specialty Services department at FedEx Express, in collaboration with aircraft engineers. Results and best practices were presented at conferences, including at one IATA Time and Temperature Task Force meeting.
The B777F aircraft was the first type of airplane studied among all FedEx Express planes, since it is the flagship of our long-haul fleet. A specific characteristic of B777F aircraft is that its three cargo compartments can be heated or cooled during flights. During the research, dozens of calibrated temperature devices were attached around cargo compartments at various heights and precise locations in one particular B777F aircraft.
The research work was thoroughly designed and prepared by FedEx Express, leveraging the airline’s expertise to obtain security clearances and authorizations to place devices onboard. In this way, reliable measurements could be collected for several months all over the world. FedEx pilots supported the research studies by selecting various temperature settings as directed. Analysis of the results exhibited the occurrence of temperature gradients, with container bottoms being several degrees colder than the top levels. At the same height, some cargo areas proved also colder than others, especially around the cargo door. Initial temperature distribution results were confirmed in another B777F aircraft number, as well as through temperature measurements collected on shipments transiting B777F planes.
Once the aircraft temperature behavior was fully understood, default temperature settings were optimized and implemented for B777F flights, with the goal to maintain room temperature in some compartments while minimizing fuel consumption and avoiding freezing. Conditions are slightly different for each flight because of the time and environmental conditions on tarmacs at departure, as well as the placement and nature of shipment containers within the cargo area. Nevertheless, a reproducible temperature range could be established onboard FedEx planes through proper controls.
Innovative proprietary B777F temperature software was designed and tested internally, enabling FedEx Express to collect histories, archive data measurements and assess pilot compliance to default temperature settings. The software can even collect and transmit temperature measurements of the internal sensors in near-real time at regular intervals during flights, therefore providing tools to minimize the risk to temperature sensitive shipments worth millions of dollars. This is extremely important to customers shipping temperature sensitive products, particularly those in the healthcare sector where the value of the goods is high and the risk of excursion can be severe.