The DC-8’s JT3D turbofans were replaced by these CFM56s in 1986 following its acquisition by NASA.
Some 100 small tube-shaped dropsondes were dispensed in-flight during the Iceland mission to obtain vertical wind profiles and transmit information on air temperature and moisture.
NASA DC-8-72 (N817NA) at Keflavik, Iceland, in May 2015 for the polar winds research flights.
After being dropped through the fuselage from around 19,000ft (5,800m), the dropsondes transmit data for up to 12 minutes.
Some scientific instrumentation is loaded onto the aircraft by using openings in the outer skin or replacing windows with plugs containing sensors.
The DC-8-72 worked alongside the German Aerospace Center's Falcon for the polar winds research flights.
NASA DC-8-72 N817NA at Keflavik, Iceland, in May 2015 for the polar winds research flights.
Two or three scientists are allocated to each experiment aboard - and close co-ordination is required with the flight crew to plan flight operations that are both safe and meet scientists’ requirements.
Despite its age and analogue cockpit, NASA research pilot Wayne Ringelberg praised the DC-8-72's solidity and performance.
Around 25 people can be carried in the very spacious cabin, where wide vintage first class seats are surrounded by equipment racks.
