Three Contrails "Descending" over Denver on Jan 31, 2021 [Military, C-17A Globemasters]

[Mick West]

Source: https://twitter.com/skilldrick/status/1356341980922478592



Source: https://twitter.com/MickWest/status/1356348321862877184


They also show up in this video compilation:

Source: https://www.youtube.com/watch?v=tg_v-rE0tT8

Info about the planes shows up on Radarbox:

COHO71 and COHO71 show up on FlightAware, TCM to CHS
https://flightaware.com/live/flight/COHO71/history/20210131/1601Z/KTCM/KCHS
https://flightaware.com/live/flight/COHO73/history/20210131/1603Z/KTCM/L 36.71268 -94.47856

And presumably there was a third plane with no ADS-B accompanying them (not entirely uncommon with military planes)

The small kink in the path is magnified by perspective compression:

 

[Keith Beachy]

A 3 Ship... When flying formation in Tankers (KC-135 1976-1996), we flew stacked up 500 feet 1 mile in trail. We had a block altitude of 1000 feet. Not sure of current airlift formation, they are offset in the video. Tankers flew inline, then go to echelon formation during air refueling. Lead tanker squawks for the entire formation, and the other aircraft would go to standby on the transponder.

A discrete transponder code (often called a squawk code) is assigned by air traffic controllers to uniquely identify an aircraft. This allows easy identity of the aircraft on radar. Squawk codes are four-digit octal numbers; the dials on a transponder read from zero to seven inclusive.