Many surveillance aircraft have flown near or over Ukraine in recent weeks. You may have seen the maps of their tracks which have appeared on social media, thanks to Flight Radar 24, ADS-B Exchange, and other flight tracking websites.

They have included US Air Force E-8 JSTARS, RC-135 Rivet Joints, and RQ-4 Global Hawks; US Army RC-12 Guardrails; US Navy P-8s and EP-3s; Royal Air Force RC-135 Airseekers; and Swedish Air Force Saab 340s and Gulfstream IVs.

The one significant aircraft missing from these maps is the U-2. That’s because unlike the other aircraft mentioned above, it flies above 60,000 feet. This is the Upper Class E airspace wherein aircraft are not required to transmit Mode S or ADS-B Out signals for air traffic control (ATC) purposes. When U-2 pilots reach 60K on climbout for an operational mission, they switch off their transponders, and stop talking to ATC.

That may change, now that new types of flying vehicles are beginning to inhabit the upper atmosphere, mostly for communications relay and internet connectivity. They include solar-powered aircraft such as the Airbus Zephyr, and stratospheric balloons such as the Project Loon scheme. The latter was ended a year ago by parent company Google, which said it was already a technical success but likely to be a commercial failure. That’s just as well for U-2 pilots, since the possibility of encountering a Loon balloon at altitude was already causing them concern.

In May 2020, the FAA published proposals for Upper Class E Traffic Management (ETM). It envisages a cooperative traffic management approach, including shared situational awareness to aid separation. However, the FAA does acknowledge that ETM must “accommodate government operational needs and secure national security interests” So maybe the U-2 can retain its “invisibility” above 60,000 feet.

The FAA’s concept for an ETM. Note the U-2 silhouette top left, well above 60,000ft, and the Global Hawk (right) just below 60,000ft. 

Meanwhile, I can assure you that the Dragon Lady has been playing its part in the Ukrainian overwatch. Nearly every day, one or two U-2s belonging to the 99^th ERS have been taking off from RAF Fairford in the UK and heading east. I presume that the jets based at RAF Akrotiri on Cyprus with the 1^st ERS have also been busy. Some of the flights from Fairford have lasted as long as ten and a half hours. That’s a long time to fly alone in a pressure suit. Sometimes, moreover, windy weather at the British base makes for an even more difficult landing than usual. Those pilots are certainly earning their pay. Solum Volamus!

Below: Two recent photos from RAF Fairford. They show U-2s of the 99th ERS equipped with the ASARS radar sensor, SIGINT, and the ETP satcom pod, departing and returning.