Also today (we had recorded a similar situation yesterday) we ‘witnessed’ the in-flight refuelling of a USNavy Boeing P-8A over eastern Romania.
The Poseidon, which took off from NAS Sigonella, orbited over Romania and then refuelled in flight from a USAF Boeing KC-135R (reg. 58-0118) which took off from Spangdalhem AB, Germany.
In contrast to what happened yesterday, the P-8A switched off the ADS-B transponder during refuelling, switching it back on immediately afterwards.