People in East Anglia, and the surrounding regions, are being warned they may hear or see US Aircraft taking off and landing at RAF Lakenheath and Mildenhall over the next couple of days.
The RAF say the USAF is conducting a 48-hour readiness exercise between the 2nd October and 4th October which will include "limited flying at night".
They're warning that during the exercise people may hear the aircraft taking off and landing, and transiting to training ranges over the North Sea several times between sunset and sunrise.
Colonel Will Marshall, who's the 48th Fighter Wing Commander, said: "We understand the disturbance night flying operations can cause and we will continue to minimize the impact of our training programme however possible.
"These types of exercises are necessary to ensure our Airmen maintain a level of readiness to fly, fight and win for our nation, the United Kingdom, and our allies."
Overland flying will be limited as much as possible between sunset and sunrise.
USAF say exercises like this provide both aircrew and support personnel the experience needed to maintain a ready force capable of ensuring the collective defense of the NATO alliance.
They added that the exercise doesn't include plans for low-altitude flying in East Anglia or the surrounding regions during established quiet hours.
Col. Marshall added: "During these readiness exercises, our Airmen are training to operate in all conditions.
"On behalf of the Liberty Wing and our partners at RAF Mildenhall, we appreciate the patience and understanding of our local communities during this short period of important training."