fly under (the/someone's) radar(redirected from fly under their radar)
fly under (the/someone's) radar
To go without being noticed, detected, or addressed. A: "Have you heard this band's latest album?" B: "I didn't even know it was out, it must have flown under my radar." Every year, the government promises to do something about the homelessness problem, yet every year it seems to fly under the radar again.