DCA helicopter frequency change from 134.35 to 121.275?

[baldiedc]

DCA this week changed heli freq from 134.35 to 121.275, wondering if anyone has info why?

NOTAM !DCA 07/082 DCA COM REMOTE TRANS/REC 134.35 CHANGED TO 121.275 2508030700-PERM

 

[Firemantincan]

Can confirm this is an active unlisted (RRDB) DCA Tower frequency. Unknown HELO use.