PA-44 Seminole/Turbo Seminole
Flight Crew Flight Instructor; Flight Crew Commercial
Situational Awareness
Conflict NMAC
General None Reported / Taken
Human Factors
While on final approach practicing RNAV 7R into DVT inside of I-17; without warning a BE300 accelerated underneath my aircraft. [The other aircraft] then sidestepped to 7L; where he had received landing clearance. Student pilot was practicing the RNAV 7R; with no deviation from centerline.TIS is unreliable in the area of DVT.
PA-44 instructor pilot reported an NMAC on final at DVT.