Narrative:

I was with my student practicing landings in aircraft X; as we were taking off of [runway] xxl around XA30-XB00 I had noticed another C172 taking off on the parallel runway xxr. As we were passing through 1;800 ft.; getting close to turn left crosswind; it appeared the other C172 (aircraft Y) was a little too close for comfort and then they decide to make an early left crosswind directly underneath us after they were instructed by tower to fly straight out. It appeared that they were with in 100 ft. Of us. I then announced over the radio to tower saying 'we have another cessna underneath us'. I do recognize aircraft Y as a local plane that is based out of ZZZ.

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Original NASA ASRS Text

Title: C172 Flight Instructor reported a NMAC with another aircraft while both were taking off from parallel runways.

Narrative: I was with my student practicing landings in Aircraft X; as we were taking off of [Runway] XXL around XA30-XB00 I had noticed another C172 taking off on the parallel runway XXR. As we were passing through 1;800 ft.; getting close to turn left crosswind; it appeared the other C172 (Aircraft Y) was a little too close for comfort and then they decide to make an early left crosswind directly underneath us after they were instructed by tower to fly straight out. It appeared that they were with in 100 ft. of us. I then announced over the radio to Tower saying 'We have another Cessna underneath us'. I do recognize Aircraft Y as a local plane that is based out of ZZZ.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.