Two CFI's reported having a near mid-air collision on initial climb. The other aircraft failed to respond to the tower instructions to follow preceding aircraft after takeoff and turned crosswind towards the other aircraft. Both pilots took evasive action to avoid a collision.
Synopsis
Two CFI's reported having a near mid-air collision on initial climb. The other aircraft failed to respond to the tower instructions to follow preceding aircraft after takeoff and turned crosswind towards the other aircraft. Both pilots took evasive action to avoid a collision.
Narrative
I (CFI) and my student were operating in the ZZZ airport traffic pattern; along with numerous other aircraft. At ZZZ; right pattern off of RWY XX has you turning from upwind to crosswind abeam the 'waterway'; approx. 2/3nm off the departure end. As I was on the upwind; tower instructed me to extend upwind and he would call my crosswind. So I kept flying the upwind until about a mile past the shaped waterway where tower then instructed me to turn crosswind. An aircraft was cleared to take off behind us; also operating in the closed traffic pattern; and were given the instruction on their upwind to 'follow traffic ahead' (me). They did not respond to this radio call. Instead of continuing to extend their upwind to follow me in the pattern; this aircraft (let's call them aircraft #2) turned crosswind abeam the shaped waterway. At this point; I'm on about a 1.5 mile crosswind and aircraft #2 is on about a 2/3 mile crosswind. As I turn to the downwind; tower asks aircraft #2 again if they're following traffic ahead. Again; no response is heard. Rolling through the downwind turn; I see aircraft #2 directly in front of me; moving right to left; approximately 175 feet below me (they were at TPA of 800; me and my student were ~975 feet) on their crosswind. I immediately entered a steep climbing turn to the right to avoid traffic and exited the traffic pattern towards the south. According to ADS-B data; aircraft #2 turned left when they saw me before turning right and rejoining the downwind. Both aircraft safely landed afterwards with no further issues.
Second reporter narrative
Traffic Pattern Operations with student at ZZZ with multiple aircraft in the pattern and entering the pattern. In addition; ATC was tied up with an aircraft unfamiliar flying into the class D airspace of a nearby airport. During takeoff; ATC instructed our aircraft to takeoff and follow the preceding aircraft in the upwind. Student turned right crosswind at normal point in the traffic pattern. On crosswind; I noticed that the student did not follow the preceding aircraft. At that point I took control and maneuvered the aircraft to avoid the other aircraft. In future dual given flights; ensuring that crosswind turns made by students are only to be made when traffic to follow is abeam my aircraft.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.