Airprox of the Month

The UKAB’s Director discusses in his November Insight The TCAS trap. Appearing to be ‘too close’ to TCAS equipped aircraft can cause avoidable problems. Traffic Collision Avoidance Systems are designed for the IFR environment and their Resolution Advisory commands are mandatory. In a mixed IFR and VFR environment this can create problems if the limitations of the system are not understood by VFR operators. In this case a C152 was orbiting on ATC instructions at the end of the downwind  leg to facilitate a Cessna Citation’s ILS approach. The orbit got close enough to the ILS approach to trigger a Resolution Advisory and the Citation had to go around. The Director reminds us that when flying near a commercial aircraft flying IFR, even in VMC, you need to stay well clear to avoid triggering their TCAS.