As a Director of AIME (Australian Indigenous Mentoring Experience), McMullen has helped grow Jack Manning Bancroft's highly successful education movement connecting university undergraduates as mentors for Aboriginal high-school students in urban areas. McMullen is also a Director of Engineering Aid Australia, a philanthropic organisation whose primary initiative is the Indigenous Australian Engineering Summer School (IAESS) operating in New South Wales and also in Western Australia at Curtin University, which aims to build opportunities for Aboriginal high school students to pursue tertiary studies and subsequently careers in engineering.