What does the Court do when it reviews a decision of the AAT?

FEDERAL COURT OF AUSTRALIA 

Vidiyala v Minister for Home Affairs [2018] FCA 1973

A recent decision of the Full Federal Court (sitting as a single judge)by His Honour Perry J, on an appeal from the Court below (the FCC) made some interesting observations about what the Court does in review which may be of interest to practitioners....

"...the FCC on judicial review has a limited capacity to interfere with a decision of the Tribunal. The jurisdiction of the FCC is confined to deciding whether the Tribunal’s decision was made lawfully under the Migration Act 1958 (Cth) (the Act), that is, whether the Tribunal’s decision is invalid by reason of a jurisdictional error.  This Court in turn is confined to deciding whether the FCC wrongly held that there was no jurisdictional error.  The Tribunal would make a jurisdictional error if, for example, it misunderstood the criteria by which the appellant’s visa application must be assessed under the Act or Regulations, or if it failed to hear and determine his application in accordance with the requirements of procedural fairness: Minister for Immigration and Multicultural Affairs v Yusuf [2001] HCA 30; (2001) 206 CLR 323 at [82] (McHugh, Gummow and Hayne JJ);Craig v South Australia (1995) 184 CLR 163 at 179 (the Court).  However, neither this Court nor the FCC has jurisdiction to grant the appellant a visa, to consider whether he satisfies the criteria for the grant of a student visa, or to correct mistaken findings of fact by the Tribunal: Minister for Immigration and Multicultural Affairs v Rajalingam [1999] FCA 719; (1999) 93 FCR 220 at [65] (Sackville J), [146] (Kenny J); Re Minister for Immigration and Multicultural Affairs; ex parte Applicant S20/2002 [2003] HCA 30; (2003) 77 ALJR 1165 at [114] (Kirby J).

http://www.judgments.fedcourt.gov.au/judgments/Judgments/fca/single/2018/2018fca1973