Delhi International Airport Ltd. vs Airports Economic Regulatory Authority & Ors.
Background
Delhi International Airport Ltd. (DIAL) and Mumbai International Airport Ltd. (MIAL) had earlier lost a case before the Supreme Court concerning how their "Hypothetical Regulatory Asset Base" (HRAB), a figure used to calculate permissible airport charges, should be calculated. They filed fresh applications claiming they had since discovered a previously unknown 2011 internal government letter that, in their view, showed an error in the earlier judgment because it supported computing HRAB using a "single till" method combining all airport revenue.
Decision Breakdown
The Court explained that its earlier decision had rested on the findings of two expert bodies (AERA and the tribunal TDSAT), and it would be inappropriate for the Supreme Court itself to re-examine technical calculations that the TDSAT had not actually considered. However, since the newly surfaced letter was an internal government communication that should have been placed before the regulatory authorities, the Court held that the TDSAT should now specifically examine the effect of this letter on the HRAB computation and independently decide whether the "single till" mechanism should apply, without being bound by the Supreme Court's earlier reasoning on this point. Either side would retain a right to come back to the Supreme Court after the TDSAT ruled.
Lesson Learnt
Where a party genuinely discovers new, relevant material after a judgment on a technical regulatory matter, courts may send that specific issue back to the expert tribunal for a fresh, focused look, rather than reopening the entire earlier judgment themselves.