A design shortfall that threatened to force the Mumbai Metropolitan Region Development Authority (MMRDA) to rebuild nearly 1 km of Metro Line 7A’s elevated viaduct is close to resolution. The work at risk was valued at about Rs. 2.5 bn, while construction on the affected section had nearly stopped since early 2025.

Mumbai International Airport (MIAL), which operates the city’s airport, has determined through a site survey that the additional 2.5 metres required for the line’s overhead electric (OHE) wires would not obstruct aircraft flight paths. The Airports Authority of India (AAI) has yet to issue final written clearance, including revised height-clearance no-objection certificates.

The elevated viaduct and ramp at Vile Parle East are located within the airport’s funnel zone, where structures face strict height restrictions. During planning, MMRDA’s consultant Systra did not account for the extra height required by the OHE system, leaving the design below the clearance needed for the line. The shortfall emerged in early 2025 and brought work on the section close to a standstill.

MIAL carried out the survey alongside the introduction of a new Instrument Landing System known as ILS2. Its report and recommendations have been sent to the AAI, which is expected to prepare its own assessment and incorporate the changes into the relevant clearances. MMRDA has not received written permission, although officials expect the approval process to be completed. Work has resumed at the Airport Colony station.

The height issue is not the only challenge facing the project. Construction difficulties remain at the underground stations, whose locations were shifted slightly for technical reasons. The revised sites are close to a nallah, complicating construction and making an immediate opening unlikely. A contractor representative indicated that these issues continued to affect the project, although no opening date has been announced.