The detailed project report for Kochi Metro Phase three envisages a direct airport connection and airport check-in facilities at selected stations along the Phase one and Phase two corridors. The plan also provides for increased train frequency during peak hours and reduced headway to align services with flight schedules, while specifically excluding direct connectivity to Angamaly railway station. The proposed 17.5 kilometre line is to originate at Aluva, proceed to Kariyad, pass the airport and terminate at Karayamparambu in Angamaly.

The DPR proposes 15 stations, including Thottakkattukara, Kunnampuram, Parambayam, Nedumbassery, Athani, Kariyad, Airport Railway Station, Airport, Nayathode, Kavarapparambu, Arikkal Junction, LF Hospital, Angamaly Town, Kothakulangara and Karayamparambu. The alignment runs via Nayathode, Kavarapparambu and Arikkal Junction before reaching Karayamparambu.

Cochin International Airport Ltd has held discussions with Kochi Metro Rail Ltd on the siting of the airport metro station and has identified the land in front of the Taj Hotel, between the international and domestic terminals, as the most suitable location. An escalator is planned to link the station with the airport and the location will also connect with the airport railway station to ease interchange between rail and air networks. Around 20 cents of CIAL land is to be earmarked for the project. Unlike Phase two, the DPR specifically includes parking facilities at the proposed stations.

The project is targeted for completion by 2031, with land acquisition and statutory approvals due to begin in 2027 and the overall process estimated to take around four years. The DPR considers an underground stretch near the airport only as a reference option and identifies an elevated viaduct as the most economical alignment. The Phase three project is currently estimated to cost around Rs 70-80 bn, while an underground stretch would add nearly Rs 20 bn to the cost. Officials said routing the metro to Angamaly railway station would require a return to NH 544, lengthen the corridor, increase land acquisition and raise costs, which led to its exclusion from the present alignment.