Iberia has operated from Terminal 5 for over ten years following its merger with BA. This was intended to facilitate connections to BA’s long haul network and have all BA & Iberia flights to Madrid in one terminal.
It’s not clear if this is temporary to make space to allow BA to have as many flights at Terminal 5 over the summer or a permanent move. Iberia flights are showing as staying at Terminal 3 during the winter season.
One of the few reliable pleasures of short-haul travel is flying on a wide-body aircraft, instead of the workhorse of aviation in Europe, the Airbus A320 series.
Before Coronavirus brought aviation to halt, BA and Iberia operated wide-body aircraft daily between London Heathrow and Madrid, primarily for the benefit of shipping cargo. As did Finnair between London Heathrow and Helsinki.
As airlines reduced their passenger flight schedules to skeleton services, these flights were replaced with Airbus A320 series aircraft.
In a small sign of services returning to normal, Iberia will operate Airbus A330 and A350 aircraft between London Heathrow Terminal 5 and Madrid from Sunday 14 June 2020.
This is primarily for the benefit of cargo and travel restrictions for passengers arriving in both Spain and the UK remain.
Update January 2018: This route, which currently operates on Monday, Wednesday and Saturday is suspended from Saturday 24 March 2018. Iberia’s sister airline Vueling will continue to fly from London Gatwick to Asturias three times weekly on Tuesday, Thursday and Friday. It is also possible to fly to Asturias from London Heathrow indirectly via Madrid.