Extreme Heat Aboard Spanish Flagship Juan Carlos I, as AC Failure Pushes Crew to Sleep on Deck Amid NATO Operations

Spain’s flagship amphibious assault ship, the Juan Carlos I, is reportedly experiencing a critical failure in its air conditioning systems. Broken air conditioning systems have left interior temperatures reaching up to 40 °C inside the 231 m, 26,800‑ton vessel.

The issue, which has persisted for several days, has left interior spaces stiflingly hot—so much so that some sailors have resorted to sleeping on the open flight deck to escape the suffocating conditions below. The incident highlights ongoing challenges in maintaining comfort aboard aging naval platforms, even during high-readiness deployments.

The Spanish Navy's LHD Juan Carlos I (L61), pride of the Armada Española and cornerstone of Spain’s naval aviation and amphibious operations, is currently battling an unexpected but serious technical problem—its onboard air conditioning and ventilation systems (HVAC) have malfunctioned.

Sources close to the vessel report that the ship's internal temperature has become unbearable, particularly in living quarters and engineering spaces. This has led some members of the crew to sleep on the ship’s flight deck under the open sky to find relief from the suffocating heat inside.

An internal notice authorized crew to set up sleeping mats on deck (“no mattresses or pillows from the ship”) between 21:00‑07:00—avoiding obstruction near aircraft operating zones  .

The ship has been deployed in the Mediterranean for nearly a month as part of NATO's Expeditionary Combat Group Dédalo, with the malfunction persisting for over a week.

Delay in Repairs

Although the Juan Carlos I is scheduled for a six-month dry-dock and propulsion system refit starting July 2025, leadership decided to continue operations without returning to port for AC repairs.

Plans are underway for a major overhaul at Navantia’s Cádiz yard, including propulsion issues plaguing the Siemens PODs (which have caused past maneuvering disruptions)  . The ship is expected to enter dry dock in July 2025 for six months to repair both propulsion and auxiliary systems—including the vital refrigerated climate control systems.

While the Juan Carlos I remains fully operational, the air conditioning failure underlines persistent fleet maintenance challenges. Operating in high-heat environments without climate control raises crew welfare and mission-readiness concerns. The scheduled dry-dock period offers a crucial opportunity to rectify the issues—returning the flagship to full operational and human-tolerant conditions.