Underground bunker network preserves majority of Iran air force

Despite repeated U.S. and Israeli claims that Iran’s air force had been destroyed or rendered combat-ineffective, confirmed OSINT data and post-ceasefire sightings now show that Tehran deliberately sheltered the overwhelming majority of its flyable combat aircraft in hardened underground bases — preserving an estimated two-thirds of its operational fleet while absorbing a campaign of unprecedented intensity.

When hostilities began on February 28, 2026, following the breakdown of U.S.-Iran nuclear negotiations, American and Israeli officials moved quickly to assert that Iran’s air power had been neutralized. President Trump and Israeli leadership publicly declared that the Islamic Republic’s air force had been effectively destroyed within the opening days of the operation. The reality that has emerged since the ceasefire is considerably more complicated — and more strategically significant.

Iran’s military leadership made a deliberate, doctrine-driven decision at the outset of the conflict: rather than commit its aircraft to defensive combat against a technologically superior coalition, Iranian commanders chose preservation over engagement. Virtually the entire serviceable combat fleet was dispersed into a network of underground air bases and remained there throughout the active phase of hostilities. Only after the ceasefire was announced did Iranian aircraft begin reappearing in the country’s airspace, with confirmed sightings of F-4 Phantoms, MiG-29 Fulcrums, and Mi-28 attack helicopters — the latter recently received from Russia — logged over Iranian territory in the days following the suspension of strikes.

The scale of Iran’s underground basing infrastructure made this strategy feasible. The most well-documented facility is Oghab 44 — Eagle 44 in English — first publicly unveiled by Iranian state media in February 2023 and located in Hormozgan province, approximately 160 kilometers north of the Strait of Hormuz. According to Iranian officials, Eagle 44 consists of an alert area, command post, aircraft hangars, repair and maintenance centers, navigation and airport equipment, and fuel storage — with underground facilities housing jets in secure locations and outfitting them with electronic warfare systems and various bombs and missiles. OSINT analysts estimate that a single base of that configuration can shelter and operate approximately two dozen combat aircraft, which can conduct missions directly from the facility and shelter during bombardments.

The critical vulnerability of the underground basing concept became apparent during the conflict. Satellite imagery revealed impact craters at the entrances to aircraft shelter tunnels at Eagle 44, and the damage appears to have blocked access from the underground hangars to the runway, effectively trapping aircraft inside the facility. The runway itself was also found to have been obstructed with small mounds or barriers, likely placed by Iranian forces to prevent enemy aircraft from landing. That dynamic captures the essential trade-off of Iran’s underground doctrine: the aircraft inside are survivable, but they are also operationally frozen. For a sortie to be executed, the aircraft must taxi out of the tunnel to an exposed runway — where they become immediately vulnerable to coalition fighters and loitering munitions. During the active conflict, that exposure window was lethal enough that Iran chose to leave its fleet grounded rather than risk it.

The IRGC also applied the same underground logic to its air defense assets. During active combat operations, the Islamic Revolutionary Guard Corps released new footage of an underground facility housing its medium- and long-range air defense systems, with the video showing launchers and stockpiles of interceptor missile containers. BBC senior reporter Farzad Seifikaran noted the footage on social media platform X, confirming that Iran had moved part of its air defense network into underground tunnels to protect launchers from strikes.

According to open-source tracking data, Iran lost 38 aircraft in total during the conflict, of which 36 were destroyed and two were damaged. Among the losses were five C-130 transport aircraft, twelve Chengdu F-7 fighters, one F-4 Phantom II, two F-5 Tiger IIs, two F-14 Tomcats, one Il-76 transport, one KC-747 tanker, four MiG-29s (two destroyed and two damaged), one P-3F Orion maritime patrol aircraft, two Su-22 strike aircraft, three Su-22M4 variants, one Yak-130 trainer, and three unidentified fixed-wing aircraft. Rotary-wing losses included one Bell 214, two Mi-17 transport helicopters, and one RH-53D. The vast majority of these losses were aircraft caught on exposed airfields, flight lines, or in transit — not aircraft engaged in combat maneuvering.

OSINT specialist Elmustek, who compiled one of the earliest consolidated battlefield assessments, noted that strikes in the opening phase primarily targeted Iranian missile systems, air defenses, radar assets, and legacy aircraft, underscoring the focus on degrading detection and launch capabilities during the escalation. That prioritization meant that aircraft sheltered deep inside mountain bases were not the primary target set — they were simply too difficult and costly to prosecute directly given the depth of the facilities.

Iran’s underground basing philosophy is rooted in decades of strategic calculation. Iran has adopted a fortress doctrine, using an extensive network of hidden underground air and military bases to protect itself from Israeli and U.S. strikes — a posture shaped over the last decade following the civil war in Syria, the rise of ISIS, and hardline confrontation with Israel. The aircraft inside Eagle 44 and comparable facilities are not merely hiding — they are meant to survive a first strike and remain available for follow-on operations once the threat environment permits sortie generation.

According to Iran’s official IRNA news agency, Eagle 44 is capable of storing and operating unmanned aerial vehicles and fighter jets equipped with long-range cruise missiles, and is described as one of Iran’s most important air force bases. Iran’s Armed Forces Chief of Staff Mohammad Bagheri stated at the 2023 unveiling that any attack on Iran would draw a response from the country’s many air force bases, including Eagle 44 — a statement that now reads less as a boast and more as a doctrinal declaration that was subsequently tested.

The post-ceasefire re-emergence of Iranian combat aircraft in Iranian airspace confirms that the underground survival strategy achieved its core objective. With an estimated two-thirds of Iran’s flyable combat fleet intact according to OSINT assessments, Tehran retains meaningful air power — even if the conflict demonstrated that surviving underground is not the same as being able to fight. The runway, not the tunnel, remains the chokepoint.