Ukraine’s military intelligence agency has claimed that a Russian Su-57 fifth-generation stealth fighter was damaged in an engine fire at the Akhtubinsk military airbase in Russia’s Astrakhan Oblast on October 29, raising fresh questions about the operational condition of Moscow’s most advanced combat aircraft and the impact of Ukrainian attacks on Russia’s energy infrastructure.
According to Ukraine’s Main Directorate of Intelligence (HUR), the incident occurred during the aircraft’s engine-starting procedure. In a statement published on November 2, the agency suggested that deteriorating aviation fuel quality could have contributed to the incident, potentially linking the damage to Ukrainian long-range drone strikes against Russian oil refineries.
HUR said the Su-57 was equipped with an AL-41F1 turbofan engine, also known as Product 117, and argued that fuel of inadequate quality could cause serious engine malfunctions, including catastrophic failure.
“On October 29, 2026, on the territory of the Russian military airfield Akhtubinsk, the newest multi-role fighter of the aggressor state, the Su-57, exploded — this happened during engine startup,” the Ukrainian intelligence agency said.
It estimated the aircraft’s value at approximately $150 million, although the actual cost of an individual Su-57 can vary depending on its configuration, production arrangements and associated equipment.
The allegation has not been independently verified. Russia’s Defence Ministry has not publicly confirmed damage to a Su-57 at Akhtubinsk, and there has been no independent evidence establishing that poor-quality fuel caused the reported incident.
Nevertheless, the claim highlights a potentially important vulnerability in Russia’s military aviation supply chain. Ukrainian attacks on oil refineries and other energy infrastructure have increasingly targeted facilities that support Russia’s fuel production, transportation and distribution networks.
The reported incident comes amid growing Ukrainian efforts to disrupt Russia’s energy infrastructure, particularly oil refineries that supply fuel to the country’s armed forces and civilian economy.
Ukrainian drone attacks have repeatedly targeted Russian refining facilities, forcing operators to suspend or reduce production at several plants. The disruptions have raised concerns about the availability of refined petroleum products, including aviation fuel, which is essential for maintaining Russia’s military aircraft fleet.
In August 2026, HUR warned that Russia was becoming increasingly dependent on imported aviation fuel because Ukrainian attacks had disrupted domestic production. The agency subsequently highlighted shipments of aviation fuel from India, including supplies originating at the Vadinar refinery in Gujarat, operated by Nayara Energy.
The refinery has particular significance because of its ownership structure. Russia’s state-controlled oil giant Rosneft holds a 49.13% stake in Nayara Energy, while Kesani Enterprises and associated investors, including Russia-linked United Capital Partners, hold another 49.13%.
The European Union has described the Vadinar facility as the biggest Rosneft refinery in India.
HUR has also identified efforts to transport aviation fuel from India to Russia through complex maritime arrangements. In one reported shipment, nearly 40,000 metric tonnes of Jet A-1 aviation fuel were loaded at Vadinar aboard a tanker before being transferred at sea to another vessel. The receiving tanker subsequently delivered more than 37,000 tonnes to Russia’s Far Eastern port of Nakhodka, according to Ukrainian intelligence.
These developments illustrate how Moscow has sought alternative supply routes as Western sanctions and Ukrainian attacks complicate its access to refined petroleum products.
However, the import of aviation fuel does not itself establish that Russian military aircraft are operating with substandard fuel. Nor has HUR presented evidence demonstrating that imported fuel was used by the Su-57 involved in the October 29 incident.
The connection between refinery disruptions and the reported engine failure therefore remains an intelligence assessment rather than an independently established technical explanation.
The Akhtubinsk airbase is an important Russian military aviation facility in Astrakhan Oblast. It is associated with flight testing and the development of advanced Russian combat aircraft, making it a significant location for the country’s military aviation programme.
The facility has previously been targeted by Ukrainian long-range drones.
On June 8, 2024, HUR announced that Ukrainian forces had struck a Su-57 parked at Akhtubinsk, approximately 589 kilometres from the front line.
To support its claim, the agency released before-and-after satellite images. According to Ukrainian intelligence, the aircraft appeared intact in imagery from June 7, while images taken the following day showed blast damage and burn marks around the parking position.
HUR described the operation as the first known successful strike against a Russian Su-57.
The agency subsequently provided additional details about the damage. Its spokesperson, Andriy Yusov, said one aircraft had suffered significant damage, while another had sustained lighter damage and might be repairable.
A Russian military-linked Telegram channel, Fighterbomber, which is closely associated with the Russian Aerospace Forces, also acknowledged that the airbase had come under attack.
“Yes, yesterday the airfield in Akhtubinsk was attacked by a UAV. Three pieces arrived. The Su-57 was damaged by shrapnel; it is now being determined whether it can be restored,” the channel reported.
It added that if the aircraft could not be repaired, the incident would represent the first loss of a Su-57 in history.
The acknowledgement was significant because Russian military-linked sources rarely provide detailed assessments of damage to sensitive military aircraft following Ukrainian attacks.
The 2024 incident demonstrated that Ukraine could reach a strategically important Russian aviation facility hundreds of kilometres from the front line. The latest reported incident, if confirmed, would represent a different type of setback: an aircraft allegedly lost or damaged without a direct Ukrainian strike.
The latest incident follows another reported Ukrainian operation against Russia’s Su-57 fleet in April 2026, when Ukrainian drones struck the Shagol military airfield in Russia’s Chelyabinsk Oblast, approximately 1,700 kilometres from Ukraine’s border.
Ukraine’s General Staff and the commander of its Unmanned Systems Forces (USF) confirmed that several Russian combat aircraft had been hit during the April 25 operation.
On May 1, the USF said follow-up satellite reconnaissance had confirmed damage to at least four aircraft: two Su-57 fifth-generation fighters, one Su-34 fighter-bomber and another aircraft of an unidentified modification.
The Unmanned Systems Forces also published video footage incorporating satellite imagery as evidence of the operation.
USF commander Robert Brovdi, known by his callsign “Magyar”, explained that targeting the Su-34 and Su-57 was important for reducing Russia’s ability to conduct airstrikes against Ukraine.
The Su-34 is one of Russia’s principal strike aircraft, capable of carrying various guided bombs and missiles to attack military facilities, infrastructure and other targets at considerable distances.
Brovdi argued that destroying Su-34 aircraft would reduce the number of Russian airstrikes, save civilian lives and ease pressure on Ukrainian air defence systems.
He also described the Su-57 as particularly dangerous because of its low-observable technologies and advanced combat capabilities.
Russia acknowledged that Ukrainian drones had attacked the Chelyabinsk region on April 25. Regional Governor Alexei Texler said the drones had attempted to strike an infrastructure facility, adding that there were no casualties or reported damage.
However, Russian authorities did not confirm that any military aircraft had been hit. Ukraine’s claims about the aircraft damage therefore remained unacknowledged by Moscow.
Another reported setback occurred on July 23, 2026, when a Russian military aircraft crashed during a training flight in the Moscow region.
Russia’s Defence Ministry confirmed the crash but did not identify the aircraft. It said the pilot had successfully ejected and was not in danger.
“The aircraft crashed in a deserted area, and there is no damage on the ground,” the ministry said.
However, an unidentified source cited by Russian newspaper Kommersant identified the aircraft as a Su-57 fighter. According to the report, the crash occurred in the Odintsovo district during a training flight, and the pilot escaped without injuries.
Russian aviation observers subsequently identified the approximate crash location as being around six to seven kilometres from Zvenigorod, near the villages of Lutsino and Shikhovo.
Kommersant also reported that investigators had opened a criminal case concerning possible violations of flight safety or flight preparation procedures.
Although the Defence Ministry did not officially confirm the aircraft type, the reports raised further questions about the reliability and operational availability of Russia’s relatively small Su-57 fleet.
The Su-57, developed by Russia’s Sukhoi design bureau, is the country’s most advanced operational fighter aircraft and a central element of its efforts to modernise military aviation.
Designed to combine reduced radar observability, advanced sensors, electronic warfare capabilities and multirole combat performance, the aircraft is intended to compete with Western fifth-generation fighters such as the American F-22 Raptor and F-35 Lightning II.
It is designed to conduct air-superiority missions, attack ground targets and engage threats using a combination of air-to-air and air-to-ground weapons.
However, Russia has faced challenges expanding production and deploying the aircraft in significant numbers. Its relatively limited fleet means that damage to even a small number of Su-57s can have an outsized effect on the programme.
The aircraft’s AL-41F1 engine, also known as Product 117, powers the current operational configuration. Russia has also been developing a more advanced engine for future production versions.
HUR’s latest allegation raises an additional concern about the vulnerability of advanced military aircraft to disruptions beyond the battlefield. If fuel shortages or quality-control problems begin affecting aviation operations, the consequences could extend beyond individual aircraft losses.
Nevertheless, the cause of the October 29 incident remains unconfirmed. Engine-startup failures can result from several technical problems, and there is currently no independently verified evidence that contaminated or inadequate fuel caused the reported explosion.
Russia’s Defence Ministry has not commented on the alleged incident at Akhtubinsk, while no independent confirmation has established the full extent of the damage or whether the aircraft was completely destroyed.
If Ukraine’s account is confirmed, the incident would add another setback to Russia’s effort to maintain its advanced fighter fleet, following the reported damage at Akhtubinsk in 2024, the Shagol airbase attack in April 2026 and the July crash near Moscow.
For Ukraine, the significance extends beyond the loss of an expensive aircraft. The reported incident also provides an opportunity to highlight how sustained attacks on Russian energy infrastructure could create pressure on the logistics and supply chains supporting Moscow’s military operations.
