Stranded F-35B fighter in TVM not a good sign for Trump and Lockheed Martin

There could not have been a more embarrassing advertisement for fifth-generation F-35 stealth fighters than a broken down F-35B, seemingly abandoned in a coastal airport located at the southernmost tip of India's west coast.

The F-35B, which was part of Britain's lead frigate HMS Prince of Wales, made an emergency landing at Thiruvananthapuram airport in Kerala on the night of June 14 and has ever since remained grounded.

On June 25, 11 days after the fighter made the distress landing, the British High Commission said the aircraft would be moved to a maintenance hangar of the Air India (in the Thiruvananthapuram airport) once "UK engineering teams and specialist equipment" land in Kerala to move the aircraft safely.

The timing of the F-35's malfunction, too, could not have come at a worse moment for Lockheed Martin, the manufacturer of F-35s. It was early this year, on February 13, that the US President Donald Trump met Indian Prime Minister Narendra Modi in Washington, and in a joint press conference said: "We are also paving the way to ultimately provide India with F-35 stealth fighters."

Trump's impromptu offer caught India by surprise. Later in the day, Foreign Secretary Vikram Misri put the offer in context. "I don't think with regard to the acquisition of an advanced aviation platform by India, that process has started as yet. So this is currently something that is at the stage of a proposal. But I don’t think the formal process in this regard has started as yet," Misri said.

India does not possess a fifth-generation fighter. China has J-20, which had entered service in 2017. Pakistan is co-developing JF-17 fighter with China.

India's domestic Advanced Medium Combat Aircraft (AMCA) programme is nowhere near operational readiness. India's spearheads are of Russian origin: Su-30MKI, Mirage 2000, and MiG-29. All fourth or 4.5-generation.

A fifth-generation fighter is an improvement over fourth- and 4.5-generation fighters. Unlike them, the fifth-generation fighter will have phantom properties like invisibility and supersonic speed. Stealth coatings and shaping, internal weapons bay, advanced radar and sensors, integrated avionics, and the ability to 'supercruise' or fly faster than the speed of sound (supersonic).

Russia's Su-57 is not seen as dependable as it is widely believed in aviation circles that the technology required to make the aircraft truly fifth-generation has not yet been developed.

In this backdrop, F-35 seems like a tempting prospect. But the cost is daunting. One aircraft costs between $80 and $110 million, the costliest fighter plane ever.

Forget the cost, the grounded F-35B in Thiruvananthapuram has spotlighted far graver issues with the F-35 model. Mainly, its reliability and maintainability factors.

The F-35 has three variants: F-35A, F-35B, and F-35C. All share the same engine and stealth characteristics, the main difference being the manner of takeoff and landing. It was F-35B that landed in Thiruvananthapuram and it has what is called the 'short takeoff and vertical landing' capability. Meaning, it can drop on a carrier ship like a stone. The other two possess the conventional landing and takeoff capabilities.

Aviation experts point to three main reliability metrics: Mean flight hours between critical failures (MFHBCF), Mean flight hours between removal (MFHBR) and Mean flight hours between maintenance events -- unscheduled (MFHBME-U).

MFHBCF includes all failures that render the aircraft unsafe to fly, along with any "equipment failures that would prevent the completion of any defined F-35 mission". It includes failures discovered in the air and on the ground.

The latest annual report (2024) of the US Department of Defence (DoD) says that critical failures happened to all the three F-35 variants far sooner than the incident-free flying hours prescribed for them by the DoD. Meaning, all three broke down quickly than is acceptable in aviation standards.  

MFHBR indicates the degree of necessary logistical support and is frequently used in determining associated costs. This metric includes removal of an item from the aircraft for replacement. The DoD report says that the MFHBR of F-35B and F-35C have never reached the operational requirement set by the DoD ever since these fighters began service in 2015. F-35A managed to go beyond the requirement once, in 2023.

In short, these fighters require frequent removal of spare parts than is economically sustainable. MFHBME-U measures maintenance workload due to unplanned maintenance. Maintenance events are either scheduled (inspections or planned part replacements) or unscheduled (failure remedies, troubleshooting, replacing worn parts such as tires).

For F-35C, the time taken for the next unscheduled maintenance has always been lower than what was prescribed by the DoD. Result: higher maintenance costs. The other two variants, however, improved the time between unscheduled maintenance stops beyond the sustainable limit fixed by the DoD after years of underperformance; F-35A after 2020 and F-35B after 2021. The F-35B landing in Thiruvananthapuram was an unscheduled event.

The maintainability standards of the F-35s in the US fleet are also below par, according to the 2024 report of the DoD. There are two measures by which maintainability is assessed. Mean Corrective Maintenance Time for Critical Failures (MCMTCF) and Mean Time to Repair (MTTR).

In both these metrics, all the three variants fare way below the standards set by the DoD. "MCMTCF remains almost double or more than the threshold requirement," the report said. MCMTCF indicates the average time for maintainers to return an aircraft from 'Not Mission Capable' to 'Mission Capable' status. MTTR is the average time for all unscheduled maintenance actions, like the one set in motion in Thiruvananthapuram airport. The inordinate time taken to repair the aircraft validates the DoD finding.

In addition to these reliability and maintainability blemishes, the modernisation plan for the F-35s (Block 4) and a radical software update (Technical Refresh-3) for them have been considerably delayed. No wonder the foreign secretary was circumspect when asked about Trump's offer.

The delay in making the F-35B stranded in Thiruvananthapuram 'Mission Capable' will further dent the credibility of Lockheed Martin's stealth birds. It looks like the US has had enough of Lockheed Martin. It is Boeing that has bagged the contract for the development of sixth-generation fighters for America.