Three jets, one in each F-35 variant, will be delivered in a flight test configuration to support upgrade efforts.
The Pentagon has awarded Lockheed Martin a contract to deliver three F-35 fighter jets configured for flight science and test work.
Approved on 23 April, the $177 million contract covers three F-35 aircraft – one in each of the single-engined fighter’s variants: the conventional take-off and landing F-35A, short take-off and vertical landing F-35B, and carrier-based F-35C.
The latest order follows the delivery of a test-instrumented F-35A to the US Air Force in September.
The Pentagon operates only a small fleet of flight-science F-35s, a point which has been cited as contributing to delays in rolling out new upgrades for the fifth-generation stealth fighter and ultimately driving up costs.
Washington famously halted deliveries of new F-35s for a full year between 2023 and 2024 due to protracted delays at Lockheed in certifying the Technical Refresh 3 (TR-3) configuration, which provides improved onboard computing power needed for long-term upgrades to weapons, sensors and communications.
That suite of upgrades are collectively known as Block 4 – a programme which is now five years behind schedule, according to auditors at the US Government Accountability Office.
“Currently, Block 4 costs are over $6 billion more and completion is at least five years later than original estimates,” the GAO noted in a September report.
Delivery of the first Block 4-configured F-35 is now projected for 2031.
The new, albeit small, fleet of flight-science aircraft will help Lockheed and the Pentagon complete the certification process for the new configuration.
Those three F-35 test jets will be used “to replace the ageing original flight science aircraft in support of preventing a capability gap for flight test and allow for future, holistic testing of Block 4 capabilities and other future capabilities for the Joint Strike Fighter programme,” the Pentagon said in the contract announcement.
In addition to Block 4, the Pentagon is pursuing multiple complex and expensive projects to upgrade the F-35’s electrical power generation and onboard cooling to contend with draws that now exceed original design parameters.
Those efforts include the Engine Core Upgrade programme to re-core the jet’s Pratt & Whitney F135, for which P&W is under contract and currently performing design work.
A separate programme to upgrade the F-35’s Honeywell-made Power and Thermal Management System is also being considered, but has not yet received full commitment from the Pentagon.
All of those upgrade efforts will require test aircraft or risk becoming bogged down and delayed as have the TR-3 and Block 4 projects.
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