|03-Dec-2007 20:55 | Permanent Link
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(click to view full)by Johan Boeder in The Netherlands. Earlier versions of this article have been published in the Dutch press and Defense-Aerospace. DID has worked with the author to create an edited, updated version with full documentation of sources.
On May 3, 2007, during the 19th test flight of the prototype of the F-35A Joint Strike Fighter (JSF), a serious electrical malfunction occurred in the control of the plane. After an emergency landing the malfunction could be identified as a crucial problem, and it became clear that redesign of critical electronic components was necessary. Producer Lockheed Martin and program officials first announced there was a minor problem, and later on they avoided any further publicity about the problems.
The delay has become serious, however, and rising costs for the JSF program seem to be certain. In Holland, Parliament started a discussion again last week. Understanding the background behind these delays, and the pressures on European governments, is important to any realistic assessment of the F-35's European strategy – and of the procurement plans in many European defense ministries…
The Fateful Incident
(click to view full)On December 15, 2006 the experienced Lockheed Martin chief test pilot Jon Beesley takes off for the first time with the JSF (Joint Strike Fighter), also known as F-35 Lighting II. The coming years, some 3000 Joint Strike Fighters are scheduled to be delivered to replace F-16 and Harrier fighters in the USA and in the air forces ad navies of several European countries. In most cases, replacement contenders are some combination of the Eurofighter, Rafale, Gripen and JSF. In many cases, the new fighters must also be available by 2014-2018 ultimately, when early-model F-16s bought in Europe will reach their end-of-life stage. Any further delay brings high maintenance costs, and too low operational availability.
After a series of 7 quite successful flights, the test flight program stops in February 2007 to fix some minor problems in the JSF flight control software. This is not unusual in the early stages of a test flight program. In March 2007, the JSF returns to flight status and takes off for the first supersonic flight. At the end of April the JSF prototype AA-1 takes off several times a week. But then, destiny strikes. On May 3, 2007 with the second test pilot Jeff Knowles at the stick, a serious malfunction hits the JSF. At 38,000 feet (12 km) level flight and at a speed of some 800 km/hour, the plane executed a planned, 360-degree roll but experienced power loss in the electrical system about halfway through the manoeuvre.
In an emergency procedure, power is restored and Jeff Knowles regains control of the plane. The pilot cuts short this 19th test flight and makes an emergency landing in Fort Worth, TX. Due to control problems with right wing flaperons, the JSF has to make that landing at an exceptional high speed of 220 knots (350 km/hr). The plane's undercarriage, brakes and tires are damaged. The plane is stopped, surrounded by emergency vehicles, and towed away, but several eyewitnesses take pictures of the emergency landing.
Lockheed Martin technicians identify a component in the 270-power supply as the culprit in the near-accident. The JSF's new technology includes new electro-hydrostatic actuators (EHAs) for the flight control system, replacing more conventional hydraulic systems. In April 2007, chief test pilot Jon Beesley told Code One Magazine that the EHAs were production versions, and that testing could be restricted to the AA-1:
"The electro-hydrostatic actuators, or EHAs, are another excellent example of risk reduction we're accomplishing on AA-1. This is the first real electric jet. The flight control actuators, while they have internal closed-loop hydraulic systems, are controlled and driven by electricity—not hydraulics. The F-35 is the only military aircraft flying with such a system. We proved that the approach works on six flights of the AFTI F-16 during the concept demonstration phase of the JSF program. We already have many more flights on EHAs on this test program. Because we are flying production versions of the EHAs on AA-1, we won't have to prove the EHA design on subsequent F-35s."
After several weeks of evaluations, the engineers learn that there are serious design problems in this new electrical system. Expensive redesign will be necessary.
'No serious problem'?
(click to view full)Normally whenever the JSF takes an itty-bitty baby step, the manufacturer reports it to the media for PR purposes. First engine run? Reported. Roll-out? Reported. First flight? Reported. First Wheel-up flight? Reported. But "first emergency landin