Warplanes: The Stealthy F-15 Battles The F-35

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April 16, 2009: Boeing recently unveiled its newest 5th generation fighter the, F-15SE (Silent Eagle) which could well be a F-35 killer on the export market. The aircraft is essentially an F-15 with improved radar and avionics and a modified airframe to add stealth (resistance to radar detection). Conformal fuel tanks mounted underneath the airframe create two internal weapons bays. Each bay has two stores hard points; an upper swing out weapons rack and a lower trapeze with separate doors. The trapeze can carry a 1000 pound JDAM (Joint Direct Attack Munition) or an AIM-120 AMRAAM (Advanced Medium Range Air-to-Air Missile). The upper swing out weapon rack can be fitted with a rail to mount an AMRAAM or smaller AIM-9X Sidewinder missile. It also can be fitted with a 500 pound bomb. All four hard points can carry two SDBs (Small Diameter Bomb) each.

Apart from the internal weapons bays, the major retrofit to the airframe is the two tail fins canted 15 degrees outwards to eliminate nose ballast and the trim, reducing the radar cross section towards the sides. The aircraft’s frontal radar signature has been further softened out by using radar absorbent coatings to the airframe, particularly to the leading edges. Boeing claims the end-result is an aircraft that can match the frontal-aspect stealth profile of any fifth generation fighter in configurations cleared by the US government for export release. The US government has very strict regulations on export of aircraft with low radar signature. For an example the USAF’s primary air superiority stealth fighter the Lockheed Martin F-22 is not cleared for export. Boeing acknowledges the F-15SE’s stealth improvements do not help against ground-based radar systems, which are critical for waging offensive strikes against opponents armed with surface to air missile systems. Lowering the F-15SE’s thermal signature - a critical stealthy feature for the F-22 - is also not part of Boeing’s plans. But it says the F-15SE is aimed at international customers who are more likely to use the aircraft for defensive, counter-air operations where the aircraft would be harder to detect by airborne radar of an enemy aircraft.

Another key feature of the F-15SE is its electronic warfare system. Boeing has selected the BAE Systems digital electronic warfare system (DEWS), which includes a digital radar warning receiver, digital jamming transmitter, integrated countermeasures dispenser and an interference cancellation system. This enables the aircraft to continue to jam enemy radars even as its own radar and radar warning receiver (RWR) continues to function. The main sensor for the aircraft will be the Raytheon APG-63(V)3 active electronically scanned array (AESA) radar.

Boeing’s estimated cost for a new aircraft is $100 million,  including spares and training. However, if the existing F-15E customers want to retrofit their aircraft to the F-15SE standard, the company would undertake same at a much lesser cost. Boeing plans to offer the aircraft initially to Israel, Japan, Singapore, Saudi Arabia and South Korea, with all being current F-15 customers.

The unique feature of all the improvements is that the aircraft can be quickly reconfigurable to its former non stealthy standard. With its new sensors and the Electronic Warfare suit plus it’s 14 ton payload makes it a front runner in the non stealth multi-role fighter market at any case. 

Although Boeing doesn’t admit the implications of the arrival of the F-15SE on the export market for the F-35, the shrinking defense budgets of many counties who were potential customers for the F-35 may be attracted to the new aircraft. Already two customers on the F-35 prospect list (Israel and Singapore) are on the list of potential customers for the F-15 SE, and a third, Japan is due to make a request for proposals for its F-X fighter program. The F-35 still being under the specification and over-budget adds more weight in to the Boeing’s prospects. Independent analysts also see potential markets for the SE in Taiwan and in other Middle East countries such as UAE and Kuwait. However according to Boeing, USAF the largest F-15 operator, still is not an “official” sales target. -- Chaminda Perera