raptors

Boeing’s 757 Flying Test Bed was recently spotted carrying a stealthy underwing infrared sensor pod under its fuselage. This may be the first time this aircraft, better known as ‘The Catfish’ because of its unique and highly modified nose profile, has ever been seen lugging around a store on this station. The pod itself is part of a larger “Raptor 2.0″ upgrade package being developed for the F-22. Catfish has served as a key systems integration testbed for the Raptor since the 1990s.

Jerod Harris caught Catfish with the pod under its belly as it came in to land at Edwards Air Force Base in California on Monday. Edwards is the main hub for U.S. Air Force test and evaluation activities, and Catfish has been seen there many times over the years as part of its work. The aircraft, which carries the U.S. civil registration code N757A, also happens to be the first 757 ever built, and took to the skies for the first time back in 1982.

As already noted, Catfish has already played a central role in the story of F-22. The aircraft’s heavily modified nose is designed to directly replicate that of the Raptor, and contains the same AN/APG-77 active electronically scanned array (AESA) radar as the fighter. The swept wings on top of the cockpit were also designed to support testing of the conformal antennas for the Raptor’s AN/ALR-94 electronic support measures system and other components of its ‘fused’ sensor suite. The aircraft has supported the development of a wide array of other systems for the F-22, and is packed inside with additional equipment to support those needs in particular, including a replica of the Raptor’s cockpit. You can read more about Catfish and its general history here.

So it is not surprising then that the heavily modified 757 would also be used now to help with continued testing of the new underwing infrared sensor pods for the Raptor. Carrying the pod under the forward end of the fuselage would offer the sensors inside a good open field of view to the front, as well as to the left, right, and down.

The stealthy pods have been test-flown on actual F-22s for years now. At the same time, there are only a limited number of Raptors available, in total, and they are notoriously fuel-hungry, maintenance-intensive, and otherwise expensive to operate. If the particular test plan calls just for level flight, and over extended periods of time, a platform like Catfish could be an attractive alternative. With space for dozens of engineers and technicians in its main cabin, and workstations for them, the aircraft would also offer very different options for testing and evaluating the pod while in-flight. A North American Sabreliner business jet has also been used to test these pods in the past.

The capability, in general, for Catfish to carry stores under its fuselage might open up additional possibilities for utilizing the aircraft in support of other testing efforts, if it hasn’t already.

Catfish would also be well suited to supporting testing of other elements of the Raptor 2.0 package. Under the current plan, the Air Force’s F-22s are also set to get a new integrated distributed infrared search and track (IRST) system called the Infrared Defensive System (IRDS).

IRST systems have seen a renaissance across the U.S. military in recent years, as well as elsewhere globally. IRSTs detect and track targets via their infrared emissions, making them particularly valuable for helping spot stealthy targets with features designed to reduce their radar cross-sections. The sensors are also immune to radio frequency electronic warfare jamming and operate passively, meaning they do not emit signals that could alert a target to the fact they are being tracked. IRSTs can also be used to cue or otherwise be linked to other sensors, including AESA radars. This data fusion can provide higher fidelity tracks of multiple targets, as well as improved situational awareness overall.

Increased demand for IRSTs has led to a commensurate increase in demand for testing using multiple platforms. This, in turn, has been a major component of a general uptick in U.S. military flight testing in recent years to support a variety of new, advanced programs.

Other elements of the Raptor 2.0 upgrade plan include new stealthy drop tanks, improvements to the jet’s stealthy features, radar capabilities, electronic warfare suite, and more, as you can read about in detail here.

At least a portion of the Raptor fleet is also set to receive modifications to enable them to act as airborne controllers for Collaborative Combat Aircraft (CCA) drones. The Air Force’s F-22s are set to be the service’s first tactical jets to be used in that role, though others will follow.

The F-22 upgrade work is reflective of current Air Force plans to keep the Raptors in service for decades to come. In 2024, the Air Force said it no longer had a firm retirement schedule for the fighters.

Raptors have been used in recent years as surrogates to support work on the Next Generation Air Dominance (NGAD) initiative, a component of which is Boeing’s F-47 sixth-generation fighter. As such, Catfish will have already been feeding into those developments, which are now firmly a top Air Force priority.

At the same time, Catfish is now 44 years old. Boeing 757s, in general, are increasingly disappearing from service globally as they become more complicated and cost-intensive to sustain. Especially with the work ongoing now on the F-47, it seems likely Boeing will start looking toward a new highly specialized testbed aircraft modified to reflect the particular physical geometry, unique avionics, and other features of the new fighter.

Similarly, the F-35 family also has a dedicated test jet, the Boeing 737-300-based Cooperative Avionics Testbed, nicknamed the CATbird. There are several other airliner and business jet-based testbeds flying globally today, though Catfish is certainly one of the largest and most visually distinctive. Improving digital simulation and modeling tools could allow for less reliance on surrogate testbed aircraft in the future, but they will in no way be eliminated.

China notably has something of a clone of Catfish based on a Russian-made Tupolev Tu-204C airliner, which itself was designed as an analog to the 757. The Chinese jet’s primary purpose has been supporting the development of the J-20 stealth fighter, the country’s closest answer to the F-22.

In the meantime, Boeing Catfish remains a very important part of continued work to improve and expand the capabilities of the F-22. This now extends to testing of specialized underwing pods for the Raptor.

Special thanks again to Jerod Harris for sharing his pictures of Catfish carrying the stealthy sensor pod with us.

Contact the author: joe@twz.com