Sense and Avoid issues

A new threat has arisen to the Global Hawk and Triton programs. All work on the Exelis Air-to-Air Radar Subsystem (AARS) has stopped since April. The AARS is the "See and Avoid" radar system that would be installed on both the RQ/MQ/EQ-4 and other UAV systems to allow them to operate in areas where commercial flights operate. Without a sense and avoid system the UAVs can't operate without a chase aircraft to broadcast an IFF signal for ATC to follow (most don't carry a transponder).

Work was halted on April 25th due to cost overruns and "technical issues". The Navy is the lead on the development of the system, and is working on finding a substitute for the Exelis system.

The U.S. Navy stopped work four months ago on a crucial part of the MQ-4C Triton unmanned air system and is working to find a substitute, service and industry officials confirm. The Exelis Air-to-Air Radar Subsystem (AARSS) sense-and-avoid radar project was halted April 25 due to technical problems and cost overruns, the Navy said last week.

A sense-and-avoid capability is “vital” to the MQ-4C, according to Tom Vice, president of Northrop Grumman's Aerospace Systems segment. Triton is designed to operate in oceanic airspace, where there is no outside radar surveillance. The radar or an equivalent sensor is required so the UAS can avoid colliding with a “non-cooperative” aircraft that is not using any other collision-avoidance system.

AvWeek

The Navy is planning both TCAS and ADS-B on the Triton platform, but they are searching for a replacement for the ABSAA capability. The problem relates to miniaturizing and cooling the AESA radar needed. They are at the very edge of the envelope for the technology and it's leading to problems.

AvWeek

“This is hard stuff,” he added. “The first UAS with no-kidding sense and avoid is hard stuff.”

No, it really isn't. In fact, its really a very simple task IF you stop trying to jam all that equipment into an unsuitable airframe. The problem they are really facing is, if they are honest, SPACE.

You do not take a Hawker Hunter and try to get it launching off a deck armed with 4 Phoenix missiles and a brace of Sparrows either side and call it a Tomcat. No, you build a Tomcat.

Northrop should fall on their sword on this one, and evolve the twin engine design and really put a supremely capable and effective platform onto the Triton role.

reply to post by Astr0


That's the impression I got from reading the article. They're finding out the hard way that this stuff only goes so small, and they're trying to make it smaller.

reply to post by Zaphod58


AESA miniaturization and flat panel optimisation is being pioneered by Northrop. I posted before about an effort using the B-2B as a test platform.

To be honest, Northrop rolling out a TACIT BLUE style UAV for the Triton role would just simply wipe the floor with any opposing designs from say LM or Boeing.