New airborne mine-clearing system

July 5, 2009 · Posted in Blogroll, Uncategorized · 1 Comment 

ramics Wired’s Danger Room reports on a new airborne naval mine-clearance system being developed by Northrop Grumman. The system is based on a Seahawk helicopter firing high-speed underwater supercavitating projectiles:

Mounted on a helicopter, it combines a sensor to see through water with a 30mm cannon, which can take out a mine with a single shot.

The difference is in the ammunition. When a RAMICS round strikes the water, the pressure wave from blunt tip produces a bubble which surrounds the projectile. This reduces friction so, unlike other projectiles, the bullet keeps its velocity underwater.

A possible counter-torpedo role is also mentioned:

However, the success of RAMICS in tests suggests another alternative. If you can have a Phalanx gatling gun on the deck of a ship to defend against missiles, why not have something similar to destroy incoming torpedoes? RAMICS shows that it’s possible to detect a torpedo underwater using a laser-based sensor, and a 30mm supercavitating round which can destroy a mine can certainly destroy a smaller, think-skinned torpedo. The main question would be accuracy – but RAMICS has proved more accurate than expected in tests, and only needs one shot.

In fact, this is exactly the approach taken by Darpa’s Very High Speed Torpedo Defense project. Testing of the sensor, targeting mechanism and projectiles are being carried out this year in a variety of sea states. (Elsewhere, it’s been suggested that an underwater gun pod, firing supercavitating rounds may be used rather than one above the water).

F-22 stealth maintenance problems?

July 3, 2009 · Posted in Blogroll, Uncategorized · 1 Comment 

F22_formation Steve Trimble reports on an interesting story related to the stealth-related maintenance of the F-22. A former LockMart engineer who worked on the F-117, B-2 & F-22 programs is to file a lawsuit against the company for allegedly conceiling deficiencies on the radar-absorbent material (RAM) coatings of the stealth fighter:

The pending lawsuit accuses Lockheed of knowingly providing defective coatings used to reduce the aircraft’s radar and visual signatures, and covering up the problem by adding 272kg (600lbs) worth of extra layers.

There is an interesting section that sheds some details on the successive RAM layers:

The F-22 requires three layers of coatings to reduce its radar signature, according to Olsen’s statements in his case. A primer seals the surface of the aircraft skin and helps with the adhesion of the next layer. Next, a conductive coating with silver flakes mixed with polyurethane materials is applied to keep radar waves from bouncing back to the emitter source. Finally, a topcoat layer has properties, including metallic materials, to reduce heat, which lowers the risk of radar detection.

"If those coatings are not effective, the other stealth measures of the aircraft’s design are negated," the lawsuit says.

The engineer claims that Lockheed deliberately and protractedly evaded government attention on this matter:

Olsen claims he witnessed Lockheed management misleading USAF officials about the quality of the stealth coatings. Olsen’s supervisors instructed him not to speak at meetings with USAF officials. […] Lockheed also schemed to avoid government inspections of the coatings, secretly shipping batches of the stealth materials to the homes, the lawsuit states.

Obviously, if the accusations prove to be sound, this revelation may cast doubt to the entire concept of the F-22s presumed degree of stealth, as well as its maintenance requirements. While the fighter is also a supreme aerodynamic airframe (1.5M supercruise at 65.000ft can, by itself, shrink the engagement envelope of enemy weapons significantly), it is the stealth factor that is supposed to be the chief enabler of the fighter’s advanced combat potential. On the other hand, RAM is only part of the stealth design; careful shaping by itself has a significant contribution to the overall RCS (see our Waypoint primer on stealth).

The excessive maintenance requirements, if true, may also have negative consequences on the overall operational availability of the aircraft – a particularly pressing concern in light of the successive cuts that have limited its total production to just under 200 airframes.

The Register, in its own coverage of the news, adds the inevitable political angle:

President Obama and his Defense Secretary Robert Gates want to cease manufacture once the US air force has a total of 187 F-22s; however, politicians from districts where the Raptor is made are resisting them. Furthermore, although Gates has managed to partially bring the US airforce to heel by replacing its two top bosses last year, institutionally the service passionately desires a much larger Raptor fleet.

Gates’ desire to save money for combat troops by purchasing drones and "affordably stealthy" F-35s, more useful for strike missions, is backed by the other US services for different reasons. Furthermore, the White House has signalled that President Obama may deploy his veto against attempts to maintain the pricey Raptor in production. Nonetheless, it’s plain that Gates has a fight on his hands.

STRATFOR commentary on US-Russian summit

July 2, 2009 · Posted in Blogroll, Uncategorized · Comment 

Some nice insight from G. Friedman on the important issues of the upcoming summit in Russia. Watch it in HD if possible (much better map clarity etc.).

Greece to procure SPICE 1000 & 2000

July 1, 2009 · Posted in Blogroll, Uncategorized · 2 Comments 

090630aIn a move that is possibly a reaction to the Turkish development of indigenous JDAM-class guidance kits, the Greek MoD announced a tender for procuring an unspecified number of SPICE 1000 & SPICE 2000 guidance kits for Mk83 and Mk84 bombs respectively:

SPICE 2000 is optimized for launch at high speed & altitude, for maximum stand-off range. For example, when released at 42.000 ft at high subsonic speed, gliding range reaches up to 60km. The system does not perform post-launch rise prior to the terminal dive, so it is not suitable for low-level launch [e.d. other guidance kits like the Paveway-III perform this maneuver  to enable low-level release]. A typical mission profile may include ingressing at low altitude and performing a steep ascend prior to launch, to maximize stand-off range.

SPICE 1000 has a different arrangement, with two fold-out wings instead of fixed trapezoidal stub-wings, which provide better glide performance and thus improved launch range.

Reportedly the launch platform for the weapon system will be the F-16C. The tender is projected to be concluded by late August.

If procured in sufficient numbers, the guidance kits should significantly improve the EPA’s ability to perform strikes against comprehensive integrated air-defense systems.

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