Flying High This Past Week: 22 February-1 March

So here's what's been getting a lot of page views this past week here at TAILS THROUGH TIME:

• The Boeing PBB Sea Ranger: The Best Flying Boat at the Worst Possible Time: Quite naturally the most recent aviation history article for this blog is going to lead things off on this installment of "Flying High This Past Week". One of the most fascinating areas of aviation history for me are those aircraft that either never went into production like the Sea Ranger or those that never left the drawing boards like the Focke Wulf Ta 183 "Huckebein". Look for more articles in the future from me that cover either unbuilt aircraft designs or aircraft that never went into production. What are often aviation dead-ends often leave a legacy for future designs. In the case of the Boeing PBB Sea Ranger, it left an unexpected legacy with Boeing that still plays a big part of the company today. 
• Tactics Over Technology: The Thach Weave: There's no argument that first six months of the Second World War in the Pacific that the Japanese Mitsubishi A6M Zero was ascendant as one of the aircraft apex predators of the skies. The Battle of Midway wasn't just a turning point in the Pacific War but it also represented a turning point in the fortunes of the Zero even though the stubby Grumman F4F Wildcat was still the main fleet fighter of the Navy and definitely not in the same class as the Zero. At Midway, the skipper of VF-3, Lt. Commander Jimmy Thach, instituted a new tactical maneuver called the "Thach Weave" that gave Wildcat pilots a fighting chance against the Zero.
• The Most Ambitious UAV Ever: Quartz/AARS: In the 1980s over $1 billion was spent on a stealthy UAV called the Advanced Aerial Reconnaissance System which was code named Quartz. It was a flying wing UAV that would penetrate Soviet airspace in times of war and search for the road and rail mobile ICBMs of the Soviet Strategic Rocket Forces. Boeing won the contract for the AARS over Lockheed but in 1992, Quartz was canceled, but it's believed the work that went into the design may bear fruit with a next-generation bomber to succeed the B-2A Spirit should the joint Lockheed/Boeing team be selected over Northrop Grumman. 
• The Ultimate Superfortress: The B/RB-54: This was the ultimate evolution in the Superfortress design lineage as a longer legged, faster, and even bigger version of the B-50 Superfortress which was itself quite an improvement over the wartime-era B-29. While it never flew let alone enter production as it came on the scene just as jet aircraft like the B-47 Stratojet were entering the picture, it did leave the drawing board. The B/RB-54 prototype was 75% complete when the program was canceled with its funding shifted to the Stratojet program. 
• One Powerful Helicopter Gunship: The ACH-74A "Guns A-Go-Go": Only four of these gunship Chinooks were built and flown into combat in Vietnam 1966-1968. To the best of my knowledge, these beast machines are the only helicopter gunships to ever go into combat with an unobstructed 360-degree field of fire.

That's all for this installment of "Flying High This Past Week". Stay tuned to TAILS THROUGH TIME- there will be a new aviation history article posted here every five days. The next one will be going up on 3 March. And don't forget last week's installment of "Flying High This Past Week"!

The Most Ambitious UAV Ever: Quartz/AARS

One of the most ambitious if not the most expensive UAV design effort came in the 1980s as the Cold War was coming to its climax. Over $1 billion was spent on a black project called the AARS- Advanced Airborne Reconnaissance System or known by its code name, Quartz. The Quartz UAV was designed to be a very stealthy, long-endurance UAV that would penetrate Soviet air space in a time of war and identify what were called "strategic relocatable targets"- the rail- and road-mobile ICBMs of the Soviet's Strategic Rocket Forces. Quartz was sponsored by the US Air Force and the NRO, National Reconnaissance Office.

The requirement for a 24-hour endurance and low-observability tested the limits of aerospace technology of the day. In 1983 Lockheed and Boeing were selected to develop concepts for the Quartz program. Lockheed's initial design was a giant aircraft with a 267-foot wingspan propelled by two turboshaft engines driving massive 47-foot propellers. The engines were actually dual-cycle turboshaft/turbojet engines, with the engines operating as jets and the two-bladed props locked in horizontal for takeoff and landing. Once at cruise altitude, the engines shifted into turboshaft mode to drive the large props.

Little is known of Boeing's design for Quartz other than it may have been a flying wing design along the same lines as the Lockheed proposals. The need for low-observability and autonomous operation in denied airspace resulted in an expensive design that was compounded by the fact that only a few Quartz UAVs would be needed- the technology used was so sensitive that only the strategic imperative made it worth the risk of losing the aircraft in the event of malfunction or shootdown.

As the costs of the program soared, it became a victim of an inter-agency squabble between the CIA and the NRO who wanted Quartz and the USAF, who was losing interest due to the rising costs. In 1990 Lockheed and Boeing were directed to combine their efforts which resulted in a jet-powered flying wing not too dissimilar from the Northrop B-2 Spirit stealth bomber. As the costs still continued to climb, the USAF continued to back away from the program and even a redesign for a slightly smaller version failed to bring the USAF back aboard. Quartz was cancelled in 1992 when the NRO finally withdrew from the program as well.

In the 1990s, there were three "tiers" of UAV development based on operational capability. "Tier I" was for a low-altitude system that became the Gnat-750 UAV. "Tier II" was for a more capable medium altitude system based on the Tier I craft and that became the current Predator UAV family. The specification for "Tier III" would have been filled by the Quartz project, but with its cancellation, Tier III was split into two- Tier II+ was for the Quartz's performance without stealth and this became the RQ-4 Global Hawk UAV. Tier III- ("Tier III Minus") was stealthy but without the performance and payload of Tier II+. This design became the RQ-3 DarkStar. DarkStar, a joint effort between Boeing and Lockheed, had little in common with Quartz and itself would be canceled in 1999 in favor of further development of the Global Hawk.

However, it's believed that the current Lockheed/Boeing proposals for a next-generation bomber (the picture included in this blog post) are nearly identical save the cockpit to the resultant Quartz design.

Source: International Air Power Review, Volume 15. AIRtime Publishing, 2005, "Focus Aircraft: HALE/MALE Unmanned Air Vehicles Part 1: History of the Endurance UAV" by Bill Sweetman, p63-69.