Boeing Condor

In the 21st century UAV development is advancing in leaps and bounds as rapid developments in technology allows even more capability to be packed onto a small air vehicle. Most UAVs are designed to conduct general ISR missions, rather than being tailored for a particular single mission, allowing them to be employed in a wide variety of roles, but this wasn’t always the case. Back in the 1980s, before most members of the public were even aware of UAV operations, the US Air Force often issued a requirement for a UAV tailored for a specific mission – a good example is the Teledyne Ryan AQM-91A Compass Arrow designed to photograph the Chinese nuclear test site at Lop Nor. The downside of this policy is generally the small number of UAVs required, which pushes up the cost and if the mission if abandoned, for whatever reason, the requirement for the UAV disappears as well. This is exactly what happened to another ‘black’ programme from the period – the Boeing Condor.

From what can be uncovered about this programme, it appears that back in the early 1980s the USA needed a highly specialised UAV for a classified mission, possibly ELINT. Exactly what this mission was has still not been made public, but I imagine it probably involved North Korea, but that’s just my guess and I made be very wide of the mark. Sometime in the mid 1980s the Defence Advanced Research Projects Agency (DARPA), probably acting on behalf of the USAF, NRO or CIA, issued a requirement for a High Altitude Long Endurance (HALE) UAV and, presumably after the usual companies such as Lockheed and Northrop had also submitted their proposals, Boeing won the $300 million contract with it’s first large scale composite design which it named the Condor.

Boeing Condor

The UAV was well named because with its sailplane-type laminar-flow airfoil wing it had an aerodynamic efficiency close to that of a glider, with a cruise lift/drag ratio of 40:1. The Condor had a wing span of over 200 feet, a larger wing span than either the Boeing 747 or even the massive Boeing B-52 bomber – the wingtips flexed up to 41ft on some flights. The Condor had a narrow boxy fuselage, just 52 inches high by 34 inches wide (1.32 m by 0.86m) designed to allow external sensors and antennas to easily be fitted. The Condor could easily be dismantled to allow it to be transported in a large plane, such as a Lockheed C-5A Galaxy.

Boeing Condor Continental TSOL-300-2 engine

Power was provided by two six-cylinder opposed, twin supercharged, liquid cooled, Continental TSOL-300-2 engines driving three-bladed composite propellers 16ft (4.9m) in diameter through a two-speed gearbox and, although the vehicle demonstrated an un-refuelled flight duration of 80 hours, the design goal was actually 150 hoursThe two 175 horsepower engines were boosted by two stages of exhaust driven superchargers and these, together with the huge wings and gearbox shift at 43,000ft, gave the Condor the ability to cruise above 65,000ft - on one of its test flights the Condor set an altitude record for piston-powered aircraft of 66,980ft.

Boeing Condor

The actual payload the Condor was designed to carry has never been revealed, however, on test flights it carried around 1,800lbs (815k) of test instruments, so it could have carried a wide variety of sensor simultaneously. Around 60% of the weight of the Condor was fuel, all of which was carried in the wings and the Condor’s gross take-off weight was 20,000lbs. Because of the weight of the fuel carried in the wings, the Condor was limited to a maximum speed of 140kts. Weight was kept to an absolute minimum and a ‘dolly’ and two outrigger wing mounted wheels were used at take-off and detached as the Condor got airborne. For landing a tandem nose wheel and a fuselage mounted skid were used. The Condor had a very low radar and heat signature footprint, making it electronically almost invisible and very difficult to track. From the outset Condor was designed to operate completely autonomously and used duplicate redundant flight control computers operating over 60,000 lines of FORTRAN code, however, the Condor also carried a SATCOM communication link on the rear fuselage that allowed the mission profile to be amended in flight. During the eight-flight test programme Condor flew over 300 hours, including a last flight of 58.11 hours and was considered a success, but then the mission it had been designed for was abandoned, probably for political reasons, and the Condor was cancelled. The Condor was mothballed in 1990 after an expenditure of around $400 million and then later donated to the Hiller Museum in San Carlos, California where it remains on display to this day.

Boeing HALE

However, that is not the end of the story. Although the Northrop-Grumman Global Hawk has been in service for some time, the requirement for a slower HALE still appears to be doing the rounds and a number of companies are working on their designs. Using much of the technology and lessons learnt from the Condor programme, Boeing and a team of partners are currently working on a large, hydrogen powered HALE UAV. The new UAV is believed to be similar in size to the old Condor design, but would have 10 days endurance and much work is going into developing lightweight insulated liquid hydrogen tanks. Another company named AeroVironment (AV) have also built a HALE with a 15m wingspan named the Global Observer that was first tested in 2005. The Global Observer is powered by electric motors running off a single power plant, probably a fuel cell. Two models have been proposed by AV, the GO-1 with a payload of 135-180kg and the larger GO-2 with a 450kg payload.

AeroVironment's Global Observer

Although Boeing appeared to lose out when the Condor was cancelled, it appears that the money used in the Condor has not been wasted and the information obtained during the test programme can be used to inform this new programme. Which design might eventually make it into production is the next issue, but my money would be on Boeing. If the Boeing design eventually goes into production I hope it will be called the Condor II and make an appearance in public, but I suspect it will disappear into a ‘black’ programme and remain hidden for many years to come.