Boeing Condor – one of the world’s largest drones
Drones and Remotely Piloted Aircraft
By Jon Welte
Even before Wilbur and Orville Wright flew in 1903, aircraft have flown without pilots. In 1871, Frenchman Alphonse Penaud developed a technique of propelling small airframes with rubber bands turning a propeller. Considered a toy today, in the 19th century such technology was harnessed for aerial experimentation. Competitions involving such rubber-powered models shaped new generations of aircraft designers.
As engine technology advanced, so too did the size and scope of unmanned aircraft. In 1896, Samuel Langley flew a steam-powered, unpiloted model airplane a distance of nearly a mile. Although Langley’s later efforts to build and fly a full size airplane failed, designers continued to use flying models to further research into airfoils and control systems.
These early model aircraft could not be controlled in flight. In some cases it was possible to pre-set control surfaces prior to launch, but full control from a distance was not possible. As the Wrights had discovered, controllability is the key to aviation—and its first flowering in unmanned flight stemmed from the Navy’s need for air defense.
In 1921, General William “Billy” Mitchell led a dramatic demonstration in which a detachment of US Army airplanes sank a number of ships with aerial bombs, most famously a World War I German battleship. Developing countermeasures against hostile aircraft became an important consideration for navies around the world, and the British Royal Navy placed a high priority on air defense.
By the early 1930s, Royal Navy warships were fitted with anti-aircraft armament, yet training was not realistic. Gunnery practice consisted of firing on target banners towed behind manned aircraft. Banner-towing planes could not replicate the flight paths an actual hostile aircraft might take, and the gun crews were restrained for concern of accidentally hitting the tow aircraft. In 1932 the Fairey Aircraft Company converted three of its scout biplanes into Fairey Queens, able to be flown by remote control. The first two aircraft crashed just seconds into their first flights, but the third survived multiple missions and demonstrated the ability of a remote-controlled, full-size airplane for use in drilling air defense gunners.
Encouraged by the technology, Great Britain commissioned the development of a new remotely piloted airplane, the de Havilland DH-82B Queen Bee. Derived from the de Havilland DH-82 Tiger Moth training biplane, the Queen Bee could be flown either by a pilot aboard the airplane or by a simple rotary dial controller and radio system that could be placed on the ground, in a ship, or even aboard another aircraft. The sturdy and stable trainer proved to be an ideal platform for a simple robotic airplane; the rear cockpit was converted to hold mechanical servos to manipulate the controls, and to simplify matters the ailerons were locked in place. Flight was managed with elevator, rudder and throttle control only. Over four hundred Queen Bees—named partly in reference to the earlier Fairey Queen, and consistent with de Havilland’s policy of naming aircraft after insects—were built and flown through the 1930s.
Development of the Queen Bee coincided with negotiation of the London Naval Conference. A US Navy admiral present for the negotiations observed an early test flight and directed development of a comparable American aircraft under the leadership of Lt. Col. Delmar Fahrney. Radio equipment was fitted to two different airplane types, including the Stearman-Hammond Y-1. Redesigned the Stearmond-Hammond JH-1 when fitted for remote operations, Fahrney dubbed the aircraft “drones” partly in homage to the de Havilland aircraft that inspired their development and partly in recognition of the fact that the aircraft, much like drone bees, were expendable if necessary while completing their mission. Only a handful of Stearman-Hammond airplanes were built, with a surviving Y-1 on display at Hiller Aviation Museum.
Drones of the 1930s and 1940s were “remotely operated” in the truest sense; a human pilot had to directly observe the drone’s flight and manipulate the controls by radio in real time to maintain safe flight. Gradually, they became more capable. Autopilot technology, developed for manned aircraft during the first half century of flight, was equally applicable to unmanned operations. Such systems allowed drones to control themselves to an extent when commanded to fly a prescribed heading and/or altitude, as opposed to a pilot continually manipulating the controls by radio to achieve the same results. Later, the combination of growing computer technology and better navigation tools—initially inertial navigation systems, and later Global Positioning System satellites—made it feasible to build robotic aircraft able to take off, fly a route, and land without direct human intervention.
The Boeing Condor, designed and built in the late 1980s, was the first drone to fully incorporate this technology and fly autonomously from takeoff to landing. Conceived as a high-altitude, high-endurance reconnaissance platform, the Condor’s 200’ wingspan carried it and a simulated instrument package aloft to altitudes of over 60,000’. Ultimately considered unsuitable for operational use, only two were built; one hangs in the collection of the Hiller Aviation Museum.
Today, the promise of the Boeing Condor is realized in the Northrop Grumman RQ-4 Global Hawk, a reconnaissance airplane with a wingspan of over 130’, takeoff weight over 30,000’ and the ability to remain airborne at extreme altitude for over 24 hours. One of the world’s premier observation platforms, his aircraft and its mission are similar to that conceived of for the Boeing Condor some ten years earlier.
While enormous drones like the Global Hawk fly missions spanning seas and continents, much recent attention has focused on the tiniest unmanned aircraft. Small helicopters powered by symmetrically arranged rotors have exceptional maneuverability and can be easily launched and operated from almost any location. The proliferation of these tiny drones has raised questions ranging from air safety to privacy, while opening new opportunities in fields ranging from agriculture to community policing. In recognition of this new field in aviation, the Hiller Aviation Museum opened its Drone Plex flight center in January 2016. High fidelity flight simulation equipment provides an opportunity to gain experience in remote aircraft operations, and a large, screened flight area allows both for introductory flight experiences and exciting demonstrations by proficient pilots. The Drone Plex is open to the public on weekends and select holidays, providing an opportunity for all visitors to launch a firsthand drone flight experience.
Brook, Henry. Drones, 2015