Airnews, October 2011
MECHANICAL HUMMINGBIRD
NOW I have heard most everything. According to a recent press release, US-based AeroVironment Inc. has accomplished a technical milestone never before achieved — controlled precision hovering and fastforward flight of a two-wing, flapping wing aircraft that carries its own energy source, and uses only the flapping wings for propulsion and control.
In short, a human version of the hummingbird which, according to many knowledgeable scientists and aerodynamicists, cannot fly. However, the hummingbird does not seem to have read that particular book and continues on its happy way humming all the time. The milestone mechanical hummingbird was part of the Phase II contract awarded by the US Defence Advanced Research Projects Agency (DARPA) to AeroVironment to design and build a flying prototype “hummingbird-like” aircraft for the Nano Air Vehicle (NAV) programme.
“The success of the NAV programme paves the way for a new generation of aircraft with the agility and appearance of small birds,” said DARPA NAV programme manager, Dr. Todd Hylton. The final concept demonstrator is called the “Nano Hummingbird” and is capable of climbing and descending vertically, flying sideways left and right, flying forward and backward, as well as rotating clockwise and counter-clockwise, under remote control and carrying a video camera payload.
During the demonstration the Nano Hummingbird flew in and out of a building through a normal-size doorway. “The historic achievement made by the Nano Hummingbird is an example of the leading-edge innovations introduced and deployed almost routinely by the AeroVironment UAS team,” said Tom Herring, AV senior vice president and general manager of Unmanned Aircraft Systems. “From the battle-proven Raven, Wasp and Puma small UAS to the tiny Nano Hummingbird to Global Observer, the largest, highest and longest flying UAS, AeroVironment continues to define the future of unmanned aircraft systems.”
But just look at the hummingbird’s statistics – the hand-made prototype aircraft has a wingspan of 160 mm (6,5 inches) tip-to-tip and has a total flying weight of 19 grams (2/3 ounce), which is less than the weight of a common AA battery. This includes all the systems required for flight; batteries, motors, communications systems and video camera.
The aircraft can be fitted with a removable body fairing, which is shaped to have the appearance of a real hummingbird. The aircraft is larger and heavier than an average hummingbird, but is smaller and lighter than the largest hummingbird currently found in nature. “The success of the Nano Hummingbird was highly dependent on the intense combination of creative, scientific, and artistic problem-solving skills from the many AV team members, aided by a philosophy of continuous learning, which we feel was only possible due to the unique R&D environment here at AV,” said Matt Keennon, AV’s project manager and principal investigator on the NAV project. The technical goals for the Phase II effort were set out by DARPA as flight test milestones for the aircraft to achieve by the end of the contract effort. The Nano Hummingbird met all, and exceeded many, of the milestones.
For example: it demonstrated precision hover flight within a virtual two-metre diameter sphere for one minute; it demonstrated hover stability in a wind gust flight which required the aircraft to hover and tolerate a two-metre per second (five miles per hour) wind gust from the side, without drifting downwind more than one metre and it demonstrated a continuous hover endurance of eight minutes with no external power source.
Other milestones included its ability to fly and demonstrate controlled, transition flight from hover to 11 miles per hour fast forward flight and back to hover flight; flying from outdoors to indoors, and back outdoors through a normal-size doorway; flying indoors “heads-down’’ where the pilot operates the aircraft only looking at the live video image stream from the aircraft, without looking at or hearing the aircraft directly.
To cap it all, it demonstrated its ability to fly in hover and fast forward flight with bird-shaped body and bird-shaped wings. What will they think of next? But wait - what is that hummingbirdlike toy one sees often advertised on TV for children?
AVIATION HUMOUR
They may not be “new” but they are nevertheless worthwhile repeating if only for their smile value…
One day the pilot of a Cherokee 180 was told by the tower to hold short of the active runway while a DC-8 landed. The DC-8 landed, rolled out, turned around, and taxied back past the Cherokee.
Some quick-witted comedian in the DC- 8 crew got on the radio and said: “What a cute little plane. Did you make it all by yourself?”
The Cherokee pilot, not about to let the insult go by, came back with a real zinger: “I made it out of DC-8 parts. Another landing like yours and I’ll have enough parts for another one.”
What does one call an aircraft with an all-woman crew? An unmanned aerial vehicle.
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