LUCY THM: The Fine Line Between Genius And Insanity
Friday, May 21, 2010 at 10:51PM 
From designer Pietro Terzi, the LUCY THM
Umm, the LUCY THM is, kinda unusual(!)
(5 pix + 2 videos)
I’m guessing most of you would be quick to push this unusual bizarre looking aircraft well over on the ‘insanity’ side of the table, but I’m not so quick to do so. I love outside-the-box thinking, tho I will admit that this seems to be a little more like inside-the-padded-room thinking. However, I’ve learned that it’s far more wise to wait and see if someone is on to something good before I declare that it won’t work.
The machine is called the LUCY THM (I don’t know why) and it comes from Italy and designer Pietro Terzi. And while it appears that it hasn’t flown, you should take note that Terzi has designed other aircraft as can be seen in the last image (after the jump). It’s also important to note that the workmanship on this carbon fiber airframe appears to be very excellent, which again should add some credibility to the concept. Construction on the project began in 2007.
The LUCY THM was conceived to be a ’Personal Air Vehicle’ or PAV. That’s one of the reasons that it has those odd looking pods hanging below the cockpit… you sit in it more like a motorcycle, with your legs down in the pods. It seems this arrangement is meant to make you feel more like the airplane is part of you, or as the LUCY website says: “a ‘technological suite’ worn to get yourself about in the air”.
If I read the specs right, it has a max takeoff weight of about 880 pounds, so part of the idea here is to have a lightweight airframe coupled with lots of thrust to make it have great STOL performance. And this is where I see something that I think makes a lot of sense in the design. You can see from the images that the prop has a huge diameter, over 10 feet, and it's driven by an 84hp Hirth 2-stroke engine. With the constant speed prop geared way down, this little machine should have some serious thrust! And one thing I think we overlook in aircraft design is the ‘thrust’ we get out of our engine/prop combinations. Horsepower doesn’t really mean much if a lot of it is lost at the prop. Large slow turning props can move huge amounts of air, so I’m prepared to give the designer a lot of credit for working to make an aircraft with more thrust than its weight (which is their claim). This is the reason they actually call it ESTOL (Extremely Short Takeoff and Landing), and why they also claim it would climb at 3,000+ feet per minute. Max cruise is claimed at 130 mph.
Over 10' prop up front and lots of moving surfaces in the back on the LUCY THM
LUCY THM taxi tests with yarn tufts taped on for flow visualization
Another item to note is that the wing and tail are basically riding in the air coming off that really big prop. With the engine running, I can imagine lots aerodynamic benefits from having so much air moving over those surfaces… and with the engine stopped, I can imagine something more like a 1 to 1 glide ratio followed by a prayerful flare just before you hit! I’ll take mine with a BRS please : )
I’ve been unable to determine the current status of the project. The website indicates that the ground test were completed in December 2009, with flight testing scheduled for the end of January. However, no further updates are given. I’m thinking they may have had a Capricorn 1 style revelation that it simply won’t work, but I’m still hopeful that it's considered viable. The more I look at it, the more I like it. From a pure design perspective, that has to be one of the coolest looking wings ever (thanx Batman!), and, as the video of it taxiing shows, it scoots around on the ground better than you probably thought it would.
I really hope the LUCY THM doesn’t give you nightmares, and I hope I can find out exactly which side of the line between genius and insanity it sits on. Updates to follow : )
Other designs by Pietro Terzi: the T30 Katana left and T9 Stiletto LSA right
Reader Comments (2)
THM = Terzi Hyper Mobility, according to Google translator.
Very cool. I imagine the whole thing will rotate at speed to be more horizontal, giving the rider more of a horse-racing posture, along with amazing visibility and the feeling that the wings are his own. I want one!
Turb- thanx for the translation. Definitely makes sense : )