Hi Saw some pictures some pictures of the Mini 500 homebuilt heli. There are many for sale with almost no TT. They look pretty crazy..... Im an A&P myself and heard some pretty disturbing things about the quality. Anyone have any experience with building it.
Don't know how I found it, but there was a site called yarchive.com which contained loads and loads of technical articles by various engineers. One persistent thread was an argument between whoever it was held the rights for Mini 500 manufacture and, well, everyone else. The rights holder seemed to have trouble with engineering terms that were of great concern to anyone who knew what they were doing. Of course that's just my opinion, I'm not an engineer.
Sometime many years ago around the birth of the internet , there were usergroups that were a hold over from dial up technology. There were many discussions about this toy and generally all agreed it was slightly less dangerous than using an electric toaster in a bath ( with end resullts equally predictable ), If you check out the NTSB database you will see many fatal accidents for this helicopter that had a habit of losing engine power at worst time.
Before this forum came to be I used to read and contribute to the rec.aviation.rotorcraft Newsgroup. There was always a rant about this machine. The guys were so crazy with anger as highly experienced pilots were losing there lives in it. I remember one story of a Vietnam veteran pilot a very respected man having the 67hp Rotax 582 engine fail over power lines. He used what little inertia was left in the rotors to clear the cables and had nothing left for a flare. Records of Mini-500 Crashes : http://www.provide.net/~pratt1/ambuilt/helicopter.htm http://yarchive.net/air/mini500.html
Hehe Holy sh** Guys I woldnt even dare to be near one of these things when it flew. These machines should be all scrapped! People are trying to sell sell these for 12k$. Talk about bying your own funeral. Mini 500=
I have two of them in my hanger owned by one of my students. He bought them with the idea of doing his solo time in them but I wouldn't let him do it. What he does once he has his licence is up to him I suppose although I will be advising him to stay with something safe. There are a few things about them I don't like. The yoke is really close to the mast so bumping seems to be very likely in any sort of turbulance. The Rotax engine is an issue to me but may not be to others. The actual quality of the parts seems to be quite good but anyone could have put it together and that is another problem for me.
As Flying Squirrel said I did fly both of them but I kept near to the ground and chose a nil wind day. I would not take one around the pattern. They look very good but their history is awful.
...In the beginning of the operator's manual, it stated:
"Danger! This engine, by its design, is subject to sudden stoppage! Engine stoppage can result in crash landings. Such crash landings can lead to serious bodily injury or death. Never fly the aircraft equipped with this engine at locations, airspeeds, altitudes, or other circumstances from which a successful no-power landing cannot be made, after sudden engine stoppage."
The operator's manual also stated: "Warning! This is not a certificated engine. It has not received any safety or durability testing, and conforms to no aircraft standards. It is for use in experimental, uncertificated aircraft and vehicles only in which an engine failure will not compromise safety. User assumes all risk of use, and acknowledges by his use that he knows this engine is subject to sudden stoppage."
I worked on a UAV helicopter project some years ago. One of the big problems with 2 strokes and helicopters, if the use oil mixed in the gas, is lubrication at high rpm/low power. Since the oil is in the fuel, if you reduce the power (like in an auto or descent) you reduce the lubrication. This is a great way to seize the engine. The engines, being simple and durable, may well start back up after they have cooled down a little bit, but that will be little use to you during the event.
It was Allen Barklage who died in his Mini-500. Both Allen and his brother were very knowledgeable and well-respected within the aviation community. Allen was no slouch when it came to helicopters. It was he who had been hijacked while flying a 206 at gunpoint by a woman in the back seat who wanted break her man out of prison. Somehow, he managed to turn around, disarm the woman (while beating the crap out of her, I'm sure), leaving the poor 206 to fend for itself. He later remarked something along the lines of "...the JetRanger did stuff I never knew it could do." Probably a bit of an understatement, I'd wager.
But I digress.
Having survived a hijacking at gunpoint, Allen probably thought that flying a Mini-500 was a piece o'cake. He was taking off from an airport...an airport! when his Rotax engine quit. Problem was, instead of taking off "the long way" (i.e. downwind), he chose to take off into the wind but on a path that meant he had to cross some wires. When do engines quit? At the worst possible time, of course. And his did just that.
(Look, sometimes it's better to take off downwind if the area is huge and flat and unobstructed when the alternative is a max-performance departure over wires and such. Or back-taxi so you can cross the obstacle at a higher airspeed/altitude.)
Yes, Mini-500's had a two-stroke engine. Rotax was not exactly pleased that their snowmobile powerplant was being used in helicopters. But you know...their corporate desire to move product evidently outweighed their moral righteousness or indignation, and anyway you can never specify how a product that you've already sold will be used. If somebody wants to take a perfectly good Stanley hammer and bash it against your skull rather than pound nails into wood, there's not much that the Stanley Corporation. can do about it other than put a warning sticker on the hammer that says, "CAUTION: Please do not bash this product against a person's skull or it may cause injury or death."
Mini-500 designer Dennis Fetters (now there's a name that brings back memories!) had even devised a power-enhancement kit to wring even more power out of the Rotax. Not a good thing, because as others have noted, lubrication is dependant upon throttle opening. Usually...in most applications...when the throttle is closed the crankshaft rpm decreases. Not so with a helicopter. Can you say, "Yikes!" I knew you could.
But there were other problems with the Mini-500. Like the airframe...which cracked repeatedly from all that vibration from the high-speed two-stroke engine. Like the gearboxes...which make those of the R-22 look like something from the Sikorsky or some other Russian design team. Like the main rotor blades...that more resembled bananas than anything belonging on a rotorcraft. Like that goofy "Hughes 500D-like" horizontal stab on top of the vertical fin...which may work well on a helicopter with an articulated rotor system but didn't work so well on a two-blade underslung system. Like the pitiful quality-control problems DF had... Oh dear, the list goes on!
Having said all that, we must remember that the Mini-500 was a HOMEBUILT, EXPERIMENTAL aircraft. To measure it against or compare it to *any* certified helicopter is simply folly. It was a machine to go out in on nice, sunny days and practice autorotations...which it did rather well (out of necessity?) from published reports at the time. But I wonder what Stan's or Igor's or Frankie P's first machines looked like? Sure, sure, we've learned from their <ahem> collective mistakes since then, but experimental helicopters are always going to cause "us" (the knowledgeable) to shudder and go, "Man, I'd *NEVER* fly that!" And in truth, they are scary. The ones I saw used hardware in the (hot) engine compartment that were fiber-lock nuts! Personally, I would use something else if it were mine - locking devices that would not melt, in other words.
And if I did own one that I built (you know, if I suddenly started dropping LSD or mainlining some other hallucinogenic) I would fly it! I'd go out and hover and play, and go up and shoot precision autos (aiming for the ground, hitting same). I would probably *not* use it to go to the south of France for the weekend. And if I crashed and killed myself, I'm sure the preacher's first words at my funeral would be, "Dearly beloved, we are gathered here today to pay tribute to an amazing...an amazing...an amazing dumbass. A dumbass who's dumbassiness is unparalleled in modern society. A dumbass who was so dumb that he put his ass in an HOMEBUILT, EXPERIMENTAL helicopter, of all things. Dear God!" And the congregation (both of them) will nod sorrowfly in agreement.
On Sunday Nov 29th 1998 Gilbert Armbruster left for a short flight in his Mini-500 and never returned. He was found on Wed Dec 2nd and had not survived the crash. No data is present at this time. I do not think the NTSB has completed their investigation yet. Gil was a great Mini-500 pilot and had logged more than 200 hours in his ship. He spent a lot of time tweaking his aircraft and in February 1998 gava a seminar on balancing of the Mini-500 at our Dallas Meeting. Gil was recently asked to head up our Builders Association because of his dedication to flying and improving the reliability and safety of the Mini-500. Gil was very active on the rec.aviation.rotorcraft forum and was loved and respected by all. The aviation world has lost another great aviator and will be missed by all of us. Say hello to Allen for us Gil........
"In memory of Allen, Gil, and the others that have gone west before him".
Check out this forum! http://www.mini500.com/oldmini/channel4.html Builders concerns about the safety in the 500. One bloke says he only dares to hover it, 3 feet max. Also Dennis Fetters is covering his on ass in the forum, Pretty pathetic.
Sombody kill this stupid machine for good please!!!