Indian inventor dies in homemade helicopter accident • Hacker News Board

Re: Indian inventor dies in homemade helicopter accident

#41

Post by jacquesm » Mon, Aug 16, 2021, 5:56 AM UTC

bombcar wrote: post #25

eurasiantiger wrote: post #18

I saw the video. The rear propeller disintegrated during operation, seemingly from material failure. Two of the blades shot out to the ground and the third went into the main rotor a short while after, unbalancing it and causing the blades to hit the fuselage and the helicopter to jump, twist and throw the pilot out. Very sad accident indeed. It makes one think that maybe the ”hero inventor” stereotype does not lend…

All those OSHA rules are "written in blood" as they say - and there are reasons for "stupid" rules like seatbelts and such - likely he would be alive had be been solidly strapped to the machine (thought of course he could have died other ways).

If not on this flight then on one of the subsequent ones, experimental helicopters are not something for those not schooled in materials science. The good news is that nobody else got injured or killed, that could have easily happened.

When I built that windmill I spent hours planning individual welds, ensuring no inclusions, grinding the mating surfaces to get a perfect fit before welding, annealing them properly, magnafluxing them afterwards to make sure that it wouldn't come apart due to some weld inclusion. It had a safety factor of four because there was a house within throwing range of the blades, and a variable pitch windmill is essentially a helicopter in a different plane. Design speed was 600 RPM, the hub was spun to double that with some weights attached and the plane of rotation angled such that even if it came apart the debris would not cause any damage.

As soon as you start spinning large things fast you need to be really careful.

A windgust managed to overspeed it (it is very impressive to see your homemade windmill break the sound barrier at the tips) and the machine survived without any damage at all.

That was very briefly the most power that it ever made. When the storm died down we pulled it down and modified the governor to ensure that that would never happen again, better safe than sorry.

Re: Indian inventor dies in homemade helicopter accident

#42

Post by wolfretcrap » Mon, Aug 16, 2021, 5:57 AM UTC

zapdrive wrote: post #33

wincy wrote: post #15

He didn't have a helmet or so much as a seatbelt in the helicopter. The tail rotor flew off, hit the main rotor at a high speed, which knocked him sideways, out of the fuselage. It was at this point his head came into contact with the spinning main rotor, likely killing him instantly. A seatbelt seems like it would have saved his life. It was recorded, which is how I know this, I honestly wouldn't suggest looking for…

Safety comes last in India. Everywhere from construction to road, safety is usually the last thing people spend money on. I'm saying this as an Indian living in India.

Safety costs money.

All those masks, gloves, helmets are not cheap in India. Saddest thing is even if it's being made in India the raw material for making this comes from China and taxed by Indian customs.

If you've choice between buying yourself protective gears vs a new welder to weld the rotor which one do you think will be take him one step closer to his dream?

Sure protective gear can give him more time but most have choices to make, if he could fly this helicopter off the ground, highly likely he also knew about the protective gears yet he choose to not have any maybe because he didn't have much money.

Re: Indian inventor dies in homemade helicopter accident

#43

Post by diskzero » Mon, Aug 16, 2021, 5:58 AM UTC

rolleiflex wrote: post #32

diskzero wrote: post #13

It is sad his passion to build and create ended with this accident. I have built and flown my own aircraft and even with excellent supervision and safety procedures in place, I still wonder if an improperly deburred rivet hole or a bad batch of resin will end up being the cause of my demise.

That sounds very interesting, have you written about it somewhere? I (and I’m sure many others here) would find it fascinating to read about.

I wish I had the drive and discipline to write about some of the things I have done; airplanes, software projects, etc. but I just get so caught up in the process itself, I don't have the energy to to write about the process. I love reading other peoples descriptions of their journeys and am envious they can do amazing things and also write about them during and after.

Re: Indian inventor dies in homemade helicopter accident

#44

Post by jacquesm » Mon, Aug 16, 2021, 5:59 AM UTC

wolfretcrap wrote: post #34

wincy wrote: post #15

He didn't have a helmet or so much as a seatbelt in the helicopter. The tail rotor flew off, hit the main rotor at a high speed, which knocked him sideways, out of the fuselage. It was at this point his head came into contact with the spinning main rotor, likely killing him instantly. A seatbelt seems like it would have saved his life. It was recorded, which is how I know this, I honestly wouldn't suggest looking for…

I am also a farmer and inventor based in India. Problem is that we do not have many tools, indian made tools cost 3-4x of Chinese tools and have 2x worse quality on average 80% things which exist in West (made in China) does not exist in India on top India doesn't make many things. Plus we suffer from too many middlemen problem, where the end product is inflated away beyond the affordability of masses. Not everything…

Yes, this is a very good point. Access to good tools is essential to do this kind of work safely, you can have all the knowledge in the world, if you can't measure accurately, test your welds non-destructively, machine things without adding stresses that the material is ill equipped to handle and assemble properly then it is very easy to mess things up in a critical way. Miss an inclusion in a weld (which could very easily happen), have some vibration due to imbalance, a hairline fracture from metal fatigue and with a helicopter as your project it can only end in one way.

Re: Indian inventor dies in homemade helicopter accident

#45

Post by jacquesm » Mon, Aug 16, 2021, 6:00 AM UTC

colechristensen wrote: post #36

eurasiantiger wrote: post #18

I saw the video. The rear propeller disintegrated during operation, seemingly from material failure. Two of the blades shot out to the ground and the third went into the main rotor a short while after, unbalancing it and causing the blades to hit the fuselage and the helicopter to jump, twist and throw the pilot out. Very sad accident indeed. It makes one think that maybe the ”hero inventor” stereotype does not lend…

You can build your own aircraft, you just can’t shoot from the hip. From the description, the man wasnt killed by one mistake but at least a dozen at the same time, and all of them avoidable by a one man operation. You don’t design an aircraft to fly, you design it to fail in ways and for reasons that are very well understood, then you design several ways for each impossible failure to happen gracefully.

Helicopters are particularly unforgiving in this respect.

Re: Indian inventor dies in homemade helicopter accident

#46

Post by CyberRabbi » Mon, Aug 16, 2021, 6:02 AM UTC

SapporoChris wrote: post #3

>The inventor taught himself the basics of aeronautical engineering using YouTube and over two years built a single-seater helicopter using a car engine and scrap metal. I am speaking without enough knowledge. But I have to wonder if this serves as a harsh criticism of Youtube. I do understand Youtube is a mixed bag of resources. More structured learning might have resulted in better understanding of material strengt…

This was my first reaction too but probably every DIY/educational video I’ve seen on YouTube has had strong warning disclaimers before introducing the material. Generally most people would be extremely cautious around industrial machinery that moves at high speeds, let alone ones that you design yourself. The higher the stakes, the higher the caution should be. I don’t know how that got lost here, he seems to have had a crew too.

Re: Indian inventor dies in homemade helicopter accident

#47

Post by dharmab » Mon, Aug 16, 2021, 6:02 AM UTC

SapporoChris wrote: post #3

>The inventor taught himself the basics of aeronautical engineering using YouTube and over two years built a single-seater helicopter using a car engine and scrap metal. I am speaking without enough knowledge. But I have to wonder if this serves as a harsh criticism of Youtube. I do understand Youtube is a mixed bag of resources. More structured learning might have resulted in better understanding of material strengt…

I had this experience learning to work on cars and motorcycles. Initially I learned from videos, trial and (expensive) errors. Years later I got my hands on an official Honda tech manual and some real engineering knowledge and realized just how basic, incomplete or mistaken most of YouTube was on the topic.

Re: Indian inventor dies in homemade helicopter accident

#48

Post by vagrantJin » Mon, Aug 16, 2021, 6:05 AM UTC

Saw the "English version" of Indian news articles keep refering to the guy as a high school dropout in the headlines and sub headings. That's a mighty odd description that has nothing to do with the incident. I found that rather derisive and left a bitter aftertaste.

Education does not neccesarily prevent accidents. Even spacecraft, built by the best engineers in the world, with the best materials, tested for years, routinely fail and sometimes get people killed after spending 100s of millions of dollars.

Re: Indian inventor dies in homemade helicopter accident

#49

Post by coupdejarnac » Mon, Aug 16, 2021, 6:15 AM UTC

rolleiflex wrote: post #32

diskzero wrote: post #13

It is sad his passion to build and create ended with this accident. I have built and flown my own aircraft and even with excellent supervision and safety procedures in place, I still wonder if an improperly deburred rivet hole or a bad batch of resin will end up being the cause of my demise.

That sounds very interesting, have you written about it somewhere? I (and I’m sure many others here) would find it fascinating to read about.

Peter Sripol on youtube has made four airplanes from scratch.

Re: Indian inventor dies in homemade helicopter accident

#50

Post by zdkl » Mon, Aug 16, 2021, 6:16 AM UTC

Natsu wrote: post #35

wincy wrote: post #15

He didn't have a helmet or so much as a seatbelt in the helicopter. The tail rotor flew off, hit the main rotor at a high speed, which knocked him sideways, out of the fuselage. It was at this point his head came into contact with the spinning main rotor, likely killing him instantly. A seatbelt seems like it would have saved his life. It was recorded, which is how I know this, I honestly wouldn't suggest looking for…

Back in college, one of my advisors was a control systems engineer. He showed me the matrix of PDEs for the helicopter & the control system. There was also a simulator where the height of the helicopter was fixed and you could just tilt the main rotor forward or back to move and you could try this with or without a control system. The helicopter was completely uncontrollable without the control system. In the simulat…

The old line of rotary-wing aircraft "beating the air into submission" is so gloriously accurate on every level. Those pilots are wired different, kind of like submariners (checklists, roles/responsability, ...) in order to deal with their complex environment.