[thkoutsidthebox]

Hi folks,

A long time ago I started a thread discussing the viability of alternative air transport, because I was thinking about doing a Thesis for my degree course on it. I can't find the thread so I'm posting a new one!

Anyway, the thread was ongoing but when I realised that it was a viable idea to do a thesis on, I had to delete all my posts and stop posting because it obviously had to be my own work and I couldn't put everything on the internet (Although I did reference CncZone). Anyway, my thesis is complete, the degree course is finished, and the title I went with was 'A Study on The Viability of Alternative Air Transport'.

It was mainly supposed to be an academic research based thesis, but I wanted to build a working scale model at 1/3rd scale also. As it turned out I just didn't have the time to build a scale model, but I did build a test rig and conduct some practical testing. The thesis ran about 20,000 words so all I can post here is the main points, and open the topic again for discussion to see what peoples thoughts are, or if anyone has actually built their own aircraft !

As a chapter of the thesis I evaluated the 'Hiller Flying Platform', the 'Moller Skycar', the 'Performance Aviation Group - Individual Lifting Vehicle', and the 'Trek Aerospace Springtail'. They were evaluated under the headings 'Stability', 'Endurance', 'Safety' and 'Everyday Practiality'. I then worked on a basic design of my own incorporating what I saw as the good from these and one or two other ideas I had myself.

I also decided on what I believed were the main requirments for what I named the 'Personal Air Transport System' (PATS). These were:

1. The aircraft must be capable of transporting a minimum of 1 person using the medium of air, from an initial Point A on the groud to a final Point B also on the ground.
2. The distance from initial takeoff Point A to final destination Point B must be reasonable for useful purpose, and the aircraft should be capable of this traverse without requiring refuelling.
3. The aircraft must have a comparable end retail price to a small family car or large motorbike.
4. The aircraft must be able to takeoff or land within confined spaces without the need for runways or helipads.
5. Authorization to legally operate the aircraft must be outside the current licensing requirments for a Private Pilots License.
6. The aircraft must be easily operable and safe.
7. The aircraft must be in accordance with all regulations for its class of aircraft.

1 Person was defined as being 86Kg (189.8 pounds) which is the average male weight according to the US CDC.

To decide what was 'reasonable for useful purpose' I used commuting data from the National Statistics Agency, and determined that a minimum of 1 hours flying time was required.

Other random points:

I decided that the complexity in getting the inner surface of the nacell close to the prop tips for the entire circumferance, and hence increased manufacturing cost of using ducted fans was not viable. Plus they were difficult to source for testing. So I tested 22" wooden props to see if regular propellers were viable to generate the thrust required. I tested a 22"x6 2 blade prop, a 22"x6 4 bladed prop, and a 22"x14 4 bladed prop. All tractor props.

In summary I found that using two regular props would be viable for an alternative transport vehicle.

The max weight to be in accordance with Annex 2 of EU Regulation 1592/2002 was 300kg but obviously the lighter the better. Being below this weight would allow the aircraft to be exempt from standard regulations, and also the pilot to be exempt from licensing requirements. For initial building and testing, there are a variety of other items in that annex which would allow me or you to build and operate a small test aircraft while being excused from the regulations. I'm sure the FAA regulations have similar exceptions for research aircraft.

Using a four blade 22"x6 prop instead of a 2 blade gave a 16.895% thrust increase for the same rpm. I decided on a thrust reserve of 25% above that needed to lift the maximum 300Kg. Two 48" props rotating at 5203.162 rpm would give enough thrust for an operable aircraft. The tip speed at this rpm and diameter does not reach the speed of sound threshold, but the diameter and speed can be altered to find the best result.

Also, I didn't test any cowl designs, and using a bell mouth design should give a thrust increase which would lead to a smaller diameter prop. My initial ideas were to get a basic concept in mind, and hence the image below looks rather unweildy and heavy. The second image gives my reviewed thoughts about a lighter more viable airframe with two instead of one engine/s.

I decided that a flying surface was necessary to generate lift from the very beginning of forward movement and hence immediately start to take the strain of lift-off from the engines. As forward speed increased, lift would increase relative to it. The wing would be operating automatically using a tilt sensor to always remain parallel to the ground regardless of the attitude of the aircrafts body (Ignore vertical position in image below which would be for stowage). The aircraft would be capable of a transition to horizontal flight for efficiency and speed. Obviously the transition is the biggest hurdle, getting something that goes straight up and down is only a matter of thrust vs mass. First is lift...then control...then the transition.

Anyway, I'm open to all ideas. The remarkable thing is that SWMBO gave me permission to build this full size if I can save the money!!! I was thinking maybe two small moped or motorbike engines would work, but they might be too heavy. If they would work, then the main expense would be props....how much are full size fized pitch props I wonder....perhaps five blade...control initially would be mechanical or electrical, with the intention to look at getting a control board and automatically stabilised controls later......not sure if I can afford this, but I'd love to try!

Thanks to the EAA and Hiller Aviation Museum in america for their help. No thanks to the IAA who didn't even bother returning my calls!

So Im sure someone has thoughts....anyone wanna help build this?

[thkoutsidthebox]

Attachments seemed not to work in last post....I'll try again!

Edit: Still not working....I'll try to fix it at the weekend when I have a better connection.

[Anthony333]

Air Transport in the 21st Century is a strong evidence to show that our global system is dependent. It takes less time to transport in air travels so it is easy to go.
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Anthony

WideCircles

[thkoutsidthebox]

....uhmmm.....What ?

[High Seas]

Ohhh - fun project and interesting/good ideas too!

Personal air transport is an answer to the existing air-mass transport model:
1. Go where you don't want to be - the "nearest airport"
2. To fly to where you don't want to go -- The closest to desired destination airport
3. With all the intermediate - don't want to stop here but must to connect.. ad Nauseum airports. (well till you puke anyway).

It is interesting because it smacks in the face of the mass transit - the idea is good, and has some possible paybacks in dollar cost/time/mile -- if the right fuels are used. The airline costing has/was always based on passenger seat/mile. Now with fuel costs - that model may still be viable for long haul - but not short.-- Hmm did my soap box come out of the closet? - BACK -- BACK!

Have you seen the NZ "hummingbird" personal VTOL aircraft? Or the recent bio-fuel flight records?

Re: Licensing - The US now has had for several year the Light Sport Aviation License - anything similar in Ireland. Less complex than a private and would meld well with personal transport.

MPG ought to be ok with moped/small cycle engines - noise and other concerns?

STILL - - I Like it! And I will stay tuned!
:cheers: Jim

BTW - I kinda like the idea of personal airships as well -- as long as we may wind up messing with hydrogen in vehicles - let's all get a Zep' too!