20 minutes or 20 miles ?

Hello Paul Musille.

You wrire:
“The 20 mile statement applies to the aspirational GoFly vision and not the competition itself. Teams should follow the stated official Rules and Guidelines.”



Thank you, because it is now officially clarified by GoFly that the winner of the GoFly grant Prize is not necessarily a “device capable of flying 20 miles while carrying a single person.”


Thank you, also, because it was clarified that the “20 minutes” in the “Flying Demonstration 2.2. GoFly Guidelines/Rules” was not a typing mistake.
The correct is the “20 minutes” (even if this allows a less than 7 miles range for the winner of the grant prize).
The “20 miles” is the mistake.



Since “The 20 mile statement applies to the aspirational GoFly vision and not the competition itself”, let me wonder:

Why the “aspirational GoFly vision” is so much limited to only 20 miles?

Since the “20 miles range” is merely a vision and not a requirement of the GoFly contest, do change it to “200 miles range” which is a really useful range.
With only 20 miles range (current GoFly’s vision), a personal flying device can(?) hardly reach the nearest gas or energy station to refill its tank or to recharge its batteries.



And here is my “Million Dollar Question”:

Is your grant sponsor, “the” BOEING, aware that the “20 miles range” is only a “vision” (an advertising trick), and not a requirement of the competition?

Thanks
Manolis

@man pat
Dont you have better things to do? How many times they have to tell you its 20 minutes with 10 minute reserve. They write the rules, if you dont like it then dont participate.

@Birdman
Amen! At first I read man pat's writings. Now they are just irritating.

@Ken Burner
In response to your post to me on March 18th 2018. You are right, and I stand corrected. Thank you!

@Lazer
You can now provide a direct link to a post you would like to reference, for clarify! Click the far right "hyperlink" icon next to the post you'd like to mention and you'll get a unique link for that post that you can use to help direct others to what you are referencing.

Hello.
No comments
Thanks

Advise for anyone who is registered, taking into account the spirit of the Go Fly prize, goal is to exceed ALL aspects of the rules. not try to meet one and usurp the others. Speed, Endurance, Range, Sound. The rules are the minimum threshold to compete.

If it cannot exceed them all, it's a waste of time, because it is not commercially viable anyways. This isn't academics, there's no bending the rules if it falls short. Exceed them all and safely, put up time. This is a doer's competition, all the technologies are now in existence to leap this sector forward.

Hello Drew Blair.


You are right.


One scenario:

The X is a personal flying device which is substantially underpowered, slow and unreliable, but very quiet (70dBA) and compact (5ft maximum dimension).
The X can barely fly with 30kts speed during the 6nmi speed test around the two pylons.
Immediately after the speed test, for the sake of reliability (the X can barely fly for 20 minutes even hovering) and for minimizing its fuel consumption, it just hovers loitering.

The Z is another personal flying device. Say, the Z is the Delta Wing of the famous Yves Rossy (known also as the JetMan) modified so that to be capable for a relatively quiet (74dBA noise) vertical take-off and landing, while its optimum mileage is at 120kts cruising speed wherein the reliability and the controllability of the Z are at their optimum.
The maximum real speed of the Z is 188.4kts.
The maximum dimension of the Z is also 5ft.

Suppose that both, the X and the Z comply with all the thresholds of GoFly competition.

At the Flight Demonstration (2.2. of the Rules / Guidelines), the X takes 3.5 points for its small size (maximum dimension 5ft), 4.25points for its quietness (70dBA) and 0 points for its speed (30kts).
Total score for the X: 7.75 points.
Counting the total distance the X covered during its Flying Demonstration, it is only 6nmi=6.9miles because after the speed test it was loitering hovering to complete the 20 minutes flying duration requirement (and to save fuel).

At the same Flight Demonstration (2.2. of the Rules / Guidelines), the scoring of the Z is 3.5 points for its size (5ft maximum dimension), 3.25 points for its quietness (74dBA) and 0.88 points for its speed (>120kts).
Total score for the Z: 7.63 points.

(worth to note here: the slowly flying X is OK with the two pylons and the reversals of its speed each time it passes a pylon; for the fast flying Z the speed measuring procedure is not fair because when it flies at 150kts it can’t reverse its speed direction: the best the pilot of the Z can do is to fly on the periphery of a circle having diameter the distance of the two pylons; but in such a case, the real speed of the Z is pi/2=1.57 times higher than the speed measured by the GoFly judges.)

The distance covered by the Z during the Flying Demonstration is:
6nmi*pi/2 around the pylons (which takes 3.0 minutes with 188.4kts speed)
and
((20-3)/60)*120 = 34nmi at loitering.
In total the Z covered 43.4nmi=50miles, i.e. more than 7 times more than the distance covered by the winner X.


If nobody else of the contestants is quieter than 74dBA, then the grant winner is the X personal Flying device, and it wins not only the $1,000,000 Grand Prize, but also the $250,000 prize as the quietest compliant entry.


Attached is a video of Yves Rossy flying above Dubai, around the SkyScrapers (pylons?).

Thanks
Manolis

I know Yves, good guy. That video, is not just a PR video, he's plane nutz since childhood. Big ditto. He is literally the type of person who would also sign up for the Go Fly challenge, if he was not under contract in Dubai. He moved his entire operation there, royal family paid for it all. I have something similar designed, for ground take off. it's not vtol though and longer span. You could jump off running down a hill, and off you go. He's seen it, said last time we talked, get it built. I respond, gimmi the money to dude. right now building a quarter scale cessna citation, on the side.

Pylon's I kind of agree. I think it should be a 3 point pylon, to make the speed course more oval/semi oval with straight away in front of the flight line/judging, like a nascar track, ie daytona. Then can show the turning abilities, while able to maintain speed as well. Some will have a harder time turning at high speed, while easier at a lower speed.

Me personally, I am bias'd because my entry is serious and highly refined, will do well on the point system overall. But I am also hoping everyone's entry's are high caliber. I am hoping everyones entry's are close to market ready. It's not just a competition for me, but I too dream of it. Stay positive.

@man pat
I dont understand your obsession with such a simple clearly defined rule. If it is not in the rule book it doesn't matter. Do you think racing teams claim exceptions because of a broad statement made for marketing?

It is funny how your own example answers your questions. The equation for points is simple. BTW if you could make a 74dBA jet engine you would be a billionaire overnight. Keep up the good work.

Hello Drew Blair

It is a pity Yves Rossy, “the” JetMan, is not “free”.


Regarding the speed measurement and the pylons:

With the existing two pylons they could make a correct measurement of the maximum speed:
the personal flying device starting from a distance increases its speed and, moving on the line connecting the two pylons, passes over the nearest pylon and then over the distant pylon. The pylons distance and the time required defines the maximum speed.

Imagine the case the two pylons were not at 1/2 nmi, but at 1/20 of a nmi away from each other.

Thanks
Manolis

Hello Milo.

You write:
“It is funny how your own example answers your questions. The equation for points is simple. BTW if you could make a 74dBA jet engine you would be a billionaire overnight. Keep up the good work.”

It writes: “a modified Delta Wing”.
Modified may mean to replace the Jet-turbines by less noisy (and more fuel efficient) propulsion units.
Worse than their noise, is the extremely low BTE of the small jet turbines: ~2-3% brake thermal efficiency while an internal combustion engine has some ten times higher.
With so small BTE the range and the flying duration drop a lot.


You also write:
“I dont understand your obsession with such a simple clearly defined rule. If it is not in the rule book it doesn't matter. Do you think racing teams claim exceptions because of a broad statement made for marketing? “

Let’s put “my obsession” in numbers:

Suppose you decide to fly somewhere 100 miles away with the grant winner ($1.25millions) of the GoFly Prize, the X personal flying device (see four posts ago) which has 6.9miles real / tested minimum range, has 30kts maximum speed and is gas-guzzler.

You need to take-off and land 100/6.7=15 times for refuelling / recharging.
You need also gas or battery stations at least every 7 miles along you desired direction.
And you need 3 hours in the air (and additional time in the gas or battery stations.
The worst is the risk during the 15 takes-offs and landings.

Now suppose the Z personal flying device (the loser, that which won nothing) besides its way higher speed, has also a good mileage at cruising (say 50mpg) and a long range (say 250 miles).
Note: the last two crucial characteristics (the mileage and the range) have a total scoring of net zero.
The Z takes off and lands 100 miles away in less than 45 minutes (120kts cruising speed), having consumed less than half of the fuel in its 5 US-gallons tank, which means it can return to its basis without refuelling.

I try to show to the GoFly heads (and to Boeing) that the original “20 miles” goal (see the slides of the CNN / BOEING video in a recent post) is way more correct and useful than the “20 minutes” flying duration goal.

Even the “20 miles” goal is too short. To be useful a personal flying device needs way longer minimum range.


Quote from the home page of GoFly:
“What we are seeking is an “everyone” personal flying device, capable of being flown by ANYONE, ANYWHERE.”

How can you go ANYWHERE if your range is only 20 miles? (or better say 6.9 miles?) What if the “ANYWHERE” is an island 50 miles away?

In order a personal flying device to be for “everyone”, it has to be affordable. A $2,000US personal flying device is for everyone, while a $200,000US is not.

Despite they are important characteristics, the points for the range, the mileage and the cost are zero.


As you see the rules and guidelines do need some amendments in order to push the inventors / designers / doers / makers / dreamers to the right direction.


For the GoFly heads:
Don’t listen to me, but do ask (and listen) the JetMan Yves Rossy, or someone like Rossy.

Thanks
Manolis

Hello all.

In the well known "HomeBuiltAirplanes" forum, in the thread "Prize Money" (the GoFly contest), a member says:

“It is completely possible that the rule changes were done because Boeing's original rules were seen as too demanding, or that the rules were finally admitted to be unrealistic, and the company wanted to avoid the negative perception that this would cause.”


Here is a reply (which is also a proposal for BOEING) :

"If the goal of the 20 miles is unrealistic, the Boeing besides changing the rules to “more realistic ones”, should also declare a new prize, the “RANGE PRIZE”, e.g. as follows:

A prize of 5 million US dollars will be granted by BOEING to the one who (obeying all the rules / requirements of the GoFly contest) will demonstrate with his personal flying device a 50miles range (carrying a single person, without refuelling or recharging).

For every 10 miles above the 50 miles range, the “RANGE PRIZE” increases by 1 million dollars (i.e. for a 250miles range, the “range prize” becomes 25 million US dollars).

If the 20 miles is an unrealistic goal, the 50 miles and the 250 miles are impossible.
So, there is no risk for BOEING’s money with such an immposible goal."

Thanks
Manolis