20 minutes or 20 miles ?

Hello all.

At its beginning (first sentence), the GoFly site ( https://www.herox.com/GoFly ) starts with:

“Design and build a safe, quiet, ultra-compact, near-VTOL personal flying device capable of flying 20 miles while carrying a single person.“


However,
according the following quote,
in the Fly-Off Tasks and Measurements,
in the final demonstration,
instead of a 20 miles demonstration endurance, the requirement is a 20 minutes total flight demonstration endurance.


Quote from https://www.herox.com/GoFly/guidelines :
2.2. Flight Demonstration
For the flight demonstration, the device, with full operator (or dummy stand-in) weight, must complete a single flight profile that successfully includes all of the following tasks:
1. Takeoff and climb without violating the takeoff/landing envelope.
2. Conduct a speed run of six laps around a 1 nmi course.
3. Demonstrate the capability to abort a landing by performing a touch & go without violating the takeoff/landing envelope.
4. After loitering such that total flight demonstration endurance is greater than 20 minutes, descend and land without violating the takeoff/landing envelope.
End of quote.


According the previous:

A Personal Flyer having an average speed of 30kts (the minimum threshold) will cover 10nmi (11.5 miles) in the 20 minutes of the Fly-Off test.
Actually, the 30kts speed is required only “flying around the two pylons”, which is a 6nmi (~7 miles) distance. The rest time the Personal Flyer can just hover (loitering).

In comparison, a four times faster Personal Flyer, flying permanently at its top speed, will cover in the 20 minutes of the Fly-Off test 40nmi (46 miles), receiving only 0.9 points more than the first slow flying Personal Flyer (in a 9 points total maximum scoring).

If the first (the slow) Personal Flyer is a little less noisy (for instance 70dBA instead of 75dBA of the second (the four times faster one)), the winner is the four times slower.


Am I missing something?

Thanks




The 6 nmi nominal length of the course is divided by the total time for the speed run to yield the speedscore in units of knots.during the 6 rounds knts
(loa Personal Flyers ten times faster than the final winner, is punished to cover 200 miles while the winner will cover just 20.

With 20 miles a 5 times faster Personal Flyer

Am I missing something

Thanks
Manolis

Hello.

The part of the message after the
"Am I missing something?
Thanks"
must be deleted.

Thanks

GoFly has not specified the exact judging criteria by judges, only that judges decisions are final. Your example shows one will have better final fly-off score but is far from being a winner.
Guideline: "The device must be designed and built to maximize the fly-off score while meeting or exceeding the following specifications."
So fly-off score is probably one of the judging criteria but isn't the only measure.

@man pat
Hello GoFly.

It is strange that the following crucial question:

“20 minutes or 20 miles?”,

asked 3 days ago,

is not yet officially answered by the GoFly heads.


Please read again the first post of this topic and explain how you can check, with your “2.2. Flight Demonstration”, if a personal flying device is capable of flying 20 miles while carrying a single person.


Here is a simple example.

I propose and bring for demonstration a personal flying device X.

The “size” of the X is 5 ft (3.5 points).
The “noise” of the X is 70dBA (4.25 points).
The average speed around the two pylons is 30kts (0 points).

Suppose also that the X personal flying device satisfies all the rest thresholds / requirements (those which do not count in the scoring of the Go-Fly competition).

FINAL SCORING for the X personal flying device:
7.75 points (from 8.63 points top possible scoring).


The “Flying Demonstration” is defined in 2.2.

For the first part of the Flying Demonstration:
“Takeoff and climb without violating the takeoff/landing envelope”,
the X flies for 30 seconds, and covers 0 nmi.

For the second part of the Flying demonstration:
“Conduct a speed run of six laps around a 1 nmi course”,
the X flies for 12 minutes and covers 6 nmi (which means 30kts average speed).

For the third part of the Flying Demonstration:
“Demonstrate the capability to abort a landing by performing a touch & go without violating the takeoff/landing envelope”,
the X makes another 30 seconds, and covers 0 nmi.

So far, the X personal flying device is flying for 30seconds+12minutes+30seconds=13 minutes, and has covered 6nmi = ~7 miles.

For the fourth part of the Flying Demonstration:
“After loitering such that total flight demonstration endurance is greater than 20 minutes, descend and land without violating the takeoff/landing envelope.”
the X hovers for another 8 minutes to complete the 20 minutes flying requirement (the total distance covered remains at 7 miles).


Suppose all the rest personal flying devices of the competition are scored under 7.75.
The winner of the grand prize is the X personal flying device.

Did the winner of the Go-Fly prize proved, at the Flight Demonstration, that it is "capable of flying twenty miles while carrying a single person"?

NO.

The only that was proved is that the X personal flying device is capable of flying only 7 miles while carrying a single person.


Depending on the answer of the GoFly heads to the question”20 minutes or 20 miles?”, we talk for two completely different competitions.

The winner of the “20 minutes GoFly” contest, may not even be scored in the “20 miles GoFly” contest.

Are the above pure maths?

If something is confusing, please let me know to further explain.

Thanks
Manolis

@man pat
Hey man ,
Your over thinking this thing, doesnt matter what we think , go by the rules, the 20 miles is a goal not a requirement,
The test is a moch 20 mile coarse to demonstrate the ability to fly 20 miles, even if it is short a little. Dont forget you need 50% reserve energy also,
so you need the capacity to fly 30 minutes,

@man pat
Excerpts from Overview:
"...vote on each such decision after careful consideration of the testing protocols, procedures, guidelines, rules, regulations, criteria, results, and scores set forth in the Master Team Agreement and these Competition Guidelines..."
"...for all competition calculations, measurements, and results, where not specified in the Rules and Regulations..."

I would not hang up on "Final Score" so much. It is not the ONLY judging criteria. It is just one part of "consideration".
Judges are experts in the fields where they are judging and people too.
They can vote on what's in the guideline AND what's NOT in the guideline at their discretion.
I would not be surprised even if they select lower score winners for seeming cut and dry area such as "smallest", "quietest" prizes, let alone grant prize winner.

In addition to the grand prize. There are separate prizes for smallest and quietest entries. That indicates, the grand prize winner might not be the smallest or quietest.

@Lazer
Or the fastest.

Hello all and thanks for your responses.

However the point is not what you, or I, think.

The point is only what GoFly heads think, and what rules they will apply for the choice of the winner.

My simple question “20 minutes OR 20 miles?” is a warning for GoFly that they are arguing their own claims and rules.

To make the problem even clearer for the GoFly headquarters:

In my last post, I present and use “my” X personal flying device .

The X is designed to be barely capable for keeping the 30knots speed only during the “speed run of six laps around a 1 nmi course”.
The X cannot continue at the same 30kts speed (say, due to reliability issues, or due to fuel (or energy) consumption considerations, or . . .).
Suppose that after the “speed run of six laps around a 1 nmi course”, the speed of the X drops to only 11.3kts = 13mph (it is OK according the current rules of GoFly Prize).

In order my X personal flying device to comply with the “20 miles" fundamental requirement of the GoFly Prize (read again the first sentence of the GoFly web site), it needs to prove that it is "capable of flying twenty miles (without a stop) while carrying a single person".
And the only way / opportunity to prove it, is at the Flying Demonstration 2.2.

During the “Flying Demonstration 2.2.”, see my last post again, the X covered only 7 miles flying for 13 minutes.
In order to cover the remaining 20-7=13 miles at 13mph speed (see above), it needs to fly for: 13miles / 13mph = 1hour.

So:

1. According the “20 miles” rule, the X has to keep flying for 1 hour and 13 minutes (i.e. for 73 minutes, which is 3.65 times longer than the 20 minutes).

2. According the “20 minutes” rule, the X has to keep flying for only 20 minutes (which is only 27% o the above calculated 73 minutes), covering only 7 miles (and not 20 miles).

As you see, the difference is not just big, the difference is huge.

So, is the GoFly Prize for “20 minutes or 20 miles?”

Thanks
Manolis

@man pat
This is funny.
It is like watching Larry, Curly and Moe in action.
By the same argument, my "Y" flying device is capable of flying at 300 mph and finishes the said course in under 2 minute.
Then it drops to snail's speed @ 0.029 mph. What to do with 18 minutes? 18 minutes can't even cover 1 mile. For 13 more miles, it will have to fly for
449 hours in the air. Will the judges wait for 449 hours to watch it finish?

@man pat
As far as I understand the rules. It is not 20 miles or 20 minutes. You must be able to do both.
Think of the issue this way. You have 3 goals.
1. Speed 30 kt's or greater.
2. Total flight time with reserves of 30 minutes or greater. (20 minutes demonstration flight and 10 minute reserve.)
3. Be able fly 20 miles without refueling.
Those are all requirements. If you can only fly at 30 kt's, then you will have to increase your flight duration to 40 minutes so you can make the 20 mile distance. If for some reason you can only fly 30 kt's for the 6 mile speed run and can only fly 15 kt's after that, you will have to increase your flight duration accordingly to meet the 20 mile distance requirement.

Good subject!
Performance vs. duration vs. distance is something we all have to consider and design into our concept vehicles.

@man pat
Forget the 20 mile thing. It is 20 minutes plus a 10 minute reserve. The 20 miles has been discussed in the Webinars. It's wording for the press, and is not in the rules.

@Lazer
There is no 20 mile requirement. This issue has been addressed in other forums and in the Webinars.

@man pat
Here is a link to the Webinars. A lot of get info there.

Let me try that again. https://www.herox.com/GoFly/35-documents.

@Ken Burner
The 20 miles comes from the "Vision Section" of the contest Overview. It states in bold letters the "The goal of the GoFly Prize is to foster the development of safe, quiet, ultra-compact, near-VTOL, personal flying devices capable of flying twenty miles carrying a single person."

I realize the 20 miles distance is not included in the Guidelines 2.2 Flight Demonstrations. However, GoFly has stated what the goal of this competition is, and "capable of flying twenty miles" is part of it. You can choose to except it or deny it. It is for you and your team to decide.

You directed people to the webinars. Most of the lecturers started there presentation saying that the information they give might contradict the GoFly rules or guidelines. In all cases, the GoFly rules / guidelines are what we go by. Not what is said in the webinars.

What is best for all of us, in this situation, is for Paul to give us an official ruling on the 20 mile distance. Hopefully he will post and say the capability to fly 20 miles without refueling or recharging is not a requirement. That would be great, and would make things easier.

Hello all.


@Psi
You write:
“This is funny.
It is like watching Larry, Curly and Moe in action.
By the same argument, my "Y" flying device is capable of flying at 300 mph and finishes the said course in under 2 minute.”

With 300mph, the 20miles are covered in 4 minutes.
Give another minute for the take-off, landing and abort-landing tests, and you have a 5 minutes total flying duration.



@Psi
You also write:
“Then it drops to snail's speed @ 0.029 mph. What to do with 18 minutes? 18 minutes can't even cover 1 mile. For 13 more miles, it will have to fly for
449 hours in the air. Will the judges wait for 449 hours to watch it finish?”

Good point.

It shows the lack of reasoning (of common sense) behind the “20 minutes flying requirement”.

Think of it the reverse way:

You with your fast “Y personal flying device”, and I with my slow “X personal flying device” take-off from the roof of the same building to go flying to the same destination 20 miles away.

You arrive to the destination in 4 minutes.
I arrive to the same destination more than 40 minutes later.

The several times shorter time you are flying is by itself a great safety advantage over the slower flyer.

The 300mph speed of your personal flying device is another great advantage over my slowly flying personal flying device: just imagine the case I fly along the sea shore and the wind starts blowing at 32kts towards the sea (while my top speed is only 30kts).

According the “20 minutes” rule,
the Concorde that flies 2-3 times faster than the competition,
should loiter for some hours above its destination to give time to the competition to arrive…



@Laser
You write:
“What is best for all of us, in this situation, is for Paul to give us an official ruling on the 20 mile distance.”

Exactly.

This is what I asked from the beginning, four days ago.

It is a competition wherein the contestants should know (and have the right to know) the rules, because the rules is the basis for the design of their personal flying devices.
And the rules must be crystal clear from the beginning.

After all, each team has to pay several hundreds of dollars to participate even in the Phase I. So, it is not for free.


@Laser
You also write:
“Hopefully he will post and say the capability to fly 20 miles without refueling or recharging is not a requirement. That would be great, and would make things easier.”

To make things even more “great and easier”, they could reduce the range to 20m (meters, not miles).

Quote from the GoFly / BOEING Vision:
“The goal of the GoFly Prize is to foster the development of safe, quiet, ultra-compact, near-VTOL personal flying devices capable of flying twenty miles while carrying a single person.
What we are seeking is an “everyone” personal flying device, capable of being flown by ANYONE, ANYWHERE.”

What I propose, is:
To replace any reference to “20 minutes” by “20 miles”.
And then to increase the “20 miles” range to “50 miles”, or to “100 miles”, or better to “200 miles”.

With 20 miles range, one is sure: you can not go ANYWHERE you like.

Thanks
Manolis

@man pat
I copied a section of FAQ page (https://www.herox.com/GoFly/faq) below that addresses the question of a 20 mile range :

Q: Will we be required to demonstrate a 20 mile range?
A: GoFly has designed the single flight profile required in the Fly-Off such that devices capable of completing it will also be capable of achieving useful range. An explicit demonstration of maximum range is not required.

Hello Paul Musille


I read in your response:
“GoFly has designed the single flight profile required in the Fly-Off such that devices capable of completing it will also be capable of achieving useful range”.


The “single flight profile” as designed by GoFly (“GUIDELINES, 2.2. Flight Demonstration”) CANNOT confirm / guarantee that devices capable of completing it are also capable of achieving “a 20 miles range”.

Unless by the term “useful range” GoFly no longer means the original “20 miles range” target.
But then, GoFly should correct their web pages, and their announcements in the press, accordingly; say like: “we are not looking for a 20 miles MINIMUM range, any longer; what we are looking is personal flying devices capable of flying a “useful range” carrying a single person.



The “single flight profile” as designed by GoFly is not sufficient to assure that devices capable of completing it are also capable of achieving “a 20 miles range”:

A personal flying device having 30kts / 34.5mph speed (this is the speed threshold set by GoFly, and this can be the speed of the winner of the grant GoFly Prize) cannot fly 20 miles into 20 minutes; only 11.5 miles at most*** (11.5 miles = 34.5mph * 20 minutes).

(*** if you read my previous posts, you will see that the allowable / possible / acceptable average speed of the grant winner can be even smaller, because the 30kts speed is required only during the speed test around the pylons, which reduces the actual range (the “useful range”) of the grant winner at only 6.9 miles!)

To fly 20 miles at a 30knots / 34.5mph speed, it takes: 20 miles / 34.5mph = 34.7 minutes

In case GoFly and BOEING discovered a method to evaluate in 20 minutes an endurance test having a duration of 34.7 minutes, it would be great, and they should apply for a patent to the US-PTO for it.


For those entering for the first time today in the GoFly web site, the “20 miles” minimum range appears the dominant requirement:

GoFly OVERVIEW web page:
“The goal of the GoFly Prize is to foster the development of safe, quiet, ultra-compact, near-VTOL personal flying devices capable of flying twenty miles while carrying a single person.”

GoFly GUIDELINES web page:
“RULES
The goal of the GoFly Prize is to foster the development of safe, quiet, ultra-compact, near-VTOL personal flying devices capable of flying twenty miles while carrying a single person.”

All the following web pages of GoFly:

TIMELINE web page,
DOCUMENTS web page,
ADVISORS web page,
PARTNERS web page,
BE_A_MENTOR web page,
COMMUNITY web page,
FAQ web page,
FORUM web page

start with :

“Design and build a safe, quiet, ultra-compact, near-VTOL personal flying device capable of flying 20 miles while carrying a single person.”


From the Press:

From https://www.aopa.org/news-and-media/all-news/2018/february/15/future-of-flight-includes-2-million-payday ,February 15, 2018:

“The two-year contest fosters the development of safe, quiet, ultra-compact, near-vertical-takeoff-and-landing (VTOL) personal flying devices capable of carrying a single person 20 miles.”


From https://www.telegraph.co.uk/business/boeing-uk/jetpack-hoverboard-travel-reality/ , 1 FEBRUARY 2018:

“GoFly, sponsored by Boeing, is challenging the world’s brightest inventors, designers and engineers to design and build a personal flying device. It must be capable of near-vertical take-off and landing, and able to carry an individual for 20 miles without refuelling or recharging.”



I also read in your response:
“An explicit demonstration of maximum range is not required.”

A demonstration of the MAXIMUM range would be a useful demonstration showing an important (the most important after the safety) characteristic of each personal flying device. But if GoFly does not want to know how long each contestant can go with a full tank, or with a fully charged set of batteries, it is up to GoFly.

However a demonstration that each personal flying device has a MINIMUM range longer than 20 miles is mandatory.

The “Flying Demonstration” as it is defined in 2.2. of GUIDELINES, is not sufficient for this, as explained in the previous.


AGAIN:
In case GoFly and BOEING have invented a procedure to evaluate in 20 minutes an endurance test having a duration of 34.7 minutes, it would be of more worthy than the GoFly competition itself.

Thanks
Manolis

@man pat
The 20 mile statement applies to the aspirational GoFly vision and not the competition itself. Teams should follow the stated official Rules and Guidelines.