Aircraft/Flight enthusiasts/engineers - What do you make of this?

[Danny]

Lads and Ladies,

I was just doing my usual relaxing on the comp and browsing the net and was looking up some different aircraft stuff online and came across this site.

The supressed Burnelli aircraft design

Yeah, It's a long read, but I don't know what to make of it. Sounds like a bit of sensationalism and conspiracy theorism typical of some crazed yanks, but I'm not prepared to change my views at the helm of some wack job freedom fighter calling conventional commercial aircraft "dangerous tubes of doom"

He even goes so far as to attempt to refute the statistics of flight being the safest mode of transport.

Like I said, It's too late for coherent thought for me, I don't know what to make of this, and thought it'd be a good one for discussion here.

-Dan

[Ohio XB]

I took a quick look through of the site. I'll read it some more but I don't have high expectations and don't have too much time to waste.

The fact that the B-2 bomber and the F-22 fighter are built on a similar, if not the same, principle of fuselage design is not proof of how wonderful the design is. The fact is these planes only exist in recent times, and the F-22 in particular, because of modern computer technology. The design is Sooooo unstable that it takes a lightning quick computer to make all the minute adjustments in order to keep the planes in the air and under control. So if the author wants to use them as a comparison he needs to take this into consideration.


Having said this, I once found a site that a woman had made condemning the act of breast feeding infants as the cause for the enfatuation that men have with breasts and leads to the raping of women. Yeah......really....


Steve

[Jim Goose]

Originally Posted by Ohio XB

The fact that the B-2 bomber and the F-22 fighter are built on a similar, if not the same, principle of fuselage design is not proof of how wonderful the design is. The fact is these planes only exist in recent times, and the F-22 in particular, because of modern computer technology. The design is Sooooo unstable that it takes a lightning quick computer to make all the minute adjustments in order to keep the planes in the air and under control. So if the author wants to use them as a comparison he needs to take this into consideration.


Steve

Er... you do realise that the designs of fighters DELIBERATELY made unstable in for them to be manoeuvrable?
The f-16 is simple "classic" design, yet it is now 30yrs old and was deliberately designed to be unstable.
The F-16 relies on its computers to keep it from swapping ends in the air.
It isnt a lifting body design, nor is the F-22 a lifting body design.

The B2 is a flying wing (yes classed as a lifting body) and does not have a tail in order to keep it stable. It relies on computers to keep it level as well.

If you go back into histroy the USAF had the B-49 flying wing, which orginally was propellor driven, then later 8 jet engines. There were NO computers to keep it stable, just good aerodynamics. It was quite stable.
It was a pure flying wing being flown in the 1950s and decades ahead of its time...

The designs shown by Burnelli show a lifting body with either canards or conventional tail, there is nothing unstable about it at all.

[wrongwaynorris]

Whack Job Conspiracy Theorist Alert , some people just have nothing better to do with their lives .

[74_XB_Ute]

Sounds like this Burnelli cartel are planting a seed to try n set up a monopoly themselves with this supposed you beaut Burnelli Lifting body design.
Their main objective is survivabilty in a crash. It seem tho that they havent taken into account how to egress people when their Burnelli design has actually crashed. Their concept has a wing to fuselage contact area that seems to take up around 80% of the structure. Their design also has the fuel cells located only in the wings. So if a crash occurred and an aircraft fuel fire existed....yep it's Johnny Cash time for everyone because they will be burning in a ring of fire!!
They also talk about crashworthiness over airworthiness. Airworthiness isn't just about suspending a jet in the air in the most efficient manner. It's about the whole scope of aviation processes that comply with aviation standards to ensure the jet doesnt drop out of the sky and crash. Crashworthiness is a difficult thing to incorporate into modern aircraft because when everything has turned to s#%t and you are falling out of the sky.....the laws of physics arent really on your side at 1100kph.
To me it just seems that someone has a bee in their bonnet about the bigger players in aviation. For me i'd rather be kickin back in my seat with a bourbon n coke and getting ready to watch the inflight telly rather than putting my goggles n scarf on and getting ready for a 68 hour flight to LA. Yep might be just a tad safer at 130mph but I much prefer speed n comfort.

[Jim Goose]

That website has been around for quite a while now.

The lifting body design has been used in a few concept designs shown in the late 1980s, but never went anywhere.

A circular fuselage is easier to design and to pressurise.
A fat lifting body would be difficult from a structural point of view to turn into a pressure vessel.
Look at submarines, they are mostly circular or oval in cross section.
(Though im no structural engineer...)
This is also the reason why windows in airliners are circular/ oval (in pressurised aircraft)
The other drama is there is a maximum time set (depending on how many seats) on evacuating an aircraft once it has crashed as well as a the number of emergency exits needed.

A simple tube is easier for people to escape from as they are relatively close to an exit plus exits are simpler to install.
But all of this can be overcome of course.

The lifting design is a great concept however... in aerodynamic terms.
That new aerocar (flying car) which there was a thread on here about is a lifting body design in order to keep the wings as small as possible...
The old SHORTS 330/340 which Qantas regional used many yrs ago was kinda a lifting body!

[74_XB_Ute]

Originally Posted by Jim Goose

A circular fuselage is easier to design and to pressurise.
A fat lifting body would be difficult from a structural point of view to turn into a pressure vessel.
Look at submarines, they are mostly circular or oval in cross section.
(Though im no structural engineer...)

Yep...when you get up inside the tail of a 737 and take a look at the aft pressure bulkhead....it's just a big circular cap like an LPG cylinder...or any pressure vessel for that matter.

[Danny]

Originally Posted by Jim Goose

"The other drama is there is a maximum time set (depending on how many seats) on evacuating an aircraft once it has crashed as well as a the number of emergency exits needed."

"The old SHORTS 330/340 which Qantas regional used many yrs ago was kinda a lifting body!"

Re the emergency exit time, that is exactly what I thought. Such a wide aircraft with presumably many rows of seating and only two outer walls with emergency exit doors would be an absolute atrocity to evacuate in an emergency, so in the case of a crash, you'd have far too many rows of people, with not enough doors to evacuate from.

As for the Short 360 (yes I remember them, Sunstate and Qantas Link used em), wow, ugliest most scary looking plane I ever saw (even though I am sure they were safe)!

-Dan

[Kryton]

Originally Posted by Website

Airplanes are primarily designed and built to withstand air pressure and turbulence, but tests are rarely conducted to find out what happens to a plane and the people in it when it hits the ground, a body of water, or an immovable structure, such as the 14th Street Bridge in Washington, D. C.

Absolute rubbish.
Crash tests ARE performed, data IS collected and then used in the next generation of aircraft to make them safer.
Passenger crash tests are also done.
Not wasting my time reading the rest of the site.
Sounds like your typical misinformed sensationalist biased one way agenda.

[Powdered Toast Man]

Originally Posted by Jim Goose

This is also the reason why windows in airliners are circular/ oval (in pressurised aircraft)

Actually generally speaking the windows are rounded so there are no sharp corners to act as stress concentrators for crack formation and propagation when the fuselage is subjected to fatigue stresses.

I'm also no pressure vessel expert but I believe you are right on the tubular shape being the simplest most cost effective form of one.

[Danny]

Originally Posted by davway

Absolute rubbish.
Crash tests ARE performed, data IS collected and then used in the next generation of aircraft to make them safer.
Passenger crash tests are also done.
Not wasting my time reading the rest of the site.
Sounds like your typical misinformed sensationalist biased one way agenda.

Just what I thought. I skimmed over it very lightly and hence why I posted the site here to see what others thought.

[Jim Goose]

Originally Posted by davway

Absolute rubbish.
Crash tests ARE performed, data IS collected and then used in the next generation of aircraft to make them safer.
Passenger crash tests are also done.
Not wasting my time reading the rest of the site.
Sounds like your typical misinformed sensationalist biased one way agenda.

Actually no, aircraft have never been crashed tested in order to gain certification. Only its airworthyness is tested.

All those old videos you see of remote control airliners being crashed were only done to serve specific testing of fuel additives and as afterthough by the NTSB etc.... it was NEVER done to test crashowrthyness prior to certifcation.

However certain things are built into the airliner in order to try and make a crash survivable these days.
Seats and seat rails must meet a certain "G" rating in an impact.
Materials in the cabin must be flame retardant.
Engines are also designed to break off cleanly in the event of a ditching (as clearly seen in the Hudson river crash 2 yrs ago).
Self sealing fuel tanks.
Redundant systems.

Computer modelling can predict how an aircraft crumples nowadays, but it is not a requirement to meet a certain standard.

Passenger trains are the same, there is no "crashworthyness" testing carried out.... but they have emergency exit requirements etc etc...

You simply can not make a plane meet a certain crash standard as you can not predict how it impacts the ground or what it hits, or where the terrain is...

If a wing fails in flight due to a fire there no amount of "crashworthyness" built into an airframe that will save you as you plummet 500mph into the ground, however you can build into the wing 3 or 4 spars, redundant controls, fire proofing certain components, engine extinguishers etc in order to contain that fire.