US Joint Heavy Lift

[taildragger]

From what I've been reading commercial BWB seems "held-up" mostly due to the needed changed in international airport layouts to accommodate such aircraft. Apparently they won't be able to interface with standard passenger egress-ways without significant upgrades. There is also a LOT of concern with the airlines of people not being anywhere near a window as this is apparently of significant concern according to passenger surveys.

Militarily I've seen the concepts being applied to the BWB before, something (IIRC) called an Airspace Battle Control Aircraft though the last one recall was based on a 747 airframe. I wish I could find something on the idea again because the article I had at one time showed a 747 launching cruise-missiles, missiles (vertically launched from an extended "hump" actually) and launching, recovering, and refueling UCAVs. I'd actually always thought that the idea of recovering and reconfiguring UCAVs was bogus until I found the "Aircraft Carrier Aircraft" thread on this site ;D

Randy

I think a bigger factor holding back a commercial BWB is the difficulty of creating an efficient pressure envelope in the shape available. A cylinder is a good shape for a lightweight pressure vessel (that's why it's used to package Cheez-Whiz), the flattish shape of a BYB isn't, especially if the interior needs to be uninterrupted by structural members. This consideration wouldn't be a factor for a pure aerial refueling tanker application, but a pure tanker (as opposed to the universally adopted tanker/transport combination) probably doesn't need a body at all, blended or not.
Another factor delaying adoption of the BWB configuration for airliners is the g-forces that would be imposed on the outboard-seated passengers by normal rates of roll.

Taildragger

Note: Cheez-Whiz is a registered trademark of the Kraft Foods Corp. The views expressed by Taildragger are his alone and do not reflect the opinions of Kraft Foods, it's management or employees regarding aircraft configuration or trivia.

 

[AeroFranz]

Another factor delaying adoption of the BWB configuration for airliners is the g-forces that would be imposed on the outboard-seated passengers by normal rates of roll.

I always thought that as well, but BWB proponents claim this is not an issue. I've tried to find out more about it, but the closest thing I could find was about the F-82 Twin Mustang, and how according to pilots no matter on which side you were sitting, it always felt like you were on the centerline. Now, that's with a relatively short offset from the roll axis, but what happens when you're 20-30 feet from it?
Anyone has more info?

 

[sferrin]

Another factor delaying adoption of the BWB configuration for airliners is the g-forces that would be imposed on the outboard-seated passengers by normal rates of roll.

I always thought that as well, but BWB proponents claim this is not an issue. I've tried to find out more about it, but the closest thing I could find was about the F-82 Twin Mustang, and how according to pilots no matter on which side you were sitting, it always felt like you were on the centerline. Now, that's with a relatively short offset from the roll axis, but what happens when you're 20-30 feet from it?
Anyone has more info?

A question for White Knight 2 pilots.

 

[F-14D]

Hi,

here is a heavy transport project powered by four
push-pull engines.

I believe this illustration dates back to the early '80s, as one concept for a four proprotor Tilt-Rotor. Note that the aft proprotors tilt down.

 

[F-14D]

From what I've been reading commercial BWB seems "held-up" mostly due to the needed changed in international airport layouts to accommodate such aircraft. Apparently they won't be able to interface with standard passenger egress-ways without significant upgrades. There is also a LOT of concern with the airlines of people not being anywhere near a window as this is apparently of significant concern according to passenger surveys.

Militarily I've seen the concepts being applied to the BWB before, something (IIRC) called an Airspace Battle Control Aircraft though the last one recall was based on a 747 airframe. I wish I could find something on the idea again because the article I had at one time showed a 747 launching cruise-missiles, missiles (vertically launched from an extended "hump" actually) and launching, recovering, and refueling UCAVs. I'd actually always thought that the idea of recovering and reconfiguring UCAVs was bogus until I found the "Aircraft Carrier Aircraft" thread on this site ;D

Randy

I think a bigger factor holding back a commercial BWB is the difficulty of creating an efficient pressure envelope in the shape available. A cylinder is a good shape for a lightweight pressure vessel (that's why it's used to package Cheez-Whiz), the flattish shape of a BYB isn't, especially if the interior needs to be uninterrupted by structural members. This consideration wouldn't be a factor for a pure aerial refueling tanker application, but a pure tanker (as opposed to the universally adopted tanker/transport combination) probably doesn't need a body at all, blended or not.
Another factor delaying adoption of the BWB configuration for airliners is the g-forces that would be imposed on the outboard-seated passengers by normal rates of roll.

Taildragger

Well, there's no money around to develop a pure tanker aircraft as opposed to a derivative of another design. The market's just too small.

One other concern for a BWB airliner is how do you evacuate the passengers seated in the center in an emergency in the required time unless you put in so many emergency exits you affect structure?

 

[Simon666]

One other concern for a BWB airliner is how do you evacuate the passengers seated in the center in an emergency in the required time unless you put in so many emergency exits you affect structure?

Why would people in the center be affected? I would think it is the number of exits and the width of escape paths (or speed with which people lining up for the exit can move) that matters mostly. Not that I'm familiar with the topic.

 

[AeroFranz]

I think distance from the exit is the issue. if you are in the center of a BWB, you maybe several times farther away from an exit than on a 'tube' airliner.

 

[blackstar]

I would think it is the number of exits and the width of escape paths (or speed with which people lining up for the exit can move) that matters mostly. Not that I'm familiar with the topic.

A sidenote story, not directly related to the BWB discussion:

Back in the early 1990s the British did a study of exiting from an airliner after a crash. They filled up an airliner with people and then had them do an emergency evacuation. They did this multiple times and different scenarios, and provided cash incentives for getting out first (everybody got paid, but the first 20 or so people out of the aircraft got paid more). What they discovered was that assuming the fuselage remained intact, the biggest determinant of who got out first was not distance to an exit, but "personality." Simply put, those who were most determined to exit first (and get the money) had a much higher chance of doing so. Fighting for your life and not caring if your fellow passengers died increased your chance of survival a great deal.

 

[F-14D]

I think distance from the exit is the issue. if you are in the center of a BWB, you maybe several times farther away from an exit than on a 'tube' airliner.

That's exactly the issue, unless you put a lot more emergency exits in, and that affects structure. Not insurmountable, but certainly will raise questions as to whether it's worth the effort. Imagine if you are sitting in the center of an aircraft like this:

 

[Matej]

Not all the BWB are that bad, just the Boeing's one Airbus has much more optimised design in the meaning of the safety/emergency procedures. I think that the specific study that I am talking about has to do a lot of the DLW work rather than the Airbus itself. This is certainly good for the passangers, but I am not sure how significant it is, when the BWB is used as the transport or air tanker.

I wrote a short analysis about the safety solutions on the Airbus A20.30 a few years back here: http://www.hitechweb.genezis.eu/transport6.htm

 

[blackstar]

Apropos of nothing, I took these a week and a half ago.

 

[F-14D]

Not all the BWB are that bad, just the Boeing's one Airbus has much more optimised design in the meaning of the safety/emergency procedures. I think that the specific study that I am talking about has to do a lot of the DLW work rather than the Airbus itself. This is certainly good for the passangers, but I am not sure how significant it is, when the BWB is used as the transport or air tanker.

I wrote a short analysis about the safety solutions on the Airbus A20.30 a few years back here: http://www.hitechweb.genezis.eu/transport6.htm

I don't know.... It looks like there'd be some issues here as well. I'm not sure how good it oiuld be to have folks exiting underneath the fuselage (if I read your notes correctly), and I note that it appears that at least four of the exits require escaping passengers to climb a set of stairs to get to them (and will those doors open upwards with no power without pulling a passenger's arms?).

Again, certainly doable, but at an economical cost?

 

[shedofdread]

In this sort of application (heavy lift), one of the major difficulties that I can see is that of pressurisation. It's very easy to make a tube style fuselage strong enough (without weight penalty) to withstand the pressure but a BWB fuselage would want to 'balloon' under pressure. Hence requiring internal structure which makes loading harder and loses the advantages of the open acrchitecture load space that a BWB style arrangement promises.

*edit* all of this rather agrees with already posted by Taildragger - oops

 

[Simon666]

I think distance from the exit is the issue. if you are in the center of a BWB, you maybe several times farther away from an exit than on a 'tube' airliner.

The amount of water that pours out of a sieve per second is proportional to the number of holes and the water height (=pressure). Assuming pressure is constant for our analogy of passengers out of an airplane, that leaves only the number of holes determining the outflow per second. The problems that I could see is that the locations where you can place an emergency exit are limited and indeed possibly affecting the already troublesome structural efficiency.

 

[AeroFranz]

I approve modeling the problem using physical analogy. In fact, were I trying to find an engineering answer, I would probably use the same approach. However, there are limits to the applicability as models are, of necessity, a simplification and rely on approximations. Water pouring out of a bucket obeys laws in a rigorous way; panicked passengers may not be as regimented. Flow of passengers between seat rows/aisles, and the interaction between passenger*passenger*passenger... (^n) is likely to introduce non-linearities. I don't know how industry predicts this, but I can see why a real-life test is always required.

 

[Triton]

From the Dewline October 22, 2010:

According to the CRFI, the next C-130 may have to carry up to 190% more payload and assume a new mission -- mounted vertical maneuver. Taking on the MVM mission means dropping off medium-weight armored vehicles -- think Bradleys, not Abrams -- in places the enemy does not expect. Long, concrete runways? Not any more. Fifteen hundred feet of level, hard-packed surface? That might work. Perhaps better: a clearing big enough to land a really big tiltrotor or helicopter.

Table Summary of the capabilities request for information (CRFI) issued by the USAF's Aeronautical Systems Center about the Joint Future Theater Lift (JFTL) program on October 22, 2010 (attached).

Source:
http://www.flightglobal.com/blogs/the-dewline/2010/10/usaf-asks-industry-to-answer-c.html

 

[hesham]

From Flightglobal May 2006;

the Sikorsky CH-53K heavy lift helicopter.

 

[fightingirish]

Leading Edge (AW&ST blog) - JCALS: A Common Answer to Joint Airlift

 

[vstol]

Boeing 2010 product card on their extra wide Chinook for the German Future Transport Helicopter requirement.

 

[AeroFranz]

Interesting. It doesn't say payload capacity. I wonder how this compares to the -53K?

 

[yasotay]

Interesting. It doesn't say payload capacity. I wonder how this compares to the -53K?

Probably. CH-53K is 99 ft long if you figure 1/3 is tail boom, then they are in the ballpark for usable cabin space. Given the tandem rotor is using all of its available power for lift...

 

[sferrin]

Interesting. It doesn't say payload capacity. I wonder how this compares to the -53K?

Probably. CH-53K is 99 ft long if you figure 1/3 is tail boom, then they are in the ballpark for usable cabin space. Given the tandem rotor is using all of its available power for lift...

But it would fall far short of the CH-53K in power. The K will have more power than a Halo (Over 22,000hp) whilst this Chinook varient would only have about 13,500hp. That's going to make a big difference.

 

[AeroFranz]

we've got to look at discloading as well to gauge lifting capability, although that's quite a power disparity, I agree.

 

[Jemiba]

There's more than a superficial similarity to the Eurocopter FTH proposal, I think.
http://www.secretprojects.co.uk/forum/index.php/topic,538.15.html

 

[ADVANCEDBOY]

I really doubt they will build a heavy -lift chopper . it smells as usual- CGI paperware. Russkies cranked out Mil 38, are now heavy into development of mil X1 and Ka -92, while I really doubt Sikorsky or Boeing will develop anything of significant size. My bet is Boeing will continue improving the old Chinook horse until they run out of alphabet and rather use C-130z( as of zilch) mod than construct a new one.Let`s not forget Sikorsky had to outsource beyond recognition s-92 helibus in mid 90ies to Mitsubishi, so an independent domestic engineering of nex gen cargo lifter is highly unlikely, considering a plethora of serious projects has already been grounded, Comanche, venture Star, a-12, Raptor, etc. One thing is to pull out a toy sized X2 onto youtube, building a Mil-26 competitor is a comletely different story.

 

[ADVANCEDBOY]

besides, Sikorsky already had a twin rotor project of a large helicopter in early 90ies- Sh-x. Where on earth is it? You have to realize they do these CGI inoculations now and then to stop the market share from swooning. if shareholders persist, they gnash teeth and build a scale demonstrator, then the party is usually over.

 

[sferrin]

I really doubt they will build a heavy -lift chopper . it smells as usual- CGI paperware. Russkies cranked out Mil 38, are now heavy into development of mil X1 and Ka -92, while I really doubt Sikorsky or Boeing will develop anything of significant size. My bet is Boeing will continue improving the old Chinook horse until they run out of alphabet and rather use C-130z( as of zilch) mod than construct a new one.Let`s not forget Sikorsky had to outsource beyond recognition s-92 helibus in mid 90ies to Mitsubishi, so an independent domestic engineering of nex gen cargo lifter is highly unlikely, considering a plethora of serious projects has already been grounded, Comanche, venture Star, a-12, Raptor, etc. One thing is to pull out a toy sized X2 onto youtube, building a Mil-26 competitor is a comletely different story.

I guess you never heard of the CH-53K. :

 

[Grey Havoc]

Boeing seems to be still pushing the aforementioned 'Super Chinook'.

 

[sferrin]

Boeing seems to be still pushing the aforementioned 'Super Chinook'.

It's all they've got.

 

[yasotay]

Boeing is pretty savy as aerospace companies go. Doubt they would invest time/effort if they did not smell the possibility of a sale. Given the weights that tactical wheeled vehicles are getting to, not to mention their cube, might be a need for a bigger Chinook out there.

 

[sferrin]

Boeing is pretty savy as aerospace companies go. Doubt they would invest time/effort if they did not smell the possibility of a sale. Given the weights that tactical wheeled vehicles are getting to, not to mention their cube, might be a need for a bigger Chinook out there.

Don't know if you've looked before but if you examine the Chinook family tree there are several BIG might-have-beens back in the wood pile.

 

[Apophenia]

Don't know if you've looked before but if you examine the Chinook family tree there are several BIG might-have-beens back in the wood pile.

Yes, but as Yasotay said, things have changed with recent developments in tactical vehicles.

 

[donnage99]

Anyone got additional image of this concept?

 

[Rafael]

Anyone got additional image of this concept?

Quad-Tilt-Rotor (QTR)?

 

[donnage99]

stealthed up version of the quad tiltrotor
http://www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckScript=blogScript&plckElementId=blogDest&plckBlogPage=BlogViewPost&plckPostId=Blog:27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post:64a0cb8a-a643-4b25-83a5-48ae60ae33de

 

[Mat Parry]

stealthed up version of the quad tiltrotor
http://www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckScript=blogScript&plckElementId=blogDest&plckBlogPage=BlogViewPost&plckPostId=Blog:27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post:64a0cb8a-a643-4b25-83a5-48ae60ae33de

"Bell, meanwhile, had the scariest graphic ever on its stand".

 

[Stargazer]

stealthed up version of the quad tiltrotor
http://www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckScript=blogScript&plckElementId=blogDest&plckBlogPage=BlogViewPost&plckPostId=Blog:27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post:64a0cb8a-a643-4b25-83a5-48ae60ae33de

"If you have a sensation at this point that someone is using mind-altering chemicals, you are not alone"
ROTFL!!!! ;D

 

[donnage99]

and if anyone has the video or even images of the Boeing's canard-rotor-wing proposal for JHL, it would be great.

 

[Stargazer]

Is this the one?

 

[yasotay]

There was no serious CRW Joint Heavy Lift work done. Conversely there was considerable work done on the QTR.