Simviation Forums

Another future airliner is in development....
http://www.aviationweek.com/aw/generic/ ... 090809.xml

Here's the deal, I know the design is proven and works, but can't we have some company vary it up a little bit with the looks.
Airliners these days all look the same (to me), with the only sort of variety coming from DC-9/MD-80s with their rear mounted engines, and the increasingly rare DC-10 or MD-11 sighting.
Tube, two under-wing engines, same body width/length.....ugh....

You want this.

http://www.airliners.net/photo/American-Airlines/Boeing-707-123/0541868/L/

What? That just looks like a longer 737 with four small engines instead of two big ones.

What you want is this: http://www.nasa.gov/centers/langley/ima ... -81-01.jpg

That's different.

What? That just looks like a longer 737 with four small engines instead of two big ones.

What you want is this: http://www.nasa.gov/centers/langley/ima ... -81-01.jpg

That's different.

Oooooooooooooh!

Oooooooooooooh!

Vicker planes always remind me of this:

http://i50.photobucket.com/albums/f313/ ... jax_cu.jpg
http://i50.photobucket.com/albums/f313/ ... 7_Ajax.jpg

I think after 40 years of large commercial airliner development they have found the correct balance of aerodynamics, reliability, and economy.

Sad to say that there probably won't be much change in this type of configuration for the foreseeable future.

What they didn't know or have back in the '60's and '70's led to many different types of design.

Just an observation.

They haven't solved the asymmetric problem though.

They haven't solved the asymmetric problem though.

What do you mean?

I can tell you exactly why the blended wing concepts have not been pursued, not enough windows.  You would have most of the passengers sitting in the middle of that large aircraft, with only a few of the expected window seats.  Airlines wouldn't buy it.

They haven't solved the asymmetric problem though.

What do you mean?

Having the engines half way out along the wings make it fairly inefficient if one fails. Having them close to the centreline of the aeroplane, such as a DC-9, VC10, BAC 1-11 & 727, means it has a lot less of an effect should you lose an engine. In a 4 jet in the configuration of the A340, 747 and 707 type, lose two on one side, and compared to say the VC10/IL62, life could be very interesting, and lead to a very aching leg!

I believe that's one of the reasons many light twin engined aircraft actually have worse safety records compared to single engined light aircraft. If one engine fails at low speed, the plane will probably crash as the rudder doesn't have enough authority to counteract the torque generated by asymmetric thrust. The solution was to build a physically asymmetrical aircraft, like the Scaled Composites Boomerang. This allows the engines to be spaced much closer together, with the CoG in between them, so an engine failure has only a small impact on flying qualities.



Airliners don't have this problem, however. Only a bigger rudder is required. I wonder if FBW in some aircraft automatically adjusts for an engine out...?



Also, on the flip side... if an engine disintegrates on the VC-10, for example, then it has the possibility of taking out the other engines.

Airliners don't have this problem, however. I wonder if FBW in some aircraft automatically adjusts for an engine out...?

I suspect in more modern types it does.


[quote]Also, on the flip side... if an engine, for example, disintegrates on the VC-10, then it has the possibility of taking out the other engines.

The aft (tail) mounted engine on the DC-10 and MD-11 cannot operate on suction (from the engine mounted boost pump) alone, but requires the tank mounted Jettison/Override pumps to be operating. The wing mounted engines on said aircraft can operate from suction alone.

Are all tail-mounted aircraft like this, or only the DC-10 / MD-11?

Thanks.

The 727 will operate without the tank pumps operating (except for starting) as long as the low pressure and high pressure engine pumps are operating.

Not a true suction feed, but as long as the engine pumps are running so will the engine.

I suspect the wing mounted engines on the jets you mention are mostly gravity-fed.