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Boeing aircraft generally have a pointy nose, which seems to me to imply better aerodynamic qualities, less drag etc. Airbus aircraft on the other hand have rather bulbous noses.

Is this difference to give Boeing and Airbus aircraft a consistent, distinctive visual appearance, or is there any specific aerodynamic reason for the different designs?

enter image description here

This image is only an example and my question is not about any specific model.

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    $\begingroup$ I would highly doubt the engineers at Airbus ended up with the design (of the nose) they did because of "better identification" $\endgroup$ – CGCampbell Feb 26 '15 at 14:24
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    $\begingroup$ "More pointy" isn't necessarily synonymous with "lower drag" $\endgroup$ – Jon Story Feb 26 '15 at 14:44
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    $\begingroup$ @JonStory related $\endgroup$ – Federico Feb 26 '15 at 14:49
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    $\begingroup$ aerodynamics involve the design of the whole fuselage, including the tail. $\endgroup$ – Manu H Feb 26 '15 at 20:27
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    $\begingroup$ @Firee Right. I was just saying that I'm not sure your implication that Boeings generally have 'pointier' noses than Airbuses is actually true, aside from the 747 vs. A380 case. It doesn't appear to be the case when comparing the A330 vs. B767, for instance. $\endgroup$ – reirab Mar 3 '15 at 16:16
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The answer to this is, in part to do with corporate culture and part aerodynamics.

The corporate culture and history part is that Boeing have always built their noses that way and senior engineers have a tendancy to return to designs they have used successfully before. If you look at the nose of a 747 and the nose of B-17 you'll see some distictive similarities that follow through all the major Boeing aircraft. This isn't surprising as lead designer of the 747, Joe Sutter, started working for Boeing on the 707 project under the direction of the engineers that designed the early flying forts. Airbus is a newer company with a different corporate culture. They tend to embrace new design techniques like CFD computer modelling to a greater extent and this leads to slightly more efficient but less aestetically pleasing nose and wing designs.

The science side is related to the speed that modern airliners travel at (around 0.85mach). At these speeds aircraft begin to encounter a phenomena called 'Wave Drag' which is the incremental build-up of compressive shockwaves along the wings and fuselage as the aircraft approaches the speed of sound. The effect of wave drag is to drastically increase the overall drag affecting the aircraft increasing the power output required from the engines.

There are several methods of combating wave drag, the first of these is the swept wing that has been a feature of trans and supersonic aircraft since WW2. The optimum angle of the wings sweep is determined by the cruising speed of the aircraft. A more recent innovation is the Transonic or 'Whitcomb' Area Rule which states that:

"Two airplanes with the same longitudinal cross-sectional area distribution have the same wave drag, independent of how the area is distributed laterally"

Wave Drag can be reduced by attempting to match the cross sectional proportions of an aircraft as closely as possible to those of a Sears-Haack body (an aerodynamically perfect shape for supersonic flight) This why airbus planes have blunter nose. it is also why there are strange bulges under the wing roots of the A380. they are both attempts to make the planes cross-section conform to a Sears-Haack body more closely.

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    $\begingroup$ Welcome to the site. The pictures of Sears-Haack bodies that I can find do not look very blunt. Also, Mach 0.65 is a bit slower than most jet airliners cruise at. $\endgroup$ – fooot Mar 9 '15 at 16:20
  • $\begingroup$ A true sears-haack body is 'pointy' because it is idealised for flight at exactly mach 1. The shape can be varied by biasing the centre of mass forwards or backwards for flight above or below the speed of sound so a 'slow' S-H body will be blunter. The aerospace designer then has to approximate the cross-sectional ratios within his design. Thanks for pointing out the typo with the cruising speed. edited to fix. $\endgroup$ – JonS Mar 9 '15 at 16:25
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    $\begingroup$ The Boeing B-29 nose looks rather blunt to me. I do not think that the nose design back then was driven by branding. Also, wave drag would not explain nose shapes - on airliner noses we will not find supersonic flow. $\endgroup$ – Peter Kämpf Mar 11 '15 at 21:01
  • $\begingroup$ Actually wave drag begins to be an issue for planes travelling as slowely as 0.65 of mach. during WW2, fighter pilots in steep dives found their control sucrfaces would lock up because of it. at 0.85 it is a definate problem and the whole of the aircraft, including the nose, contriubutes to the solution. $\endgroup$ – JonS Mar 12 '15 at 9:50
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Airbus and Boeing are not the only airplane manufacturers who see the nose shape as something to sharpen their brand. Look at the Schleicher gliders (the left picture shows an ASW-20) and compare their pointed nose to those of Schempp-Hirth, which is distinctively more blunt (the right picture shows a Discus).

Alexander Schleicher ASW-20 (left) and Schempp-Hirth Discus T (right)

The shorter nose will incur higher induced speeds, but a shorter boundary layer and less wetted surface. Which is better depends on the particular flow situation.

Or take the canopy shape of Glaser-Dirks gliders which stand out with their stretched-out shape which allows even the feet of the pilots to be bathed in sunlight (see picture of a DG-300 below). This is like a brand label.

DG-300 over the Alps

Disgruntled Boeing engineers told me once that they spent three months optimizing the tailplane-fuselage intersection of the Boeing 767, only to have their design rejected by upper management because it looked "too much like McDonnell-Douglas". Yes, the outside shape is important to management to express their brand.

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  • $\begingroup$ Peter, it's absolutely amazing that an airliner would be designed with "body look" in mind! Thanks for this info ! $\endgroup$ – Fattie Oct 10 at 15:18

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