Why no engines on top of wings?

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Registered: 17-03-2016
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March 17, 2016 11:07:05

With today's quieter engines wouldn't it make sense, less debris from the ground being sucked up, safer for ground personnel, ditching on ocean/land, giving it a flater profile. Better aerodynamics on rotation?

Registered: 2015-12-15
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#2 March 17, 2016 20:16:31

There are a few example of airplanes with the engines on the top such as the HondaJet or the An-72.
A problem of this configuration is the aerodynamics, in fact the flow of air on the top surface of the wing is meticulously controlled because it must be a laminar flow, adding the engines on the top makes things unpredictable and very different along the wingspan. You can see that the engines on the HondaJet are very far from the wing and on the An-72 the engines are behind the wings because they don't need to influence the flow.
An other problem is the maintenance, hanging them under the wings makes them much more easily accessible, this mean less time for maintenance so less time the airplanes are on the ground bigger is the gain for the companies.
The last is because the aircraft designer are lazy, so change the structure of an airplane means do all the calculations and test again, hence more time and more money.
Just look the commercial aircrafts in the last 50 years and you will see that basically they are all equal.

Edited adminIT (March 17, 2016 20:16:59)