# What should be the size of a lifting body aircraft that can carry 5 passengers (385kg/850lbs)?

So I just want to know the size of an aircraft with a lifting body that would fly at low altitudes (around 40 meters/100 feet), and at low speeds (maximum 200 km/h 124 mph). But I don't know if these numbers are even useful to the question.

I tried to search for more aircraft like that, but most of them just fit a single person (the pilot).

I did find some illustrations from reentry lifting body aircraft (like the Martin X-23 Prime), but I can't tell if they are 1:1 or simply an illustration.

I did find the Wainfan Facetmobile FMX-4 quite simple and interesting, I don't know how fast and how high this aircraft can fly, but I think it could be a simple way of scaling things up.

I found this video of the FMX-4 showing its frame and engine (and other stuff), I don't know if it will be useful, but...

• Lifting bodies are good for high speed descents like reentry. I’m no engineer, but even without math I can tell you that you will have difficulty flying 5 adults at 124 mph in a craft shaped like that. You will need some more wingspan. Nov 10, 2022 at 3:26
• "This isn't flying. It's falling with style." Nov 10, 2022 at 7:50

The term "lifting body" as it is defined does not match with slower than 200km/h flight speed, since those are very low aspect ratio, thick & highly loaded flying wing meant to also fly hypersonic.

The Facetmobile you mentioned has a far lower wing loading, which is a good approach. Further searching for images of this particular aircraft lead to this example too :

It may be possible to increase the Facetmobile wingspan and fit passengers side by side.

Another approach could be to scale up well known lifting bodies such as X-24 or HL-10, build them as a light structure covered with fabric, and fill those with a lifting gas, since lifting bodies tend to maximize their volume to surface ratio.

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• Wow! You even made a 3d model to illustrate your answer! This is really cool! Nov 11, 2022 at 1:16
• accepting an answer too fast may discourage other to answer, you can move or remove a checkmark anytime, thanks btw Nov 11, 2022 at 8:26

Going slow the problem is lift. Going fast the problem is drag. What you have there in the picture is essentially a scaled-up paper airplane design, which works surprisingly well provided there is enough thrust available.

Birds fold their wings back for higher speed flight. Turboprop carriers also feature undersized straight wings.

What is needed for craft such as these is the ability to take off and land at higher airspeeds. You won't be landing one of these in the bush or at a small local airport.

Other than that, scaling should be easy. One might plan for a bit more than 375 kg, considering 5 people, the pilot, and fuel.

• which works surprisingly well provided there is enough thrust available. I think it is safe to say that given enough thrust, anything works surprisingly well. ;-) Nov 10, 2022 at 8:10
• @DeltaLima - Yes! Just look at the F4 Phantom. :-) (My absolute favorite airplane as a kid)
– Jim
Nov 10, 2022 at 17:16

NASA extensively studied lifting bodies back in the 60s. Its repository is therefore full with the relevant documents.

I think this, this and this could be useful for your project, but there are really many more.

Anyway I agree with the answer of @qqjkztd: lifting bodies were designed to study the re-entry phase of the future space shuttle and their main purpose was to glide (not fly) at extreme Mach numbers.

Maybe the kind of aircraft you are looking for is a flying wing?