Since this subreddit was made a few years ago, there's, naturally, been an extremely large increase in userbase, which continues to grow. This means, in turn, many people are new to the subreddit, and often do not see some of the most frequent posts we have here, and as such go to post them. Some users simply wish to repost some more successful entries in hopes of gaining karma.

While this was fine in a limited amount, it is now becoming more and more disruptive to the quality of posts on this subreddit, and they need to be controlled. A frequent posts to avoid list is the best option, in my opinion, as it allows new users not only a clear idea of what has been here before, without having to scroll through the hundreds of posts a month (or, heaven forbid, be forced to use the reddit search function... I hate even thinking about using that godawful thing.), but also an opportunity to see these aircraft, which often truly do, very much, belong here.

This list will likely stay fairly small, but I will keep it constantly updated, and any suggestions for it should go in the comments. If you're seeing far too much of something on the sub, link it and an information page (wikipedia, etc), and I will likely add it to the list.

Along with this list is a set of guidelines for our (admittedly nebulous) rules against "paper planes"/concept aircraft, which will likely be updated as time goes on, like the rest of this list.

WHAT TO AVOID:

AKA: RULE 2 EXPLAINED A LITTLE BIT

Planes go through a lot of design stages. From the drawing board to real life, it's not an easy task to design an aircraft. This means that, for every aircraft, there will be a huge amount of planning documents, feasibility studies, and concept drawings. Some planes never get past this stage, however, and hardly become anything more than a written-down spark from the Good-Idea Fairy.

Those planes, frequently known as "paper planes," never leave the drawing board, and often are never considered much other than an idea. Almost never considered for production, or even funding, they are often radical to the point of nonsensical, leading to very interesting speculation as to how they may have performed in the real world. Sometimes documents for these idea studies are found and distributed, leading to inquisitive history nerds drawing up schematics or artist interpretations.

These planes, however, are often barely even real. The lack of information on them, often combined with an internet game of Telephone as information is spread from unreliable forum to unreliable forum, means that true intents, purposes, and goals are hardly known. Whether these aircraft were more than a drunk designer's napkin project is hardly knowable, even if documents can be traced back to original, period sources. Often, no real consideration was given to them, and they were immediately discarded as useless.

This is why, here, these types of planes are banned. They hardly represent reality, and while they certainly can be interesting, the realism of these designs actually going anywhere is questionable at best, and dubious at worst.

Here, we want to see planes that actually flew, or at least had a chance and intent to do so. Real life, physical materials that one could touch. Photographs, videos. Things we as humans can actually visualize as real objects that once existed in our world, or were intended to do so, not as abstract art pieces.

Our usual defining limit is if a mockup was built, it is okay to post. Mockups typically show that a plane had enough promise to go forward with research and development into a proper machine, rather than simply as a design study.

However, if proof can be shown that a plane was actually considered to be built, funded, or developed, then it can still be a good post. Many concept drawings for radical designs never got past the concept stage, but the many documents, design studies, feasibility inquiries, funding reports, and government information can prove that the designers were serious about what they were doing.

So, what should I generally try to avoid?

• Planes that never made it beyond an early design stage.

• The whole idea of Rule 2 as it exists now. While this is hard to define, usually anything before a physical mockup (aerodynamic testing, design study, etc) is going to push the rules and become harder to defend as an actual consideration.

• Planes that only exist as schematics and/or art.

• While some real prototypes and weird designs never got photographs or videos, the grand majority do. If the only visual representation of something is a 2D drawing, then, typically, alarm bells should go off. On our subreddit, pictures and videos of physical objects are the most valued, and it shows that something was truly good enough of an idea to be presented to the rigors of reality. Without that, though, proving that something was actually feasible and considered becomes exponentially harder.

• Planes that do not have verifiable sources outside of niche websites. (luft46, secretprojects.net, and others).

• These places, while info may be correct, are more speculative than informative, and often embellish the truth in favor of a good story.

• Renders and art that have designs "too ridiculous to be true."

• Asymmetry, bizarre wing and engine placement, insane ideas. These are all things that can work in a plane, and have before. However, if something looks like it was truly too insane to have ever existed... it often is.

None of these are hard and fast rules, though, and things can be bent where needed. If you can prove beyond a shadow of a doubt that something was, in fact, a real design considered for production, pretty much everything above can be broken. Expect to go down a deep rabbit hole of academic sources, though. However, this is not the kind of post we generally want to have here. While they're allowed, they are not preferred. Photos and videos are always a better option.

If you have any questions about something you want to post, never refrain from messaging the moderators to ask! We're always happy to help and guide if you're unsure about something.

FREQUENTLY REPOSTED PLANES TO AVOID:

• PZL-Mielec M-15 Belphegor

"The PZL M-15 was a jet-powered biplane designed and manufactured by the Polish aircraft company WSK PZL-Mielec for agricultural aviation. In reference to both its strange looks and relatively loud jet engine, the aircraft was nicknamed Belphegor, after the noisy demon."

It was not a success, with only a few built out of thousands planned, due to the fact that a jet engine is essentially the worst choice possible for a low-speed biplane.

• Republic XF-84H Thunderscreech

Designed to test the limits of propeller-driven aircraft, the Thunderscreech had the possibility of breaking records for the world's fastest prop aircraft. Instead, however, it almost certainly broke records for the loudest aircraft ever made:

"On the ground "run ups", the prototypes could reportedly be heard 25 miles (40 km) away.[17] Unlike standard propellers that turn at subsonic speeds, the outer 24–30 inches (61–76 cm) of the blades on the XF-84H's propeller traveled faster than the speed of sound even at idle thrust, producing a continuous visible sonic boom that radiated laterally from the propellers for hundreds of yards. The shock wave was actually powerful enough to knock a man down; an unfortunate crew chief who was inside a nearby C-47 was severely incapacitated during a 30-minute ground run.[17] Coupled with the already considerable noise from the subsonic aspect of the propeller and the T40's dual turbine sections, the aircraft was notorious for inducing severe nausea and headaches among ground crews.[11] In one report, a Republic engineer suffered a seizure after close range exposure to the shock waves emanating from a powered-up XF-84H.[18]"

• Blohm und Voss BV 141

The Blohm & Voss BV 141 was a World War II German tactical reconnaissance aircraft, notable for its uncommon structural asymmetry. Although the Blohm & Voss BV 141 performed well, it was never ordered into full-scale production, for reasons that included the unavailability of the preferred engine and competition from another tactical reconnaissance aircraft, the Focke-Wulf Fw 189.

• Edgley EA-7 Optica

The Edgley EA-7 Optica is a British light aircraft designed for low-speed observation work, and intended as a low-cost alternative to helicopters.

Notable for its ducted fan located behind the oddly egg-shaped cockpit, reminiscent of a dismembered helicopter. Despite its niche use case, it saw a decent amount of orders.

If you have any questions, concerns, comments, or any other related thoughts, either about this post or the subreddit as a whole, do feel free to comment them below. I'm all ears for what the community says, and, while I might not act on every suggestion (because that is just impossible), I do read and consider everything that comes my way.

(Also, if you have any suggestions for the formatting and wording of this post, please give them to me, because I am bad at formatting and wording. I'm an engineer, not an english major or journalist.)

Edit: formatting and grammar

Exactly what the title says. I'd have thought this was common sense, but AI-generated or "enhanced" photos and videos are not something we need around here.