Why are props at the back of a ship but at the front on a plane?

[Flyingriki]

Originally Posted by newhaul

Good looking lil canard. Where is she ported? (Would love.some stick time )

Thank you! Very kind of you.

Northern Cal. We fly up to Arlington every year for the big flyin and one evening, usually Friday, fly out to Friday Harbor for dinner. Stop by and you can probably scare up a ride. Usually a dozen or more canards, enough to have our own row in homebuilt camping.

[Flyingriki]

Originally Posted by Guy

Airplanes are not designed to crash. The Long EZ in the post above is about as dangerous as it get's, but who cares?

Now THAT'S the dumbest thing I've read all month! Data shows we are quite safe. And no, I'm not going to waste time pulling up the stats which are numerous and extensive on homebuilt aircraft. Particularly for someone that offers uninformed bs like that as fact.
Actually accumulated by an expert in the field in association with FAA, AOPA and EAA.

[a64pilot]

For a conventional aircraft design, engine in front is more stable.
(First powered aircraft was a pusher) look at the Wright flyer

There are many reasons for few successful certified pusher designs, but often don't have to do with it being a pusher. Look at OMAC and better yet, Beech's Starship, and Lear's fan.
None were successful, but the reasons had nothing to do with them being pushers.

[JasonDS]

Thanks for the replies. When someone points it out to you about pushing the water over the hull and seaways, it makes sense. I had already thought about running aground scenarios as well as weight distribution but was thinking more alone the lines efficiency and fluid dynamics.

[a64pilot]

OK, I deleted a few posts as they were not nice, let's no insult each other please

[UNCIVILIZED]

Well, on ships anyway, putting the screws up front & sonar dome in the back would make for lousy submarine detection. And while, yes, some ships do have towed array sonar systems for use in the open ocean, they're not common. Where as sonar up front is. And sonar up front can also be used for mapping, as well as piloting when you don't know the depth or underwater terrain ahead. So if I'm on the ship, I'd prefer it if she didn't have her primary eyeballs in her ass
And then there are everyone else's wise words on this.

[model 10]

Hey, "Pud Knocker" is a semi-respectable term. Any half ass pilot can be a pud knocker, but you do need to be a pilot to be one. When I called the person with the long ez a "pud knocker", it was well deserved.

[jimbunyard]

Utility, design fitness...one can stick 'em on both ends...

These are called Voith/Schnieder or cycloidal propellors or drives, and can 'pull' in any direction...

[DefinitelyMe]

Presumably prop ventilation would be a big problem if they were mounted forward on a boat, from pitching but also just from sucking air down in front of the prop. A few years ago I tried mounting an outboard engine between the hulls of an old tornado catamaran. It didn't work very well because the prop just sucked air down from the surface and ventilated itself. To get around the problem you either have to put something in front of and above the prop (like a hull!) or have the prop mounted really deep, which means lots of drag from the lower unit.

Don't know anything about planes but the answers above all make sense. I've always wondered though - if you want the air above a wing to be moving faster than underneath it (the principle of lift) why mount the engines under the wings? Why not above them?

[model 10]

Originally Posted by DefinitelyMe

why mount the engines under the wings? Why not above them?

That is pretty deep man, check out the new Honda jet.

[puffcard]

Many ferries have a prop and rudder in the front and rear.

[newhaul]

most multiengine prop driven aircraft that have the engines mounted on the underside of the wing for structural strength the actual propeller extends both above and below the wing. ( for both pull and pusher props)

[AKA-None]

Originally Posted by sailstoo

Where's Bob Perry when you need him?

Over on SA

[ZULU40]

On aircraft prop at the back (pushers) gets closer to the ground with the potential for blade strike with the runway on rotation at take off, and during flare on landing. Also rear props are generally louder (outside the aircraft) which goes against airport noise abatement.

Anything that should fall off the aircraft or be thrown out will go through the prop disk, damaging the prop requiring engine shut down and a forced landing. Ive seen this with a gyrocopter pilot throwing sweets to kids while flying next to an airshow crowd. Just the weight of a few sweets going thru the prop was enough to set up heavy vibration from prop imbalance making him cut the power and execute an immediate forced landing.

Props at the front (tractor) have non of those issues and they energise the air to the rudder on power up, especially important on take off, where props tend to grip the air more at bottom of the downblade stroke, swinging the aircraft on power application. Nearly all aircraft that do substantial work are multi engine, where the engines are fitted to the wings which kinda ends the argument either way.

[Stemci]

If props were at the bow I wonder how long it would take for Dolphins to learn not to get chewed up??��