Jump to content
Sign in to follow this  
  • entries
    33
  • comments
    19
  • views
    21,698

How do aircraft stop?

bobbyburns

454 views

The average aircraft will usually suck up a couple thousand feet in order to stop. The average single piston engine aircraft will take less, and a 747 will take much more (>5000ft).

This creates a problem. Aircraft have insane amounts of momentum upon touchdown, and pavement isn't cheap. In addition, we can't have "mobile" airports for military use - so how are we able to deploy combat ready aircraft to anywhere in the world within a matter of hours?

Well, we made mobile airports. And, they float!

The aircraft carrier was first used in 1920. Essentially, it was a floating street where some aircraft landed, and others careened into the ocean, killing their pilots. There was no effective and safe way to stop aircraft on such a small distance.

As of 2013, things have changed. The modern aircraft carrier is a small metropolis, with crews of more than 2,000 sailors. The technology has improved to a point where we're able to launch and recover 90 aircraft on the same ship.

But how do we do it? Simple - Hydraulics!

Laid across the aircraft carrier's deck are four wires. When an aircraft, like the F/A-18 in the video below, hits the deck, the aircraft "catches" one of those wires on a hook attached to the fuselage of the plane. The wire then rapidly sends kinetic energy of the aircraft to "hydraulic dumping systems" that, in simple terms, tug on the aircraft until it's stopped.

It's like a ship with massive, hydraulically-backed rubber bands.

But landing is only half of the story.

How does the F/A-18 launch from the carrier? Sure, it could take off like a conventional airplane, but the runway is far too short! The aircraft would simply fall off the deck. *insert splashing noise here*

We needed some sort of "catapult" to get the aircraft moving fast enough so that the wings could produce more lift than the aircraft's weight.

So, we used what we were experts in - Steam! By pressurizing a tank to very high PSIs, that potential energy is released, dragging the aircraft by yet another hook across the deck with a final velocity of anywhere between 120-150 Knots. These catapults will soon be replaced by electromagnets, that use electric currents to create strong magnetic fields to propel the aircraft into the air. These systems are far less expensive than conventional steam catapults.

  • Like 1


1 Comment


Recommended Comments

Might I say, a work of art! How long did it take to finalize the systems of the Carrier, allowing it to land planes and launch them at such a short distance for takeoff?

Share this comment


Link to comment
Guest
Add a comment...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Terms of Use

The pages of APlusPhysics.com, Physics in Action podcasts, and other online media at this site are made available as a service to physics students, instructors, and others. Their use is encouraged and is free of charge. Teachers who wish to use materials either in a classroom demonstration format or as part of an interactive activity/lesson are granted permission (and encouraged) to do so. Linking to information on this site is allowed and encouraged, but content from APlusPhysics may not be made available elsewhere on the Internet without the author's written permission.

Copyright Notice

APlusPhysics.com, Silly Beagle Productions and Physics In Action materials are copyright protected and the author restricts their use to online usage through a live internet connection. Any downloading of files to other storage devices (hard drives, web servers, school servers, CDs, etc.) with the exception of Physics In Action podcast episodes is prohibited. The use of images, text and animations in other projects (including non-profit endeavors) is also prohibited. Requests for permission to use such material on other projects may be submitted in writing to info@aplusphysics.com. Licensing of the content of APlusPhysics.com for other uses may be considered in the future.

×
×
  • Create New...