The past week and half have been a steep learning curve, especially for those who don’t normally follow aviation. Navigating the jargon of the business can be confusing and separating all the acronyms can get in the way of understanding the situation.

What this post is: an attempt to put together some pieces of information so that reading the news doesn’t mean looking up a new acronym every two words. If you’re confused at all by ACARS vs TCAS, or you think ADS-B is what kicks in when your car hits a patch of ice, this post should shed a little light and I’ll do my best to update this post with answers to any questions you may have.

What this post isn’t: a compendium of theories of what happened to flight 370. If you’re looking for that, there are plenty of other places willing to entertain wild speculation.

So what are we talking about?

What kind of plane is it?

Malaysia Airlines Flight 370 is a Boeing 777-200ER, registered 9M-MRO, pictured below. The 777-200ER has a range of 7,725 nautical miles and can carry over 45,000 gallons of fuel. This particular aircraft is powered by Rolls Royce Trent 895 engines.

Primary vs. Secondary RADAR? And what’s ADS-B?

We’ve heard a lot about primary and secondary radar—and transponders, but more on that below—this week, but isn’t radar just radar? Not quite. Primary radar is what most people think of when they hear radar. Primary radar sends microwaves out and waits for them to bounce back telling the radar station that an object exists and its distance from the radar station. Secondary radar provides aviators and air traffic controllers with a much more precise way to monitor aircraft. Secondary radar sends a signal to a plane that is equipped with a transponder, which receives and interprets the signal and then sends a corresponding signal back to the radar installation with information about the plane’s position. ADS-B (Automatic Dependent Surveillance-Broadcast) is a newer system takes this a step further. Planes equipped with ADS-B determine their own position via satellites and then broadcast that information to air traffic control and other aircraft. Websites like FlightRadar24 and Planefinder compile ADS-B data from aircraft and provide for real-time tracking of flights. The data generated by ADS-B is what much of the original discussion of MH370’s disappearance revolved around.

Update March 18, 9:40amCT: Here’s a great article by AP’s Scott Mayerowitz and Joan Lowy on why airplane transponders have an off switch.

A screen capture from FlightRadar24 showing the last broadcast position of MH370.

What is ACARS?

ACARS or Aircraft Communications Addressing and Reporting System allows aircraft and ground stations to communicate short messages via radio frequency or satellite. These short messages can be related to air traffic control—such as a new route, or to maintenance—the airplane automatically telling the airline that the engine needs to be checked upon landing, or to something more general, like the weather ahead.

What are “Satellite Pings?”

Tim Farrar of TMF Associates, a firm specializes in satellite communications, provides an excellent and detailed overview of the satellite pings on the TMF Associates blog. MH370’s onboard terminal contacted an Inmarsat-3 satellite roughly every hour allowing investigators to construct the two possible arcs where MH370 could be.

Two possible arcs on which MH370 may reside. Image source/WSJ.

MH370 pinged the Inmarsat-3 satellite orbiting over the Indian Ocean (the blue satellite in the image below).

Coverage of the Inmarsat-3 satellite network. Image source, courtesy Inmarsat.

Now what is this TCAS I’m hearing about?

TCAS—Traffic Collision Avoidance System—is the most plainly named system here. TCAS is designed to do exactly what it says: avoid collisions. TCAS uses the plane’s transponder to monitor other aircraft in the area and warn pilots of any danger of collision.

Are satellite pings different than locater pings? What is a underwater locator beacon?

The underwater locator beacon pings and the earlier satellite pings are different. Attached to ever airplane’s black box is an underwater locator beacon—also known as an underwater acoustic beacon—that emits an acoustic pulse when immersed in fresh or saltwater. Once submerged the beacon emits one ping per second. The beacons are designed to withstand immense pressures and can operate for 30 days at a depth of 20,000 feet under water. When wreckage is found specialized equipment like the U.S. Navy’s Towed Ping Locator 25 can be used to detect the beacon’s pings and the airplane’s black boxes.

A example Underwater Locator Beacon, similar to the one on MH 370. Image courtesy Wikimedia Commons.

So now, when you’re watching the news or scrolling through twitter, you’ll have a bit of an idea of what is being discussed. What else would you like to know? Let me know in comments and I’ll do by best to answer your questions.

Here are my favorite 2013 Aviation Photos, enjoy!

United 777-222/ER (N798UA) at the O’Hare Run on the Runway

JAL 9 headed to Narita takes off from RWY 28R at the O’Hare Run on the Runway

This American Airlines livery won’t be around much longer and I was very happy to get such a good shot. I was even happier to be out spotting with Jon Ostrower, Jason Rabinowitz, Gavin Werbeloff, and Bruce Bere, all avgeeks in the extreme.

American Airlines Boeing 767-323/ER on short final for RWY 22R. Because of the shifting winds that day, we spent a good portion of our time driving back and forth from one side of the airport to the other.

American Eagle Embraer E170-200-LR (E175) on short final for RWY 28R. This was my first shot of the E175 up in the air.

Etihad Airways Boeing 777-3FX/ER on short final for RWY 28R. This shot was a good cap to a day of great shots and great company as I got to meet Jay, the man behind the O’Hare Aviation YouTube channel.

For this shot of an SAS Airbus A330-343X I just happened to be in the right place at the right time. I had wandered down to the beach by my house to shoot and it just happened to fly right overhead.

Whenever I have access to the ramp, the weather is gloomy. It’s just a fact of life that I’ve come to accept. But for the E175 unveiling that gloomy weather turned into an asset.

This summer I headed up to EAA Airventure or just “Oshkosh,” with Jaunted editor Cynthia Drescher. Oshkosh is an amazing collection of aviation from all over the world. From vintage civilian and military aircraft to experimental aircraft to hot air balloons. As the sun began to set, the hot air balloons got fired up, making for a great shot.

A 1943 Lockheed L-18 Lodestar’s Wright R-1820 engine at Oshkosh.

“Panchito,” a B-25J Mitchell Bomber flies at Oshkosh.

What are your favorite aviation photos of 2013? Let me know in comments.