kottke.org posts about flying

Can you fly a plane on Mars?

posted by Jason Kottke   Jan 30, 2013

Another fine installment of XKCD's What If? series: What would happen if you tried to fly a normal Earth airplane above different Solar System bodies?

Unfortunately, [the X-Plane simulator] is not capable of simulating the hellish environment near the surface of Venus. But physics calculations give us an idea of what flight there would be like. The upshot is: Your plane would fly pretty well, except it would be on fire the whole time, and then it would stop flying, and then stop being a plane.

(via stellar)

Plane crash recorded on Russian dash cam

posted by Jason Kottke   Dec 30, 2012

As we've previously discussed, many Russian vehicles are equipped with dashboard video cameras. The other day, one such dashcam caught a plane crash on video:

See also driving in Russia.

Human-powered helicopters are hard to build

posted by Jason Kottke   Oct 16, 2012

A team at the University of Maryland are building a human-powered helicopter in an attempt to win the Igor I. Sikorsky Human Powered Helicopter Competition. To win the $250,000 prize, the helicopter must fly for 60 seconds, reach a momentary altitude of 3 meters, and stay within a 10 meter square. This is surprisingly difficult.

The NPR story that the video accompanies is here. (via ★interesting)

Is poor cockpit design to blame in the Air France 447 crash?

posted by Jason Kottke   May 02, 2012

In June 2009, an Air France flight from Rio de Janeiro disappeared without a trace. The disappearance turned crash and the questions started: how did a state-of-the-art plane go down so suddenly and who was to blame? The plane's black boxes were finally recovered after two years of searching and there's a case to be made that the design of the cockpit controls may be at least partially responsible for the crash.

The official report by French accident investigators is due in a month and seems likely to echo provisional verdicts suggesting human error. There is no doubt that at least one of AF447's pilots made a fatal and sustained mistake, and the airline must bear responsibility for the actions of its crew. It will be a grievous blow for Air France, perhaps more damaging than the Concorde disaster of July 2000.

But there is another, worrying implication that the Telegraph can disclose for the first time: that the errors committed by the pilot doing the flying were not corrected by his more experienced colleagues because they did not know he was behaving in a manner bound to induce a stall. And the reason for that fatal lack of awareness lies partly in the design of the control stick - the "side stick" - used in all Airbus cockpits.

Phil Taylor is my new favorite Brown

posted by Aaron Cohen   Mar 23, 2012

Phil Taylor is a 335 pound defensive tackle for the Cleveland Browns. He is also an expert airplane troll. Seriously, some of you out there, and you know who you are, could learn a thing or two.

Click through to see the rest of the Tweets and Phil's row mate looking miserable.

(Thanks, Gareth)

What do all the controls in an airplane cockpit do?

posted by Jason Kottke   Mar 15, 2012

A seemingly innocuous question: What do all the controls in an airplane cockpit do? When he saw this question posted to Quora, pilot Tim Morgan posted a 9000-word essay on how modern airplanes work, including, yes, what all those little cockpit dials and knobs do.

Every airplane is different. Unlike learning to drive a car, you can't just hop from one plane to another. A pilot needs familiarization (and in some cases, a whole new type of license) to fly a different kind of plane. Some are piston-powered; some are jet-powered. Some have electrically-driven controls; some are hydraulically-driven. Some have emergency oxygen; some don't. And so on. All the switches, dials, and knobs in the cockpit control the various aircraft systems, and every aircraft has different systems.

Megan Garber wrote a behind-the-scenes piece about Morgan's answer for The Atlantic.

Morgan says, "I took the time to go over it again and verify that everything was correct. I used an operations manual from a 737 simulator to check my facts." And "in the end it was a very personally rewarding experience, because I had had the operations manual lying around and had been meaning to really study it, and now I finally had my excuse."

So answering the Quora question was as much about learning as it was about sharing. And as for Morgan's overall motivation? "I can tell you with certainty that it is related to my pathological interest in aircraft," he says, "and in general a love to write and share knowledge."

Airport security: the Dick-Measuring Device or molestation?

posted by Jason Kottke   Oct 29, 2010

Jeffrey Goldberg on the TSA's new security theater measures, including pat-downs that are so humiliating and uncomfortable that people won't mind using the scanning machine that shows them naked.

I asked him if he was looking forward to conducting the full-on pat-downs. "Nobody's going to do it," he said, "once they find out that we're going to do."

In other words, people, when faced with a choice, will inevitably choose the Dick-Measuring Device over molestation? "That's what we're hoping for. We're trying to get everyone into the machine." He called over a colleague. "Tell him what you call the back-scatter," he said. "The Dick-Measuring Device," I said. "That's the truth," the other officer responded.

The pat-down at BWI was fairly vigorous, by the usual tame standards of the TSA, but it was nothing like the one I received the next day at T.F. Green in Providence. Apparently, I was the very first passenger to ask to opt-out of back-scatter imaging. Several TSA officers heard me choose the pat-down, and they reacted in a way meant to make the ordinary passenger feel very badly about his decision. One officer said to a colleague who was obviously going to be assigned to me, "Get new gloves, man, you're going to need them where you're going."

The agent snapped on his blue gloves, and patiently explained exactly where he was going to touch me. I felt like a sophomore at Oberlin.

Drinks on the go

posted by Jason Kottke   Oct 06, 2010

What do people drink on trains?

On Metro-North and the Long Island Rail Road, beer is the best seller by far, accounting for more than half of all drink purchases. Budweiser and its calorie-conscious cousin, Bud Light, make up about 45 percent.

Vodka is far more popular than other spirits, making up half of all hard liquor sales. (One bartender, who spoke on the condition of anonymity for fear of losing her job, confided that her stockbroker customers "all drink vodka," while construction workers "are all about the beer.") Gin and scotch are a distant second and third.

What do people drink on planes?

While much has been made online about ginger ale's unexpected aerial dominance (apparently one in ten drinks ordered in economy on American Airlines is a ginger ale, compared to its puny three percent terrestrial market share), there seems not to be a sustained geographical analysis of the beverage consumption patterns on different routes and airlines — or even different seat positions. Do window-seat people disproportionately favour vegetable juice, for example, or is that just the case on the routes I've been flying?

And what do people drink with goats? Would you, could you, with a goat? Oop, sorry, things got a little Seussical there.

The interior design style of dictators

posted by Jason Kottke   Aug 23, 2010

Nick Gleis shoots the interiors of corporate jets owned by African dictators and other heads of state. I couldn't decide which jet interior was the gaudiest, but this one is definitely a contender because of the classy naked ladies on the wall of the bedroom.

Dictator Jets

Who knew that African dictators were so nostalgic for the set design of Star Trek: The Next Generation?

Hypersonic: more super than supersonic

posted by Jason Kottke   May 27, 2010

The US Air Force, Pratt & Whitney, and Boeing are jointly developing a hypersonic aircraft that can travel faster than existing cruise missiles. It's powered by a crazy-sounding "air-breathing hypersonic engine that has virtually no moving parts" and reached a speed of 3500 mph in a recent test.

"This is truly transformational technology," Brink said. "This engine can be considered the next step in aviation. It's as big of leap as it was when we went from propellers to jet engines."

You can read more about scramjet engines on Wikipedia. (via @bldgblog)

Fake pilot flies passengers for thirteen years

posted by Aaron Cohen   May 18, 2010

Thomas Salme turned himself from maintenance engineer into 737 pilot with several hours of flight simulation and some basic license forgery skills. He flew for 13 years without problem until he was busted in the cockpit at Schipol airport with 101 passengers aboard.

The documents look different everywhere in Europe. An Italian airline doesn't know what a Swedish license looks like. And you can forge all the IDs you need.

(via @mdisalvo)

The SR-71 flight manual

posted by Jason Kottke   May 12, 2010

Some parts of it are still classified but most of it is available to read online.

Why is flying hard?

posted by Jason Kottke   Feb 12, 2010

Nelson Minar on why flying is so difficult (in comparison to driving).

Cars only steer in one dimension; planes steer in two. Even a level turn is hard in a plane, you have to coordinate two controls, except sometimes you deliberately uncoordinate them. Managing engine power is harder in a plane: two or three controls in a piston, not just a single pedal. And then there's auxiliary controls you have to use occasionally: flaps, carburetor heat, fuel tank selector, etc. Even starting a plane requires carefully using four controls in the proper relationship.

My dad was a pilot and used to let me fly when I was little, like 5 or 6. It was easy in clear weather, easier than driving a car in fact...just keep it level. I actually didn't even need to touch the yoke much of the time...the plane just flew itself. When I got older, I realized that what made it so effortless was that my dad was taking care of the hard part, the 95% of flying that doesn't involve moving any of the controls. What made it look so effortless for him, even when things got tough1, was the 10,000+ hours in the cockpit of a plane, flying.

[1] Like when he made a crosswind landing in a Cessna 172 ahead of an oncoming storm which we later learned had spawned some tornadoes while running a bit lower on gas than was generally acceptable by the plane's captain. He'd already attempted one landing, aborting after the wind dropped us like 10 feet in half a second while about 30 feet from the ground. The sensation of that crosswind landing — of gliding over the runway twenty feet off the ground at ~60-80 mph while pointed about 30 degrees off axis and then, just before touching down and presumably tumbling down the runway wing over wing, straightening out for a surprisingly gentle landing — was one of the freakiest things I've ever experienced, partly because I wasn't scared at all...I knew he'd get us down safely.

First video from a plane, 1909

posted by Jason Kottke   Oct 22, 2009

This short film was made in 1909 and depicts Wilbur Wright flying one of his airplanes around an open field. At 1:38, they attach the camera to the plane and shot what is thought to be the first video footage shot from a powered flying machine.

Then the plane started up again, followed a launching pad and took off: the camera was fixed for the first time on the ground that gave way...and the emotion was there, so great you could almost touch it! The image was as unstable as the cabin of the plane flying at low altitude, flying over the countryside and gradually approaching a town.

(via @ebertchicago)

The most remarkable airplane of the 20th century

posted by Jason Kottke   Jun 26, 2009

A short appreciation of the SR-71 Blackbird, an airplane that was literally faster than a speeding bullet.

"It wasn't like any other airplane," he told me. It was terrifying, exciting, intense and humbling every time you flew. Each mission was designed to fly at a certain speed; you always knew the airplane had more. It was like driving to work in a double-A fuel dragster."

The skin of the plane's fuselage was a whopping 85% titanium, which was purchased, during the Cold War, from the Soviet Union.

Update: See also SR-71 Groundspeed Check, Google Map of where all the Blackbirds are, and SR-71 Disintegrates Around Pilot During Flight Test:

Everything seemed to unfold in slow motion. I learned later the time from event onset to catastrophic departure from controlled flight was only 2-3 sec. Still trying to communicate with Jim, I blacked out, succumbing to extremely high g-forces. The SR-71 then literally disintegrated around us. From that point, I was just along for the ride.

(thx, doug, clay & tom)

Flying over glowing cities

posted by Jason Kottke   Jan 28, 2009

Timelapse video of a cross country flight at night, flying above clouds glowing with city lights.

My advice to you is to make the video full screen, put in your headphones and enjoy the soothing ride. (via migurski)

Flight 1549 simulation

posted by Jason Kottke   Jan 19, 2009

The BBC did a flight simulation of US Airways flight 1549 that shows what the water approach looked like from the cockpit. (thx, david)

Video footage of Hudson River plane crash

posted by Jason Kottke   Jan 18, 2009

I'm still fascinated by the water landing of US Airways flight 1549 on the Hudson River late last week. Here are a few more things I've seen related to it over the last couple of days.

First the videos. Someone visiting the Bronx Zoo caught the plane on video, flying low in the sky just after the bird strike. A Coast Guard video monitoring station got a shot of the plane just after it splashed down...you can see the spray from the impact flying in from the left of the video just after the 2:00 mark.

Soon after the plane hits, the camera zooms in and you can see just how quickly people get out and onto the wings. And then this video shows it most clearly:

Look how low and level and steady Sully guided that thing in! Amazing!

The NY Times has a couple of good pieces in their extensive crash coverage. I loved reading what various passengers had to say about the crash, lots of little moments of heroism in there.

The life raft attached to the plane was upside down in the river, just out of reach. Mr. Wentzell turned and found another passenger, Carl Bazarian, an investment banker from Florida who, at 62, was twice his age. Mr. Wentzell grabbed the wrist of Mr. Bazarian, who grabbed a third man who held onto the plane. Mr. Wentzell then leaned out to flip the raft. "Carl was Iron Man that day," Mr. Wentzell said. "We got the raft stabilized and we got on." A man went into the water, and the door salesman and the banker hauled him aboard. He curled in a fetal position, freezing.

The Times also comes through with the 3-D flight graphic I asked for the other day but they upped the ante with a seating chart of the plane where you can click on certain passengers' seats to read their thoughts. Mark Hood in seat 2A described the landing:

When we touched down, it was like a log ride at Six Flags. It was that smooth.

The whole thing is still so amazing. Looking at the underside of the plane as they lifted it from the water last night, you can see the damage to the bottom of the plane and just how close they all were to being flung all over the place or sinking quickly or a number of other different outcomes.

On Chesley B. "Sully" Sullenberger

posted by Jason Kottke   Jan 16, 2009

A comment via email from my dad, himself a pilot, about yesterday's Hudson River plane crash:

This pilot ran out of altitude and airspeed but not ideas. He did a great job of flying, and as a CAPTAIN, he has shown why he wears the four bars!!!

This is an example of quiet professionalism, training, skill, and bravery. Our craft usually goes unnoticed many times a day, but today, we saw our best work!!!

I remember once going to collect my dad after he'd landed his plane in a farmer's field in an emergency. Of course, it was a much smaller plane — they're a lot easier to land without engines and glide well. That and he was accustomed to landing amongst the corn and hay...we had a grass strip cut out of the field behind our house that he used all the time.

Hudson River plane crash

posted by Jason Kottke   Jan 15, 2009

A US Airways plane bound for Charlotte just crashed into the Hudson River after aborting its takeoff from LaGuardia Airport. It's still sitting in the river, slowly sinking with people standing on the wings being rescued by ferries. Photos on Flickr.

Plane Crash

Update: Ferry rescue swarm. Very close-up photo of people standing on the wings waiting for rescue by Janis Krums.

Update: Here's a screenshot from a flight tracker showing the altitude of the flight....1800, 2800, 3200, 2000, 1600, 1200, 1300, 400, 300... The flight tracker has since taken the data offline.

Update: Reports are that everyone is OK. !!! Here's a nautical chart of the area in question showing the dept to be around 50 feet.

Update: Some media coverage at NY Times, CNN, and Gothamist. From the CNN article:

The plane approached the water at a gradual angle and made a big splash, according to a witness watching from an office building. "It wasn't going particularly fast. It was a slow contact with the water that it made," said the witness, Ben Vonklemperer. "It appeared not to have landing gear engaged. This was bigger than a puddle-jumper or sea plane. It was a silver aircraft and it basically just hit the water," Vonklemperer added.

Update: They're saying it's a bird strike...sounds like a bird got sucked into an engine? Here's another photo of people standing on the wings, waiting for rescue.

Update: Looks like they got everyone off and that the plane is sitting quite a bit lower in the water.

Plane Crash

Gothamist reports that the plane is being towed to Chelsea Piers.

Update: The NY Times has this helpful map:

Plane Crash Map

Also, an office mate (from Buzzfeed) just got back from checking out the plane and he said by the time he got to the river, the plane had past Christopher St. and when he left, it was pretty close to Canal St. and "moving amazingly fast". (thx, scott)

Update: Another Flickr set of the plane floating in the river.

Update: Maybe this is what the crash looked like?

Wikipedia notes that water landings where everyone survives aren't all that unusual, although this seems like a larger plane than most of the others noted.

In 1963, an Aeroflot Tupolev 124 ditched into the River Neva after running out of fuel. The aircraft floated and was towed to shore by a tugboat which it had nearly hit as it came down on the water. The tug rushed to the floating aircraft and pulled it with its passengers near to the shore where the passengers disembarked onto the tug; all 52 on board escaped without injuries. Survival rate was 100%

The flight details on FlightAware are back up. (thx, jesse)

Update: Here's a brief video of Ethiopian Airlines Flight 961 which crashed in the Indian Ocean after being hijacked and running out of fuel.

125 out of 175 passengers died.

Update: On the always-timely MetaFilter, a bird strike researcher has some interesting things to say.

The first recorded birdstrike happened in 1908 to Orville Wright, no more than a few months after the first powered planeflights.

Surely years and not months... (thx, mike)

A live shot on the TV just now (6:00pm) reveals that the plane is now down at the Battery and they look like they're trying to secure it or haul it out of the water (likely the former).

Update: A blogger at i'm not sayin, i'm just sayin mapped the plane's location leading up to the crash using the info from FlightAware. Does anyone want to bang out a quick 3-D version in Google Earth that shows altitude as well?

The dangers of precision air travel

posted by Jason Kottke   Dec 19, 2008

William Langewiesche wrote a long piece for the January 2009 issue of Vanity Fair about the September 2006 collision of a Legacy 600 private jet and Gol Flight 1907 over the Amazon basin in Brazil. It is a tale of "a paradox associated with progress and modern times".

Navigational precision poses dangers not immediately apparent. In the Legacy, it was based on three systems. The first was an ultra-accurate altimeter, capable of measuring the atmosphere with such finesse that at Flight Level 370 it could distinguish the Legacy's altitude within perhaps five feet. The second was almost as accurate. It was the airplane's satellite-based G.P.S. receiver, a positioning system that kept track of the airplane's geographic location within a distance of half of its wingspan, and that, linked to a navigational database, defined the assigned airway with equal precision. The third was an autopilot that flew better than its human masters, and, however mindlessly, worked with the altimeter and G.P.S. to keep the airplane spot-on. Such capability is relatively new. Until recently, head-on airplanes mistakenly assigned the same altitude and route by Air Traffic Control would almost certainly have passed some distance apart, due to the navigation slop inherent in their systems. But this is no longer true. The problem for the Legacy was that the Boeing coming at them on the same assigned flight path had equipment that was every bit as precise.

Interesting throughout, it becomes downright gripping about 2/3rds of the way through. The interplay between and the eventual reversal of the pilot and co-pilot of the Legacy is fascinating.

Update: Joe Sharkey, who was on the Legacy jet when it collided with the 737, doesn't like Langewiesche's article very much, calling it a "journalistically disgraceful article".

I'm not a pilot but my dad was and I flew all the time with him when I was a kid. I know what Sharkey is talking about when he says that flying a plane is not like driving a car; once you get in the air and are pointed in the right direction with the autopilot on, there's not a whole lot the pilot is required to do. But in my reading of the article, I don't think Langewiesche was saying that the two Legacy pilots in particular were screwing around or negligent. They were acting pretty much how any other two pilots in the same situation might act. Langewiesche's point seems to be: the experience of flying a plane like the Legacy, with all the technology that's there to help pilots — good and bad — do their jobs, might actually be made worse and more dangerous by that technology. Also that, as he stated at the beginning of the article, there were a whole lot of different decisions and non-decisions that converged to make that event happen...a huge pile of bad luck.

As for not talking to any of the people on the Legacy for the article, I don't think that's as significant as Sharkey asserts. Everyone who was aboard the Legacy jet that day is likely feeling pretty defensive about the whole thing given the intense reaction against them by the Brazilian government, the pilots doubly so given that they're involved in a lawsuit. A prudent journalist would rightly be worried about the veracity of a narrative offered up in these circumstances, almost two years after the fact. Instead, Langewiesche chose to rely not on opinions and recollections but on the available data — the cockpit voice recordings, air traffic control records, etc....how people actually behaved in the situation, not how they say they acted or what they thought about it. Put it this way: if Sharkey and Langewiesche were to write competing books about the collision, the former based on extensive interviews with those involved and the latter based only on the available evidence, neither would be much closer to "the truth" than the other. (thx, scott)

Paper plane contest

posted by Jason Kottke   Oct 21, 2008

Upcoming: paper plane contest in NYC on November 1. (via cory (nice portal!))

Airport security theater

posted by Jason Kottke   Oct 17, 2008

I don't know if this is sadly hilarious or hilariously sad. Jeffrey Goldberg took all sorts of crazy stuff through airport security — "al-Qaeda T-shirts, Islamic Jihad flags, Hezbollah videotapes, inflatable Yasir Arafat dolls (really), pocketknives, matches from hotels in Beirut and Peshawar, dust masks, lengths of rope, cigarette lighters, nail clippers, eight-ounce tubes of toothpaste (in my front pocket), bottles of Fiji Water (which is foreign), and, of course, box cutters" — and almost nothing was ever taken away from him or was a source of concern for airport security personnel.

We took our shoes off and placed our laptops in bins. Schneier took from his bag a 12-ounce container labeled "saline solution."

"It's allowed," he said. Medical supplies, such as saline solution for contact-lens cleaning, don't fall under the TSA's three-ounce rule.

"What's allowed?" I asked. "Saline solution, or bottles labeled saline solution?"

"Bottles labeled saline solution. They won't check what's in it, trust me."

They did not check. As we gathered our belongings, Schneier held up the bottle and said to the nearest security officer, "This is okay, right?" "Yep," the officer said. "Just have to put it in the tray."

"Maybe if you lit it on fire, he'd pay attention," I said, risking arrest for making a joke at airport security. (Later, Schneier would carry two bottles labeled saline solution-24 ounces in total-through security. An officer asked him why he needed two bottles. "Two eyes," he said. He was allowed to keep the bottles.)

So hard to pick just one excerpt from this one...it's full of ridiculousness. I don't care how many blogs the TSA launches, this is a farce. (thx, anthony)

TSA Communication Plates

posted by Jason Kottke   Oct 03, 2008

Evan Roth has been putting metal plates with messages and symbols cut into them into his carry-on luggage when he goes through security at the airport.

Here's Roth's idea, which he calls "TSA Communication" and tells me has already made it through three trial airport runs: Take a metal plate, stencil and cut out a message — words or an image — place the plate at the bottom of your carry-on bag, and watch what happens as the TSA employee operating the airport X-ray machine notices ... or doesn't notice.

So far, he's used plates with outlines of the American flag, a "NOTHING TO SEE HERE" message, and something he calls The Exact Opposite Of A Box Cutter, a plate with a box cutter shape cut out of it.

Flight pattern maps

posted by Jason Kottke   Oct 03, 2008

A map of the world showing a simulation of all of the air traffic in a 24-hour period. Here's a higher-quality video. Like Aaron Koblin's Flight Patterns videos, only not just covering North America.

How to land a 747

posted by Jason Kottke   Sep 26, 2008

A checklist for landing a 747, presumably in a emergency.

1. Get on the radio, and tell whoever's listening that you are landing a 747.

Emirates' Airbus A380

posted by Jason Kottke   Aug 06, 2008

Photos and video of an in-flight tour of an Emirates Airbus A380, a passenger jet that can be configured to carry more than 850 passengers at a time. This particular plane had room for 399 economy, 76 business class, and 14 first class passengers (ensconced in suites, not just seats). There was a bar, showers for first class passengers, video cameras on the tail, nose, and underside of the plane that you can watch during the flight, and a relatively soundproof cabin (even during takeoff). (via capn design)

Old airline menus

posted by Jason Kottke   Aug 04, 2008

A large collection of old airline menus. The collection is poorly organized but worth poking through (check out Air France and Pan Am). Tracked this down after reading this short piece in the Times about a private menu collection, complete with a tiny image of some menus that's barely worth the effort of clicking the link.

The first plane crash

posted by Jason Kottke   Jul 29, 2008

The first death of an airplane passenger occurred nearly 100 years ago.

It was Sept. 17, 1908. Orville Wright was showing off a new "aeroplane" at Fort Myer, Va., for about 2,000 people, including Army brass. He took up a 26-year-old lieutenant in the Army Signal Corps, Thomas E. Selfridge, "an aeroplanist himself," according to the report in this newspaper. Contemporary accounts vary, but the pair apparently made three and a half successful circuits at an altitude of about 75 feet, before a propeller split and hit other parts of the plane, causing it to crash. Orville was badly hurt.

First Plane Crash

From the NY Times account of the crash on Sept 18, 1908:

The aeroplane has made three complete circuits of the big parade ground and was dashing around a curve at the far end of the field on the final lap of its fourth when the propellor blade broke. It snapped short off close to the shaft and was hurled sixty feet away.

The aeroplane seemed to tip sharply for a fraction of a second, then it started up for about ten feet; this was followed by a short, sharp dive and a crash in the field. Instantly the dust rose in a yellow, choking cloud that spread a dull pall over the great white man-made bird that had dashed to its death.

$50 airline

posted by Jason Kottke   Jul 01, 2008

Almost everything on David Owen's airline costs $50.

Laughing out loud at anything in any movie, whether it is playing on the cabin system or on your own DVD player, is fifty dollars per incident. Asking me to turn off my reading light so that you can see the screen better: also fifty dollars.

If you and your spouse are dressed almost identically, or if you are carrying your passport in a thing around your neck, or if you are wearing any form of footwear or pants that you clearly purchased specifically to wear on airplanes, or if you make it obvious (by repeatedly turning around and talking to passengers in seats not adjacent to yours) that you are travelling with a group, the charge is fifty dollars.