Gadling

Welcome to Gadling's feature, Plane Answers, where our resident airline pilot, Kent Wien, answers your questions about everything from takeoff to touchdown and beyond. Have a question of your own? Ask away!

Luke asks:

I happened to catch a show the other night about the oxygen generators used in planes. I know that this source of oxygen creates massive amounts of heat when in use. What are the precautions that are taken to insure that a generator will not accidentally activate during a routine flight and perhaps cause a fire? Plane Answers is awesome. Love Planes, but hate to fly.

Thanks for your time...

Thanks Luke.

I passed this question along to my friend Ed, in maintenance. He offers some pretty good insight into just how those oxygen generators work.

Here's his take:

Well, first off the oxygen generators are installed above your seat in the overhead bin, and the mask doors are held in place electrically.

Now there are two ways they can be deployed; one way is through a decrease in cabin pressure, and the second method is to use a switch in the flight deck.

When the masks are deployed you pull on the mask and this action starts the flow of oxygen.

As you pull the mask there's a lanyard or cable attached to a firing pin – when the cable is pulled out of its locked position the pin fires a primer, much like on a round of ammunition and this starts the chemical reaction with calcium carbonate which, when burned, produces oxygen.

Firing off the canister causes the temperature to reach around 500 degrees Fahrenheit, but the passengers are protected by the case around the canister. Of course by the time the canister has burned out the pilot will have brought the plane below 10,000 feet where there is no need for supplemental oxygen. As a side note, the canisters will burn about 30 minutes give or take a minute or two.

Thanks Ed! Great insight.

David asks:

Hi Kent,

Lovely post on the Paris Air Show, and it got me thinking. As a pilot in general, is there an airplane or class of airplane that you dream of flying?

Styggiti took this HDR shot at Kenwood, California. The tone mapping technique used isn't too unrealistic, and because of the wonderful detail and stunning sky, I think it deserves a spot in Gadling's Photo of the Day.

HDR photography combines three or more images that are shot at different exposures and combined using some sort of HDR software to create a rather stunning shot. Occasionally the pictures can look a bit too science fiction, but Styggiti managed to get just the right amount of detail in this picture of a winery in California.

Are you a Flickr user who'd like to share a travel related picture or two for our consideration? Submit it to Gadling's Flickr group right now! We just might use it for our Photo of the Day!

Welcome to Gadling's feature, Plane Answers, where our resident airline pilot, Kent Wien, answers your questions about everything from takeoff to touchdown and beyond. Have a question of your own? Ask away!

Darren from Engadget asks:

Hey Kent!

Just got back from a LIR -> ATL -> RDU trip, and I thought of a question. When the plane (we were on a 737) is just seconds from touching down on the runway, it feels & sounds like the plane suddenly accelerates. For a few minutes leading to landing, it feels like we're slowing down, and right before the rubber hits the road, there's like a small burst in speed, followed by touch down and then massive wind as I assume the engines are thrown in reverse to stop us.

So, what's that acceleration just before touch down for? Or am I dreaming? Thanks!


Hi Darren,

Nope, I'm sure you experienced this.

Occasionally if a pilot is a bit slow (say 2 or 3 knots below your 'target speed') they can add a small boost of power in the flare to cushion the inevitable thump of a landing. But it's really not a very good technique to use regularly.

And some pilots don't just use it when they're a tad slow, but they use it as a substitute for a finessed flare on every landing.

It can lead to a very 'flat' and fast landing. Touching down like this eats up a lot of runway unnecessarily and puts more wear on the brakes and tires.

You'll hear in this takeoff and landing video the instructor repeat "flare and squeeze" to the captain as he's about 30 feet over the runway. He's telling him to start his flare, or round out the glide path angle to allow for a smoother touchdown and to "squeeze" or pull the power back to idle before touching down.



And you're right, the noise you're hearing after landing comes from the reverse thrust mechanism which is simply a set of 'blocking doors' that divert the thrust out the sides of the cowl and forward, angled away from the engines.

The biggest orders of the Paris Air Show were racked up by Sukhoi, the Russian aerospace firm best known for its fighters.

The 98-seat airplane is the first to come from the country since the fall of the Soviet Union and is slated to compete with the new Bombardier CSeries and Embraer's E-Jets.

Sukhoi claims the operating cost of the Superjet 100 will be 10-15% lower than either of its competitors.

The airplane made its public debut at the 2009 Paris Air Show and racked up 27 firm orders with 17 options at the show, an impressive total considering the otherwise gloomy mood in Paris.

Carriers from Italy, Indonesia, Russia, Spain and Armenia have ordered the jet, bringing the total firm orders to 149 so far. It may be time for a U.S. carrier to take a look at this airplane as well.

Gadling was there for the public flying debut of the Superjet 100:

The Paris Air Show restricts access to press and industry professionals from Monday through Thursday, which would seem to make it the ideal time to visit the show, assuming you could get your hands on a pass.

Gadling editor Grant Martin and I managed to attend, hoping to see some of the latest innovations for future travelers. We caught the new Boeing 787 electronic window shade on video and watched the debut flight display of the Sukhoi Superjet 100 airliner.

Exhausted from the traveling that day, we decided to enjoy the perfect weather to catch the flying display on Wednesday. I even came back on Sunday to compare the differences in the show between the industry days and the general public weekend show.

Even though there are huge crowds on Friday, Saturday and Sunday, the overall mood is much more friendly, with a greater sense of excitement present. Just take a look at these two pictures of the show to see if you can sense the difference:



Shoot me if I ever attend an airshow in a suit:



There were just a few smiles during the week, but the crowd really seemed to be enjoying themselves over the weekend. No doubt the economy has been in the back of everyone's mind in the industry, while the general public attended the show simply to be entertained.

And entertained they were. Video after the jump.

Gallery: Paris Air Show 2009

Yesterday we showed you how passengers on the 787 will have it 'made in the shade.' When I first heard about the electrically dimmable window shade feature, I asked Randy Baseler, then VP of marketing at Boeing, whether this type of technology might find its way into the pointy-end of the airplane.

Randy explained back in 2006:

Here is what we can tell you at this point. The flight deck on the 787 does not currently have dimmable windows. The demands of the flight deck are different from those for passenger windows, as would be the technology involved. We're working hard on coming up with a way to do this in the flight deck, and we're looking at a solution that might be retrofittable.

So when I saw a 787 window on display at the PPG booth at this year's Paris Air Show, I just had to know. Will we finally be able to throw out our plastic stick-on shades or, worse yet, a newspaper, map or cabin safety briefing card? Pilots are desperately in need of dark shading on the sunny side of the airplane.

Boeing has in the past decade offered a sliding yellow shade that doesn't really block much sunlight, and there have been various plexiglass shades previously, but these only supplement the passenger safety briefing cards and newspapers we cram into the window to block us from the sun.

Mark Cancilla of PPG explained that there's a solar reflective coating on the 787 windows which would help reduce the temperature in the cockpit. He also pointed out the gold tint, caused by the thin-film gold that's needed for the airplane's anti-fog system.

If you've been following the development of the Boeing 787, you may have heard about the electronic shades on their extra-large passenger windows.

So far, we've had to imagine how effective this technology would be, knowing it would be over a year before the first revenue flight of the Dreamliner.

Luckily, we managed to find the PPG Industries booth at the Paris Air Show, and scored a demonstration of this signature feature of the 787 known as Alteos Interactive Windows.

We've all been on airliners with plastic shades that frequently become stuck between the interior panel above the window. Sitting in that seat can be torturous on a sunny day. Not to mention the scratches they produce on the plexiglass inner pane.

Boeing and the airlines have found that these mechanical window shades represent an added maintenance cost, and for that reason, these reliable electronic shades will be a standard feature on all Boeing 787s and possibly other airliners in the future.

Passengers will be able to control the windows through five different settings, which take about a minute and a half to go from full dark to fully bright, at least on the version we saw. While this delay is a limitation of the design, the gradual transition could be a nice feature for passengers sleeping nearby.

Mark A. Cancilla, Director of Commercial Transparencies at PPG gave us a demonstration:

Welcome to Gadling's feature, Plane Answers, where our resident airline pilot, Kent Wien, answers your questions about everything from takeoff to touchdown and beyond. Have a question of your own? Ask away!

Shane asks:

What are the official FAA regulations regarding passengers being up with the seatbelt sign on? On every flight, prior to the sign being turned off, passengers get up to use the washroom and rarely to do the flight attendants ask them to return to their seats. Is there discretion allowed here? Thanks so much for the knowledge and please keep it coming.

Hi Shane,

I answer a lot of these questions while on my crew rest break in the back of the airplane since it's impossible to sleep on the first break during the meal service.

I mention this because both times I read through your question the flight attendant came on with a reminder over the PA that the seatbelt sign was on and that she would appreciate it if the passengers who were up and about could please return to their seats. The irony gave me a chuckle.

She handled this in the way the FAA requires. If people are up with the sign on, flight attendants are required to make the passenger aware that the sign is on and that they should be seated with their seatbelts fastened.

But if you've really got to go, it may be necessary to ignore the sign. I didn't give you permission, and neither did she, but if you have to go, you have to go. Smile and say "I'll be careful. It's an emergency."

She's not required to force you into your seat, but she may continue to warn you of the sign. Just don't let it get to a point where you're ignoring a direct request from a flight attendant. There are specific rules against that.

Gadling's photo of the day today was taken by Sean Roskey, who managed to capture this shot of Gadling's editor, Grant Martin enjoying a tour of the 767 cockpit given by yours truly before heading off to the Paris Air Show.

Given Grant's near destruction of Virgin Australia's 777 simulator, we made sure he didn't touch anything.

Are you a Flickr user who'd like to share a travel related picture or two for our consideration? Submit it to Gadling's Flickr group right now! We just might use it for our Photo of the Day!

Welcome to Gadling's feature, Plane Answers, where our resident airline pilot, Kent Wien, answers your questions about everything from takeoff to touchdown and beyond. Have a question of your own? Ask away!

Caroline asks:

Can someone tell me why the pilot sometimes turns on the seatbelt sign but it's seemingly for no reason? I recently flew Dubai to London and he (or she) kept putting it on however nothing happened. Especially annoying as I needed the bathroom at the time?

Hi Caroline,

There are a couple of possible explanations for a seatbelt sign that turns on and off frequently.

Occasionally we'll get reports from airplanes in front of us warning of turbulence ahead. It's best to get the seatbelt sign on if we get a report like this to prevent any injuries to passengers standing in the aisle.

Deciding when to turn the sign on after experiencing some un-forecasted and unreported bumps can be a challenge. Some pilots don't mind turning the sign on and off as the conditions permit and some will turn it on, only to forget about the sign when the ride improves, thus making every passenger feel like a criminal for using the lavatory for the rest of the trip.



There are some pilots who are concerned enough about the liability involved when turning the sign off that they'll insist on keeping it lit for the duration of the flight. This actually creates a riskier situation since passengers will disregard the sign, even during periods of turbulence, completely eliminating the point in having a sign in the first place.

There's another explanation that might surprise you. Pilots have been known to get calls from flight attendants asking for the sign to be turned on so they don't have to deal with people becoming stuck in an aisle between their carts or otherwise getting in the way of the service.

And occasionally there can be a rather large group of people congregating around the galleys chatting it up. One of the ways to disperse this crowd had been to use the seatbelt sign. This isn't exactly what the sign was intended for, of course.