Plane Answers: Tapping into ATC communications, tracking aircraft and a 60 second takeoff rule?

by Kent Wien on

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!

Ronald asks:

Is there a site where you can listen to aircraft during approach and take off, and what is the site that the news media uses to show air traffic over the US?

Hi Ron,

Take a listen to the live audio feeds that LiveATC.net provides. Many of the controllers at New York’s JFK airport enjoy a large following because of this great service.

For real-time depictions of traffic, FlightAware.com is an amazing site that lets you view all the flights currently over the U.S. and Canada by city, airline, aircraft type or “N” number. Combine this with LiveATC and you’ve got a great view of what’s involved in getting around the country from a pilot or a controllers perspective.

If you’d like to listen to Air Traffic Control on your next flight, read on:
Tim asks:

On two recent flights on United, one of which was delayed in LGA for 3 hours due to weather, the pilot turned on the ATC station on one of the radio stations so we can listen. Two of the best flights of my life. I was up all night (was LGA-SFO) listening to ATC talk to our pilots as well as all the other pilots. What are the rules with this?

This is a unique service offered by United and their pilots on ‘channel nine’ of their inflight audio. I’m not aware of any other domestic carrier that offers this feature to passengers. You may not always hear it on every United flight either, because it’s entirely up to the pilots whether or not they turn it on. A visit to the cockpit to ask if there would be any way they could turn on the channel 9 audio for you might be helpful.

If you do enjoy this service, then please don’t critique the pilots on their radio work while you’re getting off the airplane. You wouldn’t want to encourage them to turn off the audio, now, would you? Give them a big thanks and let’s hope the feature spreads to other carriers. I know I wish we offered this at my airline.

Tim adds a second question:

What do the lights on the end of the wing indicate? I see red, green and others.

Those are navigation lights, just as you’ll see on a boat. Left is red, right is green and the tail light is white. They don’t flash, and they’re mainly to tell if an airplane is coming toward you or going away. The airplane also has white strobe lights, usually on the wing-tips and a red ‘anti-collision’ light on the top and bottom of the fuselage.

For landing, we have landing lights that illuminate the runway, turn-off lights for lighting up a taxiway during a turn as well as a taxi light, which is usually on the nosewheel strut and is used for taxiing of course.

Geoff asks:

I have heard that if a plane (irrespective of whether it is a small plane or a large one) does NOT takeoff within 60 seconds of starting it’s takeoff run it will NOT takeoff at all.

Well, Geoff, now you have me timing all of the takeoffs I’ve made this past week. Most have been in the 35 to 40 second range in the 757, which is an overpowered airplane. But this video of an Illyushun 76 shows just how long a takeoff roll can last. And another video taken from the passenger seat of an Airbus A340 might give you an idea of how it feels to be on such a long (54 second) takeoff run.

But I’ve never heard of a time limit for takeoff. I do remember that when flying a three-engined 727 on a two-engine ferry flight (without passengers), there was a requirement to reach 100 knots in the first 30 seconds or the takeoff would have to be discontinued.

And Geoff follows up:

I also have a question about the different flight levels that ATC gives out for an IFR flight. When ATC initially gives a plane its flight level it seems to be anywhere from a low altitude to a somewhat higher altitude. Are they made because that is the point where ATC will change to another station or are they given to allow for a more efficient use of gravity to speed up or slow down a plane? They often seem like arbitrary numbers however I’m sure there is a reason for them.

You’re close, Geoff. ATC does have different sectors, such as the low altitude center which extends to FL230 (23,000 feet). So pilots are often cleared initially to FL230, but they usually won’t have to level off at that altitude, since ATC will hand them off to a high altitude center controller who can clear the flight to a higher flight level in their area.

Leveling off before reaching the optimum cruise altitude costs fuel, so controllers try their best to give ‘unrestricted’ climbs if they can, traffic permitting.

Once the airplane is at its most efficient altitude, it will stay there until it burns off enough fuel to step up to the next most efficient altitude. These flight levels are usually even-numbered altitudes when traveling west, such as FL320, 340, 360 or odd when flying east. But ATC may assign a different altitude than planned, and it can be at a ‘wrong way’ altitude for a time if traffic warrants.

Do you have a question about something related to the pointy end of an airplane? Ask Kent and maybe he’ll use it for next Monday’s Plane Answers

Plane Answers: Single-engine taxi, engine-out flight and ATC confusion

by Kent Wien on

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!

Julie asks:

Recently on a short flight on a de Havilland Dash 8, I noticed as we were taxiing down the runway that only one of the props was spinning, and the other one appeared to be off. I have seen this on other flights with the same type of plane, and the first time I ever noticed it I almost thought they had forgotten to turn it on (which is really, really silly I know)!

I know you don’t fly this kind of aircraft, but I thought you might have an answer anyway. I can’t really ever see into a jet engine to tell if it is spinning during taxi, so I guess it is possible that this is something regular with all twin engine aircraft and I just never knew it? Thanks Kent!

HI Julie,

I used to fly the Dash 8’s little brother, the Twin Otter. Even then, when fuel was less expensive than today, we would taxi on one engine as often as possible to save fuel.

Jets do this rather frequently too, but as you said, it’s rather difficult to tell from a distance.

There are limitations, however. We can’t taxi on one engine when we’re too heavy or when we may have to climb a bit of a hill on a taxiway, or if the taxiway may be slippery due to snow or slush. Also, on some aircraft, we need to be sure that we can give a 2 to 3 minute ‘warm-up’ time for the shutdown engine before we take off. So short taxis usually are accomplished with two engines.
John asks:

On a recent A340-500 flight the right engine sounded as if it had trouble. The flight deck crew left the side light on for about two hours and then turned them on every 2 hours after that (this flight was from JNB to ZUR). I was just wondering if we really did have a problem. We have been on many A-340 flights and have not noticed any engine noise.

Can the A-340 fly on 3 engines?

It’s hard to know if there was a problem on your flight, but you can be assured that if there were any indication of an engine issue, such as high vibration, oil loss or over-temperature, the crew would have shut the engine down.

All airliners are certified to fly with at least 50% of their power lost. So on an A340, that means any two engines could have been shut down and the airplane would still fly. They might have had to descend to a lower altitude, but they could still stay in the air.

The light you saw was a wing inspection light, used mainly to see if any ice was building up on the leading edge of the wing. It’s also used, along with all the other lights on the airplane, as an enhancement to the “see and be seen” philosophy when in the vicinity of the airport while on approach.

I’ve ridden in the back of a 737 while pilots were taking their checkrides. One engine was pulled to idle throughout much of this training and I was rather surprised to discover just how difficult it was to tell from the passenger cabin when we were flying on one engine.

While it’s never routine to have to shut down an engine in-flight, an engine failure on a four-engine aircraft is far from catastrophic.

Rishi writes:

I was wondering if you could explain to me the following two questions, please. First, why is that when I listen to ATC talk to pilots that one or both of the parties speak reasonably slowly, and understandably, but then, a moment later, they talk so darn quickly and un-intelligibly?

Second, given that ATC talks really fast at times, how do you pilots ever get to understand what they say? I’m quite surprised because I hardly ever get to catch the name of the airlines when the controller speaks so quickly. Please explain how you get used to this. . .

Hi Rishi,

There are times when pilots have to “read back” instructions from ATC. Those read backs are often spoken rather quickly. Complicated instructions that aren’t routine in nature are spoken much more clearly. So if the phrase is something that’s expected, such as a clearance for an approach or landing, clarity often suffers.

For an example, take a listen to www.liveatc.net and click on one of the audio streams of your favorite airport. After a while, you’ll notice the controllers giving nearly the same instructions to each airplane as they clear them for the approach. It might take an understanding of instrument flying to grasp what’s being said, but you’ll get the idea.

My favorite feed is from Caracas, Venezuela. Listen to the Delta and American flights going in there try to comprehend what’s being said, in between all the Spanish that’s spoken to the other aircraft.

Often it’s not the accent that’s so difficult to understand in a foreign country, but it’s the lack of awareness of the phrases used. I remember the first time I heard a French controller rapidly say “I-call-you-back,” instead of the more common, “Standby” that I was used to.

“Wha..?” I asked the captain.

I’ve now heard that phrase so many times, it doesn’t matter how strong the accent may be, I know what they’re saying.

LiveATC is a great resource for anyone who’s learning to fly or who might be working on an instrument rating.

Do you have a question about something related to the pointy end of an airplane? Ask Kent and maybe he’ll use it for next Monday’s Plane Answers feature.