47

I grew up in a family hot air ballooning business, and while I haven't been involved in a few years, I can answer your question in two words: They don't! Taking Off As far as collisions go, the other answers have mostly addressed this: hot air balloons only control vertical movement, so with all the balloons experiencing the same wind, they'll move at ...


46

Admin stuff, emails, chat with a colleague if you are not alone on shift, read up on (ever changing) procedures, eat, read a book, make sure the coffee machine works, meditate, watch TV. Anything goes, really, as long as you keep an eye on the radar and stay close enough to hear the radio and answer the phone. Of course, this is all assuming that there are ...


36

The perspective on that photo makes it hard to tell, but it looks like many of the balloons are still on the ground. So it's not quite as chaotic as it appears. There is no direct horizontal control. All they can do is ascend or descend to catch the preferred wind. How do they steer those away from each other to avoid mid air collisions? For the ...


30

The balloons just float, there is no thrust so no wake etc. If there is a constant wind, all balloons have exactly the same speed. Only local phenomena can create differences in horizontal relative distances, such as: Wind gusts and wind direction changes Wind shear Local updrafts A local difference in wind speed will accelerate first one, then the second ...


27

The only reason for your flight to operate at such low altitude is because it is cheaper for them to do so. As you said it is due to weather, other route/altitude may not be available. They can cancel the flight but that is likely to be costly. They may have to find accomodation for you and crew until they can put you to the next flight. Sub-optimal flight ...


26

I used the playback function of Flightradar24 for the 18th at 23:00 UTC, and the amount of traffic above 10,000' (filtering by altitude) seemed very normal compared to other days. I'm baffled as to why they flew so low, but I can address your fuel question in some detail. The difference in fuel consumption is ~693 kg of fuel, and would cost an extra ~$415, ...


23

Traffic is fairly predictable. They operate with more personell during rush hour and with much less at night, so it rarely happens that a controller is idling. During peak times there are separate controllers for apron operations, clearance delivery, taxiing, takeoffs and landings, arrivals, departures and for each en-route sector. During slow times, a ...


16

It was because they could get there faster on a "TEC route." IFR flights are subject to congestion management at the ARTCC level, which means they have to wait their turn in line to be allowed into the airspace. That used to be done with holds (and still is in many other countries), but the US will slow down aircraft, reroute them or even delay takeoff to ...


11

While ATC's primary goal is to prevent collisions, it is also responsible for the efficient movement of aircraft through the airspace. That requires a strategic approach to managing air traffic to get aircraft from point A to point B safely and in a timely manner. The primary tool ATC uses is the flight clearance. If air crews follow their clearances ...


10

Think of the ATC system as the road network, traffic lights, road signs, and police. TCAS is a standalone device in your car that warns you the guy coming at right angles to the intersection in front of you is going to run the light and T-bone you. Whether you have such a device or not, it doesn't change how the traffic control system work. TCAS has ...


9

Pilots can request a particular runway approach course and landing but in a controlled environment they are at the mercy of ATC. At high traffic (read busy) commercial airports they are unlikely to get their request. As far as I know, shy of an emergency declaration you cannot insist on a non standard runway and expect to get it. At a quiet class C or D ...


9

As a general average, Chicago O'Hare (KORD) seems to do somewhere between 1.5 and 2 operations per minute (so roughly one takeoff or landing every 30-40 seconds). I based this on data from the FAA's Air Traffic Activity Data System - Terminal Operations report, and specifically looked at November 23 through November 30 of 2014 (17835 operations, over 8 days ...


8

Linear programming (LP) is an optimization method that finds the highest (or lowest) possible value of a set of linear equations given a number of linear constraints. There are a number of objectives in Air Traffic Management that may be described by linear equations. Runway throughput for example: twice as many aircraft can be seen as "twice as good". Or ...


8

With two runways, usually, one is dedicated to arrivals, and the other is dedicated to departures. That's the simplest way to handle separation -- only in-trail separation is involved. That's usually the way traffic is managed at Heathrow (LHR) and Dubai (DXB), two of the world's busiest two-parallel-runway airports. At Heathrow, when in a westward flow (...


8

Note that the Netherlands is a bit of a special case. Below FL245, Air Traffic Control is provided by Luchtverkeersleiding Nederland (LNVL, the Dutch Air Traffic Control) and Dutch Mil (Dutch military ATC). Until one year ago, the Dutch military operated from their dedicated air traffic control centre in Nieuw Milligen. Since January 2018, they are ...


8

How many private jets land at Heathrow airport per day? None! January 2018 movements, source: CAA Related: Where does an A-lister land when they waft in from paradise? Yes, Luton To try to explain why this absence of business planes at a large airport, its important to understand that private aviation in Americas and in Europe are not seen the same ...


6

TCAS is sort of a fallback, last-resort system used in case all else fails. TCAS works within the scope of what happens within the next minute or so, and will require the involved aircraft to perform fairly extreme maneuvers to avoid a collision. TCAS has one single purpose: to ensure that two (or more) aircraft that have already gotten much too close will ...


6

Definition There are two key performance indicators that are used to measure the key performance area 'airport capacity': Peak arrival [declared] capacity Peak arrival throughput. What is the capacity of 2 near parallel runways? It depends if the 2 runways are operated in mixed or segregated mode. For the US, the two active runway case average value (...


6

Separation minima in Europe are pretty much identical to the rest of the world, since almost all countries base their aviation regulations on ICAO recommendations. To summarize: The minimum vertical separation is 1000 ft. In theory, above FL290, the minimum is 2000 ft, but since all European countries have implemented reduced vertical separation minima (...


4

No. The holding pattern can have any inbound course, and any direction. The holding pattern course/direction, depends on departing/arriving traffic, and many other factors. London Heathrow has a clockwise and counterclockwise hold on the fix LYDD. Thanks to Pondlife for pointing LYDD out!


4

In Europe, the Network Management uses the Computer-Assisted-Slot-Allocation (CASA) algorithm in the Enhanced Tactical Flow Management System to allocate the departure slots. The CASA algorithm is a heuristic that follows the 'first-planned-first-served' principle and shifts departure timeslots of flights that would otherwise violate sector capacities. ...


4

When I was working at the FedEx hub in Memphis the pushback times were scheduled every six minutes from 1:48 to 4:00. That's 22 slots for well over 100 flights, so there were several scheduled in each slot. They were set up so only one aircraft in any particular section of ramp would be trying to push back at the same time. There would always be a queue at ...


4

It would not change the ATC system at all, since TCAS and ATC work on completely different levels and have vastly different purposes. We even have an ICAO recommendation clearly stating that ATC procedures should not be changed based on ACAS implementation: The planning of air traffic services and the determination of the level needed for these services ...


3

To avoid all the Class this and that stuff, just think of controlled (tower with a clearance required) and uncontrolled airports. If a controlled airport, the runway is assigned by the tower controller, normally based on the favorable wind. Normally, you use the runway assigned by the controller, unless you have a reason to use another one. Thing is, you ...


3

Commercial airliners generally fly IFR as such they do what ATC tells them to do. They are not free to chose their own path. The airway system in the USA and elsewhere on the globe stems from the pre-GPS era when VOR's and other ground based nav aids were the predominant method of navigation. Airways tend to be either between VOR's or between points you can ...


3

-RA is the METAR code for light rain. LOCIGS is low ceilings, and TSTMS is thunderstorms.* * Air Traffic Management Glossary of Terms (faa.gov).


3

The delays you mentioned are imposed by Eurocontrol to manage traffic flow all over Europe: Even when an aircraft is ready to depart, it may still be delayed by ‘flow management’ (ATFM). You may well hear that your flight is ‘waiting for its Air Traffic Control slot’ and this is explained in another article. In short, if there is a problem that will delay ...


2

Just to add some more insight here. The question of aerodynamics and size keeps being asked. It is for the most part not relevant. Balloons move slow, at the speed of the wind near the equator basically. They relatively quickly get up to speed. During events like this it may appear to be chaos to you from one photo, but it is not, the crews are ...


2

[Adapted from a comment I previously posted] I have an anecdote which bears on this, at least for the case of takeoff. In 1988 I was on a flight leaving O’Hare and the radio comms were on one of the audio channels while we waited to taxi. Among the traffic we heard was something which caused me a bit of concern: a pilot being told to use a runway he thought ...


2

That’s a typical alternate route to KBOS by sending them direct to FJC VORTAC thence routed eastward. I suspect the real reasons for this are reduction of traffic congestion for NYC arrivals by ATC. On lighter days, they’re typically given the ROBUC3 arrival into KBOS immediately after departure from KPHL.


Only top voted, non community-wiki answers of a minimum length are eligible