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As the coronavirus outbreak means more and more people are avoiding air travel, airlines have been forced to run empty or near-empty 'ghost flights' in order to hold onto coveted airport slots.
- A ‘slot' is simply the permission of the airport operator for an airline to land a plane (and then take off – each slot is effectively a landing/take off pair). This gives not just the right to land the aircraft, but also to use all necessary airport services and infrastructure.
- The Worldwide Airport Slot Guidelines (WASG), provide the industry with a single set of guidelines for airport slot management and allocation. The slot planning process is the essential back bone to allow the industry to plan operations to the world's most congested airports, avoiding what would otherwise be chaos.
- During landing we want high lift and high drag, so the flaps and slats will be fully deployed. When the wheels touch down, we want to decrease the lift (to keep the plane on the ground!), so you will often see spoilers deployed on the top of the wing to kill the lift. Spoilers create additional drag to slow down the plane.
- GD&T - Profile Tolerancing PMPA Technical Conference Rapid Response to Make the Cut. Corona, California. Grand Rapids, MI.
In our previous article (see 'What's the Difference Between VME and OpenVPX?'), we laid out the differences between VME and OpenVPX. In this edition, we'll go into detail on the differences between VPX and OpenVPX.
The VPX (VITA 46) specification started around 2005 and was ratified in 2007 as the next generation of VME. However, to handle the speed and differential signaling of switch fabrics, a new connector was required—the MultiGig RT2. There are many benefits with VPX/OpenVPX, including:
• Inherent reliability of a fabrics-based approach
• High-speed MultiGig RT2 connector rated to about 10 Gb/s
• Standard SERDES data-rate options of 3.125, 5.000, and 6.250 Gb/s (with 10 Gb/s and beyond becoming more popular)
• Defined areas for control plane, fabric plane, management, etc.
• Options for system management per VITA 46.11
• Fully tested and rugged differential connectors
• Guide pins on the backplane for easy blind-mating
The architecture is primarily used in defense and aerospace applications, but has found application in some test-and-measurement, research, and other markets. VPX was rapidly adopted by many of the previous users of VME/VME64x architectures. Since it utilizes the same 3U or 6U Eurocard form factor as VME/VME64x, with 160-mm-depth boards, most of the existing mechanics could be employed.
Although most of the 19-in. rackmount chassis and ATRs could be leveraged, the backplane would be completely different. Also, power requirements typically are higher, which in turn often requires more challenging cooling solutions.
As VPX grew, it became clear over time that the flexibility of the specification was less of a virtue than a serious problem. With the variances of signaling (single-ended, x1, x2, and x4, etc.) and the routing options of the various topologies, it was extremely difficult to ensure interoperability across multiple vendors. This feature is a significant aspect of an open-specification solution!
Enter OpenVPX
To address those interoperability issues, the VITA 65 specification for OpenVPX was introduced (ratified in 2009). In short, OpenVPX created profiles (routing classifications) so that vendor A's boards will talk to vendor B's boards in vendor C's backplane/chassis solution.
OpenVPX also defined the 'planes' in the specification (control, data, expansion, management, and utility planes) that grouped different types of signals/functions. Then, OpenVPX defined the signal types in 'pipe' classes, which include ultra-thin pipe (x1), thin pipe (x2), fat pipe (x4), and double fat pipe (x8) as the principal groups as well as a couple of others.
To ensure interoperability, OpenVPX created profiles of 3 categories—the Slot Profile, the Module Profile, and the Backplane Profile.
The Slot Profile defines the connector type and provides a physical mapping of ports onto a given slot's backplane connectors. Figure 1 shows a Slot Profile of a slot in a 3U VPX backplane.
The Module Profile is a physical mapping of ports onto a given module's backplane connectors. This includes any protocol mapping to the assigned port(s). For example, Table 1 shows a 3U payload module with eight ultra-thin pipes with options for PCIe Gen 1 or Gen2. The last digits (16.2.9-1 or -2) refer to the location in the specification where there's more detail. The (-1, -2, -3) refers to the speed options, such as 2.5 Gbaud/s, 5.0 Gbaud/s, etc.
The Backplane Profile shows a physical definition of a backplane implementation and the topologies used to interconnect them. It describes which Slot Profiles are used and the speed options of the backplane. See the backplane profile (BKP3-DIS05-15.2.13-1) in Figure 2 and Table 2 (where BKP3 = 3U backplane; DIS05 = distributed topology, 5 slots; 15-2-13 = location of more details in the specification; and-1 = speed of 3.125 Gbaud/s).
Figure 3 shows a photo of the backplane with the above configuration. The other options for the backplane size is 6U and the topology can be also be CEN for Centralized or HYB for Hybrid. Other standard speeds are 5.0 Gbaud/sec and 6.250 Gbaud/s. Note that the industry is already moving to 10 Gbaud/sec speeds and above. So, putting this all together, we can ensure the right types of signals/protocols are defined for a slot and which Slot Profiles can be accepted by the backplane.
OpenVPX added a couple of other minor changes to the backplane. This includes redefining two reserved P0/J0 signals Aux_Clk (+/-), redefining the Res_Bus signal to GDiscrete, and adding one P1/J1 single-ended utility signal of Maskable Reset. The Aux_Clk and GDiscrete pins were previously bussed anyway, so the change is negligible. The SysCon signal also became configurable with OpenVPX.
VPX, via the 46 specification, provided a new high-speed serial solution to embedded computing design. The specification provided vastly higher performance and reliability COTS capabilities to mil/aero and other applications. However, interoperability became a problem due to the lack of specifics in routing classifications and signal-type definitions. OpenVPX, via VITA 65 specification, provides profile definitions for the modules, slots, and backplanes so that systems will be interoperable.
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Have you ever found yourself sitting in an uncomfortable chair in the airport, or buckling up in the airplane itself, only to realize that everyone is speaking in some sort of code and you didn't get the memo?
Airport jargon can be extremely confusing, but if you learn a few of the basic meanings beforehand, then the airport shouldn't be too much of a foreign experience.
Air travel terms can be broken up into two separate categories: on the ground, and in the air. Let's start with lingo that you will hear while your feet are still on the ground.
ATC
The ATC is also known as the Air Traffic Control. They are in control of pretty much every aspect that goes into a plane's flight.
Area of Weather
If you hear the pilot announce that you are coming to an area of weather and that he has turned the fasten seatbelt sign on, this just means that there is a thunderstorm or heavy rain ahead. He will usually turn the plane to avoid it.
Approach
When you hear the pilot or crew talking about the approach, it means that the plane is beginning its descent for landing.
Airspace
The space over the land or sea area occupied by a certain state or country. A country's airspace is considered part of that country's territory and therefore subject to its authority.
Baggage
Luggage or other items passengers bring on the airplane. You can carry one piece of small baggage on the airplane, and this is called carry-on. Large baggage is kept in a special part of the airplane.
Baggage Area
The baggage area is the area of the airport that handles baggage carried by passengers. These often have several large moving belts. Passengers wait at the belt for their baggage to move to them.
Concourse
A broad, open area in the airport for the passage or assembly of people.
Concessions
Businesses inside the airport terminal are known as concessions. These usually sell food, drinks or retail goods such as magazines, books, or souvenirs to passengers.
Customs
Before you're allowed to enter the country, you have to go through customs where you will be met by a customs officer. The custom officer will check if you're carrying anything illegal into the country like firearms (guns), drugs, etc. The officer will ask you if you 'have anything to declare?' If you're not carrying any forbidden item, you should answer 'no.'
Direct Flight
When seeing the term 'direct flight' on your ticket, you probably think that will mean that your flight will take you directly to your destination without stopping, right? Wrong. Direct flight simply means that the flight number will not change, but in many cases your flight will indeed stop. You may even need to change planes completely.
Deplane
Deplane is just a fancy way of saying, get off of the plane and don't forget your belongings.
De-icing
Removing ice, snow, or frost, usually from aircraft and airfield pavements during snowy weather. This ensures safety and efficiency of operations.
Executive Lounge
A room or a dedicated area at an airport or hotel with comfortable chairs, a coffee bar etc for those travelling first-class.
Gatehouse
You have probably heard someone's name being called over the intercom, requesting that if they are in the gatehouse that they go to a specific point for whatever reason. The gatehouse is just another way of saying the boarding area where you are waiting for your plane to arrive.
Gate
In air travel, a gate is the entrance to a movable passage much like a tunnel or a bridge leading to the aircraft. This allows passengers to board the plane, and later get off at their destination.
Ground Stop
A ground stop is a procedure in which all aircraft are not permitted to take off or land at a particular airport. This usually takes place during severe storms, heavy air traffic, or sometimes, nearby terrorist attacks. This is a security measure put in effect to avoid accidents. In the event of a ground stop, outbound flights are delayed; incoming flights either circle around or are diverted to other cities. Passengers will be asked to wait in their aircraft (or at the airport) until circumstances improve.
In Range
If you hear them announcing that your flight is now 'in range' that means that the plane is in the process of landing, but hasn't touched ground yet. This announcement is to give you a heads up to get ready to board the plane, though how long it will take for the plane to actually land and be ready for passengers is never an exact science.
Jetway
Executive Lounge
A room or a dedicated area at an airport or hotel with comfortable chairs, a coffee bar etc for those travelling first-class.
Gatehouse
You have probably heard someone's name being called over the intercom, requesting that if they are in the gatehouse that they go to a specific point for whatever reason. The gatehouse is just another way of saying the boarding area where you are waiting for your plane to arrive.
Gate
In air travel, a gate is the entrance to a movable passage much like a tunnel or a bridge leading to the aircraft. This allows passengers to board the plane, and later get off at their destination.
Ground Stop
A ground stop is a procedure in which all aircraft are not permitted to take off or land at a particular airport. This usually takes place during severe storms, heavy air traffic, or sometimes, nearby terrorist attacks. This is a security measure put in effect to avoid accidents. In the event of a ground stop, outbound flights are delayed; incoming flights either circle around or are diverted to other cities. Passengers will be asked to wait in their aircraft (or at the airport) until circumstances improve.
In Range
If you hear them announcing that your flight is now 'in range' that means that the plane is in the process of landing, but hasn't touched ground yet. This announcement is to give you a heads up to get ready to board the plane, though how long it will take for the plane to actually land and be ready for passengers is never an exact science.
Jetway
A jetway is a specially designed movable walkway, much like a bridge or a corridor leading into an aircraft. This allows passengers to board or disembark a plane.
Knots
A knot is one nautical mile per hour (approx: 1.151 MPH).
Kiosk
An airport kiosk is an interactive, computerized device where people can get information or services. These are usually located throughout an airport terminal for easy access. A kiosk may be consulted about flight status, flight schedules or other inquiries. Some kiosks may be set up with a keyboard and mouse, while others may provide a user-friendly touch screen. Not all kiosks are computerized. Some are simply free-standing booths or tables manned by salespeople, where passengers can buy magazines, snacks or souvenirs.
Long-haul flight (N)
A flight that travels a long distance in one go for example a long-haul flight would be flying from New York to Sydney.
Nonstop Flight
This is the flight that you were looking for above. This flight will take you exactly where you want to go, without stopping or causing you to change planes and lose your comfortable position.
People Mover / Moving Walkway
A people mover, moving walkway (British term) or moving sidewalk (American term) is an automated mechanism that carries people across a distance of several meters. It's often utilized in airports and looks like a flat, horizontal escalator. Moving walkways are often very helpful for passengers carrying lots of luggage.
Pushback
Pushback is the procedure for pushing an aircraft backward and away from an airport gate, normally using vehicles called pushback tractors.
Ramp
Typically, a ramp is an inclined plane that allows transit between two areas that have different levels. In an airport, this word refers to a staircase with wheels, which is used to load or unload an airplane. The word is also used in sea travel, referring to an inclined walkway installed between the vessel and the port.
Runway
The part of the airport where airplanes take off or land.
Slot
The scheduled time for take-off and arrival by an aircraft.
Tarmac
The surfacing material used for airport runways, usually consisting of compressed stone or iron slag coated with tar. The term is short for 'tarmacadam'.
'Tarmacadam' is an improvement on a road-making method called macadamisation, developed by in Scottish road engineer John Loudon McAdam in the 1800s. Macadamisation basically involves layers of stone coated with a binder or cement; Tarmacadam uses a specialized tar for a flatter surface.
Transit Lounge
A room or designated area at an international travel airport where passengers wait for their flight to another country.
Take-Off
When an airplane leaves the ground, the act is termed as take-off.
Terminal
The main building of an airport that is used by passengers and cargo.
Tower
Definition Slot Machine
In an airport, the word 'tower' usually refers to the Air Traffic Control Tower (ATCT). This is a ground-based center that provides direction for aircraft, whether on the runway or in the air. From the towers, Air traffic controllers give instructions to pilots in the aircraft; these directions are for facilitating the flow of traffic, assisting pilots with relevant information, and for preventing accidents.
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