This landmark announcement marks the latest development in what has been (for the most part) a momentous success story for the US planemaker.

With the latest incarnation of the type heading towards an entry into commercial service in 2025, 精东影业 looks back on almost 60 years of the Boeing 737 family.

We will examine the various models that have featured in the 737 family range over that time. We will discover which variants have been the most successful, as well as the models that have not sold so well.

With a staggering 17,000 examples of the Boeing 737 having been produced since 1967, and with more rolling off the production line daily at Boeing精东影业 assembly plant in Renton near Seattle in the US state of Washington, there is no sign of the type精东影业 popularity waning any time soon.

With other commercial airplanes such as the Airbus A320 and the Embraer 190-E2, and more recently the Chinese-produced C919 also entering the fray, competition in the narrowbody twin-aisle aircraft market remains higher than ever.

So what is it that has made the Boeing 737 family the enduring success story that it has become, and what does the future hold for Boeing精东影业 highly popular and seemingly ageless twinjet?

Overview  – The birth of a legend

The first flight of a Boeing 737 took place in April 1967. Therefore, and quite remarkably, 2024 will mark the 57th anniversary of this momentous event. Quite an accomplishment when you consider that humans only mastered the art of controlled powered flight 120 years ago!

The fact that the 737 remains in production after nearly six decades is a testament to its reliability, versatility, and its long-lasting appeal among operators and passengers alike,

With 17,213 of the type ordered to date, it would be fair to say that the 737 has been a huge success story for Boeing. Indeed, the aircraft has become one of the most successful aircraft ever made (in terms of numbers sold), surpassed only by the likes of the ubiquitous Cessa 172 (with over 45,000 built) and matched by the utilitarian Douglas DC-3, of which 16,000 examples rolled off the production line.

With every variant of the 737 that has been developed, each has offered technological developments and changes in capacity and capabilities that keep airlines ordering more.

It is that ability that the 737 has developed that means it offers the right solution in its size category to airlines time and time again. And with new orders for the type being made all the time, there is no shortage of customers wanting the type in their fleets.

Development of the iconic passenger airliner

Having already enjoyed commercial success with its 707 and 727 models, Boeing realized that there was a gap opening up at the lower end of the scale for a versatile commercial passenger plane.

As demand for air travel soared with the dawning of the jet age, increasing numbers wanted to take to the air. But while the 707, with its four-engine configuration, had captured the market for long-haul flying, and the 727 was perfectly sized for the longer US domestic trunk routes, airlines called for a smaller jet capable of fulfilling a variety of missions.

Using technological know-how built up through the development of these predecessors, Boeing designed an aircraft capable of taking on the smaller new entrant jets such as the British Aircraft Corporation 1-11, the Douglas DC-9, and to a lesser extent, the French Sud Aviation Caravelle.

However, spotting inefficiencies in the designs of these three types, Boeing decided to take a different path. This decision would ultimately serve the company well over the following six decades while each of the other designs would eventually falter.

Mounting the two engines under a relatively low wing rather than mounting them on the rear fuselage near the tail would create several benefits for operators. It reduced ambient cabin noise for passengers and reduced the height of the landing gear length, leaving the engine nacelles closer to the ground to facilitate easier inspection and maintenance.

Of crucial importance, however, was that wing-mounted engines allowed for a wider cabin meaning that airlines could seat passengers in a six-abreast configuration, rather than the five-abreast offered by its competitors. Ultimately this would change the entire operational economic landscape of the Boeing 737, giving it a huge advantage over its rivals.

Wing-mounted engines also meant that passengers could be loaded and unloaded from both forward and rear doors. This led to speedier turnaround times, resulting in higher aircraft utilization and increased return on investment.

Introducing the Original 737 family

The launch model of the 737 family was the 737-100 series. The design process for this new type was started in May 1967, with the program being given the formal go-ahead in November of that year.

In February 1965, the first orders for Boeing精东影业 latest product were received from Lufthansa, followed by United a month later. With firm orders already placed, the prototype 737 took to the air for the first time on April 9, 1967. The 100 series could seat up to 115 passengers in a single-class configuration.

Fairly quickly into the design process, it was established that airlines needed a slightly larger passenger payload than the 737-100 could offer. This led to Boeing developing a lengthened version of the base model which became the 737-200.

Two sections were added to the fuselage: a 36-inch (90cm) section forward of the wing and a 40-inch (100cm) section aft of the wing, giving a maximum capacity of 130 passengers with a 28-inch seat pitch.

All other dimensions between the two variants remained the same. On April 5, 1965, the -200 series was launched with an order for 40 from United Air Lines. Development and production of the two series ran simultaneously.

Certification from the Federal Aviation Administration for both new models was achieved in December 1967. The first commercial flight of the 737-100 took place in February 1968 with Lufthansa, while the 737-200 had its first revenue service with United in April 1968.

In the end with the 737-200 offering better economics than its smaller sister, just 30 series 100s were built, with 30 going to Lufthansa, five to Malaysia Airlines, and two to Avianca in Colombia, with the prototype being retained by Boeing. The last airworthy 737-100 flew its final revenue service for Aero Continente in Peru in 2005.

The -200 series faired far better than the shorter variant. In total, 1,114 of the type were built between 1967 and 1988.

Arrival of the Advanced 737-200

In April 1971, the first flight took place of the 737-200 Advanced. As well as incorporating certain modifications introduced on later -200s, the -200 Advanced included major wing improvements such as new leading-edge flap sequencing, an increase in the droop angle of outboard slats, the extension of the inboard Krueger Flaps leading to a significant increase in lift and a reduction of take-off & approach speeds for better short field performance.

From production line number 400, all subsequent 737-200s were built to the Advanced standard.

Other variants of the 737-200 were offered by Boeing during its production run. Convertible (or 鈥渃ombi鈥�) variants were built to carry either passengers or freight or in some limited cases, both simultaneously. A Quick Change (QC) variant was introduced later which allowed conversion between passenger and cargo configurations to be achieved within an hour with seats fitted on pallets that could be easily removed through the large forward cargo door.

Other versions of the 737-200 include several military variants. Designated the T-43A, 19 were built for the US Air Force as navigation and multi-engine trainers, while others included maritime patrol, radar testbed, and avionics flying lab versions.

Enter the Classics: the Boeing 737-300/400/500

The 737-200 was succeeded in 1984 by the 737-300. This was a much quieter, larger, and more economical aircraft and contained a host of new features and improvements over its predecessor. The new model was developed in part to meet the challenge being laid down by the European-made Airbus A320.

The new 737 model featured many aerodynamic, structural, cockpit, and cabin features that were developed by Boeing for its new generation 757 and 767 models. The type also adopted newly introduced CFM International CFM-56 turbofans replacing the noisy and fuel-thirsty Pratt & Whitney JT8Ds of the original models.

Other changes included a full revamp of the flight deck instrumentation. New equipment included a new Flight Management System with a fully integrated Digital Flight Control System, autothrottle, Flight Management Computer, and dual laser gyro Inertial Reference System, plus the fitting of Electronic Flight Information Systems CRT displays.

One of Boeing精东影业 objectives for the new model was to retain a high degree of commonality with the 737-200. This provided savings for airlines in terms of maintenance, spares, and tools for existing 737-200 operators.

Also, the aircraft was designed to have similar flying qualities, cockpit arrangements, and flying procedures to minimize training differences and permit a common type rating between the -200 and -300.

The first flight of the 148-seat 737-300 took place in February 1984 and 1,113 were built in total.

The Boeing 737-400, which first flew in February 1988, was a further stretch of 2.8m (9ft 6in) over the -300 to provide a higher passenger load. Given the increased fuselage length of 36.45m (119ft 7in) of the -400, a ventral tail skid was installed to prevent tail scrape damage on over-rotation.

Passenger capacity was increased to 174 on the -400. However, this required two overwing exits on each side of the cabin to comply with evacuation rules. In all, a total of 489 737-400s were built.

To satisfy customers of the original 737-200 who did not see a need for a larger model such as the 737-300, Boeing also offered a shorter version of the new Classics in the form of the Boeing 737-500.

The 737-500 (originally known as the 737 Lite or the 737-1000) is the shortest of the Classics. It combined the original length fuselage of the -200 but with the various improvements of the -300 and -400.

However, the economies of scale offered by the longer 737-300 meant that the -500 was the least popular of the Classics. A total of 388 -500s were built.

The last of the Classic series of 737s was a Boeing 737-400 (registered OK-FGS) which was delivered to CSA Czech Airlines on 25 February 2000.

The Next Generation 737 family

Deciding to fully update its best-selling airplane family to prepare for the 21st century, Boeing unveiled its 737-X program in June 1993. This was on the basis that Southwest Airlines agreed to purchase 63 new aircraft from a newly updated range. The new range eventually became known as the Boeing 737 Next Generation.

The model selected by Southwest was a refreshed 737-300 to be known as the 737-700. order from Southwest Airlines for the 737-300X. This became the 737-700, 22cm (9in) longer than the original 737-300, and seating up to 149 passengers.

The Next Generation was designed to have 33% fewer parts than the Classics thereby reducing production time.

To satisfy the needs of existing 737 customers as well as attract new ones, the Nex Generation series initially featured three variants similar in size to the outgoing Classic family. While the -700 was similar in size to the -300 it replaced, the shortened -600 replaced the -500 while the -800 took over from the -400.

The first of the Next Generation models to fly was the -700 with the first flight taking place on February 9, 1997. The -800 variant followed on July 31, 1997, followed by the -600 on January 22, 1998.

On September 1, 1999, a significant milestone was reached in the Boeing 737 program when the Boeing 737-700 was certified for 180-minute ETOPS operations, meaning it could operate for longer over water and allow routes such as Honolulu to Los Angeles to be flown.

In 1998, a super stretched version of the 737-800 was launched to meet the demands of certain US carriers that wanted an aircraft that shared commonality with their existing 737 fleets but could carry more passengers. Consequently, the 737-900 was launched and the model first flew on August 3, 1999.

With almost all of the 737 Originals and Classics largely gone from the skies albeit with a dwindling number of exceptions, the Next Generation family has become the backbone of the 737 operating fleet nowadays. In terms of sales, the 737-800 model has by far been the best seller with 5,205 built to date (of all variants including passenger, cargo, combis, BBJ, and military derivatives).

The next bestseller in the Next Generation series is the 737-700 with 1,289 delivered. On the back of key orders from United and Alaska Airlines, the 737-900 (of all variants) sold relatively well with 565 delivered.

The 737-600, which was built to replace the poor-selling 737-500, did not fare well in the commercial market, selling just 69 examples.

While the 737-800 has become the mainstay of worldwide 737 operations today, it is also becoming popular in the freighter market with older examples being converted as they reach the end of their passenger-carrying life.

The arrival of the MAX

In 2006, Boeing began to discuss a successor for the 737NG. For a while, as the plane maker mulled the next step, it considered both replacing the 737 with a brand-

new airplane, or re-engining the 737NG with more efficient engines, and making other changes for a newer generation.

By the summer of 2010, Boeing still hadn’t made a decision, and analysts expected that it wouldn’t until the following year. Then, in December 2010, rival Airbus announced the A320neo family (neo = “new engine option”), a re-engined, more efficient version of its A320, the main competitor to the 737.

Boeing knew the A320neo was coming but was still taking its time to decide on the ideal, productive, and most sustainable solution to combat it. In spring 2011, the company was still leaning toward building a new plane, rather than re-engining the existing 737 airframe.

Then, W. James McNerney, Jr., Boeing’s CEO at the time, received a call from American Airlines’ chief executive, Gerard Arpey. Arpey reportedly said that his airline was close to a deal for hundreds of Airbus narrow-body aircraft, warning that Boeing had to be more aggressive and timely to win its business.

Until that point, American Airlines had exclusively purchased from Boeing for more than a decade. Desperate to win the order, Boeing ditched the idea of designing a whole new airplane (which could take up to 10 years to get in the air) and instead pivoted to placing new engines on the 737 to create another new generation of the workhorse.

It took a few months to finalize the design, but it wasn’t quite fast enough to prevent American Airlines from defecting. In July, the carrier announced its order for 130 A320ceo and 130 A320neo jets, with an option for 365 more. It also said that it would order 100 of Boeing’s not-quite-ready next-generation 737.

The launch of the MAX family

Just one month later, Boeing announced the 737 Max family, consisting of four differently sized models: the 737 MAX 7, MAX 8, MAX 9, and MAX 10. The design of the 737 MAX had a few appeals for both Boeing and, more importantly, the airline customers to whom it had to sell the planes.

As with the transition from the 737 Classic to the 737NG, the 737 MAX retained a great degree of commonality with its predecessors, meaning one pool of pilots and ground staff could work on both planes, with some supplementary training, rather than having to be certified on a new aircraft type.

Pilots ultimately were only required to take a brief tablet-based course, rather than training in a simulator, like they would for a new plane.

The fact that it was an existing, already certified airframe, which comprised the body and wings of the plane, only with new engines and avionics, meant that Boeing would not have to undergo the same lengthy certification process it would for an all-new airplane.

When the 737 MAX was announced, it already had a not-quite-firm order from American Airlines. By November 2011, Boeing said that it had 700 commitments.

Fast-forward almost exactly four years to August 2015: the first 737 MAX fuselage rolled off the factory line, and in December, the first plane 鈥� a 737 MAX 8 named “Spirit of Renton was finished. The plane was eventually delivered to Southwest.

On January 29, 2016, the MAX made its first test flight, performing without any unusual incidents.

Following a year of test flights and data-gathering, the MAX gained certification from the FAA in March 2017, followed by other global regulators later that month.

The first 737 MAX delivery was made on May 16, 2017, to Malindo Air, a subsidiary of the low-cost Indonesian carrier Lion Air. The first passenger flight took off on May 22, 2017.

Flight control issues and two MAX accidents

Two early accidents involving the loss of two 737 MAX 8s (Lion Air on October 29, 2018, and Ethiopian Airlines on March 10, 2019) were attributed to a new flight control system designed exclusively for the MAX family and eventually saw the whole worldwide fleet of MAXs delivered so far (230 aircraft) grounded.

Boeing’s desire for the MAX to retain commonality with the NG family is what eventually led to the two accidents.

The engines on the MAX were larger, positioned further forward, and higher up on the wing than the engines on the 737NG. That caused the plane to behave differently. For example, it could cause the nose of the plane to pitch upward in some situations, like low-speed flight, or flight with a high angle of attack when the plane is being flown manually.

To compensate, Boeing designed automated software called Maneuvering Control Augmentation System (MCAS), which would automatically activate to stabilize the pitch and nudge the aircraft’s nose back down “so that it feels and flies like other 737s.”

With that in place, the MAX could share the same type of rating as the 737NG, and pilots could fly the two families of 737 interchangeably, meaning airlines could have one pool of pilots capable of flying both planes.

Notably, however, Boeing did not include training on MCAS in the pilots’ manual, reasoning that the software would work in the background. The manual did include a discussion about the trim stabilizer, however.

MCAS would only activate when the plane was being hand-flown, meaning when the autopilot was off. The plane would have to be flying relatively slowly, and the nose would have to be pointing high enough, or the angle of attack would need to be high enough, to be at risk of causing the plane to stall.

Crucially, MCAS was designed to take effect when just a single sensor showed that the angle of attack was high. That meant that if one of the two sensors was damaged or faulty, it could activate.

Onwards and upwards

Since the issues involving the MAX accidents, and the type being grounded worldwide for around 18 months, the MAX has made a remarkable recovery. That said, CNN referred to the MAX grounding as “the most expensive corporate blunder ever.” Indeed, the whole affair was extremely damaging for Boeing and the airlines that had ordered the MAX.

Airlines sued Boeing for losses incurred. There were also extensive costs for repairs to the aircraft. Boeing estimates it incurred a direct cost of $20 billion due to the MAX grounding. This included $8.6 billion paid to airlines in compensation. This does not include compensation and legal liability for the crash victim’s families.

The grounding also took its toll on aircraft orders. Before this, the MAX was selling well. By January 2019, Boeing had recorded just over 5,000 orders for the MAX. Significant orders were lost through 2019 and 2020, though, during the type精东影业 grounding. In 2019, it lost 93 orders. And in 2020, 641 were lost. These figures included cancelations from both airlines and leasing.

However, since the MAX took to the air once again the program has gone on to great success and has carried on Boeing精东影业 legacy of building successful narrowbody jets.

At the start of 2024, the MAX series has sold 6,951 examples. The leading model, the 737 MAX 8 is running away with the lead having been ordered 5,160 times (including all variants including the 737 MAX 8200 high-capacity version). Next comes the yet-to-be-certified MAX 10 at 1,037 sales followed by the MAX 9 at 386.

The MAX 7 which is also still undergoing certification is following the Boeing 737 tradition of the shortest variant being the slowest to sell, with 368 aircraft ordered to date.

Versatility is the key to the 737精东影业 success

There can be no doubt that the Boeing 737 has become one of passenger air transport success stories. With almost 60 years of commercial service and with new aircraft being delivered almost daily, there is no sign of the 737s appeal waning any time soon.

Offering a range of variants from cargo aircraft to military versions, and long-range ETOPS models to the ultra-high density 737 MAX-8200 variant) the 737 family appears to have the narrowbody requirements of airlines covered, and as such, will continue to compete with the Airbus A320 family for many years to come.

IATA airport codes are commonly used by airlines and travel agents, while the ICAO system is听primarily used by air traffic control (ATC).听听

In this article, we will discuss airport codes in more detail, including their history, types and common usage. 

History of airport codes

The history of airport codes can be traced back to the 1930s when airlines began using two-letter codes to identify airports. However, this system proved to be insufficient as more airports were being built around the world and airports began to share similar two-letter codes.

It was around that time that ICAO was established as a United Nations agency in 1944 to support standardizing and regulating international air travel ever since.

A year later, IATA was founded in 1945 as a trade association for the world’s airlines. Today it plays a key role in the airline industry, developing industry policies and standards, providing training and consulting services, and managing the airline industry’s settlement systems. 

In the late 1940s, IATA introduced a听three-letter airport identification听system allowing for a greater number of permutations, and this is still in use today.听Similarly, following its creation, ICAO established Flight Information Regions, along with its coding system, to manage air traffic and simplify airport identification.

While IATA codes are primarily used for commercial purposes, such as ticketing and baggage handling, ICAO codes are used for operational and safety purposes, such as ATC and flight planning.

Naming conventions of airport codes

The ICAO精东影业 four-letter codes are assigned based on a standardized numbering system that provides information about the location and type of facility. The first letter of the code indicates the region of the world in which the facility is located, as follows: 

A: Africa 

B: Asia听

C: Europe 

D: Middle East 

E: North America 

F: South America 

G: Oceania 

The second letter provides more specific information about the location within the region, such as the country or region, while the third and fourth letters are assigned sequentially to identify individual airports or other aviation facilities within the same location. 

For example, the ICAO code for Heathrow Airport in London, England is EGLL. The 鈥楨鈥� in the first position indicates that the airport is located within Europe, while the 鈥楪鈥� in the second position identifies the specific country (in this case, the United Kingdom). The 鈥楲L鈥� in the third and fourth positions are assigned sequentially to identify Heathrow as a unique airport within the United Kingdom.听

In comparison, IATA codes are rather random. While some use three letters of the city where they are located (Las Vegas-Harry Reid听International Airport is LAS, Hong Kong International Airport is HKG), others follow national naming conventions or refer to the name of the airport itself (Paris-Charles de Gaulle Airport is CDG, New York-John F. Kennedy International Airport is JFK).

The code for Los Angeles International Airport, for example, was initially “LA.” However, as the use of three-letter codes became the norm, a new identifier was needed. To keep some consistency with the previous code, an “X” was added to the end, creating the now-familiar LAX code.

Europe airport codes

Europe has a wide range of IATA airport codes, with many popular cities having multiple airports. For example, London’s five major airports are:  

• Heathrow (LHR) 
• Gatwick (LGW) 
• Luton (LTN)  
• London City (LCY)  
• Stansted (STN) 

Codes for other popular European airports include: 

• CDG (Paris Charles de Gaulle) 
• FRA (Frankfurt Airport)听

• FCO (Rome Fiumicino) 
• AMS (Amsterdam Schiphol)听听
• BCN (Barcelona) 

International airport codes

Some international airport codes include: 

• JFK (John F. Kennedy International Airport in New York City) 
• LAX (Los Angeles International Airport) 

• ORD (Chicago O’Hare International Airport) 
• YYZ (Toronto Pearson International Airport), and  
• DXB (Dubai International Airport). 

Finding airport codes

Passengers can easily find their airport codes by checking their airline tickets, boarding passes, or baggage tags. They听can also be found on airport websites and in travel guides.

Additionally, there are numerous online resources that list them, such as the , which has a comprehensive list of all airports and their corresponding codes.听

A microburst is a weather phenomenon that can pose a significant danger to aircraft during takeoff and landing, as well as impact on general aviation safety in general. A microburst is a sudden, powerful downdraft of air that occurs when a thunderstorm’s updraft reaches its maximum intensity and collapses. As the downdraft hits the ground, it spreads out in every direction, creating a burst of wind that can be incredibly strong and consequently difficult for aircraft to handle. 

What are the main types of microbursts?

Wet microbursts occur when rain falls through a dry layer of air, causing the rain to evaporate rapidly and cool the air. This cooling effect makes the air become denser, and as a result it sinks rapidly towards the ground, creating a strong downdraft. The strength of the downdraft can be significant, reaching speeds of up to 150 mph. 

The temperature and humidity of the air influence the formation of wet microbursts. For wet microbursts to form, the air needs to be dry at lower altitudes, and there must be a moist layer of air above it. Wet microbursts are most common in areas with low humidity, such as deserts. 

On the other hand, dry microbursts occur when there is no rain and a column of sinking air that evaporation has cooled creates the downdraft. This type of microburst is typically more challenging to detect because there are no visible signs of precipitation. The sinking air creates a strong downdraft that can be as powerful as a wet microburst, reaching speeds up to 100 mph. 

Dry microbursts are most common in areas with high humidity, where the evaporative cooling effect is more pronounced. They can be particularly dangerous because they are more difficult to detect and predict than wet microbursts.  

What are the main stages microbursts go through? 

The downburst stage is the first stage of a microburst, caused by a sudden descent of air towards the ground. During this stage, the descending air can reach speeds of up to 150 mph. The downburst stage is the most dangerous one for aircraft, because it can cause a sudden loss of altitude and airspeed. Pilots need to be especially vigilant during this stage and take quick action to maintain control of their aircraft. 

The second stage of a microburst is the outburst stage. This occurs when the descending air hits the ground and spreads out in all directions, creating strong gusts of wind. It can produce gusts of wind of up to 45 knots, which can create severe turbulence and affect the stability of an aircraft. Pilots must be prepared to contend with strong gusts of wind during this stage and to take measures to maintain control of their aircraft. 

The third and final stage of a microburst is the cushion stage. During this stage, the descending air rebounds back upward, creating turbulence. This can cause sudden changes in altitude and airspeed, which can be challenging for pilots to manage. Pilots must be alert during this stage and take necessary action to maintain a safe and stable flight path. 

Dangers associated with microbursts and how pilots respond to them

Microbursts have the potential to be incredibly dangerous for aircraft. They create sudden, strong gusts of wind that can cause an aircraft to lose altitude rapidly, or even crash. The wind shear associated with microbursts may cause sudden changes in airspeed, which can be difficult for pilots to control. If they encountered a microburst during takeoff or landing, pilots might not have enough altitude or airspeed to recover, making it a critical situation. 

To avoid the dangers of microbursts, pilots rely on weather radar and visual cues to detect potential areas of turbulence and avoid flying through them. Pilots are trained to react by increasing engine power, adjusting their flight path, and taking other evasive maneuvers to avoid the strong downdrafts involved. It is essential for pilots to receive proper training on microbursts to ensure they can react appropriately and safely in such a situation. 

Aeromexico Flight 2431 

On February 24, 2019, a tragic accident caused by a microburst occurred involving Aeromexico E190 flight 2431. It resulted in a loss of control by the pilots and ultimately a fatal crash. While the sudden downward wind from the microburst was a significant factor, it wasn’t the only cause. The pilots were also responsible for lacking situational awareness which contributed to the disastrous outcome. 

Bad weather & unauthorized training caused Aeromexico E190 crash

• Civil Aviation

byClement Charpentreau

2019-02-26

A transponder is an electronic device found on aircraft that helps to identify them on air traffic control (ATC) radar screens. It is an essential component of the secondary surveillance radar system (SSR), without which the air traffic control radar beacon system cannot display secondary information.  

Transponders allocate a unique transponder code to each aircraft in controlled airspace, enabling air traffic control officers to easily identify specific planes on a busy radar display using SSR. 

The transponder gets radio signals from ground-based interrogators, which are radar beacon transmitter-receivers, and responds by producing a particular pulse or group of pulses that are only sent to the interrogators that match the transponder’s set mode.听

Historical background

The history of transponders dates back to their initial use in military applications. Military authorities developed the concept of an Identification Friend or Foe (IFF) system, enabling them to identify friendly aircraft by transmitting a coded signal interrogated by military radar, helping with command and control missions.  

These devices have become important tools for modern civilian aviation, allowing air traffic controllers to monitor and track aircraft movements more accurately and efficiently.听

Transponder types

The different types of transponders are A, C, and S.  

• Transponder A sends a code back to ATC. 
• Transponder C sends a code and altitude information or flight level data to ATC. 

• Transponder S sends code and altitude information while also receiving and reporting data to other S transponders. 

All transponders must have the capability to generate a four-digit code using the numbers 1 to 7, which provides 4,096 possible codes. 

Mode C transponders are required for flying in busy areas of controlled airspace, including entering class A airspace, flying within 30 nautical miles of primary airports in class B airspace, or flying in or above class C airspace. 

In the entire continental United States, it is a requirement for all aircraft flying at or above 10,000 feet mean sea level (MSL), not including any airspace below 2,500 feet above ground level (AGL), to have Mode C transponders installed. 
 

In accordance with Regulation (EU) No 1207/2011, all flights operating as general air traffic within the European Union and following instrument flight rules are mandated to be equipped with mode S transponders.听

Ident features and regulations

Transponders have an “IDENT” feature that enables aircraft radar response to be easily distinguishable when the IDENT switch is triggered in the cockpit by the pilot. But this should only be done upon request by ATC. The IDENT feature allows the transponder to send a signal that causes it to flash on the radar screen. 

Federal Aviation Administration (FAA) regulations mandate the testing of transponders every 24 calendar months for use in controlled airspace.  

Each transponder has four fundamental functions: On, ALT, SBY, and Off.  

• Turning the transponder on initiates the “On” function. 
• The ability to transmit altitude information is activated through the “ALT” function. 
• The 鈥淪BY鈥� function is a mode on a transponder that turns off the transmission of information while still providing power to the unit.  
• Turning the transponder off can be accomplished with the “Off” function.  

The SQUAWK feature is the most fundamental function of a transponder, as it allows for the transmission of an encoded signal with a four-digit code. SQUAWK is given to the pilot by ATC when he contacts them for flight clearance.听

Transponder codes for emergencies

The international agreement uses code 2000 for aircraft that have not received an assigned transponder code by ATC, though in some parts of Europe, 7000 is also used.  

Other emergency codes include: 

• 7500 for aircraft hijacking. 
• 7600 for loss of communication (radio failure). 

• 7700 for a general emergency.  
• 1200 for aircraft flying visual flight rules (VFR).

These are international codes.听听

ACAS and safety

To prevent aircraft collisions, collision avoidance systems have been developed using transponder transmissions. These systems rely on transponder signals to identify aircraft on air traffic control radar and provide altitude information. 

For the Airborne Collision Avoidance System (ACAS) to work, both the interrogator and target aircraft must have operating transponders. The type of information received by the ACAS depends on the type of transponder the target aircraft is equipped with.  

Two types of alerts can be issued by an ACAS system: a Traffic Advisory (TA) and a Resolution Advisory (RA). The former alerts the pilot of a potential threat while the latter indicates the maneuver to follow back to safety. An aircraft equipped with a Mode ‘C’ or ‘S’ transponder can receive a TA and a RA while an aircraft with a Mode ‘A’ transponder will not be tracked by ACAS. 

Learn more about aircraft transponders:

The architect of Wizz Air精东影业 successful formula, its CEO J贸zsef V谩radi, does not give interviews often. However, he made an exception for 精东影业 and we flew to Budapest, Hungary 鈥� on Wizz Air, of course 鈥� for an in-depth interview with one of the international airline industry精东影业 key figures.  

Watch our video interview with V谩radi discusses a broad range of topics, from the post-COVID recovery and the perspectives for future growth and market consolidation in Europe, how it compares with arch-rival Ryanair, and Wizz Air精东影业 commitment to its already ongoing expansion in the Middle East and beyond.  

We also talk about Wizz Air精东影业 ambitious plans to increase its fleet to 500 aircraft and to reach 170 million annual passengers before the end of this decade. We also touch upon other relevant topics such as the airline精东影业 approach to ancillaries, inflight product and the airline精东影业 approach to sustainability.听

According to witness statements, the feat is 鈥渘othing short of a miracle鈥� and has made them 鈥渞eally think about the future of AI鈥�. 

What happened? 

Global View News Florida first broke the story. According to the report, the incident took place onboard a Floridian Skyways Boeing 737, flying from San Juan Airport (SJU) to Tampa International Airport (TPA), on April 1, 2023.听

While approaching TPA, the pilot notified flight control that he felt dizzy and that the first officer had passed out. Shortly after, the crew squawked emergency code 7700 and stopped responding to flight control. 

According to tracking data, the aircraft experienced a significant drop in altitude, followed by a quick recovery and stabilization at a height of just 300 feet (91 meters) above the Gulf of Mexico. 

According to GVN Florida, John Williams, 45, was traveling back from a vacation in Puerto Rico with his wife, and two children, entered the cockpit, and took control of the plummeting aircraft with the help of the ChatGPT app on his phone.  

鈥淚 whipped out the app and yelled, 鈥榯ell me how to fly a plane鈥�,鈥� Williams is quoted as saying in the report.  

鈥淭he app starts explaining what knob to turn and what lever to pull and whatnot, and there you go, I鈥檓 flying the damn plane!鈥� Williams added.  

It is currently unclear how Williams was able to enter the cockpit during the uncontrolled dive. According to the report, the passenger had been on his way to the lavatory when he had 鈥渇elt something fishy was going on鈥� and decided to enter the cockpit. 

Pilot cabin doors are typically locked during flights.  

Miraculous landing 

精东影业 was able to contact Daisy [the name has been changed to retain anonymity 鈥� 精东影业], who was on the flight and witnessed the event. 

“The landing was really smooth,” she said. “It seemed far smoother than any other low-cost airline landing I’ve witnessed.” 

In the aftermath of the incident, Floridian Skyways shared a tweet by Passengers for Smoother Landings, a non-governmental organization, which describes itself as 鈥渁 grassroots movement which has never received a single cent from corporate backers.鈥� 

鈥淗ow the hell do airlines still allow human pilots to fly the planes? Dangerous and irresponsible. Put AI in charge of flying NOW!鈥� the tweet said. 

The tweet has been shared by a number of other low-cost airlines around the world. 

Technology with great potential 

Previous statements by Floridian Skyways show that the company has already tried outsourcing some work to artificial intelligence (AI). On March 20, 2023, the airline published a press release claiming that it had begun to experiment with AI assistants designed to help cabin crew distribute and manage catering on some of its routes. 

鈥淲e can鈥檛 wait for our passengers and crews to taste all the delicious treats our attendants are going to prepare with the help of our new algorithms,鈥� the airline said in the statement.  

精东影业 contacted Floridian Skyways for a comment. 

While we take the aviation industry seriously, we also believe in the importance of having a sense of humor. On April Fools’ Day, we thought it would be fun to share a lighthearted article that is not meant to be taken seriously. Please keep in mind that the information in this article is purely fictional and not based on any factual events. We hope it brings a smile to your face and provides a brief escape from the seriousness of everyday news and announcements in the industry.听

The financial support will reach T眉rkiye精东影业 Disaster and Management Authority (AFAD) and T眉rk Kizilay, the largest humanitarian organization in T眉rkiye, a part of the International Red Cross and Red Crescent Movement.

鈥淲e send our deepest condolences to the people in T眉rkiye. We stand united together, wishing you strength in this hour of grief,鈥� said Jonas Janukenas, CEO of Avia Solutions Group. 

The new design delivers tailored content to readers globally. It will improve readability of the website so that 精东影业 users can find, read, and watch their favorite aviation and aerospace content more easily.

鈥淒uring 2022, 精东影业精东影业 average monthly audience has more than doubled,鈥� said Mindaugas Gumauskas, Chief Executive Officer of 精东影业. 鈥淭herefore, addressing our audience精东影业 needs, observing overall trends in the global digital media business, and changing user behavior, we knew we had to enter a new chapter for our news, insights, and analysis website.鈥�

He added: 鈥淗aving a wide range of aviation content that we are able to deliver in one place, the 精东影业 Hub, will allow us to improve our users鈥� experience.鈥� According to Gumauskas, the new era will pair high-quality content with easier navigation, especially for mobile users, and those who also love to see visual content.

鈥淭he improvements in usability will enhance the high-quality content we have been delivering here at 精东影业,鈥� said Gumauskas.

The new website will also introduce dedicated spaces for different content types, including the latest news, analysis, feature articles, and video content. The new 精东影业 website is launched on December 9, 2022.

精东影业 is a global multi-channel aviation digital and professional hub providing news, events, and advisory services to the aviation world. With more than 1.8 million monthly readers, 200,000 newsletter subscribers and 300,000 followers on its social media accounts, the company has become one of the most recognized names in the aviation media market. Part of Avia Solutions Group, 精东影业 plays an integral part in providing end-to-end aviation solutions to customers around the globe.

The Emirates A380 aircraft and seven Red Arrow planes flew in a synchronized formation starting at Jumeirah Golf Estates and continuing along the Sheikh Zayed Road skyline before nearing the iconic Dubai skyscraper, Burj Khalifa.  

The flight was performed on November 17, 2022, to celebrate the start of the DP World Tour Championship, the prestigious international tournament of the world’s greatest golfers. 

According to , the A380 wide-body aircraft took off at Dubai International Airport (DXB) and was joined by the RAF Red Arrows as it made its approach over Jumeirah Golf Estates. As the aircraft flew at an altitude of just 1,000 feet, the seven Red Arrows released red smoke trails to signal the launch of the tournament. 

The eye-catching performance was captured by one of the championship observers. 

Emirates A380 and the Royal Air Force Aerobatic Team fly in formation to celebrate the start of the DP World Tour Championship in Dubai.

鈥� Breaking Aviation News & Videos (@aviationbrk)

The V-shaped formation then flew along Sheikh Zayed Road at an altitude of 3,000 feet while reaching a speed of 250 knots, to finally reach the Burj Khalifa before heading west towards the Dubai coastline where all planes split up and continued on to their respective airports for landing.  

Space tourism sounds exciting, but it is wildly expensive. In the early 2000s, Airbus had an idea to make it cheaper by鈥痗reating Migbus:鈥痑 transparent passenger capsule strapped to a MiG-31 fighter jet.