DISCUSSION: On the evening of Friday, July 7,2017 at approximately 11:15 PM PDT, an Air Canada Airbus A320 operating as Air Canada flight 759 was preparing to land onto Runway 28R at San Francisco International Airport after a nearly five-and-a-half-hour flight from Toronto’s Pearson Airport. However, Flight 759 was instead lined up with taxiway C (Charlie). However, the taxiway had two United Airlines Boeing 787s, a Philippine Air Lines Airbus A340 and a United Boeing 737 on it all lined up for Runway 28R. The Air Canada Airbus A320 nearly missed the four waiting jets by about 60 feet above one of the 787s as it pulled up in time to circle around. This near-miss could have been possibly the worst air disaster in history as the total number of passengers in all the jets would be twice as many as those who died in the Tenerife Accident in 1977. This incident also comes two days after the fourth anniversary of the Asiana Airlines accident in San Francisco, coincidentally on the same runway, Runway 28R.
However, the weather played a role in preventing this near-miss into being a repeat of Tenerife. Prior to the incident, several of the local Bay Area airports were calling clear skies in the hourly METARs. Also, there was a steady west-northwest wind that was roughly 7 knots, according to the KSFO METAR nearest the time of the accident. Normally, during the summer, there would be a layer of stratus coming in about the time of the near-miss. However, this was not the case as there were clear skies due to a very strong ridge and mainly dry conditions aloft. A stratus deck would have increased the likelihood of the crash as it would make it impossible for the pilots on Air Canada to have a visual of the runway lights or the approach lighting. Also, the air traffic controllers would not have been able to see the A320 and its approach. Wind was not an issue as it was oriented with Runway 28R in a way that crosswinds would be minimal which would not affect the direction of the plane.
Therefore, in the end, weather may have been the reason that the worst aviation disaster in the United States and the world was averted. Moreover, the primary catalyst for this incident was quite plausibly due to pilot error as weather conditions was favorable and visibility affected. You can read about more aviation and other applied meteorology topics here.
© 2017 Meteorologist JP Kalb
DISCUSSION: As is almost always the case when it comes to commercial aviation, nearly all pilots and co-pilots are trained to constantly avoid moving near or through any parts of deep convective storms. The reason for this is chiefly due to the fact that deep convective storms nearly always have strong updrafts and downdrafts. As pilots encounter deep convective storms they are trained to avoid such storms since they have historically had a tendency to compromise the safety of both commercial and private aircraft since they destabilize the ability for aircraft to remain in flight in a stable manner. This a direct result of the fact that flying near and/or directly through convective updrafts can lead to a given aircraft to lose altitude in a violent and rapid manner which can cause an aircraft to lose control temporarily or permanently in some cases. Hence, commercial and private pilots alike are always taught to fly around convective storms such as those captured in the images above which were taken by commercial pilots flying over #Austria before heading on over towards Croatia!
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©2017 Meteorologist Jordan Rabinowitz
DISCUSSION: As strong to severe thunderstorms continued to develop during the early to late morning hours on this first Sunday of April 2017, many commercial and private aircraft were already being affected. As if often the case during large-scale severe weather events, both commercial and private aviation interests are typically forced to deviate from scheduled flight paths. Due to the fact that severe thunderstorms often become quite deep in terms of their maximum cloud growth, this creates particularly dangerous situations for pilots who are thinking about or attempting to navigate through or around such thunderstorms. This is due to the fact that as severe thunderstorms move through any region, there are always consequential updrafts and downdrafts which can cause aircraft to loose control of their balanced flight.
Therefore, since the late 1960's there has been a consistent strong initiative towards improving the forecasting of wind shear and turbulence in association with various types of thunderstorms which occur throughout the year. As shown in the two images attached above, you can clearly see how the progression of the strong to severe thunderstorms forced hundreds of flights to divert from their original flight tracks due to the presence of the aforementioned severe thunderstorm outbreak which began to crank into high-gear much earlier today. Although this can create significant delays across many different parts of the aviation industry, "it is always to have a safe arrival than no arrival."
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©2017 Meteorologist Jordan Rabinowitz
DISCUSSION: As is known across all of commercial and private aviation, one of the most common issues to general aircraft and passenger safety is the presence of turbulence. However, something which many people do not know is that there are several different types of turbulence which are unique unto themselves. This includes varieties such as atmospheric turbulence, wake turbulence, and clear air turbulence (CAT). Having said that, these different types of turbulence are respectfully different and pose different threats at different points of a given flight. Per the article from "Insider," attached below are some more neat insights which were collected from many different pilot-based experiences from around the world as well as long-term data collected and archived within the long-term records of the Federal Aviation Administration.
Atmospheric and wake turbulence are often lumped together, but one is caused by nature and other is driven by mechanics. To explain atmospheric turbulence, many pilots liken the experience to traveling through a river in which air is the water. Like water in a river, air is constantly moving and can be influenced by several things, including obstacles (think mountains), moisture, uneven heating of the earth’s surface, weather, and temperature changes. Flights over mountain ranges, for example, often fall prey to mountain wave turbulence, which feels like a roller coaster speeding down its first big hill. "If you're in a small boat and the water isn't smooth, the faster you go, the rougher the ride will be," says Mike Arman, a flight school instructor and author of books about piloting Cessnas and operating cockpit computers. "Airplanes are exactly the same -- the faster you go, the rougher the ride can get." Commercial jets can go as fast as 600 mph, which can impact the plane’s reaction to the air current changes.
There are also mechanical factors that cause turbulence during takeoff and landing, including the wind streams that are created from a combination of the plane's propulsion and wings. In fact, wake turbulence is one big reason why takeoffs are timed several minutes apart.
On November 12, 2001, American Airlines Flight 587 took off from JFK Airport and crashed moments later into Belle Harbor, Queens. Investigators theorized that the pilot may have taken off 15 seconds too fast and run into wake turbulence from the Japanese Airlines jumbo jet that had left before it. The incident killed 260 people on board and five people on the ground. That being said, such reactions to wake turbulence are rare, particularly because the beginning of flights are so closely monitored by air traffic controllers.
Clear Air Turbulence
While passengers may expect the plane to thump and wriggle while taking off or steadying for a landing, clear air turbulence can be even more disconcerting. Here's how it happens: You’re watching the latest James Bond flick, sipping on a martini, and suddenly it feels like someone hit the ejector seat button, hurtling your stomach into space. Pilots discover clear air turbulence when everyone else does -- about the time the peanuts leap off the tray table. Clear air turbulence (CAT) doesn't show up on a radar -- a ground technology system that's currently being tested is able to listen to the infrasonic sound it emits. "In the next few years, I'd expect this technology to be in use to detect CAT for airline traffic," says Arman.
Hence, there is much we already understand about the impacts of turbulence on commercial aviation, but there is still much we do not understand as well.
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©2017 Meteorologist Jordan Rabinowitz
Thunderstorms Impact Flights Across Southeastern U.S. (credit: weathertap.com and FlightRadar24.com)
DISCUSSION: During the course of the day, evening, and now overnight period, there has been an incredibly impressive long-lived squall line which raced across a good portion of the southeastern United States. As has been case within the commercial aviation industry for more than three and half decades, commercial airline pilots are extensively trained to respect the natural power of Mother Nature and avoid flying close to or especially through strong to severe thunderstorms. As depicted in the respective screenshots of the recent regional southeastern United States radar mosaic coupled with the regional commercial aviation scene both at around 1:00 AM EST, there was a clear impact on both domestic and international flights attempting to move through the region in which deep convection was approaching or moving through. Hence, as you can clearly see in the screenshot attached above, there were a fairly large patch of airspace over the state of Florida, Alabama, and Georgia in which air traffic was kept at a bare minimum. Moreover, these patches of lessened air traffic coincided with the positioning and/or the future positioning of the stronger convective cells. Thus, it is clear that the air traffic controller network across the respective southeastern states made these incoming storms a top priority and was conveyed as such to the commercial/private airline pilots approaching the hazardous pieces of airspace being threatened by these deep convective storms.
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©2017 Meteorologist Jordan Rabinowitz
DISCUSSION: As strong winds continue to impact various sections of Central/Eastern Europe, there remains to be a serious threat to global aviation interests (i.e., both commercial and private). This threat has been facilitated by a recent low pressure system which has since moved off to the east at this point in time. However, in the wake of the low's cold front passage, there still remains to be sufficient strong winds both somewhat and well above the surface. Whenever there are strong winds in the vicinity of and even within 2,000 ft (i.e., approximately 630 meters above the surface), this creates incredibly dangerous conditions for incoming aircraft that are trying to make their final approach for a safe landing. As seen in the footage above, this aircraft arriving in Prague was incredibly fortunate based on the extremely close-call with both the rear portion and both wings experiencing potentially catastrophic damage in what ended up being an aborted landing.
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©2016 Meteorologist Jordan Rabinowitz