Hot answers tagged

38

They looked out the window! If you are talking about a developing thunderstorm, especially during the day, they can be quite easy to see in front of you provided decent visibility. Here is some good footage of what it looks like to fly around a towering cell, you will note its fairly easy to see. At night, lightning, even in the clouds tends to be a ...


32

Other answers have addressed the case of weather that's too bad for flights to operate, but another situation that can occur is congestion. Take a look at the Average Arrival Rate chart for San Francisco International Airport (SFO) (more details on this in this blog post by an airline dispatcher). During visual conditions with favorable winds, they can ...


29

I find it hard to believe that this was a holding pattern of some sort. Believe it. An hour before landing would be about the point at which the aircraft will start its descent to its destination. Almost certainly, air traffic control were delaying your flight for a few moments to ease insertion into the landing pattern at Chicago. Doing this at altitude ...


21

Yes, the effect is there, and (auto-) pilots have to compensate for it, but the direct impact of the Coriolis force is insignificant compared to the impact of any wind forces. This has been discussed on Physics SE: Coriolis force on bullet vs airplane On the other hand side, the Coriolis force (seemingly) deflects moving air masses and causes the global ...


21

Based on your provided flight info, I looked up the track history on flightradar and did see some potential traffic conflict that might have tempted the controller to route your plane that way. The first turn to the South appears to be a conflict with AAL 91, who was coming in from the North, also descending. AAL 91 executed a 90 right turn, while UAL 1709 ...


18

I´ll second John K´s recommendation of Fate is the Hunter for a first hand account of flying in the 30s and 40s. The style can be a bit too laden in floritures, trying to lend a certain mystique to flying that still existed when it was published, but the content is sound and if you want a glimpse into the aviation world of that era, it is a great read. To ...


13

You get by on your airborne weather radar which is good out to about 80 miles. You may also get help from other pilots ahead of you on your route providing PIREPS to ATC on HF, or talking to you directly if you are close enough to use VHF between each other. But as far as picking your way around cells, besides being able to see them if you are in the clear,...


12

Read the book "Fate Is The Hunter" by Ernie Gann, who was flying DC-2s and 3s for American. One of the all time great aviation books. In the 30s, they just blundered right through thunderstorms if they couldn't be visually avoided because they were embedded in cloud or it was at night, and hung on for dear life.


11

For landing aircraft, the Instrument Approach Procedures available will dictate the required ceiling (height of clouds above ground) and visibility (horizontal). The most common approach type for airlines is an Instrument Landing System (ILS). ILS Category I requires a ceiling of at least 200 feet and visibility of at least 1800 feet. With special equipment ...


9

Storms have nothing to do with this. I'm a pilot who routinely flies into both Chicago O'Hare and La Guardia. The S-turns are because of flow control into busy airports. ATC normally tries to change speed of incoming aircraft but sometimes it's not enough and delay turns are required to ensure adequate separation. If they get really backed up due to bad ...


7

I'd argue fall and spring bring more unpredictable weather, and slippery runways are year-round in the tropics. That being said, for all jet (commercial) accidents, the weather-related contributing threats are: Meteorology (e.g., failure to identify threats before a flight) 30% Windy conditions 16% Poor visibility 10% Thunderstorms 9% Icing 1% Poor ...


7

If you are in controlled airspace its very possible ATC will direct you around weather, you can find out more about that in this question. However what ATC can see on their scope varies from place to place and weather moves quickly. As such pilots can, and often do request deviation for weather. Lets say you are flying along dodging some clouds here and ...


6

There is not much gained by the third dimension for your use case. In GA you generally want to avoid any active weather. Why make it more complicated? can't go over it (performance limited) can't go under it (microbursts can kill you) => only way is to go around it and therefore no need for that 3D information.


6

Naval aircraft cannot be just left on deck without maintenance and expected to operate after an extended period of time. I will restrict this to storage on deck and avoid going into operational issues like spray effects on engines as OPs question does not ask that. There are a multitude of technologies in use to protect metal parts from corrosion, but in ...


6

The answer is "All of the above." The left hand side of this slide from a NASA Powerpoint deck pretty much covers your question. The full slide deck from the presentation can be seen here.


6

“All-weather” is a little bit of a hold-over from the WWII days where severe weather was much more of a threat to the aircraft. Between less reliable engines, delicate and finicky instruments like artificial horizons, and limited anti-ice technology, flying in adverse conditions was much harder then. Becoming completely disoriented in low visibility was ...


5

This seems to be from an older Gleim study guide. It references a now-cancelled AC 91-51A: (AC 91-51A) Ice on the leading edge, while seemingly more dangerous, can be removed using deicing systems. Ice on the upper surface is much more difficult to clear from the structure, thus making it more dangerous. This AC has been replaced by 91-74B, which ...


5

You should have an alternate planned that is forecast VFR, with appropriate fuel reserves in place, before you left. But if you didn't, you'd call an ATC unit and tell them your predicament. Maybe they can send you to VFR conditions either reported by PIREP or by calling around to other tower units in range. Otherwise, you're going to have to do an ...


4

In the USA, planes with ADS-B can receive FAA transmitted weather from ground stations for display in the cockpit. It can lag by several minutes. https://www.faa.gov/nextgen/programs/adsb/pilot/ Planes with XM weather can receive more timely weather from satellite feed for display in the cockpit. Airborne radar has the advantage of being the most immediate,...


4

NSC means No significant clouds.


4

Up to WW2, aircraft operations were highly dependent on weather. navigation used ground observations to correct for drift etc. military aircraft needed optical observations to find their targets (on ground or in the air). This limited aircraft use to daytime and put an upper limit to the amount of clouds that were acceptable. A target completely covered ...


4

You haven't told us what country you are referring to. I am going to talk about the United States regulations. There are two separate regulations that come into play. Part 91 and Part 121 or 135. Under Part 91. The pilots are allowed to commence any approach (irrespective of weather) and determine if they can continue to land based on the criteria ...


4

As John K already said in the comments, the definition for icing conditions is visible moisture at a TAT of less than 10°C. From the Boeing 737 NG FCOMv1 (SP.16.1 Supplementary Procedures - Adverse Weather): Icing conditions exist when OAT (on the ground) or TAT (in-flight) is 10°C or below and any of the following exist: visible moisture (...


4

One can easily get lost in the alphabet soup that is datalink. Both ACARS and ADS-B provide datalink applications – which can be broken down in terms of CNS: Communication, Navigation, and Surveillance. ACARS is used for: Communication: includes uplinking (ground → aircraft) weather data upon a downlink request to the company/service provider – not a ...


4

An ISA standard atmospheric day is really more like a global average. Locally and regionally, there will always be deviations from the "norm" based on the natural cycles of the sun. Overnight the temperature will cool, then the sun will rise and things will warm up again. This phenomenon also produces variations in the pressure and density over larger ...


3

Data about the height of precipitation would be useful in real-time avoidance of weather phenomena. In fact, this information is provided by NEXRAD and is known as "echo tops." Echo tops also appear in suitably sophisticated SiriusXM weather displays. However, ground based radar is not the primary tool used for weather avoidance, and in particular, ...


3

The danger of VFR flight into IMC is flying into clouds when you aren't properly trained for it. Icing generally only occurs in clouds between -20°C and +5°C. NEXRAD shows the strength of the radar returns, which is usually an indicator of precipitation intensity, though, not clouds, so it doesn't really help avoid either of those things. Regarding why ...


3

WMO Publication No. 306 - Manual On Codes - Volume I.1 - Part A, Section A, FM 15 METAR, FM 16 SPECI: 15.14.14 When no cloud below 1 500 metres (5 000 ft) or the highest minimum sector altitude, whichever is greater, and no cumulonimbus and no towering cumulus are forecast, and CAVOK is not appropriate, the abbreviation NSC shall be used. Some countries ...


3

Note that A3011 (30.11 inHg) is 1019.6 hPa, which is lower than 1020.1 (SLP201). The small difference is because SLP (unlike QNH) is corrected for the 12-hour mean temperature at the reporting station, giving more accuracy to the meteorologists. So SLP is not a metric conversion of the altimeter setting in inHg to be used by pilots accustomed to hPa – it's ...


3

Ill second Camille's answer and add the missing factor of GA vs. Commercial Aviation. The NTSB makes the 2012-2016 data available in spreadsheet format here. If you download that and combine all the accident data you will see that the overall accident data for those years, plotted by month looks something like this: This data set for even the limited years ...


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