Flying In Bad Weather shared by AJAY GIRI

By Chris Cooke

Pilots face Mother Nature's bad weather armed with data, technology and years of experience. Weather is the single biggest factor in the decision to initiate or cancel a flight. The whole process begins in operations, as pilots receive our flight paperwork. The first items I check are the destination forecast for the arrival time, the quantity of fuel at landing (in case the destination weather changes and we have to hold), and the departure weather.

We have tremendous assets available when it comes to predicting the weather. From National Oceanic and Atmospheric Administration's National Weather Service, we get Doppler radar images, satellite photos and observations; and through a network of pilot reports, we gather vast amounts of data to make intelligent decisions. However, there are weather conditions where flying is not only not recommended but prohibited. All airlines have flight manuals that list certain conditions when flying is not permitted. Grounding weather includes freezing rain, freezing drizzle, heavy snow, volcanic ash, reported wind shear, microbursts and visibility below minimums. These are just a few reasons to stay grounded until conditions improve. Summer and winter both offer pilots unique challenges. In summer, thunderstorms bring heavy rain and high winds, while the winter gives us icing conditions with snow, tricky winds and slippery runways.

Once a pilot has decided that the weather is good enough for the flight to launch, en route weather becomes the next concern. The digital world has given pilots a great resource through our in-cockpit data link sets called ACARS (Aircraft Communications and Addressing Reporting System), a fancy term for a data link. Flight dispatchers constantly stay on the watch for hazardous weather in the paths of their assigned flights. They can send instant messages to the cockpit, warning pilots of potentially dangerous conditions and the best route for avoiding them. All commercial airliners are equipped with sophisticated weather radars that make our jobs much easier and safer. The last thing a pilot wants to do is fly directly into a thunderstorm. The weather radar lets us see these storms up to 320 miles away and shows us the best places to penetrate their weak points. If the line of storms doesn't have a large enough hole for us to get through, we'll just go around it—or over it if it's not too high.
Turbulence, one of the main causes of in-flight injury, is another concern. It can be caused by a changing jet stream, a mountain wave or a number of other factors and is best indicated by pilot reports and preflight analysis of wind aloft charts. Pilots always look out for turbulence reports from other pilots and receive in-flight updates from our dispatchers highlighting areas and altitudes to avoid.
As we get closer to our destination, we pay close attention to the current and forecast weather from ACARS. If the weather looks bad, we check our approach charts to see if the ceiling and visibility are good enough for us to start the approach. If the weather is above minimums, we continue to the destination. If it falls below, we may need to hold and wait for it to improve, fuel permitting, or proceed to an alternate field with better weather. As you can imagine, the approach and landing phases are the most critical, but given the advanced avionic systems aboard most aircraft today, pilots rarely find ourselves forced to redirect to an alternate because of bad weather.

On your Mind

 Readers pose their questions on air travel.
 Q. As a passenger, do you ever second-guess what a pilot is doing? Have you reported a noise or smell? And how often do passengers do this?
Bill Parsons, Bradenton, Fla.
A. I will only second-guess a pilot if something out of the ordinary happens. For example, I was traveling with my brother and brother-in-law, who are both pilots, from Los Angeles to Las Vegas. The guy flying the airplane must have been a frustrated fighter pilot, because he was "yanking and banking" (as the saying goes) the jet around quite a bit. All three of us are former military pilots and current commercial pilots, and we all noticed what was happening—but we didn't approach the cockpit about it. Thankfully, we landed safely, and I'd never thought about it again until now.
I will not hesitate to mention an unusual noise or smell, though. We also encourage passengers to let us know if they see, hear or smell something of concern, even though it's most often not a cause for concern. Pilots sit so far up front that we don't know what's happening behind us unless something triggers a warning indication. We are happy to let you know that what happened was actually normal or to thank you for alerting us to a real problem. It's better to be safe rather than sorry.
Q. How often does the pilot make a decision himself about not to fly in weather conditions? Are there any repercussions from the airline when that decision is made?
Alice Candau, Phoenix
A. The flight bags you may have caught a glimpse of in the cockpit are full of manuals that explain everything pilots can and cannot do when flying. We will know in advance if the current conditions permit us to fly, according to FARs (Federal Aviation Regulations) and company-specific regulations. If conditions are legal, then most often, the flight will continue. If a pilot does not feel comfortable flying in the prevailing conditions, he may choose to turn down the flight. This will require the pilot to answer to operations management and may lead to additional training and evaluation. If the pilot has a good reason for turning down the flight—for example, fatigue—no further questions will be asked and the pilot will be returned to the line.