Flights Cancelled Due to Weather? Here's Why

Rain

Rain can significantly affect all phases of a flight. The main culprit is reduced visibility, forcing pilots to rely more on instrument readings.

Can a plane take off in the rain? Just like walking on a wet floor, planes can have trouble getting traction on a wet runway. This can cause planes to need more distance when taking off and landing.

If it rains very hard, the plane's engines can flood out, but modern planes have engines equipped to handle most rainstorms. Once in the air, micro downbursts and microbursts can impact flying with little advanced warning.     Another problem that rain can cause is turbulence. Pilots can encounter convective turbulence when warm, moist air rises rapidly and encounters cooler air aloft.

When rain falls through these areas, latent heat and moisture can make updrafts and downdrafts more frequent, making the plane more challenging to control.

Rain can cause rotor turbulence, especially over large bodies of water and in mountainous regions. Then, horizontal vortices or eddies extending several hundred feet into the air can form. When a pilot flies into one, the plane can be tough to control.     Planes can fly when there is lightning outside. What happens if a plane gets struck by lightning?

They have sophisticated systems and are made from materials that even allow them to be hit by lightning without causing the lightning's energy to dissipate harmlessly into the environment.     While crashes from rain are sporadic, there have been some.

One occurred on August 23, 2005, TANS Peru Flight 204. It was raining heavily when the pilot attempted an emergency landing of the Boeing 737-200 at Captain Rolden International Airport in Pucallpa, Peru.

After encountering a hailstorm and, perhaps, wind shear, the pilot failed to make the runway. Instead, he crashed into a swamp. The plane burst into flames as it impacted the ground. While 58 people survived the accident, 40 people perished.    

Snow

It can be very challenging to fly when it is snowing. One major problem is reduced visibility. While airports use snowplows and blowers to clear runways, planes can still hydroplane and skid on wet runways.

Pilots must also consider the effect of cold temperatures on air density and aerodynamics when calculating takeoff distances, climb rates, and fuel consumption.     Can a plane fly in snow? If it snows during a flight, visibility may be significantly restricted, forcing pilots to rely more on their instruments. Just like rain, snowy conditions can make turbulence more likely.

If the snow occurs near frontal boundaries, it can cause clear air turbulence. In this case, there may not be any clouds in the sky, but it is still snowing at high altitudes. Turbulence occurs when winds that are moving at vastly different speeds meet.    

One notable flight where snow contributed to a plane wreck was Uruguayan Air Force Flight 571, which crashed in the Andes Mountains on October 13, 1972.

The pilot may have had trouble seeing because of a snowstorm and instruments in the plane lacked the sophistication found in current planes. Weather reports have become more accurate. The pilot became confused about his location, and the aircraft hit a mountain ridge, searing off its wings and tail section.

Twelve people died instantly, and several more died shortly as they were unprepared to deal with the harsh weather conditions. Search and rescue operations failed to spot the plane.

Finally, Nando Parrado and Roberto Canessa climbed and hiked out of the crash site. They brought help for the 12 people who survived the crash about 75 days after the plane went down.    

Ice

Ice can be one of the most dangerous weather conditions faced by airlines. While ice can affect runways, it can also change how planes perform.

It adds weight to the aircraft and increases drag. These factors can make it harder for the plane to get lift and decrease drag speed. Ice can block air from getting to the plane's parts that need it to function properly.

In some cases, it can cause pilot instruments to give inaccurate readings.     Pilots usually get multiple warnings before ice causes problems with their aircraft, but sometimes, they ignore those warnings for unknown reasons.

That was the case with Air Florida Flight 90 that flew out of Washington National Airport, now Ronald Reagan Washington National Airport, on January 13, 1982. The ground crew responsible for deicing the plane failed to use proper procedures.

The deicing mixture was made incorrectly. Conditions were so icy on the ground that the vehicle towing the aircraft to the taxiway had trouble getting traction.

The pilot failed to turn on the plane's deicing system and tried to use heat from the aircraft in front of him to melt ice building up on his plane.

The plane only achieved an altitude of 352 feet before it crashed into a bridge and the icy Potomac River. Only five people survived the crash.     While weather can play a significant role in plane crashes, there is statistically a much larger chance of being injured in a car crash than in a plane crash.

When you need to travel, trust the experts at the airport to watch the weather for you. If your flight can leave, then sit back and enjoy the trip.