Although most modern aircrafts are equipped with weather monitoring devices, weather can change in a moments notice. Pilots must posses the knowledge to interpret these changes prior to them happening. They must be able to decide what is acceptable weather to fly through, around, and above, as well as what weather must be absolutely avoided. In the end the pilot is the one who has the final call and it is his or her job to be educated to make the right decision. This paper will talk about some of the different types of weather phenomena’s that a pilot will face in their career. The accidents listed will vary in type. I will discuss a on the ground fog related crash. I will discus a crash that was caused by wind shear and microburst on final approach. Lastly, I will discuss an accident where the weather changed in flight and the pilot did not choose to act appropriately ending in a fatal crash.
On March 27, 1977, the aviation industry suffered the deadliest incident in its history. The event leading up to two 747 passenger planes colliding head first on a runway are those that you could only suspect to be written in a movie. At 1:15pm local time at the Gran Canaria International Airport a bomb had exploded at one of the terminals. In an apparent terrorist attack authorities have no choice but to close the airport and divert all incoming flights to other airports. Two of the five large planes to be diverted to Los Rodeos Regional Airport are, Pan Am Flight 1736 from NYC and KLM Flight 4805 flying from Amsterdam to Gran Canaria (Trusty). Los Rodeos is a small airport with one major runway, one major taxiway, and several minor taxiways combining the two together. The airport is not designed to be used by such larger airplanes. After being grounded for several hours the Captain of KLM flight 4805 fears if he isn’t able to depart soon for the Gran Canaria then the flight would soon be canceled due to new company policy preventing pilots from going over their fly time. The consequences for this would be the lose of their license (Ibay). A heavy layer of dense fog has dropped the visibility to about 1000 feet. Once the terrorist threat was contained The Pan Am flight was ready for departure but waiting for the KLM flight to finish fueling. With such a dense blanket of clouds covering the runway ATC couldn't see the planes on the runway. ATC ordered that the Captain of the KLM flight to back taxi down the runway and hold for clearance. ATC then ordered the Pan Am captain to follow KLM but then pull off the runway at the third minor taxiway on the left to allow for the KLM flight to take off. Through this dense fog and a miscommunication, the Pan Am pilot felt that his plane couldn't make turn for taxiway Charlie 3 and tried to go to the forth taxiway. While he was doing so, the KLM captain without the proper clearance for take off pushed full throttle. At which time the remainder of the crew sat silent. (Ibay) Investigators believe the crew didn't challenge the captains authority due to his “superstar” status in the airline. Along with pilot and crew error, neglect, and many other operational pitfalls such as peer pressure, continuing VFR, and loss of positional or situational awareness. The KLM flight 4805 was barreling full speed down the runway. Pan Am flight hadn't cleared the runway but due to the limited visibility KLM flight struck directly into them. The crash killed 583 people. The crash could have been avoided if proper preflight planning and check lists had been performed. The silent killer in this tragedy is weather.
Various weather conditions effect flight. Fog, ice, thunderstorms, and turbulence. On August 2, 1985 over Texas Delta Air Lines Flight 1991 is approaching Dallas/ Fort Worth international airport the flight had originated at ft Lauderdale and will end in Los Angelos. Captain Edward n. Connors, age 57 is described as a meticulous pilot with adherence to company policies. The co pilot is first officer Rudolph P. Price, Jr, age 42. Delta captains who flew with price describe him as an above average First Officer with excellent knowledge on the tristar. The flight engineer is Second officer Nick Nassick, age 43. He is described as being observant, alert, and professional. He has 6500 hours of flying time. There are 152 passengers and 11 crew members. The plane is a six year old Lockheed L-1011-385-1 Tristar. The flight is instructed to descend to 10,000ft the controller instructs the flight to fly a heading of 250 towards the blue ridge approach. But captain Connors tells him that this would take them into a storm cell. The controller assigns him a new heading to avoid it. Flight 191 is getting close to a lear jet 25 in front of them. They are instructed to slow down to 180 knots. 10 degrees of flaps were added. Price states we are going to get airplane wash. Conners informs the DFW approach that they are at 5000 ft. The pilot slow down further to maintain separation with the Learjet ahead. 6:01 pm flight 191 is instructed to descend to 3000ft. The approach controller then turns the flight towards runway 17L and clears them for an ILS approach at or above 2300ft. He then instructs the flight to slow down to 160 knots. Approach notifies them of variable winds out there due to a shower out there north end of DFW. 6:04 Pm flight 191 is instructed to slow down to 150 knots. They are then transferred to the tower controller.In plane they notice lighting inside the clouds as they are on approach.Plane is a few kilometers from the runway.The plane lands short of the runway and then makes contact with a water tower. 136 people on board are killed. 25 passages and 3 crew members survive. William Mayberry, who was driving on Texas state highway 114, is also killed when flight 191 struck his car. Another person on the ground is also injured. Flight 191 can in contact with a microburst, a downdraft that moves in a way opposite of a tornado. Planes flying through it face headwinds, downdrafts, and tailwinds.in 1985 microburst we pretty unknown. Most pilots were not trained to deal with them. But captain conners appeared to have been aware that he was flying through a microburst. The pilots reacted properly and professionally. The only problem was that they were at a low altitude when the microburst was encountered. Had they had at least a thousand feet of altitude they could have recovered from the encounter.
The national transportation safety Board determines that the probable cause of the accident were the flight-crew’s decision to initiate and continue the approach into a cumulonimbus cloud which they observed to contain visible lightning; the lack of specific guidelines, procedures, and training for avoiding and escaping from low altitude windshear and the lack of definitive, real time wind shear hazard information. This resulted in the aircraft encounter with low altitude with a microburst-induced severe wind shear from a rapidly developing thunderstorm located on the final approach course.
https://www.ntsb.gov/investigations/AccidentReports/Reports/AAR8605.pdf
The flight hit a microburst-induced wind shear, which its impact of a severe downdraft and a decreasing headwind, the effect of which the pilot would have had a difficulty recognizing and reacting to in time to have an apporiprate and possible life changing reaction.