Mostrando postagens com marcador microburst. Mostrar todas as postagens
Mostrando postagens com marcador microburst. Mostrar todas as postagens

terça-feira, 6 de setembro de 2016

Emirates B777-300 Flight EK521 Tailwind Shared in Accident



PRELIMINARY REPORT





As the flight neared Dubai, the crew received the automatic terminal information service (ATIS) Information Zulu, which included a windshear warning for all runways.

The Aircraft was configured for landing with the flaps set to 30, and approach speed selected of 152 knots (VREF + 5) indicated airspeed (IAS) The Aircraft was vectored for an area navigation (RNAV/GNSS) approach to runway 12L. Air traffic control cleared the flight to land, with the wind reported to be from 340 degrees at 11 knots, and to vacate the runway via taxiway Mike 9.
During the approach, at 0836:00, with the autothrottle system in SPEED mode, as the Aircraft descended through a radio altitude (RA) of 1,100 feet, at 152 knots IAS, the wind direction started to change from a headwind component of 8 knots to a tailwind component. The autopilot was disengaged at approximately 920 feet RA and the approach continued with the autothrottle connected. As the Aircraft descended through 700 feet RA at 0836:22, and at 154 knots IAS, it was subjected to a tailwind component which gradually increased to a maximum of 16 knots.
At 0837:07, 159 knots IAS, 35 feet RA, the PF started to flare the Aircraft. The autothrottle mode transitioned to IDLE and both thrust levers were moving towards the idle position. At 0837:12, 160 knots IAS, and 5 feet RA, five seconds before touchdown, the wind direction again started to change to a headwind.
As recorded by the Aircraft flight data recorder, the weight-on-wheels sensors indicated that the right main landing gear touched down at 0837:17, approximately 1,100 meters from the runway 12L threshold at 162 knots IAS, followed three seconds later by the left main landing gear. The nose landing gear remained in the air.
At 0837:19, the Aircraft runway awareness advisory system (RAAS) aural message “LONG LANDING, LONG LANDING” was annunciated.

At 0837:23, the Aircraft became airborne in an attempt to go-around and was subjected to a headwind component until impact. At 0837:27, the flap lever was moved to the 20 position. Two seconds later the landing gear lever was selected to the UP position. Subsequently, the landing gear unlocked and began to retract.
At 0837:28, the air traffic control tower issued a clearance to continue straight ahead and climb to 4,000 feet. The clearance was read back correctly.
The Aircraft reached a maximum height of approximately 85 feet RA at 134 knots IAS, with the landing gear in transit to the retracted position. The Aircraft then began to sink back onto the runway. Both crewmembers recalled seeing the IAS decreasing and the Copilot called out “Check speed.” At 0837:35, three seconds before impact with the runway, both thrust levers were moved from the idle position to full forward. The autothrottle transition from IDLE to THRUST mode. Approximately one second later, a ground proximity warning system (GPWS) aural warning of “DON’T SINK, DON’T SINK” was annunciated.
One second before impact, both engines started to respond to the thrust lever movement showing an increase in related parameters.
At 0837:38, the Aircraft aft fuselage impacted the runway abeam the November 7 intersection at 125 knots, with a nose-up pitch angle of 9.5 degrees, and at a rate of descent of 900 feet per minute. This was followed by the impact of the engines on the runway. The three landing gears were still in transit to the retracted position. As the Aircraft slid along the runway, the No.2 engine-pylon assembly separated from the right hand (RH) wing. From a runway camera recording, an intense fuel fed fire was observed to start in the area of the damaged No.2 engine-pylon wing attachment area. The Aircraft continued to slide along the runway on the lower fuselage, the outboard RH wing, and the No.1 engine. An incipient fire started on the underside of the No.1 engine.
The Aircraft came to rest adjacent to the Mike 13 taxiway at a magnetic heading of approximately 240 degrees. After the Aircraft came to rest, fire was emanating from the No. 2 engine, the damaged RH engine-pylon wing attachment area and from under the Aircraft fuselage. Approximately one minute after, the Commander transmitted a “MAYDAY” call and informed air traffic control that the Aircraft was being evacuated.


segunda-feira, 16 de agosto de 2010

Microburst Most Likely Struck AIRES Flight in San Andrés Island


"I felt the plane descending too fast as if we were in vacuum  and following I only saw a intense brightness in the sky", said a Brazilian victim of the crashed airplane .

Another Brazilian passenger told to a Brazilian TV channel  reporter, "It was raining a lot with lightnings surround the plane as all of us could see outside the plane but there was no affliction by the passengers. The approach for landing it was apparently normal for us. Suddenly the plane started descending more fast and struck the ground abruptly".

A microburst often causes aircraft to crash when they are attempting to land (except Pan Am Flight). The microburst is an extremely powerful gust of air that, once hitting the ground, spreads in all directions. As the aircraft is coming in to land, the pilots try to slow the plane to an appropriate speed. When the microburst hits, the pilots will see a large spike in their airspeed, caused by the force of the headwind created by the microburst. A pilot inexperienced with microbursts would try to decrease the speed. The plane would then travel through the microburst, and fly into the tailwind, causing a sudden decrease in the amount of air flowing across the wings. The sudden loss of air moving across the wings causes the aircraft to literally drop out of the air. The best way to deal with a microburst in an aircraft would be to increase speed as soon as the spike in airspeed is noticed. This will allow the aircraft to remain in the air when traveling through the tailwind portion of the microburst and also pass through the microburst with less difficulty, although it is possible that for light aircraft, the descent rate induced by the microburst will exceed their maximum climb rate, leading to an unavoidable crash.)


A aeronave sofreu acidente às 06:49 GMT(03:49 Hora de Brasília), enquanto estava pousando na ilha San Andrés, Colômbia, a qual é uma ilha tipo resort com uma população de 178.000 habitantes e fica distante 190 Km da costa da Nicarágua.



The scale and suddenness of a microburst makes it a great danger to aircraft, particularly those at low altitude which are taking off and landing. The following are some fatal crashes that have been attributed to microbursts in the vicinity of airports:


Eastern Airlines Flight 66, John F. Kennedy International Airport - June 24, 1975


Pan Am Flight 759, Miami International Airport - July 9, 1982


Delta Airlines Flight 191, Dallas-Fort Worth International Airport - August 2, 1985


Martinair Flight 495, Faro Airport - December 21, 1992


USAir Flight 1016, Charlotte/Douglas International Airport - July 2, 1994


Goodyear Blimp, Coral Springs, Florida - June 16, 2005

Air France Flight 358, Toronto Pearson International Airport - August 2, 2005


One-Two-GO Airlines Flight 269, Phuket International Airport - September 16, 2007
 


PREVISÃO METEOROLÓGICA
SKSP 160500Z 07006KT 9999 FEW016 SCT200 29/26 A2990

SKSP 160400Z VRB02KT 9999 BKN016TCU SCT200 29/26 A2991

SKSP 160400Z VRB02KT 9999 BKN016 TCU SCT200 29/26 A2991
Este é o melhor exemplo das consequências proporcionadas por Microburst