Accident
On November 19, 1977, a Boeing 727-200 from TAP Air Portugal operating the Flight 425 between Brussels, Belgium and Funchal, Portugal, with a stopover in Lisbon, Portugal crashed on Madeira International Airport in Funchal after overrunning the airport’s runaway. Of the 164 people aboard (156 passengers and 8 crew), 131 were killed, making it the deadliest airplane accident in Portugal up to that point.
After the accident, an official investigation was started trying to find the exact causes of such tragic event.
Investigation
The official investigation of the accident found out that at the time of the accident there were heavy rain, strong winds and poor visibility. In addition, it was also found that after two failed attempts to land the plane, the crew wrongly opted to try for a third time, which proven to be fatal.
Apparently, when the aircraft touched the runway for the first time, it was 610m after the supposed point to do it, making the successful halt even harder. With the severe weather conditions, the plane started to hydroplaning.
With less than 1km left of runway to stop the plane, the pilot applied the maximum reverse thrust. However, the plane diverted from the runway at a velocity of 80km/h and plunged over a 61m steep bank. Eventually, it hit a nearby bridge and crashed on the beach, splitting into two different pieces and bursting into flames.
In accordance to the investigation, the aircraft was in proper flight conditions right before the impact and the Portuguese crew was competent and qualified to perform the job. The investigation found out that the crew made a mistake to land the plane so late in the runway at an excessive speed. It was also found that there were insufficient light across the runway, making the successful landing harder. Lastly, the investigation recommended Funchal Airport to increase the level of meteorological observations.
The aftermath
After this accident, TAP Air Portugal decided to halt the flights involving Boeings 727-200 to Madeira. Instead, it promoted the usage of Boeings 727-100, which was 6m shorter and carried less passengers. This decision was deemed to be the correct one, due to the short Madeira’s runway and unpredictable weather conditions of this island.
Also, after this event, in which was evident that the runway full extension could not be enough to prevent late touchdowns, several extensions were made. As of 2021, the now called Cristiano Ronaldo International Airport measures 2,781m and is capable to receive big jets like the Boeing 747 or the Airbus A340.
My own (design) suggestions that could have prevented the accident
- The pilot show have taken a precautionary measure instead of risking, by diverting to the closest airport, in Canary Islands, Spain
- Implement more efficient lights around the runway
- Before building the runway for the first time, the engineers should have made proper calculations to realize that under some circumstances an extension might be needed
- Inform the driver that after two failed attempts to land the plane, it is highly recommended to divert
- Develop the runway with better asphalt or devices that prevent hydroplaning
- Improve the efficiency of meteorological stations around Madeira Island to inform the pilots about accurate and precise conditions
References
[1] “TAP Air Portugal Flight 425”, Wikipedia the Free Encyclopedia. Accessed: January 5, 2021. [Online]. Available: https://en.wikipedia.org/wiki/TAP_Air_Portugal_Flight_425
[2] “TAP 425 – Santa Catarina, Madeira – Novembro 1977”, Fly Data. Accessed: January 5, 2021. [Online]. Available: http://flydata2.blogspot.com/2013/05/tap-425-santa-catarina-madeira-novembro.html