Mount Redoubt - Alaska
25 January 2017
Just 200 km West of Anchorage and bathing in a beautiful soft sunrise, as seen during our approach into Anchorage. One of the many active volcanos in Alaska that has erupted numerous times past century. Most notably was the 1989-1990 eruption that caused a KLM 747-400, flying from Anchorage to Tokyo, to lose thrust of all engines in flight after flying in the ash-cloud.
Just 200 km West of Anchorage and bathing in a beautiful soft sunrise, as seen during our approach into Anchorage. One of the many active volcanos in Alaska that has erupted numerous times past century. Most notably was the 1989-1990 eruption that caused a KLM 747-400, flying from Anchorage to Tokyo, to lose thrust of all engines in flight after flying in the ash-cloud.
Gliding in a shallow path towards high mountains and glaciers, the pilots frantically tried to restart the engines that were heavily damaged by the ingested ash-particles that formed a glass deposit inside the hot sections of the turbines.
While the electrical generators continued to flick on and off, power was intermittently cut off to the displays and instruments in the cockpit, adding to the stress and aggravating the situation even more.
After descending towards the mountains in a couple very stressful minutes, the crew managed to relight engines 1 and 2 at an altitude of around 13.000 (around 4km altitude) and, while the aeroplane was still descending, the other two engines were relit at 11.000ft. From this point on, the 747 was able to climb back from 10.000ft to a safe altitude and return to Anchorage for an emergency landing.
Even though an altitude of 10.000ft sounds high, the mountains and glaciers are easily reaching up to 12.000ft in that area. I can only imagine how extremely close those unforgiving peaks and glaciers must have been, with no power to gain altitude, losing cabin pressure and the cockpit instruments flickering on and off constantly.
Since this incident, together with the BA 747 that flew into an ash cloud and lost all 4 engines in 1982, aviation has become very aware of the dangers of ash clouds to airplanes. An expensive lesson but fortunately this was a lesson that was only paid by material damage.
Today, the easily recognizable Mount Redoubt stands proudly on top of the Aleutian mountain ridge and its a matter of time before she will erupt again.