"The crew went around, climbed to 8500 feet, depressurized the aircraft, opened the cockpit side window and cleaned the windscreen by hand."
"The aircraft flew into a cloud of volcanic ash [...] resulting in the failure of all four engines. [...] The cloud sandblasted the windscreen and landing light covers [...] After landing, the flight crew found it impossible to taxi, due to glare from apron floodlights which made the already sandblasted windscreen opaque."
https://www.telegraph.co.uk/travel/news/pilots-awarded-medal... / http://euromaidanpress.com/2017/07/29/ukrainian-pilot-miracu...
"Soon after take-off, at 1,300 metres above the ground, the aircraft’s nose was pummelled by hailstones the size of golf balls, shattering the windscreen and leaving the pilots unable to see." "The pilot made a decision to return and was able to land by tilting the airplane to see the runway through the side window and by good coordination with the airport’s dispatchers."
> As Flight 9 approached Jakarta, the crew found it difficult to see anything through the windscreen, and made the approach almost entirely on instruments, despite reports of good visibility. The crew decided to fly the instrument landing system (ILS); however, the vertical guidance system was inoperative, so they were forced to fly with only the lateral guidance as the first officer monitored the airport's distance measuring equipment (DME). He then called out how high they should be at each DME step along the final approach to the runway, creating a virtual glide slope for them to follow. Moody described it as "a bit like negotiating one's way up a badger's arse."
The pictures are intense!
Edit: The original title was way more focused on the fact this is a Boeing 737; I feel the new post title is a good compromise.
BTW: I think this is gaining traction because it's a 737; however, can most airplane windshield wipers clean a thick layer of dead, crushed locusts off the windscreen?
I would argue that we should change the title to "airliner." I think the title is meant intentionally to capitalize on the notoriety of the model of airplane, when this incident is not specific to that model.
The description is sometimes updated when more information comes in.
Pretty much any rubber bladed windshield wiper will not be able to clear them after they dry out and at several hundred miles an hour with equatorial air temperatures that will happen very quickly.
> That wind made me it's bitch.
As for the windscreen, I'm not sure if the 737 checklists include "depressurize and clean manually" for bug strikes, but I wouldn't be surprised if it did have instructions for general "windshield is obscured" conditions.
Section 2.17. Volcanic Ash Encounter
I learned to fly with the RAF as an air cadet. I vividly recall the first lesson in which my instructor whipped out a piece of cardboard, covered the windscreen, and said “land”.
It turns out that as long as you’ve ILS, you can do it with zero vis.
It looks like they had ILS available: https://worldaerodata.com/wad.cgi?id=ET86469
I can’t help but think a blind landing is safer than depressurising a cabin full of passengers.
Even when flying on instruments you still land visually, unless the aircraft is cat iii / autoland capable, the crew is certified and current and the airport has cat iii procedures in effect. Probably they didn't have one of these and didn't want to land with zero visibility.
Depressurizing at 8500ft is a good choice, the cabin is normally pressurized to the equivalent of 8000ft outside air pressure. So what they did was basically open the outflow valves and passengers wouldn't have noticed a thing.
Doing it in a commercial airliner full of passengers would absolutely be a last resort.
As an absolute last resort in a small piston you can try to do what we learned to do in case of a night landing where all lighting etc fails: Fly it slightly nose up, no flaps, with a 100 ft/min descend and wait until you hit the runway. You will basically fly it into the runway at a speed that doesn't break anything. Only works for small planes on a big runway.
The legality doesn't matter much if you are doing it in an emergency (say unforcast fog shutting down all runways within the aircraft's remaining range).
All available categories have a decision height > 0ft: https://en.wikipedia.org/wiki/Instrument_landing_system#ILS_...
The plane approaches, flares, and lands and keeps the plane on centerline (in some cases). Most (if not all) currently flying 737s are capable of this. The question is of course if this particular airport was ready for that (if not, I'm not sure if the autopilot would allow this) and whether the pilots were certified for this.
https://thepointsguy.com/guide/aircraft-operating-foggy-cond...
We're talking about 1000ft above Mexico city amount of altitude, here, not Mt. Everest. Any inherent risk from that is below the threshold of what's quantifiable. Skydivers routinely jump from 10,000ft.
It's another thing entirely to do it in a passenger airliner, and "depressurizing" at 8500' is nothing, you don't even need oxygen at all below 12,5 and even then only occasional usage for required crewmembers until 14,5.