Question about flying over the Pacific

There was an Ethiopian Airlines B767 flight in 1994 (I think) that was hijacked, the perps wanted to fly to Australia despite the crew's insistence that they didn't have the fuel. They ended up ditching near one of the islands in the Indian ocean (Comoros perhaps?), and amazingly there were a few survivors.

The number of wide-bodies that have ditched on water with everyone (or even a majority) surviving is exactly zero. Even with narrowbodies I don't think it's ever been done on open ocean since the 50s.

 

Most of the time, ditching in the open ocean is a whole different deal than ditching in a flat, calm harbor or river. It's tricky even in a flying boat to land in the open ocean.

 

And the training for that would be......

 

Don't run out of fuel?

 

The -1 I work with says back side of the swell/crest if you can do it. They really talk about orientation to the waves/wind speed/etc in far more specificity than is practical.

I think someone mentioned oxygen requirements. We also have a depressurized engine out ETP. This way you won’t have to choose between running out of gas or subjecting your passengers to hypoxia or worse if you can’t hold pressurization. If going to a destination near the coast this can sometimes drive your fuel requirements. Not sure if airlines do the same thing but I would assume they do.

 

A 737 ditched off of Hawaii a few months ago. It broke in half. That's pretty common in large aircraft.

 

I was friends with a NWA pilot that had to ditch a 377 in Puget Sound. He didn't lose any passengers to the ditching but one didn't pay attention to his instructions to stay on the wing and he drowned when he tried to swim ashore in the icy water of Puget Sound. Shortly after take off the airplane experienced violent vibrations. Bob asked the flight engineer if he had closed the cowl flaps and the answer was yes but the airplane started to lose altitude in spite of full power. Bob put it down in a smooth uneventful landing near Bainbridge Island. The airplane sunk but was recovered . The cowl flaps were wide open and that had caused the problem. When open, they produce extreme turbulence on the wing and horizontal tail. The FE had recently transferred from DC6's to the Boeing 377. The cowl flap switches operated in opposite directions on the DC6 to close the flaps.

 

Negative Transference

 

Yes, the “land parallel to swells” mantra is not correct for all aircraft. The procedure that is correct is usually spelled out in the operating instructions for any given aircraft.

 

Me as well but at least there is some ice to land on ;-) , but the scariest flight for me is the Johannesburg to Atlanta route, I fly it a few times a year and once of the coast of Namibia you fly the middle of the Atlanta for 10 hours plus up to Atlanta, there is NO place to land out there... Its the only route I have to keep my mind active watching movies the whole time.

 

Santa?

 

That would be from the North Pole.



Matt

 

Ok so when you do over water flights there are a lot of regulations that apply. All of these flights operate under ETOPS (extended range twin engine operational performance standards). Basically what ETOPS requires is that the jet has to be within a given flying time away from a sutable place to land. The flying time is calculated based on winds and what altitude the airplane can fly at, so in the case of a passenger airline it is based on an altitude that the passengers don't need oxygen. Most airliners have about 12 minute supply for the pax. So in the worse case scenario the plane depressurises and is forced to do a rapid descent, the ETOPS time is bassed on this scenario.
So the next part of the equasion is how much flight time is allowed to reach an alternate and this depends on many factors. One of the biggest is the maintenance record of the individual airline. So lets say we are talking about Delta. The FAA looks at how Delta is doing from a maintenance and safety stand point. Lets say you're flying on a 767 (BTW the first twin engine aircraft for extended over water flights) the FAA obviously looks at Delta's 767 fleet but they also look at how well the airline is doing with all of their aircraft. If they are doing well they can be up to 180 minutes of flying time to get to an alternate (and in some cases it can be a little longer). So lets say Delta starts screwing up a little bit. The FAA can restrict them to 120 minutes and if they really suck it can get all of the way down to 60 minutes.
So lets say we are flying Seattle to Tokyo. The flight path follows a curve that typically goes up north to the gulf of Alaska and then roughly follows the Aleutian Chain to east of the northern part of Japan. On this flight the ETOPS alternates might typically be Anchorage and then maybe Shemya, Petropavlosk, or maybe Chitose. So if a problem develops that requires a divert the plane will go to one of the ETOPS alternates. Keep in mind there often are other airports that the airplane could divert to if things got really bad. On these flights the pilots would have a pretty good idea of all of the airports that you could land the airplane at and what the weather was like at those airports.
So to answer to OPs question about LAX to HNL most likely the ETOPS alternates would be SFO and HILO.

 

You have described the airline operation using chemical oxygen generators. So, in the case of the Hawaii run at the point of no return the aircraft will need to finish the flight at the lower unpressurized altitude. Since this is less efficient it means that the aircraft is tankering a lot of extra fuel.

With a gaseous oxygen system (what more of the corporate aircraft use) they will descend briefly then return to altitude to continue the flight at normal (fuel burn efficient) altitude. Typically, the total capacity of the passenger oxygen tanks is determined by the westbound SFO/LAX - Hawaii flight.

 

Gaseous or LOX? Gaseous takes up a lot of volume.

 

That reminds me of Pan Am Flight 6, from 1956. Faked audio here, actual movie footage.

 

Here is that exact scenario....transat 236