Colocolo

I only hope you meant: this "valve" as the PTU, correct?

Colocolo

The Ancient Geek

Yup, I was using simple words for the hard of understanding in a probably vain attempt to stop some of the silly comments.

As usual the thread has degenerated into mediocrity. An Airbus expert will probably be along soon to correct any mistrakes by this tired old ex Twotter driver.

deSitter

"Running laps for three hours at only 12,000 feet over the 42C desert below likely made a few pax lurch forward for a sick sack."

ROFL it's true! The only time I've come close to air- or sea-sickness was during an interminable holding pattern for Gatwick in a DC-10. There was something about the slow steady turns always in one direction that made me ill. However the sack remained empty

-drl

aterpster

AncientGreek:

So, once the good pump was cooled off, they could restore it and have a fully functioning airplane, right? If correct they certainly did not need to be below max landing weight to effect a safe landing. That's the part I don't understand.

rog747

and the crew did not have that as they had no n/w steering

The Ancient Geek

Why would anyone want to risk landing overweight for no good reason.
They did it by the book. The max landing weight is there for good reasons and there was no reason to get down in a big hurry.

aterpster

Ancient Greek:

Shorten substantially an unpleasant ride for the passengers.

Also, in the U.S. at least, if the circumstances are such that an overweight landing would be no more risking than landing at max landing weight, then save the fuel by landing overweight. KLAS's longest runway is 14,500 feet.

VijayMallya

Risk an over weight landing? You obviously have a very in depth understanding.

The Ancient Geek

Let me put this a different way - After every incident there will be an asking of questions. If you did it all by the book you get to keep your job and someone else gets to play scapegoat.
By the time you get to landing you already know that this is not your lucky day so why push your luck.
Do it right and there might even be coffee and biscuits when you get called in by the chief pilot.

speed freek

Not technically correct.

It's considered good practice to drop the gear using the alternate system when you have a failure of one of the main systems. The idea being that the gear is a 'heavy' user and you don't want to overload the Green pump when it's supporting both Green and Yellow systems, or the Yellow pump for the same reason.

If you've lost both those systems then you have to use the alternate system anyway.

On older A320 family aircraft, using the alternate gear extension system disables the nose wheel steering.

There is a mod state to bring older A320 family aircraft up to the current spec which stops that from happening, allowing you to taxi clear of the runway.

My other point is the Blue system is powered by an electric pump, of the same size and strength as the elec pump on the Yellow system. In fact they are interchangeable, so if you're AOG away from base, without spares, you can swap the two and have three fully serviceable HYD systems again (top tip ).

It's widely believed (and demonstrated as true several times for me) that running the Yellow system off the elec pump will overheat that pump very quickly.

So, if the Blue elec pump is the ONLY pump keeping them in the air, I quite seriously doubt they would have been able to hold for three hours.

Therefore my take on this rather interesting incident:

They lost Green, lost Yellow, got Yellow back. Decided to hold for three hours (I personally wouldn't have, but I wasn't in command that day), dropped the gear using the manual system and landed safely. Finally resulting in them not being able to vacate the runway.

Thoughts?

Edit:

Also does anyone know when they dropped the gear? With the loss of two HYD systems, that would have put the aircraft in Alternate Law. Dropping the gear puts it in Direct Law, which makes the aircraft very sensitive to side stick inputs. That might explain the 'lurching' and sick pax. And they may have dropped the gear early to help with the fuel burn-off.

Checkboard: Too bloody right!!!!!! Almost threw my tea across the room shouting "just say Mayday and tell them to standby!!!". You could hear the Master Warning blasting away in the background for God's sake. What happened to Aviate, Navigate, Communicate?

AKAAB

G HYD leak in the wheel well. Loss of fluid leads to PTU Fault (can't pressurize without fluid.) Y HYD system senses overheat, but is recovered. Thus, Dual HYD Failure is now only G HYD Failure. Land ASAP is no longer valid and time is taken to assure a safe landing with ability to stop the aircraft.

FWIW - for everyone saying they should have gone to Edwards AFB, most military bases don't show up in JB Nav Databases. If the crew wasn't already intimately familiar with the area, it may have never occurred to them. Trust me, as we cross the country it's infuriating to look down at 15,000 feet of beautiful emergency asphalt (or lake beds) and not see it displayed on our nav displays. Of course, it's on the charts, but in the heat of the moment I can see the logic of staying over a viable airport and not venturing across the unfriendly terrain with the possibility of additional failures.

sevenstrokeroll

i mentioned edwards in case things got really bad

any pilot in the world that doesn't know that edwards is somewhere between las vegas and los angeles in a general sense isn't worth their salt.

las vegas has a very, very long runway and could easily have accomadated an expeditious return for landing.

there must be alot to this story...some good stuff coming out here about airbus systems.

jetblue not having major military airfields on their data base is pretty weak.

bubbers44

You have to think when you have a malfunction. Do you have no flight controls, go to the desert and land directly into the wind because you have no runways and can do what ever you want. No flaps, land at Edwards because it is long. Mine was a positive bomb threat to go off at 2500 ft going into LAX. I said I can't make it to Reno with our fuel so asked what was Edwards elevation. I saw our cabin was at 120 ft so said disregard, we are landing at LAX. I loved those movies which I thought of when told we would blow up at 2500 ft but they went to Denver. I loved flying airliners because every day was different. You could tangle with ATC, flight attendants, passengers and agents and weather and still have a good day. It was the best job of my life and made friends with all agents at every airport, especially TGU, my favorite. No regrets.

bubbers44

#124 (permalink)




bubbers44



Join Date: Aug 2005

Location: fl

Posts: 1,283




You have to think when you have a malfunction. Do you have no flight controls, go to the desert and land directly into the wind because you have no runways and can do what ever you want. No flaps, land at Edwards because it is long. Mine was a positive bomb threat to go off at 2500 ft going into LAX. I said I can't make it to Reno with our fuel so asked what was Edwards elevation. I saw our cabin was at 120 ft so said disregard, we are landing at LAX. I loved those movies which I thought of when told we would blow up at 2500 ft but they went to Denver. I loved flying airliners because every day was different. You could tangle with ATC, flight attendants, passengers and agents and weather and still have a good day. It was the best job of my life and made friends with all agents at every airport, especially TGU, my favorite. No regrets.