Airbus Hydraulic issues

I'm typed on the A320 and I can issue types on the aircraft and I understand what is going on in a situation like this.

I don't have a problem with what the crew did. They were degraded down to one hydraulic system which has an effect on landing distance and braking. The crew chose to burn off weight and remain local, again no issues there.

I have no issues either. So, I'm sure you're qualified to answer the question. If they lost system 3 of 3, what does that do to the ability to keep the airplane under control?
 
I have no issues either. So, I'm sure you're qualified to answer the question. If they lost system 3 of 3, what does that do to the ability to keep the airplane under control?

MECHANICAL LAW; No flight control computers are available. The aircraft has to be flown using the rudder pedals, trim wheel, and differential throttles as the side-stick is inop. Hydraulics are required. It is highly unlikely that mechanical law would ever occur as it would take failure upon failure of systems to get to mechanical law.
 
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Bearing in mind the above reference to Alaska 261, what's worse; stying in the air with a crippled bird or landing IMMEDIATELY even if overweight? As was pointed out, two fairly large facilities nearby.
Henning's point is they kept flying for several hours with an injured aircraft. ASAP generally means immediately. Does one risk more landing heavy or flying for hours?
And I guess I should ask why wasn't a fuel dump system put on the plane if it isn't prudent to land heavy?
 
Bearing in mind the above reference to Alaska 261, what's worse; stying in the air with a crippled bird or landing IMMEDIATELY even if overweight? As was pointed out, two fairly large facilities nearby.
Henning's point is they kept flying for several hours with an injured aircraft. ASAP generally means immediately. Does one risk more landing heavy or flying for hours?
And I guess I should ask why wasn't a fuel dump system put on the plane if it isn't prudent to land heavy?

There is an overweight landing procedure in the QRH.

The crew was dealing with a loss of 2 hydraulic systems which affect various flight controls and landing distance as well as braking and thrust reverse.

I'm not going to second guess the crew, they had an uneventful outcome.

The media has really tried to sensationalize this into more than it was.
 
I have obviously never flown an Airbus but I wouldn't even dream of going up to high altitude with a control problem. Note that they only got up to 12,000' which is not the greatest altitude for flying a jet from Las Vegas to New York.
 
I have obviously never flown an Airbus but I wouldn't even dream of going up to high altitude with a control problem. Note that they only got up to 12,000' which is not the greatest altitude for flying a jet from Las Vegas to New York.


Couple more thousand and they would have cleared, they flew for 4 hours at that altitude...:dunno: No big deal, really, I just though, if you're gonna be flying anyway, might as well head somewhere was my thought.
 
Couple more thousand and they would have cleared, they flew for 4 hours at that altitude...:dunno: No big deal, really, I just though, if you're gonna be flying anyway, might as well head somewhere was my thought.

I'm honestly surprised that it took them 4hrs to burn down to a safe landing weight at that altitude.


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Couple more thousand and they would have cleared, they flew for 4 hours at that altitude...:dunno: No big deal, really, I just though, if you're gonna be flying anyway, might as well head somewhere was my thought.
Hmmm... "Center, we have a control problem and we're declaring an emergency, and, by the way, we want to fly across the country at 14,000 and get as far as we can get. Mountains? Weather? We'll just wing it."
 
I understand that 'when' was to be ASAP, however with that being quite a bit of time away due to burning fuel, it still left options as to where.
Why in the world would they want to go somewhere else, assuming the wx wasn't horrible where they were?
 
I'm honestly surprised that it took them 4hrs to burn down to a safe landing weight at that altitude.


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I think he burned it down to minimum fuel. The less inertia, the finer control he has and the less fuel to burn in the crash.
 
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I think he burned it down to minimum fuel. The less inertia, the finer control he has and the less fuel to burn in the crash.

That's the the thing I have never fully understood....burning down to min fuel certainly gets you lighter, but less fuel in the tanks generally means more vapor which is what'll explode in a crash.


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That's the the thing I have never fully understood....burning down to min fuel certainly gets you lighter, but less fuel in the tanks generally means more vapor which is what'll explode in a crash.


:confused: Don't they inert the ullagae space in big jets? They should, simple enough to do, tankers do it. Besides, explosions aren't that bad, outside of shrapnel, it's mostly shock and flash burn. It's the long burning fuel that provides the toxic gasses and enduring heat that sears the lungs. I still 'play' with explosions, I don't 'play' with fire anymore, I know which leaves worse scars.;)

I think he did right there for sure, the two greatest hazards he was looking at were kinetic energy and enduring fire and he reduced both of those to minimum levels.
 
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I read somewhere that depending on which hydraulic system was failed, he also lost the thrust reversers. So that combined with the brakes... lighter is better. Especially in Vegas on a hot day.
 
I read somewhere that depending on which hydraulic system was failed, he also lost the thrust reversers. So that combined with the brakes... lighter is better. Especially in Vegas on a hot day.

Green system controls left reverser and normal brakes, Yellow system controls right reverser and alternate brakes. In addition he was going to be limited in flaps, which means a higher than normal approach speed.
 
So simple question. If the third hydraulic system failed, and it reverted to mechanical law. Are the landing outcomes in the SIM favorable in that scenario?
 
So simple question. If the third hydraulic system failed, and it reverted to mechanical law. Are the landing outcomes in the SIM favorable in that scenario?

MECHANICAL LAW; No flight control computers are available. The aircraft has to be flown using the rudder pedals, trim wheel, and differential throttles as the side-stick is inop. Hydraulics are required. It is highly unlikely that mechanical law would ever occur as it would take failure upon failure of systems to get to mechanical law.
 
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So simple question. If the third hydraulic system failed, and it reverted to mechanical law. Are the landing outcomes in the SIM favorable in that scenario?

Search YouTube for Souix falls plane crash, that's what you get. Personally I'd prefer to be east of the Rockies doing it.
 
Search YouTube for Souix falls plane crash, that's what you get. Personally I'd prefer to be east of the Rockies doing it.

Why not go into Edwards if you're going to fly around? Nothing to hit and lots of runway.
 
Search YouTube for Souix falls plane crash, that's what you get. Personally I'd prefer to be east of the Rockies doing it.

Completely different systems. Sorry Henning, but this is wrong.

United 232 was out of options completely. They made up procedures from sheer aeronautical experimentation. You can watch the late Denny Fitch's interview in six parts on YouTube and hear it straight from him, RIP. (He recently passed away from cancer.). There were no checklist items left.

Airbus still has a couple of tricks up their sleeve at the last hydro failure.
 
I ran some numbers and came up with this.

155 SOB equal about 130,000 ZFW.
LAS- JFK FOB would be about 28-30K.

That's a takeoff weight of about 160K.
Max takeoff is 169.7
Max Landing is 142.2

Loss of Green and Yellow hydraulics is worst case for losing 2 out of three systems. This gives a landing distance factor of 2.8 or 2.8 times the normal distance.


So at 160k, landing distance is 9500'. Plus 8% for the 2000' PA equal 10260. If you add in the 15% required safety margin, that's 11,800 feet.

Longest runway at KLAS is 25R at 14,500(with a LDA of 12,755) and the only one long enough to use assuming the winds are favorable. Landing would be flaps 3 with a Delta Vref of +25. Normal is Flaps 4 with a Delta V of + 5. There would be no normal brakes or antiskid and only seven applications of alternate brakes from the accumulator assuming the Yellow system fluid wasn't depleted. Thrust reversers are not available either.


Burning fuel down for 4 hours gets you down to under 140k and a 7800' landing distance with out a safety margin and the ability to use any of the runways at KLAS that are favorable for the winds. It migth also get you back some systems if the hydraulic systems loss was due to overheat and the system was allowed to cool.


Based on what info is available, orbiting for 4 hours to reduce weight on an aircraft with greatly reduced braking while staying close to the only useable runway within 170 nm seems like a prudent thing to do. Some guys I've discussed it with have said they would land ASAP when down to only one HYD system but it would be dependent on the situation. Until more info comes to light, I can't fault the actions of the crew.
 
Search YouTube for Souix falls plane crash, that's what you get. Personally I'd prefer to be east of the Rockies doing it.

For anyone searching it was Souix City not Souix Falls.

I landed there at night shortly after the airport reopened. You could still see the black scorch mark on the runway.
 
Man, if UAL 232 pilots (Captain Fitch being the lifesaver of the day) had had stab trim and rudder, they'd have been ecstatic!
 
I ran some numbers and came up with this.

155 SOB equal about 130,000 ZFW.
LAS- JFK FOB would be about 28-30K.

That's a takeoff weight of about 160K.
Max takeoff is 169.7
Max Landing is 142.2

Loss of Green and Yellow hydraulics is worst case for losing 2 out of three systems. This gives a landing distance factor of 2.8 or 2.8 times the normal distance.


So at 160k, landing distance is 9500'. Plus 8% for the 2000' PA equal 10260. If you add in the 15% required safety margin, that's 11,800 feet.

Longest runway at KLAS is 25R at 14,500(with a LDA of 12,755) and the only one long enough to use assuming the winds are favorable. Landing would be flaps 3 with a Delta Vref of +25. Normal is Flaps 4 with a Delta V of + 5. There would be no normal brakes or antiskid and only seven applications of alternate brakes from the accumulator assuming the Yellow system fluid wasn't depleted. Thrust reversers are not available either.


Burning fuel down for 4 hours gets you down to under 140k and a 7800' landing distance with out a safety margin and the ability to use any of the runways at KLAS that are favorable for the winds. It migth also get you back some systems if the hydraulic systems loss was due to overheat and the system was allowed to cool.


Based on what info is available, orbiting for 4 hours to reduce weight on an aircraft with greatly reduced braking while staying close to the only useable runway within 170 nm seems like a prudent thing to do. Some guys I've discussed it with have said they would land ASAP when down to only one HYD system but it would be dependent on the situation. Until more info comes to light, I can't fault the actions of the crew.

Great write up. Thanks.
 
After reading the write-up, sounds like the pilots made the right call.

I'd more question why Airbus designed the plane that way...
 
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