United A320 at Denver: "Total Hydraulic Failure"? (Let's reminisce... yawn)

[thepotato232]

Incident: United Airlines A320 near Denver on Oct 21st 2009, hydraulics failure (http://avherald.com/h?article=42198d88&opt=0)

This article clears things right up - most likely just a failure of Green, as AKAAB said.

[misd-agin]

Planes can be flown after total hydraulic failure. Not very easily, but I'd guess trying is better than just giving up and kissing your *ss goodbye.

[protectthehornet]

don't know the bus well...thought that the pitch trim was manual...guess I'm wrong.

I was spoiled with my DC9. Lose all hydraulic pumps and you have manual ailerons, rudder and elevator...also pitch trim, aileron trim and rudder trim....ok you don't have slats/flaps. you still have wheel brakes with accumulators, thrust reversers with accumulators too. gravity drop gear.

So sad that modern planes are so dependent upon hydraulics. it shouldn't be that way...not impossible at all to have something that is truly manual...sure it would cost more...but hey...what's money?

[stilton]

Well, it's simply not possible to operate the flight controls without hydraulic assistance on anything larger / heavier than a 707 for example.



So manual reversion is not an option.

[DC-ATE]

Well, it's simply not possible to operate the flight controls without hydraulic assistance on anything larger / heavier than a 707 for example.


That simply isn't true. You can fly a DC-8 until you run out of fuel without hydraulic power as long as you had a hearty breakfast.:)

[PJ2]

Agree, DC-ATE - there was no real manual reversion on the '8 - it was manual (with hydraulic boost on the aileron tabs). Very heavy on the elevator tho'.

FBW is a concession to money, (fuel savings and manufacturing costs), not technology. Automation on the other hand is both, and it's safer as well. I think the L1011 was the finest, most brilliant mix of real airplane and automation.

[hetfield]

@ironbutt

Spot on!

You know your ship.:)

[eez]

ironbutt57 is correct, without all hyd systems on A320 you don't have aircraft control...

[DC-ATE]

without all hyd systems on A320 you don't have aircraft control...

Gee.....that's comforting. Are all ABs like that?

[hetfield]

Gee.....that's comforting. Are all ABs like that?

No. Only models which had been delivered to the US to meet Boeing standards.:ouch:

[BenThere]

without all hyd systems on A320

Didn't you mean without a hyd system?

You can lose any single system of three primary hydraulic systems and operate the A320 just fine. Lose any two systems and it's more difficult, but still highly recoverable.

[fhegner]

hetfield:

No. Only models which had been delivered to the US to meet Boeing standards.

Good One !:ok:

[ironbutt57]

DC ATE..ALL Boeings since 767/757 onward are the same, DC-10, etc...etc..all require some source of hydraulic power to move control surfaces..et al Soux City 1989..remember? The "luxury" of DC (direct cable) has long been passed by..enjoy the "eight"

[DC-ATE]

ironbutt57

DC ATE..ALL Boeings since 767/757 onward are the same, DC-10, etc...etc..all require some source of hydraulic power to move control surfaces..et al Soux City 1989..remember? The "luxury" of DC (direct cable) has long been passed by..enjoy the "eight"

I'm aware of all that...thank you. That's why I retired when I did. Maybe some day we'll see 'real' airplanes return to the Friendly Skies.

BTW.....I DID enjoy the DC-8; perhaps the most of all the airplanes I ever flew. Second only to the Lockheed Constellation.

[BenThere]

My first airline job out of the military was on the DC-8. It was tough to learn, hard to learn to land, sometimes took brute force to make it go where you wanted, but it was tough and strong, overbuilt to a fault.

I've done initial training on ten airplanes now as I near the end of my career. Looking back, I never liked any airplane better than the DC-8. Once I figured it out, I always knew it would bring me home. The DC-8-73 was a masterpiece. The DC-8-62 was the sportscar of the airliners of its day.

[ironbutt57]

Yah, I missed out on those, couldnt afford to take the job for Rosie when it got offered, they ain't what they used to be..:{

[eez]

I have been told the 727 was super as well, any experience on that?

[cats_five]

<snip>
a blue RAT
<snip>


Presumably this (plus great pilot skill in the glide phase) was what allowed Air Transat Flight 236 to land safely at the Azores.

[con-pilot]

I have been told the 727 was super as well, any experience on that?

I have lost the A and B systems on the 727 on a few occasions, but fortunately never at the same time. During initial training you had to fly and land the simulator with a total hydraulic failure. Now the controls are very stiff and it is manageable. But then again, that was in a sim, not real life.

Well, I take that back. I did fly the 727 with the A and B system turned off one time after I returned from my training so I could actually get the feel of the aircraft without hydraulics, we did not do anything but make some gentle turns and of course we did not attempt to land and we were at FL-200 at 250 kts IAS. As in the sim, the controls were very stiff.

With the loss of either systems you did have strict cross wind limitations, can't remember what they were now.

[hetfield]

With the loss of either systems you did have strict cross wind limitations, can't remember what they were now.

15kts as well as F15 ldg, as far as I remember (3years FE, 5 years F/O).

kind regards

[ZQA297/30]

PJ2:ok:
Automation on the other hand is both, and it's safer as well. I think the L1011 was the finest, most brilliant mix of real airplane and automation.
Great flying airplane, runner up to it -another Lockheed, L-188 Electra.

[45989]

DC-ATE you are spot on!
Had to fly for an hour once after all fluid dumped via the stby rudder pump sys.
Brillant aircraft though. We wiil never see its like again
Since another poster brought up the subject here are my favourites of those I have been lucky enough to fly, best to worst
Dc-8-60's
B-727
B-737-200
B-737 classic
B-737 NG
Fokker 50
A320/321
A330

[thepotato232]

The DC-8-73 was a masterpiece. The DC-8-62 was the sportscar of the airliners of its day.

Any 707 drivers on board who would care to debate this claim?

:p

[DozyWannabe]

Maybe some day we'll see 'real' airplanes return to the Friendly Skies.
I suspect that's the day we find out that nostalgia ain't what it used to be. ;)

Don't get me wrong, I think the engineering quality of those birds was extremely impressive, but you're hardwiring many physical limitations into the design if you want cable reversion, which has a lot to do with why it was phased out in the first place. Also, any one cable failure is just as devastating to the controllability of an aircraft as a full hydraulic failure.

[BenThere]

I've got about 8,000 hours on the 707, too, and it was I who made the claim.

I think the key difference between the two is when you drop a 707 on the runway firmly it will bounce, and the airframe will shiver and shake. When you drop a DC-8-62 in the same way it will stick to the runway, feel rock solid and no one on the flight deck will even take note.

[DC-ATE]

Also, any one cable failure is just as devastating to the controllability of an aircraft as a full hydraulic failure.

Any ONE cable failure, possibly, but there's more than one cable for each control. A dual cable failure is highly unlikely.

The only reason we've gone the "wireless" route is MONEY.

[thepotato232]

Gotcha, BenThere. Just wondering.

I think I once heard somebody say "The DC's like a Cadillac, the 707's more like a Buick". Both are cooler than anything I'm likely to get to fly, of course.

[DozyWannabe]

The only reason we've gone the "wireless" route is MONEY.
I'd say that's one reason, but far from the only reason. Douglas themselves did away with cable control from the DC-10 onwards (and that was well on the way to production before the McDonnell merger).

Remember that the US lead in airliner design came from the "bums on seats" philosophy while our lot over in Europe were building an engineering marvel of an SST that unfortunately would never be able to pay for itself - and the only way the 747, DC-10 and L-1011 were made feasible was by ditching the cable fallback in favour of hydraulically-operated control surfaces.

It's also worth pointing out that both the Brits and the US made stonkingly over-engineered aircraft in the '50s and '60s that nevertheless were as prone to the whims of Mother Nature as any other type. At least one 707 and one BAC One-Eleven that I know of were helpless in the face of bad weather, resulting in nasty crashes and many deaths.

On a more human level, I know it stinks when it feels like a profession to which you dedicated your life seems to be de-skilled before your eyes - but the relentless march of technology means that skills that were once revered become commonplace - it appears it's just the way of things.

[DC-ATE]

On a more human level, I know it stinks when it feels like a profession to which you dedicated your life seems to be de-skilled before your eyes - but the relentless march of technology means that skills that were once revered become commonplace - it appears it's just the way of things.

I guess my timing was good as I got out at the right time; nearly 20 years ago !!

[fhegner]

eh...forgive my as a SLF to ask a 'silly' question: Were/is there any redundency on the cables in the oldtimers. I know from my bike Bullet500.... even cables can 'go fritz' !

fritz

[Swedish Steve]

Were/is there any redundency on the cables in the oldtimers

Less of the old timers.
A brand new B737 has cable operated controls with manual reversion on ailerons and pitch.
And yes there is always two paths from the flightdeck to the servo in a primary control.
Usually one pair of cables from the capt goes down the left of the aircraft, and a separate pair of cables from the F/O goes down the right of the aircraft. The runs are joined fore and aft by breakout mechanisms to allow one side to move with the other jammed, or broken.
But only one pair of cables in a secondary control.
I personally have only once seen a broken cable. On a B737 spoiler control out in the wing.

[RWEDAREYET]

Total Hydraulic Failure on the Bus will kill you, not because of pilot skill, just because it can't be flown!! Even though it may be called the "Electric JET" Hydraulics are more important!!

I flew the DC8 and the B727 as well, both are great airplanes. The Bus has great qualities as well. Large cockpit, with little noise at cruise and great cooling and heating.

I miss flying the old Boeings and Douglas aircraft, they were built like brick S**T Houses. I doubt you will see a bunch of A320's flying around 3rd world countries 40 years after coming off the assembly line. They don't have the shelf life of the older Boeings and Douglas airplanes, but it's still a nice machine to fly.

[DC-ATE]

RWEDAREYET -
I doubt you will see a bunch of A320's flying around 3rd world countries 40 years after coming off the assembly line. They don't have the shelf life of the older Boeings and Douglas airplanes, but it's still a nice machine to fly.

Most airplanes are "nice to fly". It's when things go wrong. That is when it's nice to have an airplane that you still can get on the ground without having to worry what law is in effect or do I have this or that available.

[DozyWannabe]

Maybe so, but I'd argue that in the overwhelming majority of cases you don't have to worry about law you're in or what you have available on modern aircraft - and in the rare case that you do, it's not really any different to wondering what hydraulic or electrical systems you still have after sustaining damage.

In fact, the modern aircraft go out of their way to tell you what you do and don't have in the case of a failure - and most of them will try to compensate for any problems without you lifting a finger. Now - this can be problematic in itself sometimes, but it's a problem that's been around since the first autopilots were installed on airliners.

Finally, the A320 is a tough little bird when it needs to be, as recent events have shown.

[DC-ATE]

Now - this can be problematic in itself sometimes, but it's a problem that's been around since the first autopilots weer installed on airliners.

Ahhh.....but auto-pilots can be disconnected !

[DozyWannabe]

The problems I was referring to came from autopilots disconnecting themselves when they couldn't maintain control any longer.

And Direct Law (which, as I'm sure you know, is the lowest state AI control logic degrades to) is the Flight Control Computer essentially acting as little more than an electronic relay for the pilot's sidestick inputs - it's as manual as you can get in an aircraft of that design!

[DC-ATE]

No.....actually, I DON'T know. And, from what I've read on here and elsewhere, I don't want to know. I'm talking about FBW. Can't teach an old dog new tricks, ya know. As I've said elsewhere, I'm glad I got out when I did and never had to FBW.

[DozyWannabe]

Which is a shame, as you're clearly sharp enough to understand it if you wanted! :)

And had I been around I'm sure it'd have been a pleasure to fly with you. In my opinion, the good ones all love their machines one way or the other.

[DC-ATE]

Which is a shame, as you're clearly sharp enough to understand it if you wanted!

Hey.....I had enough trouble transitioning to the jets let alone FBW !!:eek:

And had I been around I'm sure it'd have been a pleasure to fly with you.

Well, I never saw my name in the Men's room at Flight Ops, but I'm sure there were some who didn't enjoy it fully. But they were probably the SCABs who I didn't let fly !!:8

[David36]

I wonder, in case of total hydraulic loss, are the surfaces locked-in place or they are freefloating? Not necessary on Airbus, also on other big jets.