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fotoguzzi
20th Jun 2012, 10:36
[Not a pilot] Here is a non-technical account of a JetBlue emergency flight [added: on the afternoon of 17 June]. Another source identifies the plane as flight B6-194, Las Vegas to JFK, New York with 155 people on board. The same source gives the registration number: N552JB.

Panic grips New York-bound JetBlue flight when hydraulic system fails over Las Vegas - NYPOST.com (http://www.nypost.com/p/news/national/jetblue_hours_of_hell_sKTYyyOCgV9oGLeqnuIWIJ)

Dg800
20th Jun 2012, 10:56
Kudos to the reporter for getting it right at least this once regarding the burning off vs. actual dumping of excess fuel.

:ok:

pitotheat
20th Jun 2012, 11:01
Nice to see that these experts can manually land an Airbus when all the hydraulic systems fail. Perhaps they could teach us pilots how to do that - there is very limited manual reversion on the Airbus unlike the Boeing. The Airbus manual reversion allows you to maintain straight and level to reset one or more flight control computers. Airbus=total hydraulic failure=toast.

737superace
20th Jun 2012, 11:10
Good Point!!
So why did these guys hold for 3 hours when they had lost 2 out of 3 systems and were 1 failure away from being toast.
Don't tell me it was 'cos they didn't want to risk an overweight landing. Please!

fotoguzzi
20th Jun 2012, 11:15
Another technical site has some cogent comments on the options available to the pilots. I do not know if pprune.org wishes to link to possible competitors.

TURIN
20th Jun 2012, 11:23
- there is very limited manual reversion on the Airbus unlike the Boeing. The Airbus manual reversion allows you to maintain straight and level to reset one or more flight control computers. Airbus=total hydraulic failure=toast.

At the risk of turning this into a Boeing V Airbus bun fight, again. Please could someone explain what manual reversion there is in a modern Boeing compared to an Airbus In the event of a total hydraulic failure.


I'm not familiar with the B737NG. Is the manual reversion the same as the classic?

AFAIK all large modern jet transport require hydraulics for the flt controls to function. Barring the 737 perhaps.

oliver2002
20th Jun 2012, 11:41
Nice to see that these experts can manually land an Airbus when all the hydraulic systems fail.

Where do you read that 'all' hydraulic systems failed?

Flightmech
20th Jun 2012, 11:51
I was once told there were three physical cable-and-pulley type cables in the aircraft.
1. Rudder (back up input to hyd control)
2. Alt Gear extension.
3. Toilet dump (!)

Perhaps someone can confirm

Check Airman
20th Jun 2012, 12:19
Here's the link to Avherald, which is probably the next best thing to the NTSB report, and absent the usual media rubbish.

Incident: Jetblue A320 at Las Vegas on Jun 17th 2012, two hydraulic systems failed (http://avherald.com/h?article=45165c68&opt=0)

Incident: Jetblue A320 at Las Vegas on Jun 17th 2012, two hydraulic systems failed


By Simon Hradecky, created Tuesday, Jun 19th 2012 16:52Z, last updated Tuesday, Jun 19th 2012 16:52Z

A Jetblue Airbus A320-200, registration N552JB performing flight B6-194 from Las Vegas,NV to New York JFK,NY (USA) with 155 people on board, was climbing out of Las Vegas' runway 25R when the crew levelled off at 13,000 feet reporting multiple hydraulic problems, a few minutes later the crew declared emergency reporting they had lost two hydraulic systems. They needed to burn off fuel and entered a holding at 12,000 feet for about 3 hours and landed safely on runway 25R about 3:30 hours after departure and stopped on the runway.

The runway was closed for about 30 minutes until the aircraft was towed off the runway.

A replacement Airbus A320-200 reached New York with a delay of 8 hours.

FlightAware > JetBlue Airways (B6) #194 > 17-Jun-2012 > KLAS-KJFK Flight Tracker (http://flightaware.com/live/flight/JBU194/history/20120617/2053Z/KLAS/KJFK)I'm also wondering about the decision to hold for 3 hours when down to one hydraulic system. The only thing I can think of is that they considered stopping ability, and decided it was more prudent to make a later landing at a lower weight than a quick landing at a heavy weight.

Too soon to pass judgment at this stage anyway. In the interim, it appears that the crew did a good job of getting everybody back safely.:ok:

misd-agin
20th Jun 2012, 12:36
Holding for 3 hrs on one hydraulic system???

xaf2fe
20th Jun 2012, 12:37
I was always told that if the Max Landing weight is less than or equal to the Max Takeoff Weight a Fuel Dump system is not required. But if the MLW is less than MTOW then a Fuel Dump system is required. This guy had to burn off 3 hours of gas to get to landing weight. That's a BIG difference. Why is there no Fuel Dump system on the 320?

I don't want to second guess this guy (but that is what we do here), but if I just lost 2 of 3 hydraulic systems, I would get that thing on the ground. But I'm a Boeing guy, we can do that. Can you land the Bus overweight?

25R in Vegas is 14,500 feet long.

WHYEYEMAN
20th Jun 2012, 12:42
In the hold for 3 hours staring at the red LAND ASAP memo?? Surely not.

CptRegionalJet
20th Jun 2012, 12:44
Dual hydraulic failure on ECAM:Land ASAP in red....should Take about 30-45 minutes to go through all procedures including over weight landing.....but 3 hours?:confused:
By the way,it's allowed to land this plane @MTOW with a Rate of descent less than 360 ft/min.

Dg800
20th Jun 2012, 13:03
Holding for 3 hrs on one hydraulic system???

Apparently not: "The Aviation Herald however learned on Jun 20th that the green hydraulic system had been lost followed by an overheat indication of the yellow hydraulic system prompting the crew to report the failure of two hydraulic systems. The crew actioned the relevant checklists and were able to recover the yellow hydraulic system."

Lonewolf_50
20th Jun 2012, 13:09
Looks like a good job by a crew who methodically worked through their malfunction(s) to a safe landing. *tips cap*

In re the journalists ...
]One of the pilots declared an emergency and radioed Las Vegas controllers that they were dealing with “quite a few things, but the initial thing is . . . we’ve lost two hydraulic systems.”
I'd rather hear what was actually said on the radio.
The plane was loaded with five hours’ worth of fuel. Because the A320 is incapable of dumping excess fuel, the pilots circled the area south of the Vegas Strip until they’d burned enough to allow the crippled plane to land safely.[/quote]
Appreciate the explanations in this thread in re why fuel dump not required for cert. Was unaware.
An Airbus manual describes a double hydraulic failure as “improbable in operation.”
But not impossible. And as noted, they apparently got one of them back on line. Stalling an A330 is also "improbable," but it too has happened. :sad:
[quote]
Esser said an Airbus has enough backup systems that the passengers were not in serious danger. “Even if everything failed, there would have been a way to manually land the aircraft,” he said.

Methinks the reporter is mistaken, or the spokesman careless.
If "everything" fails (all hyd systems failed?) I don't think a landing manually will be a matter of controlled flight. (Perhaps differential power with engines would make some sort of control possible ... not sure)

Presuming the A330 and A320 flight control set ups are similar, my slightly out of date flight control system diagram shows that, for example, the cables on the trim wheels require hydraulic boost to move the horizontal stab. Do I understand that correctly?

Basil
20th Jun 2012, 13:30
careening wildly through the skies
Well, you want those barnacles off before the chief pilot sees you :)

Field In Sight
20th Jun 2012, 13:33
I have to admit that 3 hrs seems excessive, as always I have to say that I was not there and there could be a number of considerations missed.

If they lost the green fluid then it's likely that the yellow system was lost due to the PTU running and causing an overheat. Maybe during the takeoff inhibit phase.

They may have waited for this to cool to recover systems before making an approach.

I wouldn't like to land with accumulator only pressure, regardless of how long the runway is.

sevenstrokeroll
20th Jun 2012, 13:34
ok...we really do need an airbus guy to tell us about the hydraulic system on the 'bus

I IMAGINE there is a hydraulic system with each engine (two) plus some sort of alternate system powered by some sort of electrically driven pump.

as we have all been told, the plane can get PITCH control in an emergency from manually moving the stab trim.

that the RUDDER can be used manually (but only with hydraulic power)...please correct me if I am wrong here.

and one CAN use differential engine thrust as well to sort of steer the plane.

BUT three hours of holding? While it is tempting to burn fuel down to landing weight TO AVOID an overweight landing inspection, this is a little much. AS most of you can imagine LAS VEGAS has nice long runways for stopping in this case. I would also like to think that airbus has brake accumulators to aid in stopping if hydraulics are lost. And even accumulators to deploy thrust reversers.?

An overweight landing is not dangerous if done properly (in most cases I think of one must limit descent rate at touchdown to less than 300 fpm....compared with 500-600fpm in a normal landing) I did an overweight landing in a 737 with no problem (I had one engine unable to produce a normal ammount of thrust...but I kept it running till we were on the ground)...and I didn't wait no three hours. IT was the time to do checklists and get vectored back for the apch.


Some questionable things here...MX to be sure has to be checked and a full explanation of why three hours?

I imagine too that the landing would have been no flaps without any hyd?

oceancrosser
20th Jun 2012, 13:36
xaf2fe wrote:
I was always told that if the Max Landing weight is less than or equal to the Max Takeoff Weight a Fuel Dump system is not required. But if the MLW is less than MTOW then a Fuel Dump system is required. This guy had to burn off 3 hours of gas to get to landing weight. That's a BIG difference. Why is there no Fuel Dump system on the 320?


Someone told you bull****. Who invents crap like that? I have flown 767s that do not have fuel dumping capability (it is a customer option), and the MLW is 40 tons lower than MTOW. :ugh:

Saint-Ex
20th Jun 2012, 13:45
Airbus=total hydraulic failure=toast.

Pitothead, that`s rubbish. Look up OO-DLL hit by missile out of Baghdad. Left wing flap mangled beyond recognition, NO HYDRAULICS and landed on the runway with less than 2g recorded.

sevenstrokeroll
20th Jun 2012, 13:47
just to try to explain this fuel dump business/requirements.

Very few jets in domestic, medium range service need to have fuel dump/jettison capability.

the big thing is if you takeoff , lose an engine and have to return for landing...if your weight is too much to allow a safe go around on remaining engines, then you have a problem...and that problem is dealt with by dumping fuel.

landing overweight isn't so much the problem with the fuel dump requirement, it is the ability to do the go around after the engine out approach.

while there is a rare ability of some DC9's to dump fuel, the changeover in plane size is right around the 767...and some of the 767's DO NOT have fuel dump nor do they require it. but planes bigger than that (just a gudeline) usually have fuel dump capability.

CptRegionalJet
20th Jun 2012, 13:49
Flap/ slat availability depends on the failure combinations...

G+Y would be no flaps but slats available(Slow movement though)

hetfield
20th Jun 2012, 13:49
A300 B4

MTOW 165t
MLAW 134t

No fuel dump system!

hetfield
20th Jun 2012, 13:51
Airbus=total hydraulic failure=toast.

Pitothead, that`s rubbish. Look up OO-DLL hit by missile out of Baghdad. Left wing flap mangled beyond recognition, NO HYDRAULICS and landed on the runway with less than 2g recorded. Yes, but don't try it again.....

GarageYears
20th Jun 2012, 13:59
The Blue hyd system (elec pump + RAT backup) gives you control of the following:

Rudder
Elevators

Slats
Spoiler #3 L+R
Aileron L+R

If Yellow AND Green are gone you lose:
Trim control (yellow or green needed)
Yaw damper
Flaps
Stabilizer
NWS
Normal gear
Eng rev 1&2
Normal and Alt brakes


The latter is clearly (to me) the biggest problem - no brakes if both Green/Yellow are gone. All you have is any residual accumulator pressure. So my guess is that is why you'd what to get the aircraft as light as possible - all you've got are spoiler #3 both sides.

sevenstrokeroll
20th Jun 2012, 14:01
cptregjet

since you seem to know...is there any combination of two hydraulic failures that would leave the plane un controllable? is there a third standby?

and other than reducing weight, what reason could there be to hold for three hours...is resetting due to thermal problem possible.

I know in one jet I flew, we had a THERMAL CUT OUT OVER RIDE to use the hyd alternate system right away if needed.

CptRegionalJet
20th Jun 2012, 14:04
GY,

Blue hydraulic can't drive the flaps,only the slats;)
Dual failure "only" can not lead to an uncontrolable aircraft....

hetfield
20th Jun 2012, 14:08
3hrs hold with only one hyd system left....

Sorry, wouldn't be my choice!

sevenstrokeroll
20th Jun 2012, 14:11
captregional jet

so there is a yellow and green (eng?) and a blue system.

the blue system can give you normal aileron/spoiler, rudder and elevator?

there are reports that the plane was lurching about, with pax getting sick.

either the situation was worse than two hyd systems out, or real questions on three hour holding.

de facto
20th Jun 2012, 14:18
there are reports that the plane was lurching about, with pax getting sick.

See post 23 about yaw damper:O

GarageYears
20th Jun 2012, 15:00
Blue hydraulic can't drive the flaps,only the slatshttp://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/wink2.gif

Roger that - not sure why, but the Hyd System data I have states Blue gives you flaps, but this is contradicted by the Flight Controls data, confirming flaps require Green or Yellow.

Locked door
20th Jun 2012, 15:08
FWIW Airbus test pilots have successfully landed the A320 family in manual backup multiple times during testing. That being said manual backup is designed to allow control of the a/c during systems recovery, not to perform a landing.

There is no double hydraulic failure that could lead to loss of control, and even a triple failure leaves the aircraft flyable. From memory the yellow system has an engine and electrical pump. The green has an engine pump and the two way ptu between the green and yellow. The blue has an electric pump and an auto deploying ram air turbine pump (that also supplies backup a/c electrics). There's plenty of redundancy, but a double failure is a red 'LAND ASAP' ECAM warning.

Checkboard
20th Jun 2012, 15:10
Fill your boots:

http://i665.photobucket.com/albums/vv20/Checkboard/HydSys.jpg

and even a triple failure leaves the aircraft flyable.
Well, so much for 5000 hours of Airbus experience, then. :oh:

Mechanical back-up is rudder and trim - both need hydraulic pressure to work, so a triple hydraulic failure leaves you with NO flying controls (including trim). You have engine thrust, gear extension and passengers running forward and rearward for control - i.e. None.

(Mechanical back-up is designed to provide a minimum of control following a complete loss of electrical power (side sticks don't work!) - i.e. before you can get the RAT deployed, and the emergency generator up to speed.)

hetfield
20th Jun 2012, 15:15
FWIW Airbus test pilots have successfully landed the A320 family in manual backup multiple times during testing. That being said manual backup is designed to allow control of the a/c during systems recovery, not to perform a landing. MANUAL BACKUP has absolutely nothing to do with hyd failures.

Flightmech
20th Jun 2012, 15:26
Airbus=total hydraulic failure=toast.

Pitothead, that`s rubbish. Look up OO-DLL hit by missile out of Baghdad. Left wing flap mangled beyond recognition, NO HYDRAULICS and landed on the runway with less than 2g recorded.

Actually that was an old A300B2/B4. Not a 320 family with fly-by-wire flight controls

hetfield
20th Jun 2012, 15:32
Actually that was an old A300B2/B4. Not a 320 family with fly-by-wire flight controls

True, but doesn't make any difference if you have no hyd at all.

kwateow
20th Jun 2012, 15:41
The A380 can be flown in all-hydraulic or all-electric modes.

Saint-Ex
20th Jun 2012, 15:42
Thats true but it makes not one iota of difference if it`s fly-by-wire or not. The 320 is inherently a very stable airframe as shown by multiple manual landings during the flight test stage. Besides, your statement only said Airbus.

fantom
20th Jun 2012, 16:05
I have seen (and done) many, many sim landings off the ILS - just for confidence building - in mechanical back-up. Power for pitch control by one pilot and rudder/pitch trim by the other.

Try it.

Flightmech
20th Jun 2012, 16:05
Thats true but it makes not one iota of difference if it`s fly-by-wire or not.

Well actually it does? On some non-FBW aircraft you have manual reversion (cable to control tab as an example). I'm not an Airbus basher by the way and have nothing against the A320.

ironbutt57
20th Jun 2012, 16:06
No hydraulics=landing w thrust maneuvering only, seems to be the case from DC-10 onward

SloppyJoe
20th Jun 2012, 16:30
A330-300s also do not have fuel dumping. MTOW 233T MLW187T. You can land up to MTOW after performing the overweight landing checklist.

If engine out and heavy, or even with both engines running it may be required to start APU to supply packs or switch off packs for Go-around performance, combined with a flap 3 approach.

I assume it will be something similar with the 320.

CONF iture
20th Jun 2012, 16:45
A330-300s also do not have fuel dumping.
Some have.
Anyway, I don't know for the 320, but for a 330 at MTOW with the most critical dual hyd fail, the actual landing distance for LAS is close to 13000 feet.

mnttech
20th Jun 2012, 17:27
I knew the 105% was in the books at one time, but it looks like it has been changed to (at least in the US):
§ 25.1001 Fuel jettisoning system.
(a) A fuel jettisoning system must be installed on each airplane unless it is shown that the airplane meets the climb requirements of §§25.119 and 25.121(d) at maximum takeoff weight, less the actual or computed weight of fuel necessary for a 15-minute flight comprised of a takeoff, go-around, and landing at the airport of departure with the airplane configuration, speed, power, and thrust the same as that used in meeting the applicable takeoff, approach, and landing climb performance requirements of this part.

I have tried the no hyd landing in the A320 simulator, sporty at least IRC

sevenstrokeroll
20th Jun 2012, 19:21
Las Vegas is a bit more than 2000' above mean sea level and it is a hot area...however it has very long runway(s) and a competent CFR team.

IF the plane was truly in a unique controlability situation, edwards air force base and its 11 mile long dry lake runway is not that far away...with desert in between.

I cannot think of a good reason to fly for 3 hours before landing...somethng else could have gone wrong during that time compromising the plane. While some would say landing with brake accumulators only would make things a bit more difficult, or even the overweight landing inspection possible, it still doesn't make sense to sstay up that long with two hydraulic systems out.

someone mentioned the plane lurched due to loss of the yaw damper...I have a feeling that the plane was at relatively low altitudes and the yaw damper shouldn't have been part of that equation...

nnc0
20th Jun 2012, 20:25
Taxiing around LAS in an A320 is pretty hard on the brake temps Especially if the aircraft was coming of a quick turn. It's not uncommon at all to get the BRAKES HOT ECAM after leaving the gate and having to delay takeoff.

So the airplane could easily have had pretty hot brakes before take off and then suffered the G and Y failure. With only ACCUMULATOR pressure available for manual braking of an overweight aircraft, I'd want to be pretty certain those brakes were up to the job. If he didn't leave the gear down after liftoff, The Ground Brake Cooling Table indicates 3 hrs is not an unreasonable cooling period.

BobnSpike
20th Jun 2012, 20:50
I know why they screwed around for 3 hours burning fuel.

It is because, given their first hand knowledge of the entire situation and the condition of the airplane, in their professional judgement it was the best course of action.

Sorry to disappoint.

Think of all the lives that would have been saved if they had a link to PPRuNe that would have enabled them to solicit advice.

sevenstrokeroll
20th Jun 2012, 22:22
first, did the crew leave the landing gear down after takeoff or shortly thereafter to cool the brakes in response to ecam message?

second, a ground cooling chart is a bit different circumstance than flying around cooling the brakes by leaving the gear extended.

was it a quick turn? should jetblue discontinue quick turns at Las Vegas?

I've seen nothing so far regarding the brakes, except potential problems due to loss of hydraulics.

AS to the notion mentioned by bobnspike. If that's the case, perhaps we should shut down pprune. After all, pilots never make mistakes, right?

Is it possible that the crew was talking to jetblue dispatch/mx? And encouraged to try to ''fix'' things and then continue on to New York to save money? You know, sort of like Alaska talking to the crew that lost the MD83 to the trim problem?

No, pilots never make mistakes, they never have their company's economic interests at heart.

Matey
20th Jun 2012, 22:40
Turin
Yes the NG is the same as the Classic 737. Full manual reversion via cables etc. No hydraulics required for the essential flying controls or gear.

TURIN
20th Jun 2012, 22:51
Thanks Matey.

I now have another qustion for the Chaps landing a 320 manually.

How? Diff thrust? Or does "manual" mean that some hydraulic power remains? Manual reversion is not possible on the 320 I thought.

bubbers44
20th Jun 2012, 23:02
Unlikely they had a hot brake problem at a major airport like LAS. They probably extended the gear to help burn fuel off as I did once at TGU to land south at proper weight. Hot brakes were our concern at Fresno with shorter runways and 10 minute turns. If they lost the yellow and green hydraulic systems they would have landed hot with no flaps, only slats with the blue system seeing the chart.

No reverse and accumulator brakes so one application. No yaw dampers but at that low of an altitude who cares? What was with all the yawing? Was something else out too? Did the pilots do it? The throwing up of many passengers makes me think there was another problem. Rudder control was not proper, why? Surging engines could do this with no yaw damper.

We are waiting for more info.

MarkerInbound
21st Jun 2012, 01:07
Boeing had a good article in their Aero magazine a few years ago and said if you took off from a runway and met all the performance limits you can land on that runway and meet all the performance requirements.

the big thing is if you takeoff , lose an engine and have to return for landing...if your weight is too much to allow a safe go around on remaining engines, then you have a problem...and that problem is dealt with by dumping fuel.

Think about it, you were able to accelerate to V1, lose an engine and meet the 2nd stage requirements. During an engine out go around you're already ~V2 at the end of the runway and a couple hundred feet above the airport.

bubbers44
21st Jun 2012, 01:14
MI, I have always thought the same thing, if you were legal to lose an engine at V1 and continue you don't need to check the charts to see if on a go around at the beginning of the runway you would have to recalculate. It is a no brainer. Yes, you can return and land at your departure airport with no calculations. If you had to divert to Denver, yes, recalculate go around performance.

nnc0
21st Jun 2012, 02:34
I know why they screwed around for 3 hours burning fuel.
It is because, given their first hand knowledge of the entire situation and the condition of the airplane, in their professional judgement it was the best course of action.
Sorry to disappoint.
Think of all the lives that would have been saved if they had a link to PPRuNe that would have enabled them to solicit advice.

My point exactly - just didn't made it clear enough. Too many people speculating and second guessing why they reacted the way they did and opining they could have done better. What was the rush? Saving a few dollars? I just offerred a possible scenario experience based on our own experience out of there.

Somebody below said hot brakes aren't an issue at Vegas. Well maybe not for some but we don''t have brake fans installed on our 320s and we have tight turnarounds and we regularly take delays waiting for the things to cool down. Check your brake temps next time you have a long downhill taxi there. In an A320 the HOT BRAKES ECAM triggers at 300 deg C and once it does you can't takeoff. ( No fire extinguishing in the gear well)

TyroPicard
21st Jun 2012, 07:48
Here is a possible explanation for the 3-hour hold...

Green HYD fails, inducing Yellow HYD overheat as well (thanks, Dg800). Crew depressurise both systems per ECAM, enter convenient hold to plan for immediate landing at LAS on Blue system only.

LDR approx 10,700' from the QRH, longest runway 14,510' so no problem there.

Y HYD cools down, allowing pump to go back on during approach preparation. Crew elect to hold for a short time and see if Y HYD overheats again - it does not so they burn off to MLW and land.

hetfield
21st Jun 2012, 08:42
I now have another qustion for the Chaps landing a 320 manually.

How? Diff thrust? Or does "manual" mean that some hydraulic power remains? Manual reversion is not possible on the 320 I thought. @Turin

The correct term is MECHANICAL BACKUP (not manual backup, I'm sorry).

It is only for temporarily use, if all 5 flight control computers gave up and a reset is necessary. With MB the aircraft is controlled via pitch trim (manual) and rudder (cable). Both need hyd pressure. MB is not designed for landing, but it has been demonstrated that it can be done.

nitpicker330
21st Jun 2012, 09:06
nnc0:--
The 300c limit on the Airbus brakes before takeoff is because the Airbus has no Wheel Wheel Fire detection system. It has nothing to do with the performance of the Brakes when they get warm.

Ok

:ok:

Oh and that is a "ground cooling table"

If that table says 3 hrs on the ground then it would be 10 mins in the air!!

So, not applicable in the air with a 200 kts breeze!!

Zippy Monster
21st Jun 2012, 09:29
What was the rush? Saving a few dollars?

Dual hydraulic failure in the A320 is 'LAND ASAP (red)'.

Nobody is saying they should have rushed - you shouldn't, working through the ECAM, QRH summary and all the other associated drills resulting from it (gravity gear extension, briefing what might be a very non-standard go-around etc) is a long and complex procedure - but a red LAND ASAP is not to be taken with a pinch of salt. You can't blame people for questioning why it took them a few hours to get down.

Airbus test pilots might have landed in mechanical backup, but would your average line pilot be able to do it, perhaps never having seen it before even in the sim? I'd hazard a guess at probably not.

pitotheat
21st Jun 2012, 09:43
Saint Ex. As a TRE on the 320 for many years it is a common misconception among even experienced Airbus pilots that the manual reversion is akin to that on the Boeing with a limited mechanical linkage to some of the flying controls. In the Airbus there is no such linkage. It may well be that some have landed in the sim with all hydraulic systems out. In my experience having performed this manouvre and observed it in the sim the success rate for a non catastrophic landing is around 5% in good weather. This obviously increases with practise. However, with limited "free play" sim time after completing all of the required items and the other "nice to practise" scenarios that most of us have, in my opinion, the average crew chance of a successful outcome will be very low. In the real world faced with a triple failure and having exhausted all other avenues to recover at least one system then clearly you would give it your best shot but this is very much the last resort option in the hope that you get the hull on the airport where the emergency services are and some will walk/stagger away. This was the reason for my earlier summary but I and most that I meet are just average operators so I still stand by my original post.

ironbutt57
21st Jun 2012, 09:52
That's why it's called "mechanical backup", not manual reversion

CapCon
21st Jun 2012, 10:16
Mechanical Backup on the Airbus is not a redundancy against hydraulic loss. It's to be used "during temporary loss of aircraft electrics" whilst the backup gen comes online (from the Airbus FCOM) and requires at least one functioning hydraulic system. Good fun to try... in the SIM.

As has been said above, total loss of hydraulics on the Airbus results in loss of all flight controls.

Jockster
21st Jun 2012, 10:30
Known fault that if GREEN or YELLOW loses pressure due to fluid loss then the PTU starts BUT if there is only fluid on one one side then the PTU burns out causing the other system to leak out through the burned hole!!!

Our Company SOP is the to turn off the PTU without delay following the 'low pressure' of GREEN or YELLOW system. I think Airbus are working on a fix that this will happen automatically allowing the crew to make the decision about turning the PTU back on?

£10 says that this crew left the PTU running.

ironbutt57
21st Jun 2012, 10:35
Quite sure in a single failure ECAM alls for PTU off...

Zippy Monster
21st Jun 2012, 11:12
I think (although stand to be corrected) it depends on FWC standard?

RoyHudd
21st Jun 2012, 11:23
PTU is used after single engine failure or hydraulic pump failure. It must be switched off quickly with lo pressure, lo level, or overheat of either the green or yellow system. Otherwise one will end up with a dual hyd system failure.

Some have made reference to the 330 in their comments. Not the same. Different hydraulic system, no PTU.

Insufficient info here to draw conclusions.

hetfield
21st Jun 2012, 12:16
i'm not a pilot but dumping fuel is a customer option ??
i would have thought this was mandatory Well, dumping fuel is basically a crew option:ouch:.

To have a fuel dump system installed or not...., look to previous posts.

FLEXPWR
21st Jun 2012, 12:28
Deggers,

On A320, fuel dumping is not an option, it's plainly NOT available (unless you can pay A LOT of money to get a customized one ;) )

Locked Door, could you elaborate how the A320 is still flyable after a triple hydraulic loss? I haven't found anything in my books...

The A320 needs always at least one source of hydraulics to control the (remaining) flight surfaces. Lose all of them and your remaining flight time will be rather short.

The equivalent of a manual reversion on the A320 series is simply not called a manual reversion because there is nothing manual about it. It only means the flight computers are not able to compute and actuate surface movements with the degraded systems. Rudder will steer with pedals via cables to the tail (need at least one hydraulic system), and the pitch trim is called "manual pitch trim/only" as opposed to autotrim normally provided. The pilot moves the trim wheel, which turns a bicycle chain and actuates valves in the hydraulic block in the tail...so you still need the hydraulics.
Without the autotrim, the FBW is uncomfortable to hand-fly due to the neutral on the joystick not matching balanced elevator, so for example to fly straight and level in this case will require a constant push/pull pressure on the stick, making it sensitive to departure from steady conditions.

742
21st Jun 2012, 12:57
Not with regard to this incident, about which I know very little, but on the general subject of fuel dumping/overweight landings--

There appears to be a very strong bias in the United State/FAA land against overweight landings. It is generally not trained, or even discussed in training (in my experiance), while fuel dumping is in almost every checkride in airplanes so equipped.

This is a problem, to put it mildly.

deefer dog
21st Jun 2012, 13:12
A year or so ago a poster noted that a good percentage of (those who claim to be?) Airbus pilots appeared not to have a sound grasp of systems knowledge.

If no other thread has demonstrated the point, this one surely has. :ugh:

Checkboard
21st Jun 2012, 13:21
Possibly because Airbus produce the worst suite of manuals I have ever seen in four jet endorsements. :mad:

sevenstrokeroll
21st Jun 2012, 13:32
KUDOS TO JOCKSTER for giving us a very plausible scenario.

It might add to his case that a cable news show said: the plane had to be towed off the runway as ITS NOSEWHEEL STEERING DIDN'T WORK.

This implies, or allows me to infer, that they landed on the blue system.

that PTU seems like a weak link...and don't even get me started about the other weaknesses in the 'bus.

and in my free time in the sim...the thing I would practice is flying the thing on thrust changes, both symmetric and assymetric...just in case

and boys...if you are out west...head for EDWARDS dry lake.

sevenstrokeroll
21st Jun 2012, 13:39
and again...about FUEL DUMP...most planes don't have it and don't need it by regulation. offhand I would say that the 747, 777, 787 have it....some, not all 767 have it.

the DC8 had it, and Air Canada bought DC9's with it...though no one else has it on the DC9 and it was turned off later on the ones equipped with it.

Boeing even put out a chart that I have, but can't upload, of Boeing planes that did have fuel dump.

I think the L1011 and DC10 had it too.

There are some cases which for PERFORMANCE issues require the ability to dump fuel...and this performance is for engine(s) out go arounds. And while bubbers and others are right, you can GENERALLY come back to the runways you just took off from, there are specific situations , mainly with extremely long range planes loaded with huge amounts of fuel, that require dumping.

fuel dumping (while helpful) is not SOLELY for protecting the structure of the plane on landing.

sevenstrokeroll
21st Jun 2012, 13:44
flying ANY underwing engined airplane without hydraulics:

1. add power on both, nose goes up, plane goes up (within limits)

2. reduce power on both, nose goes down, plane goes down.

3. add power on right engine, reduce power on left engine , plane skids around to left, poorly...perhaps losing altitude, perhaps gaining.

4. add power on left engine, reduce power on right engine, plane skids around to right, poorly, perhaps losing altitude perhaps gaining.

one could with God's good graces manage a marginal landing...see Sioux city DC10 accident.

A computer program to manipulate thrust was developed for the air force (USAF) to show how a battle damaged plane could be landed...using thrust only.

Lonewolf_50
21st Jun 2012, 14:08
Gents:
Mechanical back-up is rudder and trim - both need hydraulic pressure to work, so a triple hydraulic failure leaves you with NO flying controls. You have engine thrust, gear extension and passengers running forward and rearward for control ... mechanical back-up is designed to provide a minimum of control following a complete loss of electrical power (side sticks don't work!) ...before you can get the RAT deployed, and the emergency generator up to speed.)

Mechanical Backup on the Airbus is not a redundancy against hydraulic loss. It's to be used "during temporary loss of aircraft electrics" whilst the backup gen comes online (from the Airbus FCOM) and requires at least one functioning hydraulic system.
As has been said above, total loss of hydraulics on the Airbus results in loss of all flight controls.

Locked Door, could you elaborate how the A320 is still flyable after a triple hydraulic loss? I haven't found anything in my books ... A320 needs always at least one source of hydraulics to control the (remaining) flight surfaces. Lose all of them and your remaining flight time will be rather short.

Grateful for the clarification, and FWIW, this appears to match my outdated A330 systems diagrams and systems explanation. The further commentary on fuel dumping, or its absence, is also appreciated in terms of adding to understanding. (I realize this is an A320, but the similarity in design philosophy does not surprise).

Likewise, grateful for the commentary on reasons to, or not to, remain airborne while trying to recover use of one of the two hydraulic systems that had shut down. For all the bickering, there is some very good stuff in this thread. :D

aterpster
21st Jun 2012, 14:30
742:

There appears to be a very strong bias in the United State/FAA land against overweight landings. It is generally not trained, or even discussed in training (in my experiance), while fuel dumping is in almost every checkride in airplanes so equipped.

Almost every bird I flew had fuel dumping. So, we had to go through the dumping drill in the simulator because it was a proficiency requirement that came with those types.

We didn't do overweight landings in the sim because it would have served no useful purpose.

But, starting after the first embargo in 1973, the company made it quite clear that landing overweight was the preferred course of action over dumping except perhaps with an engine failure or a missed approach OEI climb gradient issue.

From that time most crews at my company landed overweight as opposed to dumping fuel and no one ever heard from the FAA. In fact overweight landings had tacit FAA approval.

Flightmech
21st Jun 2012, 14:37
I trust these overweight landings were not a regular occurence though? Would have put the MX costs up with all those extra inspections??

Girlfriend in Akoma
21st Jun 2012, 15:17
There has been a recent case of an A319 crew not being able to switch the PTU off due to a faulty PTU switch... Therefore a single hydraulics low level activated the PTU which has overheated and taken out the second hydraulic system...

Incident: Air Canada A319 near Winnipeg on May 30th 2012, two hydraulic systems failed after leak (http://avherald.com/h?article=4506b0eb&opt=1)

Bokkenrijder
21st Jun 2012, 16:01
Not with regard to this incident, about which I know very little, but on the general subject of fuel dumping/overweight landings--

There appears to be a very strong bias in the United State/FAA land against overweight landings. It is generally not trained, or even discussed in training (in my experiance), while fuel dumping is in almost every checkride in airplanes so equipped.

This is a problem, to put it mildly. Almost every bird I flew had fuel dumping. So, we had to go through the dumping drill in the simulator because it was a proficiency requirement that came with those types.

We didn't do overweight landings in the sim because it would have served no useful purpose.Errrr, right... I'm curious, what did they expect you to do in the sim (i.e. in real life) during a engine/cargo/cabin fire that could not be contained? Spend 40-50 minutes dumping fuel? :oh:

With regards to airmanship and system knowledge this thread is an absolute shocker. United 232 at Sioux City? Swissair 111 near Halifax? Any lessons learned?

aterpster
21st Jun 2012, 17:33
Bokkenrijder (http://www.pprune.org/members/109698-bokkenrijder): 
errrr, right... I'm curious, what did they expect you to do in the sim (i.e. in real life) during a engine/cargo/cabin fire that could not be contained? Spend 40-50 minutes dumping fuel?

As I said in my previous post, overweight landings were the real world preference. Sim, in my book, is not "i.e. in real life." Never burned up a simulator yet.

Bokkenrijder
21st Jun 2012, 17:40
But, starting after the first embargo in 1973, the company made it quite clear that landing overweight was the preferred course of action over dumping except perhaps with an engine failure or a missed approach OEI climb gradient issue. As I said in my previous post, overweight landings were the real world preference. Sim, in my book, is not "i.e. in real life." Never burned up a simulator yet. Again, two very strange statements;

1) With the 1973 embargo, I assume you are referring to the 1973 oil embargo? Why would any pilot let commercial considerations take priority during a severe technical failure? The whole point of overweight landings is to save time, not fuel!

2) Why would you treat a sim session any different than a real life scenario? Isn't the the whole purpose of sim training and checking to simulate real world scenarios?

bubbers44
21st Jun 2012, 18:15
My major airline in the US advised not dumping fuel if the landing was just as safe landing over weight. I wondered how this would sound at the hearing so decided overweight landing couldn't be as safe as landing at Max landing weight so ignored their advice knowing it was put out by the management people. A few months later I got a 727 with a radar problem written off as re racked ok for service. I told the FO we have a bad radar and we need it for this flight through a tropical storm to south America so expect it to quit since they didn't fix it.

We hit a bump on the runway at rotation and the radar quit but we knew where the close in weather was so requested a straight out departure. Circuit breakers , pounding on scope and normal pilot techniques didn't work so we went off shore and dumped fuel to max landing weight and came back to MIA. Never heard a word about why didn't we land over max landing weight and no hearing. I think the hearing is when you follow their advice and land overweight and have to explain why.

nnc0
21st Jun 2012, 18:23
GIA
There has been a recent case of an A319 crew not being able to switch the PTU off due to a faulty PTU switch... Therefore a single hydraulics low level activated the PTU which has overheated and taken out the second hydraulic system...

I think that PTU switch needs an AD on it to increase the inspection interval. The current Maint progrogram schedule requires a check every 4 yrs but if it's faulty this one switch will cause a dual HYD failure..

Consider that the the PTU is always electrically supplied and the Y+G HYD delta P normally controls the on/off function. If that PTU OFF switch is faulty there is nothing to interrupt power to the PTU in the event of delta P drop. So with a faulty a switch and a leak on one side, a dual hydraulic failure is inevitable.

eg
The first step in HYD LO LVL/PRESS ECAM though is PTU.....OFF.
The switch is faulty though so the PTU continues to run.
The PTU overheats (rather quickly by the way), the seals disintegrate, and the second system drains away.
Now you've lost G and Y

bubbers44
21st Jun 2012, 18:28
If getting on the ground is a priority due to time, yes land overweight, but our company was more concerned about fuel. The bean counters were in action.

hetfield
21st Jun 2012, 18:36
I think the hearing is when you follow their advice and land overweight and have to explain why. No hearing @ my airline (major EU).

Write it down in the techlog and that is it.

BobnSpike
21st Jun 2012, 20:53
I've been saying the following prior to every takeoff above MLW for the last 20 years:

"If we have to come right back, we'll be overweight for landing. We will consider the reason for the return and the condition of the aircraft and decide whether to dump (burn, depending on the aircraft) fuel or come right back and land overweight."

I have landed overweight twice and have burned down to MLW once, because, in my professional judgement those were the best courses of action based on the circumstances.

Nobody who was not physically in the cockpit of that airplane has the information, much less the standing, to critique their decision making.

Saint-Ex
21st Jun 2012, 21:29
Pitotheat. I appreciate your comments but cannot believe that any fbw Airbus pilot thinks the manual reversion resembles that on some Boeing aircraft. A sim generally gives a reasonable interpretation of flight characteristics but is questionable when approaching the edges of the flight envelope in a heavily degraded mode.

cosmiccomet
21st Jun 2012, 22:20
According to the A320 HYD G+B Summary, the Actual Landing Distance at Sea Level for 74 tons is 3000 mts plus 3% per 1000 ft airport elevation.

I have never flown from LAS, but as far as I can see there is a landing runway with more than 4000 mts available.

So I don't see the reason for being flying for almost 4 hours after having a double hydraulic failure....something else should be around...

Don't take me wrong I am not judging the crew, I would like to know why they were holding for such a long period of time.

aterpster
21st Jun 2012, 22:46
Bokkenrijder:
Again, two very strange statements;

Your reaction is strange.

1) With the 1973 embargo, I assume you are referring to the 1973 oil embargo? Why would any pilot let commercial considerations take priority during a severe technical failure? The whole point of overweight landings is to save time, not fuel!

After the embargo and fuel prices went up, the company gave their "blessings" to overweight landings to save fuel so long as it was as safe as dumping. I tried to make that clear earlier.

2) Why would you treat a sim session any different than a real life scenario? Isn't the the whole purpose of sim training and checking to simulate real world scenarios?

Simulating an overweight landing would have been a waste of time. The simulator is "similar," not exact.

But, you have your views and my major airline and others did not share your views.

bubbers44
21st Jun 2012, 23:18
If yellow and green hydraulics were gone you have no reversers, no brakes other than the accumulators and no flaps. Think about it.

aterpster
21st Jun 2012, 23:58
bubbers44:

If yellow and green hydraulics were gone you have no reversers, no brakes other than the accumulators and no flaps. Think about it.

You are the first one, I believe, to make that definitive of a statement about what was available.

Given that, it seems like Edwards AFB would have been the place to go.

bubbers44
22nd Jun 2012, 00:16
That is what I thought about the DC10 crash with no hydraulics, just land in the desert any direction you want. Have all the crash equipment come out to meet you.

fotoguzzi
22nd Jun 2012, 00:50
[Not a pilot] Would there be a reluctance to leave the vicinity of a three-mile-long runway in favor of a fifteen-mile-long runway around two hundred miles away (with presumably few suitable landing opportunities in between)?

MarkerInbound
22nd Jun 2012, 01:09
re: why not practice overweight landings. Because it'll be the same as a "normal" landing, just with higher numbers. Do you really need to practice setting ref at 164 v. 134?

As 7 Stroke says, there are a bunch of other reasons to consider dumping. Some flight control malfunctions have a speed additive, the 727 zero flap landing is ref +60. At that point even a landing under max landing weight is going to push tire speeds.

misd-agin
22nd Jun 2012, 01:20
Typically do engine out landings right below max takeoff weight. Gives you an indication of the plane's performance.

Fly the UAL DC-10 to the desert? They were barely able to control it so flying it for an hour or two to reach the desert would have increased the risk of losing control enroute.

misd-agin
22nd Jun 2012, 01:24
[Not a pilot] Would there be a reluctance to leave the vicinity of a three-mile-long runway in favor of a fifteen-mile-long runway around two hundred miles away (with presumably few suitable landing opportunities in between)?


What do you do if enroute to the airport two hundred miles away you start having problems with the third hydraulic system?

Odds of that happening? Pretty small but what are the odds of losing two hydraulic systems?

Ashling
22nd Jun 2012, 01:43
The 320 FCTM states very clearly that a dual hydraulic failure is a MAYDAY and that you should land ASAP (in red)

Holding next to a suitable runway for the purpose of reducing weight, with this failure, is a mugs game, end of.

If you have a pressure differential between the green and yellow system of 500psi the PTU will run. If this is due to fluid loss then the good system will overheat running the PTU and so will also go down. That's why the 1st action on ECAM for green or yellow overheats, loss of fluid etc is to switch the PTU off thus preventing the loss of the 2nd system.

Snag is one of the main times you will lose the green system fluid is on gear retraction after t/o. Depending on your mod state you may not know this until your above 1500' aal due to take off inhibit restricting the warnings that come up. At that stage it may well be too late to prevent the 2nd system from failing due to an overheat. However you will get it back once it has cooled and once you've switched the PTU off it will work fine so your back to 2 systems. This may well be what occurred in this instance and if so holding to burn fuel would be fine as you only have a single failure. In fact depending on the destination continueing may be fine too.

Airbus have a mod out to prevent the after take off gotcha but I guess not all will have it?

deSitter
22nd Jun 2012, 05:55
Wow fascinating thread.

My ignorant first reaction would have been - two systems go out, and I'm thinking someone on the ground fracked up and the third is at risk, so get down ASAP, and I would have.

flydive1
22nd Jun 2012, 07:20
Reading the report it looks like initially they had 2 hydraulic systems faillure, but they were then able to recover one of them.
So at that point they were flying with 2 hydraulic systems, yellow and blue, so probably a good decision to hold and burn off excess fuel.

bubbers44
22nd Jun 2012, 08:22
They got yellow back????

sevenstrokeroll
22nd Jun 2012, 09:14
if they had yellow back, couldn't they use the ptu to power nosewheel steering through the green? assuming theyhad hydraulic fluid and just no pump on the green?

news reports said no nosewheel steering after landing.

if this plane is designed to have a failure mode that eventually causes, ''lurching'' about in flight...someone didn't think this thing through very well.

I know how important it is to get the gear UP after takeoff...in the event of an engine out and performance needs. However, losing a hydraulic system, using the PTU to get the gear up, then burning out the PTU because you forget to turn off the switch, causing an overheat in the OTHER hyd system doesn't make much sense to me.

so now the gear needs emergency extension (with no way to retract on a single engine go around) and you've lost too much.

in this case, both engines kept running, and leaving the gear down might have prevented overheating the other system.

could the "LURCHING" be lowering the main gear related????????

in the final analysis, being on the ground, wishing you were in the air is better than being in the air wishing you were on the ground.

flydive1
22nd Jun 2012, 10:01
They got yellow back????

So it seems, according to this link posted in the first page

Incident: Jetblue A320 at Las Vegas on Jun 17th 2012, two hydraulic systems failed (http://avherald.com/h?article=45165c68&opt=0)

Quote:

"The Aviation Herald however learned on Jun 20th that the green hydraulic system had been lost followed by an overheat indication of the yellow hydraulic system prompting the crew to report the failure of two hydraulic systems. The crew actioned the relevant checklists and were able to recover the yellow hydraulic system."

Dg800
22nd Jun 2012, 10:18
could the "LURCHING" be lowering the main gear related????????

Or maybe just passenger-fueled media hype?

recon67
22nd Jun 2012, 12:38
Here is the audio from that flight: http://www.youtube.com/watch?v=BvAHKyH_q_o (http://www.youtube.com/embed/BvAHKyH_q_o)

hetfield
22nd Jun 2012, 16:34
if they had yellow back, couldn't they use the ptu to power nosewheel steering through the green? assuming theyhad hydraulic fluid and just no pump on the green?
No! With manual gear extension, NLG steering is bypassed.

Machaca
22nd Jun 2012, 17:28
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.

http://i337.photobucket.com/albums/n385/motidog/B6-194track.jpg

ironbutt57
22nd Jun 2012, 17:47
green hydraulic system had been lost followed by an overheat indication of the yellow hydraulic system prompting the crew to report the failure of two hydraulic systems. The crew actioned the relevant checklists and were able to recover the yellow hydraulic system."

Makes perfectly good sense...

aterpster
22nd Jun 2012, 18:25
MarkerInbound:

As 7 Stroke says, there are a bunch of other reasons to consider dumping. Some flight control malfunctions have a speed additive, the 727 zero flap landing is ref +60. At that point even a landing under max landing weight is going to push tire speeds.

Yep. And the single engine approach and landing is no picnic in the 727 either. Loss of that second engine on departure mandates dumping ASAP.

misd-agin
22nd Jun 2012, 18:47
Most of the time shutting down the second engine in the 727 after takeoff had just created a powered glider with an excellent glide ratio. :ooh:

If you started at ISA +10 and more than 250 KIAS you'd be able to level off at approx. 2500' if you weighed 160,000 lbs or less. ISA +15 required you to weigh less than approx. 150,000 lbs. iSA +20? 145,000 lbs. :eek:

In other words, on the majority of my takeoff's, if you shut the second engine down you were going down. CKA showed me that on my IOE. Never heard it mentioned before, or after, that.

Added the two engine out performance data to my 'trip' book and briefed the weight we needed to get to before the second engine shutdown was an automatic decision.


Page 44 -

Boeing 727 Performance Handbook (http://www.scribd.com/doc/60135535/Boeing-727-Performance-Handbook)

sevenstrokeroll
22nd Jun 2012, 19:25
so it seems we have a process unique to pilots and aviators...when something bad happens we talk about it, in the universe of the internet. We offer thoughts, opinions, monday morning quarterbacking if you will. But it is all part of the process.

At first we heard, from one of the pilot's own lips that they had lost TWO hydraulic systems and had OTHER problems. From this many could say rightly that they should land asap.

Oh, but now we have recovered one hydraulic system, so we have one normal and one emergency system.

flying at 12,000' MSL over an area where the elevation is above 2000'msl, means you are about 10,000' agl give or take. Add that it is the desert and the holding pattern is where the water meets the desert, you could get jostled a bit by turbulence.

OR you could have had the manual gear extension requiring yawing the plane to help get it down and locked.

OR you could have had control problems.

questions: how long did it take to get the yellow system up and running again? did it overheat on them again and again?

and my general statement. if they had gotten yellow back, and could have landed using overweight landing check and being careful about descent rate at touchdown...they should have landed earlier. Call it SAfety and comfort of passengers as a priority.

Overweight landings if done poorly can damage a plane. But if done properly may not even require an inspection.

Was the landing now almost 4 hours after takeoff that much safer? One must consider increased crew fatigue, passengers being frightened, performance of aircraft and other things in the equation.

wondering why they lost the first hyd system too.

also, please confirm if you can that having yellow would allow for use of flaps? even at reduced rate?

Checkboard
22nd Jun 2012, 20:54
I have no problem with their holding or whatever.

The only thing I can see is, when you have an emergency, FOR GOD'S SAKE DECLARE A BLOODY EMERGENCY! :ugh: :*

It's best for ATC, saves radio time, costs nothing etc etc. :rolleyes:

bubbers44
23rd Jun 2012, 00:04
ma, my airline told us in a 727 you could not do a single engine flight unless clean and 210 knots. I asked my check airman when our check was complete if he would fail two engines at 500 ft and let's see if we can save it. He reluctantly did and failed two engines at flaps 15 V2 plus 15 and with a 100 ft descent per minute rate had a clean airplane and 210 knots at 350 feet. Many of our island airports have no terrain but lots of birds. Kind of nice to know you don't have to ditch it.

hetfield
23rd Jun 2012, 09:31
also, please confirm if you can that having yellow would allow for use of flaps? even at reduced rate?

Yes, with yellow flaps are back (slow).

aterpster
23rd Jun 2012, 14:14
bubbers44:

my airline told us in a 727 you could not do a single engine flight unless clean and 210 knots. I asked my check airman when our check was complete if he would fail two engines at 500 ft and let's see if we can save it. He reluctantly did and failed two engines at flaps 15 V2 plus 15 and with a 100 ft descent per minute rate had a clean airplane and 210 knots at 350 feet. Many of our island airports have no terrain but lots of birds. Kind of nice to know you don't have to ditch it.

Was this in the sim or the airplane? In the sim we were always at MGTOW for that scenerio.

I know first-hand from a airplane training session a very long time ago that a 707 can descend, make an IAP, and land on one inboard engine. But, Boeing didn't and doesn't doesn't go there. When I went through that one I concluded that the training captain had a screw loose.

bubbers44
23rd Jun 2012, 21:20
Sim because the passengers always complained when we did it in a real airplane. Fed Ex could do it so why can't the sky nazis do it. We got bought by the sky nazis so don't blame me.

I liked my first airline better but like PSA we ended up where we ended up, not our choice. I like Key Largo a lot so it wasn't all bad. You just had to put up with the BS of corporate crap. That is why I always flew to TGU, I felt I was at Aircal again and the BS went away. Once you got out of MIA that is.

bubbers44
23rd Jun 2012, 22:20
I guess I would rather have a category 5 hurricane in front of me than another buy out behind me. Ist that just reserved for generals?

aterpster
23rd Jun 2012, 22:22
bubbers44:

Sim because the passengers always complained when we did it in a real airplane. Fed Ex could do it so why can't the sky nazis do it. We got bought by the sky nazis so don't blame me.

When I rated in the 727 the sim was only approved for part of the training. The balance of the training and the rating ride was in the airplane. It's been a very long time but I think we did the 2-engine inop even in those old sims.

When we finally got the Level D sims or whatever then it was all in the sim.

bubbers44
23rd Jun 2012, 23:46
We did the one engine approach in the 727 but it was always level at 210 knots. I requested the loss of two engines at 500 ft at V2 plus 15 because leaving the islands that was our most fulnerable time. It worked and I think the check airman was amazed we could fly not following our training program. I never blindly followed airline procedures. I did in the sim to pass but not in the real airplane to survive. Kind of sad isn't it?

rog747
24th Jun 2012, 06:43
i really cannot fathom this jet blue incident...a 3+ hour hold and then
a c/crew brief for a possible overrun and possible pax evac upon landing...
if after 3 hours they had not got themselves comfortable and sorted things out then i do not understand why they did not return asap as loss of 2 systems is a red land asap and declare mayday.

was there an immediate pan pan or a mayday? JB reports pilots did declare an emergency LATER with 2 hyd systems out. NTSB looking at whether to investigate the whole incident.

This report is very interesting; incident to Easyjet Airbus loss of 2 systems.
http://www.aaib.gov.uk/cms_resources.cfm?file=/Airbus_A319-111_Airbus,_G-EZDM_08-09.pdf

And in this recent A321 incident Incident: Novair A321 at Gothenburg on Jun 22nd 2012, unsafe gear after departure (http://avherald.com/h?article=451986a4&opt=0)
2 days ago to a NOVAIR a/c on t/off from GOT had an unsafe nose gear warning upon retraction and was back on the ground within 15 MINS...
A/C was flying from GOT to KOS island in Greece (well over 4 hours flying time) so the immediate return landing was overweight.
should they have burned off fuel if the gear could have collapsed or does this failure mean 'land asap'?

and this 737-800 crew was 160m out of MEL e/r to NZ when they had hyd problems, turned around and were back on the ground within 80 minutes.
Incident: Jetconnect B738 near Melbourne on Jun 17th 2012, hydraulic problem (http://avherald.com/h?article=45166b1c&opt=0)

i cannot see why JB did not get back on ground fairly pronto.
4000m runway at LAS.

The Ancient Geek
24th Jun 2012, 09:27
Let me put this in simple words for those who do not understand.

If one of the main hydraulic pumps fails there is an automatic valve which opens to supply both systems from the good pump.
This is intended to temporarily minimise the effect of a sudden failure, extended use can cause the good pump to overheat and raise an alarm. They carried out the correct action which is to disable the transfer valve and allow the good pump to cool down.
They did NOT have a double failure, they had a single failed system plus an overheat warning from the good system.

Just follow the actions in the QRH (Quick Reference Handbook) and all is well. This is a simple proceedure which they are trained to follow, no great drama just a routine failure of a single system.

Having followed the correct procedure they were left with a single failure and it was perfectly safe to stooge around for a while burning off enough fuel to ensure a safe landing below the maximum landing weight.

Job done, full marks.

Colocolo
24th Jun 2012, 10:32
If one of the main hydraulic pumps fails there is an automatic valve which opens to supply both systems from the good pump.
This is intended to temporarily minimise the effect of a sudden failure, extended use can cause the good pump to overheat and raise an alarm. They carried out the correct action which is to disable the transfer valve and allow the good pump to cool down.

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

Colocolo

The Ancient Geek
24th Jun 2012, 10:39
Yup, I was using simple words for the hard of understanding in a probably vain attempt to stop some of the silly comments. :D

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
24th Jun 2012, 11:05
"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
24th Jun 2012, 12:50
AncientGreek:

Having followed the correct procedure they were left with a single failure and it was perfectly safe to stooge around for a while burning off enough fuel to ensure a safe landing below the maximum landing weight.

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
24th Jun 2012, 13:47
and the crew did not have that as they had no n/w steering

The Ancient Geek
24th Jun 2012, 14:17
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
24th Jun 2012, 16:03
Ancient Greek:

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.

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
24th Jun 2012, 16:26
Risk an over weight landing? You obviously have a very in depth understanding.

The Ancient Geek
24th Jun 2012, 16:54
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
24th Jun 2012, 17:34
and the crew did not have that as they had no n/w steering

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 :ok:).

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
24th Jun 2012, 18:29
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
24th Jun 2012, 19:28
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
24th Jun 2012, 22:47
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
24th Jun 2012, 22:58
#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.