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Why Not The Fuel Dump Option In The B6 A320?  
User currently offlineBongo From Colombia, joined Oct 2003, 1863 posts, RR: 5
Posted (8 years 11 months 5 days 2 hours ago) and read 6248 times:

Why they didn´t have the option to dump the fuel and land as they did, but saving three horrible hours flying in circles?


MDE: First airport in the Americas visited by the A380!
26 replies: All unread, showing first 25:
 
User currently offlineFrancoBlanco From , joined Dec 1969, posts, RR:
Reply 1, posted (8 years 11 months 5 days 2 hours ago) and read 6226 times:

Because the A320 family doesn´t have a jettison system.

Sebastian


User currently offlineOkie From United States of America, joined Jul 2003, 2999 posts, RR: 3
Reply 2, posted (8 years 11 months 5 days 2 hours ago) and read 6210 times:

RE: Fuel Dumping (by SlamClick Dec 10 2004 in Tech Ops)

Here is a previous discussion on fuel dumping using the search function

Okie


User currently offlineBongo From Colombia, joined Oct 2003, 1863 posts, RR: 5
Reply 3, posted (8 years 11 months 5 days 2 hours ago) and read 6202 times:

Quoting FrancoBlanco (Reply 1):
Because the A320 family doesn´t have a jettison system.

That is exactly my question, why doesn't the A320 family have a jettison system ?



MDE: First airport in the Americas visited by the A380!
User currently offlineBMIFlyer From UK - England, joined Feb 2004, 8810 posts, RR: 58
Reply 4, posted (8 years 11 months 5 days 2 hours ago) and read 6199 times:

Quoting Bongo (Reply 3):
That is exactly my question, why doesn't the A320 family have a jettison system ?

It is not needed.



Sometimes You Can't Make It On Your Own
User currently offlineBongo From Colombia, joined Oct 2003, 1863 posts, RR: 5
Reply 5, posted (8 years 11 months 5 days 2 hours ago) and read 6197 times:

Quoting BMIFlyer (Reply 4):
It is not needed.

It was needed yesterday! I mean just to avoid three hours of suffering



MDE: First airport in the Americas visited by the A380!
User currently offlineCaptOveur From , joined Dec 1969, posts, RR:
Reply 6, posted (8 years 11 months 5 days 1 hour ago) and read 6164 times:

Quoting Bongo (Reply 5):
It was needed yesterday!

Was It? Would dumping fuel have saved any lives? No, everyone lived anyway.

Quoting Bongo (Reply 5):
I mean just to avoid three hours of suffering

I fail to see how any more mental stress was caused by 3hrs of circling than coming in minutes after the problem was realized.. I think they turned off the IFE, if I was wasting 3hrs not going anywhere watching some TV would have been nice.


User currently offlineFrancoBlanco From , joined Dec 1969, posts, RR:
Reply 7, posted (8 years 11 months 5 days ago) and read 6133 times:

Smaller A/C don´t need a jettison system because, as you can see in this case, you can simply fly in circles for a few hours or even less and burn the fuel. If you don´t have that time, e.g. because of a burning engine, simply land the plane. You can´t be that much overweight with an A320.

Fuel Jettison only exists in larger planes because e.g. a fully loaded 747 with 150 tons of fuel on board would be terribly overweight and it would be dangerous to land in that case. On the other hand, burning 150 tons of fuel by flying in circles would definitely take too much time and that´s why larger A/C can dump fuel.

Sebastian


User currently offlineJetlagged From United Kingdom, joined Jan 2005, 2546 posts, RR: 24
Reply 8, posted (8 years 11 months 5 days ago) and read 6101 times:

Quoting FrancoBlanco (Reply 7):
Fuel Jettison only exists in larger planes because e.g. a fully loaded 747 with 150 tons of fuel on board would be terribly overweight and it would be dangerous to land in that case. On the other hand, burning 150 tons of fuel by flying in circles would definitely take too much time and that´s why larger A/C can dump fuel.

Fuel dumping takes a long time too, though it's faster than just burning it. A 747 on fire would land ASAP, regardless of weight.

It's nothing to do with how long it will take to burn off fuel. The requirement for a fuel dumping system is set out in the appropriate FAR. It's to do with the ability of the aircraft to climb in approach and landing configurations at max takeoff weight less 15 minutes fuel burn (making a go-around possible). Heavy three and four engined aircraft struggle in these configurations, so need to land at much lighter weights hence require fuel dumping capability.

The only reason for the 3 hour hold was to land at the minimum weight possible because wheel braking will be kept to a minimum and reverse thrust not used at all to reduce the load on the nose gear.

It would have been just the same had the aircraft been a 737.



The glass isn't half empty, or half full, it's twice as big as it needs to be.
User currently offlineRick767 From United Kingdom, joined Jan 2000, 2662 posts, RR: 51
Reply 9, posted (8 years 11 months 4 days 22 hours ago) and read 6032 times:

Quoting FrancoBlanco (Reply 7):
Fuel Jettison only exists in larger planes because e.g. a fully loaded 747 with 150 tons of fuel on board would be terribly overweight and it would be dangerous to land in that case

This is a common misconception, it is not dangerous to land overweight (provided runway length is checked and acceptable, etc..) and modern aircraft are certified to land up to Maximum Takeoff Weight in an emergency.

There may be some slight damage / overstress, but it is not unsafe.



I used to love the smell of Jet-A in the morning...
User currently offlineFrancoBlanco From , joined Dec 1969, posts, RR:
Reply 10, posted (8 years 11 months 4 days 22 hours ago) and read 6012 times:

Well, yeah, I simplified it a bit.

It´s not dangerous or unsafe to land overweight, if you have to do it then do it, of course, I just wanted to point out that a 747 landing at 397 tons is a bit different than an A320 at 54 tons.

Sebastian


User currently offlineB744F From Germany, joined Jan 2006, 0 posts, RR: 0
Reply 11, posted (8 years 11 months 4 days 21 hours ago) and read 5962 times:

It is not needed? As a safety precaution, why wouldn't you want this option? If you needed to dump as much fuel as possible to have a better chance of surviving the landing... who on earth would say NO and why?

User currently offlineFrequentflyer From United States of America, joined Jul 2005, 736 posts, RR: 3
Reply 12, posted (8 years 11 months 4 days 21 hours ago) and read 5956 times:

Quoting Rick767 (Reply 9):
modern aircraft are certified to land up to Maximum Takeoff Weight in an emergency.

Does that include the MD11?



Take off and live
User currently offlinePope From , joined Dec 1969, posts, RR:
Reply 13, posted (8 years 11 months 4 days 20 hours ago) and read 5943 times:

Quoting Jetlagged (Reply 8):
A 747 on fire would land ASAP, regardless of weight.

Ask the people on the Swissair MD11 if that's how it worked.


User currently offlineLeanOfPeak From United States of America, joined Oct 2004, 509 posts, RR: 1
Reply 14, posted (8 years 11 months 4 days 20 hours ago) and read 5922 times:

Quoting B744F (Reply 11):
It is not needed? As a safety precaution, why wouldn't you want this option? If you needed to dump as much fuel as possible to have a better chance of surviving the landing... who on earth would say NO and why?

Incorporating fuel dump capability adds weight, maintenance, and complexity. Carrying weight around adds to fuel requirements. Carrying that added fuel around adds to fuel requirements. And on and on. If a truly immediate landing is necessary, it would probably be a heavier landing with fuel dump than without it.

In this particular case, minimizing the landing weight significantly improved the chances of a successful outcome. And in this particular case, there was no time constraint to make burning off fuel unpalatable.

There is very little overlap between situations in which it is vital to get on the ground immediately and situations in which getting the weight to the bare minimum significantly improves the safety of the landing.

An A320 at MTOW is 14% over MLW. An MD-11 at MTOW is 25% over MLW. A 744 at MTOW is 50% over MLW. It's an entirely different class of problem and, for most emergencies, a 14% overweight landing should not materially impact the immediate well-being of the people aboard. The most obvious exception, of course, being landing gear misconfiguration, in which case there is generally minimal time constraint on getting the weight down.

Thanks, Frequentflyer and Pope, for alluding to SwissAir 111, as it is relevant here. That MD-11 was equipped with fuel dump and the decision was made, after a report of smoke in the cabin, to circle over the ocean to dump more fuel before landing (Remember, fuel dump isn't like a firebomber, so it does still take time to lower the level in the tanks). The ensuing crash has led not only to changes in insulation and smoke detection, but also to a greater emphasis in procedures and training on landing immediately, even if overweight, in the event of smoke in the cabin.


User currently offlinePihero From France, joined Jan 2005, 4402 posts, RR: 76
Reply 15, posted (8 years 11 months 4 days 17 hours ago) and read 5862 times:

People,

The requirement for a fuel jettisonning system is to be found in the FARs.
The pertinent articles are FAR 25.1001 and the required performance in 25.119 and 25.121.
25.1001 states :
Sec. 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 Secs. 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.

(b) If a fuel jettisoning system is required it must be capable of jettisoning enough fuel within 15 minutes, starting with the weight given in paragraph (a) of this section, to enable the airplane to meet the climb requirements of Secs. 25.119 and 25.121(d), assuming that the fuel is jettisoned under the conditions, except weight, found least favorable during the flight tests prescribed in paragraph (c) of this section.

(c) Fuel jettisoning must be demonstrated beginning at maximum takeoff weight with flaps and landing gear up "



And the two sets of performance required are :

FAR 25.119, "landing climb" (all engines operating)
"In the landing configuration, the steady gradient of climb may not be less than 3.2 percent, with--

(a) The engines at the power or thrust that is available eight seconds after initiation of movement of the power or thrust controls from the minimum flight idle to the go-around power or thrust setting; and

(b) A climb speed of not more than 1.3 VS."


and FAR 25.121,"Approach climb" (one engine out)
" In the approach configuration corresponding to the normal all-engines-operating procedure in which VS for this configuration does not exceed 110 percent of the VS for the related landing configuration, the steady gradient of climb may not be less than 2.1 percent for two-engine airplanes, 2.4 percent for three-engine airplanes, and 2.7 percent for four engine airplanes, with--

(1) The critical engine inoperative, the remaining engines at the go-around power or thrust setting;

(2) The maximum landing weight; and

(3) A climb speed established in connection with normal landing procedures, but not exceeding 1.5 VS."


These regs are quite useful to dispel at least one misconception :

For a long range airplane, the need is to dump just enough fuel to respect the performance aspect of the requirement, not to bring the weight to at most the max landing weight.

In the Jet Blue 320 case, the situation precluded a normal braking possibility,thus requiring the lightest weight possible and the longest runway available, not even mentioning the fire department preparedness.

Regards



Contrail designer
User currently offlineJetlagged From United Kingdom, joined Jan 2005, 2546 posts, RR: 24
Reply 16, posted (8 years 11 months 4 days 15 hours ago) and read 5808 times:

Quoting Pope (Reply 13):
Quoting Jetlagged (Reply 8):
A 747 on fire would land ASAP, regardless of weight.

Ask the people on the Swissair MD11 if that's how it worked.

What are you suggesting? I note you didn't quote the first sentence of my paragraph, where I pointed out that fuel dumping is itself quite a lengthy process. The Swissair crew opted to dump fuel and were not fully aware of the urgency of the situation initially. However even if they had opted for an immediate emergency landing it is doubtful whether they would have made it in time.

The people on the Swissair flight didn't really stand much of a chance either way.



The glass isn't half empty, or half full, it's twice as big as it needs to be.
User currently offlineLeanOfPeak From United States of America, joined Oct 2004, 509 posts, RR: 1
Reply 17, posted (8 years 11 months 4 days 15 hours ago) and read 5804 times:

Pihero, the question I was addressing was not, "Is it legal not to have a fuel dumping system?" but rather, "Why would any company in its right mind design an aircraft without a fuel dumping system?"

User currently onlineMir From United States of America, joined Jan 2004, 21555 posts, RR: 55
Reply 18, posted (8 years 11 months 4 days 13 hours ago) and read 5768 times:

Quoting LeanOfPeak (Reply 17):
Pihero, the question I was addressing was not, "Is it legal not to have a fuel dumping system?" but rather, "Why would any company in its right mind design an aircraft without a fuel dumping system?"

Why put one in if you don't have to? As previously stated, a fuel dump system adds complexity (and thus cost), adds weight, and has to be maintained. If that kind of thing is not required, why make an airplane that is heavier, more expensive, and more difficult to maintain than it needs to be?

The FARs are very rigorous, and if a fuel dump system would save lives in the event of a problem, you can put money down that a dump system would be required.

-Mir



7 billion, one nation, imagination...it's a beautiful day
User currently offlineHAWK21M From India, joined Jan 2001, 31679 posts, RR: 56
Reply 19, posted (8 years 11 months 4 days 13 hours ago) and read 5749 times:

Quoting Jetlagged (Reply 8):
The only reason for the 3 hour hold was to land at the minimum weight possible because wheel braking will be kept to a minimum and reverse thrust not used at all to reduce the load on the nose

Exactly.In case of another Emergency type maybe an overweight Landing would be attempted.
regds
MEL



Think of the brighter side!
User currently offlineScbriml From United Kingdom, joined Jul 2003, 12464 posts, RR: 46
Reply 20, posted (8 years 11 months 4 days 10 hours ago) and read 5728 times:
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Quoting LeanOfPeak (Reply 17):
"Why would any company in its right mind design an aircraft without a fuel dumping system?"

Would you consider Airbus and Boeing to not be "in their right mind" then? How about Cessna, Piper, etc?

As has clearly been pointed out above, in the event of an emergency requiring a return to the departing airport shortly after take off at MTOW, it's not a problem for an A320 or 737 to land heavy. I would expect this to happen, for example, in the event of an engine failure on take off.

If the situation is not life threatening, in the JetBlue case, then the sensible thing to do is burn off as much fuel as you reasonably can before you land. It's not like they flew in circles for three hours with the plane falling to bits.

It's my guess you won't see a fuel dump system on a single-aisle plane unless mandated by the certifying authorities.

Can you find any instance of a fatal accident involving A320s or 737s where a fuel-dump system would have saved a single life?



Time flies like an arrow, but fruit flies like a banana!
User currently offlinePihero From France, joined Jan 2005, 4402 posts, RR: 76
Reply 21, posted (8 years 11 months 4 days 9 hours ago) and read 5689 times:

LeanOfPeak,

I was just referring to the necessity of a fuel dumping system, as viewed by the certifying authorities.

On another angle, I look at the system as a safety device and not as an emergency tool, and I know I'm not alone in this way of thought : getting your weight down when you have to turn back to base, with a flight control abnormality for which a lower weight means a lower landing speed and a shorter landing distance...
In an emergency, meaning you've got to get asap on the ground is altogether another matter where time is the essence.And fuel dumping a luxury you you cannot afford...

On the Swissair subject, I did a few years ago a research on the survivability of an on-board uncontrolled fire. My broad conclusions were that if a landing was made within 15 minutes of the fire detection, one has 100% chance of escape. Thererafter, the chances drop by 5% per every extra minute spent airborne, to be virtually nil after 30 minutes. (These are ballpark figures, to allow me quicker decision making ).



Contrail designer
User currently offlineZeke From Hong Kong, joined Dec 2006, 8998 posts, RR: 75
Reply 22, posted (8 years 11 months 4 days 7 hours ago) and read 5666 times:

The A320 could have landed at any time, even straight after takeoff.

The reason for not using reverse it two fold...

1) The LDG WITH ABNORMAL L/G checklist specifically says "REVERSE .. DO NOT USE"
2) The LDG WITH ABNORMAL L/G checklist then calls for both engines to be shut down (ENG MASTERS ...OFF) once the main wheels are on the ground, but prior to the nose wheel touching.

The LDG WITH ABNORMAL L/G checklist is written assuming that the nose gear will collapse on landing. If this happens the engine will touch the ground, you want fuel to be shut off to the engine in this scenario.

As you don't know if the strut will collapse or not, the engine masters are cut prior to flying the nose onto the ground.

The checklist is well thought out, and covers situations of nose, one main, both mains, or all gear with problems.

Abnormal landing gear incidents are not a specific to A320s, or Airbus, or Boeing. They would be one of the more common "emergencies" pilots will be faced with.

Its of my view that the crew decided to burn off the excess fuel so their approach speed would be lower, to reduce the ground roll on the runway.



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlineHAWK21M From India, joined Jan 2001, 31679 posts, RR: 56
Reply 23, posted (8 years 11 months 4 days 4 hours ago) and read 5622 times:

Quoting Scbriml (Reply 20):
As has clearly been pointed out above, in the event of an emergency requiring a return to the departing airport shortly after take off at MTOW, it's not a problem for an A320 or 737 to land heavy. I would expect this to happen, for example, in the event of an engine failure on take

Correct term would be "Overweight Landing" & not "Heavy Landing".

regds
MEL



Think of the brighter side!
User currently offlineLeanOfPeak From United States of America, joined Oct 2004, 509 posts, RR: 1
Reply 24, posted (8 years 11 months 4 days 3 hours ago) and read 5589 times:

Quoting Scbriml (Reply 20):
Would you consider Airbus and Boeing to not be "in their right mind" then? How about Cessna, Piper, etc?

As has clearly been pointed out above, in the event of an emergency requiring a return to the departing airport shortly after take off at MTOW, it's not a problem for an A320 or 737 to land heavy. I would expect this to happen, for example, in the event of an engine failure on take off.

If the situation is not life threatening, in the JetBlue case, then the sensible thing to do is burn off as much fuel as you reasonably can before you land. It's not like they flew in circles for three hours with the plane falling to bits.

It's my guess you won't see a fuel dump system on a single-aisle plane unless mandated by the certifying authorities.

Can you find any instance of a fatal accident involving A320s or 737s where a fuel-dump system would have saved a single life?

I was one of those saying all that.  Smile What I said was that was the question I was addressing.


25 Post contains images Starlionblue : I think it was so JetBlue could get lots of free airtime Seriously though, great post. And where the heck is SlamClick? He used to fly the things.
26 AvionicMech : I think that the flightcrew were also more than likely talking to Maintenance Control on the radio as well to talk to them and see if they might be ab
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