Why can't the French dump fuel?

In article .com,
"Robert M. Gary" wrote:

In the case of the A320, or the 737, they can both land with a full load
of fuel.

Then why did Jet Blue fly around for 3 hours burning fuel before
landing back in LAX? It seems like if there is a real reason to want to
burn off fuel there would be a real way to get rid of the fuel. I can
dump fuel even in my Mooney.

I would think landing at a minimum weight would help reduce the
probability of nose gear failure. Also, 3 hours of fuel burned in
the air is far better than burning on the ground, if you know what
I mean. With respect to flying around for 3 hour... well... they could.
There was no need to land immediately.

--
Bob Noel
no one likes an educated mule

"Robert M. Gary" wrote in message

Then why did Jet Blue fly around for 3 hours burning fuel before
landing back in LAX? It seems like if there is a real reason to want to
burn off fuel there would be a real way to get rid of the fuel.

The prime objective of the three-hour fly-around was not to burn off fuel.
The time was used consulting with engineering to make sure all alternatives
and technical sources had been considered before committing to a compromised
landing. Having said that, burning off the fuel didn't hurt. While a
reduced landing weight wasn't technically required, it was still more
desirable than a heavier landing weight in the instance.

"Robert M. Gary" wrote:

In the case of the A320, or the 737, they can both land with a full
load of fuel.

Then why did Jet Blue fly around for 3 hours burning fuel before
landing back in LAX? It seems like if there is a real reason to want
to burn off fuel there would be a real way to get rid of the fuel. I
can dump fuel even in my Mooney.

As others have said, they first consulted with their dispatch and
maintenance, which took time. The original intent was to land in Long
Beach, but when they found the gear rotated, they changed to LAX. That
took more time. LAX was picked because of the longer runways, and better
emergency services.

Once they decided to head toward LAX, they had already burned a fair
amount of fuel. Any additional time flying around helped:

- Lower landing speed
- Less impact force when the nose gear dropped
- Shorter stopping distance once on ground

As to why no provision for fuel dump, I suspect it is a cost driver:
Something else to fix, something else to go wrong, plus it adds
unproductive weight.

As to why no provision for fuel dump, I suspect it is a cost driver:

Of course, everything is a cost driver. Whether or not to have carpet
is a cost decision. The real question is what the benefit side looked
like in their cost/benefit talks.

-Robert

Put another way, why provide a way to dump fuel when you can just run it
through the engines.

They didn't need to lose weight that fast, they didn't need to land 'right
now'. The fact that they flew around in circles for three hours was probably
a good thing, time to examine every possibility and double check everything
before landing.

"Robert M. Gary" wrote in message
ups.com...
As to why no provision for fuel dump, I suspect it is a cost driver:

Of course, everything is a cost driver. Whether or not to have carpet
is a cost decision. The real question is what the benefit side looked
like in their cost/benefit talks.

-Robert

"Robert M. Gary" wrote in message
ups.com...
As to why no provision for fuel dump, I suspect it is a cost driver:

Of course, everything is a cost driver. Whether or not to have carpet
is a cost decision. The real question is what the benefit side looked
like in their cost/benefit talks.

Why is dumping fuel needed? It can still climb at engine out with full
fuel, no need to dump there. If they can get up, and stay up, no need to
dump; they are safe.

What in this case? Were they in danger, flying around? No? Why dump,
then? Could they have landed immediately, in a case of immediate danger?
Absolutely. Still, you are asking. Why would they need to dump? They were
in no danger.
--
Jim in NC

Robert M. Gary wrote on 9/27/2005 14:07:
In the case of the A320, or the 737, they can both land with a full load

of fuel.

Then why did Jet Blue fly around for 3 hours burning fuel before
landing back in LAX?

The last link provided by Kev has the likely answer:
"The primary reason to burn off the extra fuel was that a heavier plane
has a faster landing speed. Since a slower airspeed on landing was the
objective in this case, the course of action was to lighten the load by
burning off some fuel and when landing, lower the nose gear at as slow
an airspeed as possible."

-Joe

The last link provided by Kev has the likely answer:
"The primary reason to burn off the extra fuel was that a heavier plane
has a faster landing speed. Since a slower airspeed on landing was the
objective in this case, the course of action was to lighten the load by
burning off some fuel and when landing, lower the nose gear at as slow
an airspeed as possible."

Joe,
You sound like an EXCELLENT advocate for having the ability to dump
fuel too!!!

-Robert

The FAA certification requirement for a fuel dump system is a takeoff
weight that is greater than 135% (I think) of the max landing weight.
They don't add the complexity and cost of a dump system unless it is
required for certification.

The 707-123 I flew had a empty weight of 120,000 lbs, max TO weight of
256,000 lbs, 112,000 lbs of fuel, a max landing weight of 190,000
pounds,(135%) had a dump system. A 757-200 at 256,000 lbs carries
83,000 lbs of fuel, max landing weight of 198,000 lbs (130%) does not.
BTW the 757 with 29,000 lbs less fuel has the same range as a 707-100
with the same passenger load.

The 707 system has standpipes that let you dump only to get you down
to max landing weight, leaving in our case about 70,000 lbs of fuel.
That being said, I'd have flown around several hours after dumping, if
there was no immediate emergency , to get as light and non-flamable as
possible before landing. Their gear problem was not an emergency and
I doubt the crew declaired one even though they asked for the
equipment. Emergencies require immediate action. (think fire) BTW a
single engine failure is not classified as an emergency either. The
aircraft is certified to climb at max takeoff weight on a single
engine.

I'm sure the airlines, EPA, and everyone else would rather the fuel be
burnt as normal rather than dumped into the air and sea. In an
emergency, planes that don't have a dump system will do an overweight
landing and and have to do an overweight landing inspection prior to
next flight. Given the choice, it's better to burn it down than do
the inspection.

Robert M. Gary wrote:

Joe,
You sound like an EXCELLENT advocate for having the ability to dump
fuel too!!!

-Robert

Robert,

Why are you in such a hurry to dump fuel? Doing that starts to limit
your time / options available for trouble shooting the problem and
diverting to another airport.

The first two memory items on any emergency checklist a

1. FLY THE AIRPLANE
2. DON'T HURRY

Dumping fuel violates #2. Besides, IF you really need to land in a
hurry, the A320 can do that at any weight. These guys took off for NY
with a full load of passengers. That means that they had a lot of fuel
onboard and a heavy takeoff weight. To land at that weight would have
required a much higher landing speed. Since they had the hydraulics
(green system) turned off to the nosewheel steering system, (per
emergency checklist) this also reduced their braking ability because
this same hydraulic system also controls the #1 engine reverse, and
normal braking, i.e. antiskid assisted braking.

BJ
A320 Capt.