Leaving all engines running at the gate

[John]

Recently at SJU I saw an IB A340-600 arrive from Madrid that left all
four engines running during the 2 hours that it was at the gate before
continuing to Santo Domingo. After all the passengers got off the
entire crew, both cabin AND cockpit crew got off and went to the
transit lounge for about an hour before returning to board for the SDQ
leg. All this time the engines were left running. In fact, they
never stopped running the whole time they were at SJU. I have never
seen an airliner do this before and was wondering if something was
wrong with this particular aircraft or if this is some kind of new
"windmilling" feature on the new A346 or something. Perhaps related,
I've heard that IB have had a horrible experience with their new A346s
and this particular aircraft, EC-INO (Gaudi), the first one they
received, is said to have given then more headaches than all the
others.

What circumcstances would make an airline leave a plane guzzling gas
for such a long time on the ground?

[Larry Fransson]

On 2004-02-03 10:40:37 -0800, John > said:

> What circumcstances would make an airline leave a plane guzzling gas
> for such a long time on the ground?

Just about none. You couldn't have any ground crew anywhere near the
aircraft doing the usual ground crew stuff (loading/unloading baggage, etc)
with engines running. And nobody in their right mind would leave engines
running without somebody on the flight deck to mind the aircraft.

It seems more likely to me that it might have been very windy at the time
and that the windmilling of the engines along with the noise from the APU
might have given the appearance of having engines running.

--
Larry Fransson
Seattle, WA

[snowy squirrel]

John wrote:
>
> Recently at SJU I saw an IB A340-600 arrive from Madrid that left all
> four engines running during the 2 hours that it was at the gate before
> continuing to Santo Domingo.

If you could see the engines turning, it means that they were shut off and
just slowly turning due to wind.

It would be very hard for maintenance personel to get near the aircraft with
all 4 engines running. And I suspect extremely hazardous (if not illegal) to
refuel while engines are running.

It is far more likely that what you saw were just engines turning slowly due
to wind.

There are situations where engines on one side are left running in extreme
cold arctic conditions, and all passenger, cargo, fuel is handled from the
other side. This is to ensure that at least one engine is available to
generate sufficient power to restart the second engine.

[Jim Davis Sr.]

"snowy squirrel" > wrote in message
...
> John wrote:
> It is far more likely that what you saw were just engines turning slowly
due
> to wind.
Reminds me of what Steven Wright once said. "I used to own a helicopter,
but had no place to park it, so I tied a rope to it, & left it running."

[John]

snowy squirrel > wrote:

>John wrote:
>>
>> Recently at SJU I saw an IB A340-600 arrive from Madrid that left all
>> four engines running during the 2 hours that it was at the gate before
>> continuing to Santo Domingo.
>
>If you could see the engines turning, it means that they were shut off and
>just slowly turning due to wind.
>
>It would be very hard for maintenance personel to get near the aircraft with
>all 4 engines running. And I suspect extremely hazardous (if not illegal) to
>refuel while engines are running.
>
>It is far more likely that what you saw were just engines turning slowly due
>to wind.
>
>There are situations where engines on one side are left running in extreme
>cold arctic conditions, and all passenger, cargo, fuel is handled from the
>other side. This is to ensure that at least one engine is available to
>generate sufficient power to restart the second engine.

Nope, those four fans were running at a pretty good clip. No wind
involved there. Besides, with the size of those things, it would take
a hurricane to keep them turning for two hours.

[Robert M. Gary]

The fans you saw were probably being turned by the wind. The noise you
heard was probably the APU running in the back. Its not unusual for a
plane to sit at the gate with the APU running in the tail of the
plane. Its a jet too and sounds like one.

John > wrote in message >...
> Recently at SJU I saw an IB A340-600 arrive from Madrid that left all
> four engines running during the 2 hours that it was at the gate before
> continuing to Santo Domingo. After all the passengers got off the
> entire crew, both cabin AND cockpit crew got off and went to the
> transit lounge for about an hour before returning to board for the SDQ
> leg. All this time the engines were left running. In fact, they
> never stopped running the whole time they were at SJU. I have never
> seen an airliner do this before and was wondering if something was
> wrong with this particular aircraft or if this is some kind of new
> "windmilling" feature on the new A346 or something. Perhaps related,
> I've heard that IB have had a horrible experience with their new A346s
> and this particular aircraft, EC-INO (Gaudi), the first one they
> received, is said to have given then more headaches than all the
> others.
>
> What circumcstances would make an airline leave a plane guzzling gas
> for such a long time on the ground?

[John T]

"John" > wrote in message

>
> Besides, with the size of those things, it would take
> a hurricane to keep them turning for two hours.

Have you ever turned a turbine engine?

--
John T
http://tknowlogy.com/TknoFlyer
http://www.pocketgear.com/products_search.asp?developerid=4415
____________________

[John Gaquin]

"John" > wrote in message
>
> Nope, those four fans were running at a pretty good clip. No wind
> involved there. Besides, with the size of those things, it would take
> a hurricane to keep them turning for two hours.

Rotor sections are *extremely* finely balanced, else they would vibrate the
engine right off the wing at operational speeds. What this means is that
the blade wheels will turn freely with very little force applied. A light
breeze will suffice, no hurricane required. In my experience, more often
than not you'll see these things turning (at least with large fan engines)
if there's any breeze exposure at all.


Regards,

John Gaquin
B727, B747

[Newps]

John wrote:


>
> Nope, those four fans were running at a pretty good clip. No wind
> involved there. Besides, with the size of those things, it would take
> a hurricane to keep them turning for two hours.

It takes very little wind to turn the blades.

[karl]

If you could see the blades turning then the engines coudn't be running.

Karl

[aptim]

"John" > wrote in message
...
> snowy squirrel > wrote:
>
> >John wrote:
> >>
> >> Recently at SJU I saw an IB A340-600 arrive from Madrid that left all
> >> four engines running during the 2 hours that it was at the gate before
> >> continuing to Santo Domingo.
> >
> >If you could see the engines turning, it means that they were shut off
and
> >just slowly turning due to wind.
> >
> >It would be very hard for maintenance personel to get near the aircraft
with
> >all 4 engines running. And I suspect extremely hazardous (if not illegal)
to
> >refuel while engines are running.
> >
> >It is far more likely that what you saw were just engines turning slowly
due
> >to wind.
> >
> >There are situations where engines on one side are left running in
extreme
> >cold arctic conditions, and all passenger, cargo, fuel is handled from
the
> >other side. This is to ensure that at least one engine is available to
> >generate sufficient power to restart the second engine.
>
> Nope, those four fans were running at a pretty good clip. No wind
> involved there. Besides, with the size of those things, it would take
> a hurricane to keep them turning for two hours.


Was the rotating beacon on? If not the engines were most likely
windmilling.

It would be to dangerous to leave one engine running at the gate. Let
alone four. Too many people and equipment in the area. Turbo fan engines
have a tendency of sucking anything that gets to close. Paper or a plastic
bag or plastic wrap that is use to wrap cargo. That's including people
too. There is just to much crape around the gate just waiting to get suck
in. It doesn't take much to damage one of those fan blades. At 20-30,000
dollars per fan blade (For a RB-211. American Airlines 757 ). I don't
think they will leave them running unless they want to be changing fan
blades more often on the A340.


aptim A&P

[Ron Natalie]

"John T" > wrote in message ws.com...
> "John" > wrote in message
>
> >
> > Besides, with the size of those things, it would take
> > a hurricane to keep them turning for two hours.
>
> Have you ever turned a turbine engine?

Yep, the wind easily turns the bypass fans. When I had a friend flying
for UPS, we climbed up into the intake of a 767. You could easily
grab the blades and spin them around at a pretty good clip. We scared
the hell out of the load master who saw the thing start to turn with vigor
and thought the engines were being start on him.

[Capt.Doug]

>"John" wrote in message> Nope, those four fans were running at a pretty
>good clip. No wind
> involved there. Besides, with the size of those things, it would take
> a hurricane to keep them turning for two hours.

Iberia usually parks at gate 27 where the prevailing wind blows up the
tailpipes. A 4 knot wind is sufficient for spinning a fan disk. If you could
see the blades, the engines weren't running.

D.