Curious incident :)

In a previous article, "Ramapriya" said:
in front of it. I noticed that the MD-11 had barely begun its turn on
the exit at the far end when smoke came off the 747 tires. The takeoff
roll had begun.

Since when does smoke come of the tires of a plane starting its takeoff
roll? I can't think of any way that could happen.


--
Paul Tomblin http://xcski.com/blogs/pt/
I think I have a new personal rule: Never watch anything which includes
the author's name in the title, particularly if the author is dead.
-- Andrew Dalgleish

Paul Tomblin wrote:
In a previous article, "Ramapriya" said:
in front of it. I noticed that the MD-11 had barely begun its turn on
the exit at the far end when smoke came off the 747 tires. The takeoff
roll had begun.

Since when does smoke come of the tires of a plane starting its takeoff
roll? I can't think of any way that could happen.



If I understood the OP correctly, the 747 was starting its takeoff roll
as an MD11 landed in front of him. The 747 probably hit the brakes
really hard.

To answer the original question (have I seen this before?): no, never. I
was once cleared into position and hold, but spotted traffic on short
final, so I held short, and told the controller about it. He apologized,
moments later a different controller replaced him.

This has happened in the USA though. You may all remember the 737 that
landed on top of a Brasilia (or some turboprop) at LAX in the late 80's.

-jav

Javier Henderson wrote:

If I understood the OP correctly, the 747 was starting its takeoff roll
as an MD11 landed in front of him. The 747 probably hit the brakes
really hard.


No, quite certain that that didn't happen. From what I saw, the 747
stood there waiting for the MD-11 to land and exit before taking off.
He probably chose to enter the runway because that portion was beyond
the threshold.

Not sure if I've conveyanced in words correctly here :\


This has happened in the USA though. You may all remember the 737 that
landed on top of a Brasilia (or some turboprop) at LAX in the late 80's.


Ah, but there's likely a difference here, as I've said above. The
aircraft in this instance was holding *beyond* the threshold.

Ramapriya

"Ramapriya" wrote

No, quite certain that that didn't happen. From what I saw, the 747
stood there waiting for the MD-11 to land and exit before taking off.
He probably chose to enter the runway because that portion was beyond
the threshold.

Not sure if I've conveyanced in words correctly here :\

I also can not imagine what could cause what you said. You said smoke left
the tires of the 747? What would cause tires of a stopped aircraft (just
beginning to roll) to smoke?
--
Jim in NC

Morgans wrote:

I also can not imagine what could cause what you said. You said smoke left
the tires of the 747? What would cause tires of a stopped aircraft (just
beginning to roll) to smoke?

Giving it full power before fully releasing the brakes?

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.

"George Patterson" wrote in message
news:1P4qf.17527$l25.6310@trnddc03...
Morgans wrote:

I also can not imagine what could cause what you said. You said smoke
left
the tires of the 747? What would cause tires of a stopped aircraft
(just
beginning to roll) to smoke?

Giving it full power before fully releasing the brakes?

Not that it *couldn't* happen, but I think that it is unlikely.

Generally, smoke only happens when there is a considerable speed difference
between the rubber and the road. If you drag a tire from a standing start,
you make a little noise, deposit some rubber (perhaps considerable), but you
don't generate enough heat to make smoke. These are my observations, but
YMMV.

Anyway, I would like to see smoke from extended brake holding while spooling
up.
I would bet that it would have to drag 10 feet or more, to build up enough
heat. It seems more likely, to me, that a little smoke came from the engine
going to full power.

A little (nah, really big) story along these lines, a long time ago on a
747.

I was in "The Ohio State University Marching Band" (TBDBITL) when we went to
the 1980 Rose Bowl. With all of the brass instruments, drums, and personal
luggage and fuel for that long trip, I have no doubt that we were at, or
very near max gross takeoff weight. I don't know how long Port Columbus
(Rickenbacker Field) was at the time, but with the weight and size of the
aircraft, and the length of the runway, it must have been close to minimum
lengths.

The pilot went to the departure end, and went down as far as he could before
turning around and lining up on the runway centerline. After a brief hold,
he spooled up the engines and held brakes for what seemed like *much* longer
than usual. I am almost sure that there were some tires sliding. The
brakes where finally released, but there was not the usual "kick in the
back" acceleration, but we did roll on down the runway, getting airborne at
what seemed like the last moment. Trip was completed successfully, but that
takeoff was exciting, for sure.

It was during the return trip that we dropped suddenly, and kicked sideways
at the same time, just as flight attendants were clearing supper trays. I
ended up with 5 or so plates held directly over my head, without a morsel
spilling on my head. "Good catch, miss, thank you," says I !!! This was
after sleeping on the floor of LAX for 5 or 6 hours, after our chartered
plane was fogged in at San Francisco. Oh, we lost the game also, and had
been up since 4:30 AM, to march in the Rose Bowl Parade. What a day!

Sorry for my ramblings. It was a good time.
--
Jim in NC

Paul Tomblin wrote:

Since when does smoke come of the tires of a plane starting its takeoff
roll? I can't think of any way that could happen.


Don't know about you but I've seen puffs come off aircraft tires, at
the start of the takeoff roll, often enough; it probably happens when
pilots advance the throttle a bit before releasing the brakes.

Ramapriya

"Ramapriya" wrote in message
oups.com...
Paul Tomblin wrote:

Since when does smoke come of the tires of a plane starting its takeoff
roll? I can't think of any way that could happen.

My thoughts exactly.

Don't know about you but I've seen puffs come off aircraft tires, at
the start of the takeoff roll, often enough; it probably happens when
pilots advance the throttle a bit before releasing the brakes.

I've never seen that, nor even heard of it. The proposed explanation you
suggest certainly wouldn't do it. Smoke comes off the tires during
touchdown because of the speed difference between the tire and the pavement,
until the tire "catches up".

During takeoff, even if the brakes are held, and even if the tires slide a
bit (which is very unlikely...usually the locked wheels can hold the
airplane still), they wouldn't smoke. They'd just rub a bunch of rubber
onto the pavement.

If you saw smoke during the takeoff roll, it came from somewhere other than
the tires.

Pete

Pete

The F-101B had enough engine power that if you held the brakes and ran
up and plugged the burners in it rotated the tires on the rim(s) and
blew them.You could see smoke as they skidded down the R/W.


Technique was to run up to around 80% and check gauges and release
brakes and advance throttle(s) to 100% and plug the burners in.

TOR was less than 1000 feet on a standard day.

Big John
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On Tue, 20 Dec 2005 11:03:22 -0800, "Peter Duniho"
wrote:

"Ramapriya" wrote in message
roups.com...
Paul Tomblin wrote:

Since when does smoke come of the tires of a plane starting its takeoff
roll? I can't think of any way that could happen.

My thoughts exactly.

Don't know about you but I've seen puffs come off aircraft tires, at
the start of the takeoff roll, often enough; it probably happens when
pilots advance the throttle a bit before releasing the brakes.

I've never seen that, nor even heard of it. The proposed explanation you
suggest certainly wouldn't do it. Smoke comes off the tires during
touchdown because of the speed difference between the tire and the pavement,
until the tire "catches up".

During takeoff, even if the brakes are held, and even if the tires slide a
bit (which is very unlikely...usually the locked wheels can hold the
airplane still), they wouldn't smoke. They'd just rub a bunch of rubber
onto the pavement.

If you saw smoke during the takeoff roll, it came from somewhere other than
the tires.

Pete

"Big John" wrote in message
...
The F-101B had enough engine power that if you held the brakes and ran
up and plugged the burners in it rotated the tires on the rim(s) and
blew them.You could see smoke as they skidded down the R/W.

Hardly relevant to the question of what happens at the *very start* of a
takeoff roll of a transport category airplane. Even in the case of the much
higher power-to-weight ratio of the F-101B (or other fighters, for that
matter), the smoke doesn't occur immediately upon power-up.

Pete