Jet extreme turns over SJ downtown approach to SJC?

A few minutes before PDT Fri 2006-09-29T20:00-0700 I was in San Jose
coming up US-Ca-I-280 from US-101 towards 7th St and Ca-87 exits, and
saw a large airplane (commercial passenger airline sized, although
could have been fedex?) take a hard turn (I am pretty sure a turn to
the right), somewhere between 50 and 70 degrees away from horizontal,
wings looking from my angle close to buildings, then level out within
a second or two, then a few seconds later, a hard turn in the opposite
direction about same angle from horizontal, also leveling out within a
second or two again, and both times very close to the buildings.
After the second turn, I couldn't see it any more since it was
shrouded by ground features, when I was approaching US-Ca-I-280 N -
Ca-87 N exit lane, nor did I see it later as I entered Ca-87 exit
ramp.

It was so strange that I drove to the airport to see if anything
happened. Everything seemed normal; I didn't see any smoke, fires on
the way by the freeway or at the airport when I got there, crazy
acting people, equipment on the airstrip, etc.. Because of nazi
driving and parking rules in the airport, I couldn't pick a random
person for a conversation to ask stuff about it. It was extremely
busy at the airport at that time.

Why would a plane do such a maneuver?

What is the experience of those on the plane?

How safe is such a maneuver?

Sunday night (2006-10-01) at 20:15, I saw a similar plane come into
the SJC airport landing approach queue at a sharp angle, with a
similar type of flying behavior to the one I saw Friday. This time it
was somewhere between Willow Glen and I-280 when it came in to its
slot. I didn't see it after that.

In article ,
Brad Allen wrote:

Why would a plane do such a maneuver?

The first example sounds like S-turns for spacing. It is very hard
to judge bank angles from the ground, and I'd be surprised if it
was even as much as 30 degrees.

What is the experience of those on the plane?

If it was a 50+ degree bank, it would definitely be an exciting
ride. Since it was much less then that, the passengers might not
have even noticed anything out of the ordinary. If it was FedEx,
the boxes don't care. The FedEx flights often will maneuver more
aggressively then a passenger jet would, but still no where near
the 50+ degrees you claim.

How safe is such a maneuver?

The planes landed safely, didn't they? The planes can handle alot more
then the passengers.

If you want to try and track which airlines were involved, try this
website: http://www4.passur.com/sjc.html

John
--
John Clear - http://www.clear-prop.org/

In article ,
John Clear wrote:
" In article ,
" Brad Allen wrote:
"
" Why would a plane do such a maneuver?
"
" The first example sounds like S-turns for spacing.

Oh. It makes sense it could be that.

Planes there come in within minutes of each other during some rushes
that I see (usually around 1PM and 6PM when the soup kitchen under it
feeds).

" It is very hard to judge bank angles from the ground, and I'd be
" surprised if it was even as much as 30 degrees.

Ok. As I age and practice my spatial relationships less than I
anticipated, it is possible my abilities underrate what I think or
thought they are or were, despite my abilities formerly overrating
what I thought they were.


" If you want to try and track which airlines were involved, try this
" website: http://www4.passur.com/sjc.html

I found it. That web site is neat! The first one I mentioned was at
(PT) 20060929T1956...T1959, flight Id AAY9873, aircraft type MD83,
route LAS-SJC, track ID 164, and it did a left then right then left
then right turns, which seems like S turns just like you said. It
dropped in altitude during that maneuver according to the web site,
but I didn't closely study those altitude changes.

The second one from a few days later was at (PT) 20061001T2014, flight
Id SWA1939, aircraft type B733, route SJC-BUR as it approached for
landing at SJC (yes, that seems wrong -- should I watch it take off to
be sure where it came from?). It came in a sort of J turn, but more
like a hook. It was looping to the left in a small arc, then it came
in and straightened out to the right to approach landing. It was that
right turn I saw that night. It sure looked more dramatic from ground
(I was a few blocks away, which is accurately recreated in the data in
that web site). It was definately less of a sharp turn from my point
of view than the one from Friday (the first one above).


"
" John
" --
" John Clear - http://www.clear-prop.org/
"


P.S., my host name based on computer model name; other abbreviations
unintended (and regretted).

" " If you want to try and track which airlines were involved, try
" " this website: http://www4.passur.com/sjc.html
"
" I found it. That web site is neat! The first one I mentioned was
" at (PT) 20060929T1956...T1959, flight Id AAY9873, aircraft type
" MD83, route LAS-SJC, track ID 164, and it did a left then right
" then left then right turns, which seems like S turns just like you
" said. It dropped in altitude during that maneuver according to the
" web site, but I didn't closely study those altitude changes.

I googled the flight ID, and got:

http://flightaware.com/live/flight/AAY9873

AAY9873
Allegiant Air, Inc. "Allegiant"
Aircraft McDonnell Douglas MD-83 (twin-jet) (MD83/Q)
Origin Mc Carran Int'l (KLAS)
Destination Norman Y Mineta San Jose Int'l (KSJC)
Other flights between these airports
Route SHEAD4 OAL HYP5
Date Friday, Sep 29, 2006
Duration 1 hour 4 minutes
Status Arrived 3 days ago (track log)
Proposed/Assigned Actual/Estimated
Departure 06:30PM PDT 06:57PM PDT
Arrival 07:36PM PDT 08:01PM PDT
Speed 433 kts
Altitude 36000 feet

So, consistent data.


The second one seems to contradict the data I got from the first web
site you mentioned above (Passur).

" The second one from a few days later was at (PT) 20061001T2014,
" flight Id SWA1939, aircraft type B733, route SJC-BUR as it
" approached for landing at SJC (yes, that seems wrong -- should I
" watch it take off to be sure where it came from?). It came in a
" sort of J turn, but more like a hook. It was looping to the left in
" a small arc, then it came in and straightened out to the right to
" approach landing. It was that right turn I saw that night. It sure
" looked more dramatic from ground (I was a few blocks away, which is
" accurately recreated in the data in that web site). It was
" definately less of a sharp turn from my point of view than the one
" from Friday (the first one above).

http://flightaware.com/live/flight/S...131Z/KSEA/KSJC

SWA1939 (web site)
Southwest Airlines Co. "Southwest" (Dallas, TX)
Aircraft Boeing 737-300 (twin-jet) (B733/J)
Origin Seattle Tacoma Int'l (KSEA)
Destination Norman Y Mineta San Jose Int'l (KSJC)
Other flights between these airports
Route J70 ELMAA FAMUK Q3 PYE LOZIT DUXBY SFO
Date Sunday, Oct 01, 2006
Duration 1 hour 18 minutes
Status Arrived over a day ago (track log)
Proposed/Assigned Actual/Estimated
Departure 06:20PM PDT 06:31PM PDT
Arrival 08:04PM PDT 07:49PM PDT
Speed 431 kts
Altitude 35000 feet

That is obviously wrong; the data from flightaware seems like it is
not incorrect but not for the flight I am interested in, and the other
web site has wrong data (wrong flight id, origination and destination,
etc.). Library closes in half a minute, so no time to figure out what
flight the one is that did the J hook.

Brad Allen wrote
Why would a plane do such a maneuver?

Most likely the following from the AIM

5-4-19. Side-step Maneuver

a. ATC may authorize a standard instrument approach procedure which serves
either one of parallel runways that are separated by 1,200 feet or less
followed by a straight-in landing on the adjacent runway.

b. Aircraft that will execute a side-step maneuver will be cleared for a
specified approach procedure and landing on the adjacent parallel runway.
Example, "cleared ILS runway 7 left approach, side-step to runway 7
right." Pilots are expected to commence the side-step maneuver as soon as
possible after the runway or runway environment is in sight.

NOTE-
Side-step minima are flown to a Minimum Descent Altitude (MDA) regardless
of the approach authorized.

c. Landing minimums to the adjacent runway will be based on nonprecision
criteria and therefore higher than the precision minimums to the primary
runway, but will normally be lower than the published circling minimums.

Bob Moore

On Tue, 03 Oct 2006 03:02:32 +0000, Brad Allen wrote:

Why would a plane do such a maneuver?

That's how I fly a localizer. Doesn't everyone?

[Well, inside the FAF. Outside, I sometimes have to turn a little more
aggressively.]

Laugh

- Andrew