Jet Crew: Reverse Thrusters Failed in Chicago - Washington Post

"Flyingmonk" wrote in message
oups.com...

I hear that IAD (Dulles International Airport, in Northern Virginia)
will be replaced by a bigger international airport also. I live ten
minutes away from IAD.


Dulles is going to be replaced? Or just expanded?

They are on-off mircroswitches, the switch completes the
circuit when the strut is compressed to the static ground
position.


--
James H. Macklin
ATP,CFI,A&P

"Marc CYBW" wrote
in message news:fAZmf.251433$ir4.208268@edtnps90...
| But a smooth landing and lowering
| the nose may have been to delicate to trigger the
automatic
| deployment of the systems.
|
|
| My goodness. How sensitive are those gear load sensing
switches?
|
| Marc
|
|
| "Jim Macklin" wrote
in message
| news:lSYmf.22834$QW2.3354@dukeread08...
| Jet Crew: Reverse Thrusters Failed in Chicago
|
| Associated Press
| Sunday, December 11, 2005; A12
|
|
|
| CHICAGO, Dec. 10 -- The reverse thrusters that should
have
| slowed a Southwest Airlines jetliner before it slid off
a
| runway at Midway International Airport and into the
street
| did not immediately kick in when the pilots tried to
deploy
| them, federal investigators said Saturday after
interviewing
| the crew.
|
| How much of a role that braking equipment played in
| Thursday's deadly accident was not immediately clear,
| though, and the investigation is continuing.
|
| The plane's flight attendants told investigators that
the
| Boeing 737 did not appear to slow after it touched down
at
| Midway in a snowstorm Thursday, said Robert Benzon, the
| National Transportation Safety Board's investigator in
| charge.
|
| "They all said it was a smooth landing, but they could
sense
| a lack of deceleration," Benzon said.
|
| He said the pilots told investigators they began
applying
| the brakes manually as soon as they noticed that the
plane
| was not slowing properly. The plane, with 98 passengers
| aboard, slid through a fence and into street traffic,
where
| it killed a 6-year-old boy in a car.
|
| Because of the blowing snow, none of the air traffic
| controllers actually saw the plane land, but more than
10
| cameras could provide additional information.
|
| © 2005 The Washington Post Company
|
|
| Automatic deployment of spoilers and thrust reversers
| depends on compression of the main gear struts and
probably
| also the nose wheel strut. The description of a "smooth
| landing" indicates pilot error in the technique usewd
for
| the landing. If the aircraft was flown on the ILS to
just
| above the surface, a slight flare and a very firm
landing to
| compress the mains, followed by quickly lowering the
nose
| they might have been OK. But a smooth landing and
lowering
| the nose may have been to delicate to trigger the
automatic
| deployment of the systems.
|
|
|
| "Marc CYBW"
wrote
| in message news:cCWmf.145990$S4.8066@edtnps84...
| |
| |
|
http://www.washingtonpost.com/wp-dyn...121001562.html
| |
| |
| |
| | --
| | M. Lattoni
| | Calgary, Canada
| |
| | Skype: marc_lattoni
| | Phone: 403.238.3731
| | eMail:
| |
| |
|
|
|
|

A greaser landing would not necessarily compress the main
gear struts, which is what controls the auto-spoilers and
unlocks the gate on the power levers for reverse.
Lowering the nose gear will put the weight on three points
and not just the two main gear, which could allow the struts
to stay extended a little longer time.

In a light aircraft, maximum braking comes with the aircraft
on all three wheel and the elevator full back because the
tail down force is pushing the main tires into the ground.
It a transport with lift dump spoilers, the elevator
position is not as critical.


--
James H. Macklin
ATP,CFI,A&P

"Jim Carter" wrote in message
t...
| Well, The Washington Post being the source explains a lot.
I was
| wondering how they get the spoilers deployed with that
nose wheel still
| in the air. Seen it done dozens of times as I'm sure most
on the
| newsgroup have also.
|
| Regards,
|
| James A. (Jim) Carter
|
|
| -----Original Message-----
| From: Matt Whiting ]
| Posted At: Sunday, December 11, 2005 12:50 PM
| Posted To: rec.aviation.piloting
| Conversation: Jet Crew: Reverse Thrusters Failed in
Chicago - Washington
| Post
| Subject: Jet Crew: Reverse Thrusters Failed in
Chicago - Washington
| Post
|
| Marc CYBW wrote:
|
| But a smooth landing and lowering
| the nose may have been to delicate to trigger the
automatic
| deployment of the systems.
|
|
|
| My goodness. How sensitive are those gear load sensing
switches?
|
| The source was the Washington Post.
|
|
| Matt
|

Jet blast deflectors, news media calls them sound barriers
(stupid news media). If a jet was a break-away or take-off
thrust it would be blowing cars off the road, those curved
steel plates deflect the jet blast upward.


--
James H. Macklin
ATP,CFI,A&P

wrote in message
ups.com...
|
| Toks Desalu wrote:
| snip............... I could see that the plane barely
missed
| the wind breakers. Since I am a pilot, I easily
recognized the no landing
| zone.
|
| I'm a pilot too. What's a wind breaker?
|
| Frank
|
|
| Toks Desalu
|
| "Marc CYBW"
wrote in message
| news:cCWmf.145990$S4.8066@edtnps84...
|
|
|
http://www.washingtonpost.com/wp-dyn...121001562.html
|
|
|
| --
| M. Lattoni
| Calgary, Canada
|
| Skype: marc_lattoni
| Phone: 403.238.3731
| eMail:
|
|
|

Sounds plausible to me, I've never flown anything bigger
than the BE1900 and the Beechjet BE400, so the exact
operational sequence is only generally known to me. I do
know that a "carrier landing" is the way to get the struts
compressed ASAP.

You raise a question about technique...If the pilot applied
brakes manually before the wheels spun up to what ever rpm
was required, wouldn't that block any further automatic
spoiler deployment?


--
James H. Macklin
ATP,CFI,A&P

"John Gaquin" wrote in message
...
|
| "Jim Macklin" wrote
in message
|
| Automatic deployment of spoilers and thrust reversers
| depends on compression of the main gear struts and
probably
| also the nose wheel strut.
|
| I've never flown the 737, but have the 727 and 747.
Boeing used to be
| pretty consistent in running systems through the models.
On both the 727
| and 747, main gear compression *and* main wheel spin-up
are both necessary
| for operation of certain ground systems like reverse
thrust, autospoilers,
| autobraking, etc. IIRC, on the 727, nose gear
compression is also required
| for autospoiler deployment. Without a trip to the basement
for research, I
| can't recall the details. I *could* believe that after a
landing in several
| inches of snow, certain main wheels may not have spun up
enough to release
| the reverse actuators.
|
|

"Flight spoilers (2 -1/2/3/4/500; 4 -NG's) augment the ailerons and are
powered by hydraulic system A (inboard) & B (outboard). Spoilers will
continue to operate with speedbrake deployed.

Ground spoilers are also from hydraulic system A.

Only the outboard flight spoilers are powered by hydraulic sys B

On landing, if armed, all spoilers will deploy when the thrust levers
are at idle and any two wheels have spun up or right gear is
compressed. If not armed, the speedbrakes will deploy when reverse
thrust is selected."

While airborne you will only see flight spoiler. On landing flight
spoilers and ground spoilers deploy.

On an 737 NG -With the Speed Brake handle in the up position and on the
ground...
Gnd Spoilers #1,6,7, & 12 between 52 & 60 degrees
Flt. Spoilers # 2,3,4,5,8,9,10 &11 between 33 & 38 degrees

The photos show the spoilers not deployeed-SOP when configuring the
aircraft for emergency evacuation. Deployed spoilers would inhibit
overwing emergency evacuation.

Not a "windbreaker". They are called "blast fences". "Windbreakers" a
males full of gas!!!!!!

As a passenger in the back, it is impossible to evaluate whether a
pilot barely missed the blast fence or not. With two decades of part
121 flying, I do not second guess professional pilots when I am a
passenger nor do I second guess the NTSB.

Not much room for errors at LGA, Reagan, or Orange County. Of course
with AA, CAL, DAL, LCC using LGA, and not SWA, you won't hear how
dangerous LGA is.

Above 10 feet radar altimeter, you can manually deploy the flight
spoilers (8 panels).

Below 10 feet radar altimeter and engines idle, flight (8 panels) and
GROUND spoilers (4 panels) are armed and can be manually deployed prior
to touchdown, wheels spin-up, or Rt. strut compression.

Sounds like something that should have been done.


--
James H. Macklin
ATP,CFI,A&P

"lynn" wrote in message
oups.com...
| Above 10 feet radar altimeter, you can manually deploy the
flight
| spoilers (8 panels).
|
| Below 10 feet radar altimeter and engines idle, flight (8
panels) and
| GROUND spoilers (4 panels) are armed and can be manually
deployed prior
| to touchdown, wheels spin-up, or Rt. strut compression.
|

I thought I heard it was gonna be replaced. I don't remember where I
heard it from.