Join Early Retirement Today
Reply
 
Thread Tools Search this Thread Display Modes
Old 07-20-2007, 12:28 PM   #21
Thinks s/he gets paid by the post
 
Join Date: Aug 2002
Posts: 1,322
Quote:
Originally Posted by REWahoo View Post
The source of the photo is Google Earth, which is a mosaic of thousands of satellite shots put together like a huge jigsaw puzzle. Most likely the photo of the aircraft on the runway and that of the aircraft on short final were taken at separate times.
Ding Ding! Give that man a cigar! That's exactly what's going on. I lined up the plane touching down with its shadow, then I lined up the plane on final with its shadow, and they are about 10 degrees different. Then I looked closely at the highway section between the two planes and you can see where it was stitched together. Good thinking!
__________________

__________________
FinallyRetired is offline   Reply With Quote
Join the #1 Early Retirement and Financial Independence Forum Today - It's Totally Free!

Are you planning to be financially independent as early as possible so you can live life on your own terms? Discuss successful investing strategies, asset allocation models, tax strategies and other related topics in our online forum community. Our members range from young folks just starting their journey to financial independence, military retirees and even multimillionaires. No matter where you fit in you'll find that Early-Retirement.org is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with our members, see fewer ads, upload photographs, create a retirement blog, send private messages and so much, much more!

Old 07-20-2007, 03:05 PM   #22
Thinks s/he gets paid by the post
Rustic23's Avatar
 
Join Date: Dec 2005
Location: Lake Livingston, Tx
Posts: 3,624
My vote is they are the same aircraft. A Airtrans Boeing 717. http://images2.jetphotos.net/img/2/5...1183651095.jpg (another shot). If you look at the pictures using google earth, the markings are the same, the difference in shadow I think is due to altitude. I don't know how many AirTrans fly out of Heartsfield, but it would seem unlikely there would be two on finale same time same day, but not impossible. It would be highly unusual for the tower to clear two aircraft and even more unlikely that the press would not find out about it.
__________________

__________________
Rustic23 is offline   Reply With Quote
Old 07-20-2007, 10:31 PM   #23
Thinks s/he gets paid by the post
BigMoneyJim's Avatar
 
Join Date: Feb 2003
Location: DFW
Posts: 2,627
The press usually gets technical details of aircraft completely wrong.

This was a twin engine plane. If one thrust reverser was engaged and the other wasn't and both engines were spooled up I think the jet would have turned off the runway and rolled and burned rather than speed down the runway too fast. Or perhaps the engine pods would have fallen off. (They're designed to do that under certain stresses...737's have dropped them a few times on takeoff, and I think the pods of the AA jet that crashed into Queens lost its pods due to shear forces before plummeting.)

Thrust reversers aren't the only way to slow down. They extend the flaps, raise air brakes and have disc brakes on the wheels. Usually all three methods are used, but I've noticed sometimes pilots favor reversers over brakes or brakes over reversers.

So I'm not buying what CNN is saying, because one bad thrust reverser doesn't lead to accelerating. The only ways I can imagine them accelerating would be if they intended to take off again or if the computer goofed up and didn't think they were landing. I don't know why you would try to take off if your wheels were already on the ground, so I'm thinking pilot confusion or computer problem. That is assuming the plane was accelerating after landing as the article said.
__________________
BigMoneyJim is offline   Reply With Quote
Old 07-21-2007, 01:11 AM   #24
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
 
Join Date: May 2005
Posts: 13,266
Big Jim....

I read some article that the reverse thruster was 'disconnected'... it had a problem a couple of days earlier and that they had 10 days to look at it... so someone disconnected... don't know what the pilot did.. but if he knew you would think he would have backed off that engine and maybe used the other... but... maybe that would have been enough to jerk it off line also.. I am not a pilot... so guessing from me here...
__________________
Texas Proud is offline   Reply With Quote
Old 07-21-2007, 09:24 AM   #25
Thinks s/he gets paid by the post
Rustic23's Avatar
 
Join Date: Dec 2005
Location: Lake Livingston, Tx
Posts: 3,624
I am not a 'large aircraft' kind of guy. I flew fighters, so maybe ReWahoo would be better to comment here. Normally lowering flaps would not be used to reduce stopping distance. Lowering flaps prior to landing slows the landing speed and that has an effect, but once on the ground, lowering flaps would increase lift which would tend to reduce brake effectiveness and therefore lengthen the landing role. There would be a trade off with drag but that decreases as speed decreases. As far as a single thrust reverse, the Boeing 717 has two engines at the tail and should be a 'centerline thrust' aircraft. Loss of one engine or thrust reverse on only one side should have limited effect. As far as the pods falling off, that should not happen with single reverse. Reverse thrust on a jet works by sliding a clam shell over the rear of the engine causing some of the thrust to reverse. If you have a jet ski with reverse you can see the same action. Stress on the engine should be the same regardless of what the other engine does. This is born out by the fact that the A/C is allowed to operate with only one operative.

Why would you try to take off if the wheels were on the ground. You landed fast, or long, knew you would not be able to stop and decided to go around. You may have made the decission before you touched down, and the engines were spooling up when you touched down, you then thought you could stop and you chopped the power. It didn't work. That is what accident investigation boards are far, and CNN's speculation just gets in the way. We should know is several months after they rebuild the A/C and review all the tapes and eye witnesses reports.
__________________
Rustic23 is offline   Reply With Quote
Old 07-21-2007, 10:10 AM   #26
Moderator Emeritus
Khan's Avatar
 
Join Date: Aug 2006
Location: Pine Island, Florida
Posts: 6,868
Send a message via AIM to Khan
Just something I heard once concerning a USAF jet crash:

If the jet is hydroplaning (very wet runway without grooves) the jet (computer) thinks it's in air mode instead of ground mode; and tries to go down instead of up.

I probably messed that up, I heard it years ago.
__________________
"Knowin' no one nowhere's gonna miss us when we're gone..."
Khan is offline   Reply With Quote
Old 07-21-2007, 10:26 AM   #27
Thinks s/he gets paid by the post
BigMoneyJim's Avatar
 
Join Date: Feb 2003
Location: DFW
Posts: 2,627
Texas Proud: There are things that are allowed to go unfixed for a time and those that aren't. (I saw a plane go out without a fairing to cover some of the flap workings.) I don't know which list thrust reversers are on, but even if they were allowed to fly with one inactive the pilot would surely be notified about it.

Rustic23: The 717 was the jet pictured in my ATL photo. The jet that crashed was an Airbus A320 with the engine pods under the wings. I was thinking the engine pods might fall off *if* one reverser were deployed and one wasn't and both engines were spooled up causing severe yaw forces...I figure either the plane would lurch off the runway to the side or the pods would torque off. Actually I think the pilot would back off the throttle as soon as he felt the plane trying to yaw.

However the linked article describes the jet accelerating down the runway after landing. The only ways I see that happening are that the pilot wanted to or the computer screwed something up. As with you I can't imagine why the pilot would want to take off again.

The only other thing would be if maybe one of the reverses was disabled and the pilot spooled up the wrong engine, but again I think the pilot would notice he's accelerating instead of decelerating. Or maybe this is the pilot error and he increased thrust instead of realizing his mistake. Actually that one sounds plausible.
__________________
BigMoneyJim is offline   Reply With Quote
Old 07-21-2007, 12:56 PM   #28
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
cute fuzzy bunny's Avatar
 
Join Date: Dec 2003
Location: Losing my whump
Posts: 22,697
Quote:
Originally Posted by BigMoneyJim View Post
I don't know which list thrust reversers are on, but even if they were allowed to fly with one inactive the pilot would surely be notified about it.

I have a buddy that used to fix planes at Travis. Some times the fixes were a little creative. He used to put duct tape on a lot of stuff to cover holes and missing hatches. It got sucked off the minute the plane took off, but then it was someone elses problem.

Pretty sure he didnt tell any of the pilots what he did
__________________
Be fearful when others are greedy, and greedy when others are fearful. Just another form of "buy low, sell high" for those who have trouble with things. This rule is not universal. Do not buy a 1973 Pinto because everyone else is afraid of it.
cute fuzzy bunny is offline   Reply With Quote
Old 07-21-2007, 01:46 PM   #29
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
 
Join Date: May 2004
Posts: 11,615
Just to add to the speculative frenzy:
-- If one thrust reverser were inop, it's easy to see how things could go wrong in a hurry. We're all creatures of habit, and many accidents that are attributed to pilot error involve either the inappropriate application of previously learned habits or some break/interruption in a previously established habit pattern that results in inappropriate decisions/actions.

After touchdown and normal landing, the pilot would have both engines near idle, then select thrust reversers on both and increase power on both (to reduce speed thereby decrease wing lift and get more weight on the wheels thereby increasing the effectiveness of the brakes.) With one inop reverser, if he went through the same motions the plane would yaw a lot and it would not slow down--it would speed up and the wheel brakes would be largely ineffective, especially on the wet runway. The first thing he'd likely suspect is a problem with the antiskid system, which is not at all what the problem was. But, with flaps at full, possibly spoilers deployed and only getting partial thrust for an undetermined reason, figuring everything out, getting the airplane properly configured, and getting off the ground in the remaining runway would be dicey (particularly given the tall buildings nearby).

But, in a few months we'll know exactly what happened. I would be surprised if the final findings don't pin a large amount of the blame on an insufficient appraisal and briefing prior to final approach concerning what-ifs given the situation at the airfield and with their airplane.

Very sad for all concerned.

Aviation is really simple--until it isn't.
__________________
"Freedom begins when you tell Mrs. Grundy to go fly a kite." - R. Heinlein
samclem is online now   Reply With Quote
Old 07-21-2007, 04:12 PM   #30
Give me a museum and I'll fill it. (Picasso) Give me a forum ...
REWahoo's Avatar
 
Join Date: Jun 2002
Location: Texas Hill Country
Posts: 42,102
Quote:
Originally Posted by Rustic23 View Post
I am not a 'large aircraft' kind of guy. I flew fighters, so maybe ReWahoo would be better to comment here. Normally lowering flaps would not be used to reduce stopping distance. Lowering flaps prior to landing slows the landing speed and that has an effect, but once on the ground, lowering flaps would increase lift which would tend to reduce brake effectiveness and therefore lengthen the landing role. There would be a trade off with drag but that decreases as speed decreases.
Rustic23 is correct. Flaps are not lowered after landing to reduce stopping distance, at least not on any large aircraft that I'm familiar with. Lowering them further (they are at least partially lowered as part of the landing process) upon landing would have exactly the effect Rustic23 mentions - increase lift and make the wheel brakes less effective.
__________________
Numbers is hard

When I hit 70, it hit back

Retired in 2005 at age 58, no pension
REWahoo is offline   Reply With Quote
Old 07-21-2007, 04:41 PM   #31
Thinks s/he gets paid by the post
BigMoneyJim's Avatar
 
Join Date: Feb 2003
Location: DFW
Posts: 2,627
Okay, perhaps flaps aren't lowered further after landing, by they sure are sticking down quite a ways before landing.




And then there are the spoilers which I errantly referred to earlier as "air brakes". They reduce lift in addition to increasing drag.
__________________
BigMoneyJim is offline   Reply With Quote
Old 07-21-2007, 05:25 PM   #32
Give me a museum and I'll fill it. (Picasso) Give me a forum ...
REWahoo's Avatar
 
Join Date: Jun 2002
Location: Texas Hill Country
Posts: 42,102
Quote:
Originally Posted by BigMoneyJim View Post
Okay, perhaps flaps aren't lowered further after landing, by they sure are sticking down quite a ways before landing.
All else being equal, on a short, wet runway such as this one you would expect to use all the flaps you had (lower them fully) to achieve the slowest possible approach speed.
__________________
Numbers is hard

When I hit 70, it hit back

Retired in 2005 at age 58, no pension
REWahoo is offline   Reply With Quote
Old 07-21-2007, 05:40 PM   #33
Give me a museum and I'll fill it. (Picasso) Give me a forum ...
REWahoo's Avatar
 
Join Date: Jun 2002
Location: Texas Hill Country
Posts: 42,102
I wonder if we will ever know what really caused the accident. This doesn't inspire much confidence in Brazil's aviation expertise:

SAO PAULO, Brazil (AP) -- A radar failure over the Amazon forced Brazil to turn back or ground a string of international flights Saturday, deepening a national aviation crisis just hours after the president unveiled safety measures prompted by the country's deadliest air disaster.

Further shaking Brazilians' confidence, authorities announced that they had mistaken a piece of the fuselage from Tuesday's accident for the flight recorder and sent it to a laboratory for analysis.
__________________
Numbers is hard

When I hit 70, it hit back

Retired in 2005 at age 58, no pension
REWahoo is offline   Reply With Quote
Old 07-21-2007, 08:50 PM   #34
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
 
Join Date: May 2004
Posts: 11,615
This performance is going to stick in my mind the next time I get aboard an Embraer-built regional jet.
__________________
"Freedom begins when you tell Mrs. Grundy to go fly a kite." - R. Heinlein
samclem is online now   Reply With Quote
Old 07-24-2007, 06:30 PM   #35
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
HFWR's Avatar
 
Join Date: May 2005
Location: Lawn chair in Texas
Posts: 12,964
Quote:
Originally Posted by BigMoneyJim View Post
DFW has fuel stores just offline from the runways near northeast air freight. (Two white circles upper center of the view. You can tell the active runways from the skid marks near the end.) Delta 191 hit them in 1985. They were dented for years...might still be if you look closely (in person, not in the Google photo) on the West side. On this article about Delta 191 the "Investigation & Clean Up" link in the box to the right has photos of the wreckage and the damaged fuel drums.




I don't have to. I got stranded at ATL a couple of Thanksgivings ago and got stuck with a motel that--as best I could tell by the sound--was only inches from the wheels of the landing jets. I'm pretty sure maker D on the map was my motel.
Just to clarify, those are water storage tanks...
__________________
Have Funds, Will Retire

...not doing anything of true substance...
HFWR is offline   Reply With Quote
Old 07-24-2007, 07:22 PM   #36
Recycles dryer sheets
 
Join Date: May 2007
Posts: 290
Quote:
Originally Posted by HFWR View Post
Just to clarify, those are water storage tanks...
Sure, and what is water? Hydrogen and oxygen.
It's another Hindenburg waiting to happen.
__________________
bpp3 is offline   Reply With Quote
Old 07-24-2007, 07:35 PM   #37
Thinks s/he gets paid by the post
 
Join Date: Aug 2002
Posts: 1,322
According to this FAA airport design circular, fuel storage tanks are not allowed inside the Runway Protection Zone (RPZ). The RPZ is 200 feet beyond the end of the runway. 200 feet?! That should make everyone feel better.

http://www.faa.gov/airports_airtraff...0_13_part1.pdf
__________________
FinallyRetired is offline   Reply With Quote
Old 07-24-2007, 07:55 PM   #38
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
HFWR's Avatar
 
Join Date: May 2005
Location: Lawn chair in Texas
Posts: 12,964
Quote:
Originally Posted by bpp3 View Post
Sure, and what is water? Hydrogen and oxygen.
It's another Hindenburg waiting to happen.
__________________
Have Funds, Will Retire

...not doing anything of true substance...
HFWR is offline   Reply With Quote
Old 07-24-2007, 09:19 PM   #39
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
cute fuzzy bunny's Avatar
 
Join Date: Dec 2003
Location: Losing my whump
Posts: 22,697
Quote:
Originally Posted by bpp3 View Post
Sure, and what is water? Hydrogen and oxygen.
It's another Hindenburg waiting to happen.
...
Attached Images
File Type: jpg huge manatee.jpg (97.8 KB, 0 views)
__________________
Be fearful when others are greedy, and greedy when others are fearful. Just another form of "buy low, sell high" for those who have trouble with things. This rule is not universal. Do not buy a 1973 Pinto because everyone else is afraid of it.
cute fuzzy bunny is offline   Reply With Quote
Old 07-24-2007, 11:21 PM   #40
Thinks s/he gets paid by the post
BigMoneyJim's Avatar
 
Join Date: Feb 2003
Location: DFW
Posts: 2,627
Quote:
Originally Posted by HFWR View Post
Just to clarify, those are water storage tanks...
Oh. Nevermind then.

Actually that makes a lot of sense given that there is a fire station nearby and no fuel truck depot nearby.
__________________

__________________
BigMoneyJim is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Your worst moments / worst failures? Nords Other topics 28 07-13-2007 12:03 AM
Worst case scenario. Sam Other topics 34 04-03-2007 08:04 PM
WORST JOB mathjak107 Life after FIRE 46 05-24-2006 11:33 PM
Best & worst living costs Nords Life after FIRE 0 05-13-2005 07:18 PM
"reasonable worst case" SWR: 2.55% amt FIRE and Money 38 11-12-2004 05:52 PM

 

 
All times are GMT -6. The time now is 03:20 PM.
 
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.