Aircraft has slid off runway at MDW

[SuperFLUF]

Any 737 drivers out there know the factored landing distance for the conditions?

The 737-700 Normal landing distance chart (unfactored) includes Max reverse thrust, ISA conditions, and 2% downslope. The numbers assume a threshold crossing ht of 50ft and include 1000ft of air distance (landing exactly at touchdown markers).

In all cases Max Manual braking provides a shorter stop than max autobrakes.

for a landing wt of 120k (8k under max), which is probably heavier than they were, the Flaps 40, max manual braking numbers for a 7 kt tailwind are as follows:

Fair braking: 6393ft, subtract 310ft for every 1k below 120k landing wt.
Poor braking: 8705ft, subtract 430ft .........

These numbers are just a wag from the AFM, WN like all majors most certainly has a more detailed runway analysis system to produce data specific for the runway and conditions.

 

[minitour]

Fair braking: 6393ft, subtract 310ft for every 1k below 120k landing wt.
Poor braking: 8705ft, subtract 430ft .........

....wow...

 

[9GClub]

Washington Post, 12/10/05:

". . . . Officials said that three planes had landed on the same runway-- 31C-- in the 30 minutes before Flight 1248: a 757, a 737, and a Gulfstream G4. The pilots of the first two planes reported that the first two-thirds of the runway were clear but that braking on the last third of the runway was 'fair to poor' because of the snow. The pilot of the G4, who landed 2 1/2 minutes before [1248], said conditions were 'fair to poor' along the entire length of the 6,500-foot runway. . . ."

1248 should not have attempted that crap.

-Snow
-Short runway
-Tailwind!?

I heard from another source (forget where) that it plowed through the fence at about 40KT-- which doesn't sound like that much until you factor in the 120+ touchdown speed. This thing bled off less than 100KT in-- let's be generous-- 4,000 feet? 'Fair to poor' nothing..... more like 'gimme a break to hang it up.'

 

[9GClub]

I heard from another source (forget where) that it plowed through the fence at about 40KT-- which doesn't sound like that much. . . .

Clarification-- plowing through a fence at 1KT (and/or 1+ Gs... bwahahaa) is probably just as remarkable as plowing through it at 40KT.

 

[SkyBoy1981]

Said like a true amateur that has never flown anything bigger than a Bonanza and never landed in the snow.

 

[Guitar rocker]

Washington Post, 12/10/05:

". . . . Officials said that three planes had landed on the same runway-- 31C-- in the 30 minutes before Flight 1248: a 757, a 737, and a Gulfstream G4. The pilots of the first two planes reported that the first two-thirds of the runway were clear but that braking on the last third of the runway was 'fair to poor' because of the snow. The pilot of the G4, who landed 2 1/2 minutes before [1248], said conditions were 'fair to poor' along the entire length of the 6,500-foot runway. . . ."

1248 should not have attempted that crap.

-Snow
-Short runway
-Tailwind!?

I heard from another source (forget where) that it plowed through the fence at about 40KT-- which doesn't sound like that much until you factor in the 120+ touchdown speed. This thing bled off less than 100KT in-- let's be generous-- 4,000 feet? 'Fair to poor' nothing..... more like 'gimme a break to hang it up.'

9Gclub......In your expert opinion, somehow you must have already ruled out the fact that there were no mechanical malfunctions such as brakes, reversers, etc? You are the inexperienced type of kid who likes to second guess the actions of the pilots and determine what they did wrong before all the facts are known. Someday when you fly something that doesnt require carb heat, just maybe you'll get it. Until then, dont second guess the SWA pilots or anyone for that matter as that is truly unprofessional and rude. More than anything, you should realize that this could have happened to anyone.

 

[SkyBoy1981]

I seem to have run across quite a few of these private pilot types lately that are quick to criticize the crew in this accident. Some of them have even been quite experienced. Whats the deal here? Do some of you have no respect for your fellow aviators (airline or not)? Or do you see this as a chance to enhance your own ego by putting down two highly experienced pilots?

 

[SkyBoy1981]

Just out of curiosity I ran the Landing distance numbers on the computer program I use for the Gulfstream II that I fly. The factored wet runway distances came out as follows:

Runway 31C = 5,938ft (5,826 available)
Runway 13C = 5,123ft (6,060 available)
Runway 4R = 5,123ft (5,928 available)

Obviously the numbers for a boeing 737 would be different but it is interesting to see the effect that a "light" tailwind component vs a light headwind component can have on the distances. (815ft in this case)

I looked at my Jepps for MDW the other night after this happened, and if I recall correctly on the back of the 10-9 it showed an available landing distance on 31C based on following the VASI of just over 4900'. Did I miss something?

 

[satpak77]

http://myairplane.com/databases/approach/pdfs/00081ILD31C.PDF

 

[SkyBoy1981]

Ah, I see. That 5826 figure is based on landing just beyond the threshold according to the 10-9A. A landing beyond the glideslope (around the 1000ft markers) would leave an available landing distance of about 4900', which is probably a more realistic figure given the weather conditions. Is that correct or am I missing something?