Water evacuation Conundrum

[hawk37]

Flew Continental as SLF. Was surprised to read their safety card on the 757 200, and find they show that in the case of a water landing, the over wing emergency exits are NOT to be used. Further, it shows the emergency raft(s) stowed in the overhead(s) by the over wing exits. The other 6 exits do come equipped with slides that also function as rafts though. In addition, the diagram showed carrying the overwing raft forward up the aircraft aisle to a non overwing exit, and deploying it from there.

Continental's EMB 145(?) jet, with about 56 seats, had a safety card saying the opposite, to use the overwing exits and not the others, in the event of a water landing.

Anyone have an idea why the two types would be so different?

What does the A320 safety card say?

[Capt Claret]

Perhaps different aircraft have different ditching characteristics.

[muduckace]

I am surprised to hear this of the 757 may be due to the size of the exit and flotation devices, as for the EMB145 there is only one door (stairs too) may prove to be an obstruction and would allow for more water to enter the cabin, the overwing sounds logical in it's case. The other factors are egress and the amount of PAX., in any egress you want to generally have everyone heading for the nearest exit to egress as quickly as possible.

[hawk37]

"Perhaps different aircraft have different ditching characteristics."

Anyone have access to the manufacturer's trials?

[Intruder]

This issue illustrates why even a seasoned flyer should review the emergency card before EACH flight! One of those "minor" differences may be lethal if you're not acutely aware...

[rusty_fork]

In a ditching on the A320, the overwing exits are useable, however, the slides are not. The aspirators used for slide inflation are below the waterline which means that the slide will not inflate correctly. Also the overwing slides cannot be detached from the aircraft.
Maybe the 757 could have a similar set-up?

[hawk37]

So....back to my original question, if the ERJ 145 and the A320 use the overwing exits in a ditching (as rusty fork says), why not so on the 757 200?

Maybe, when they repacked the 757 rafts after the first inspection, they could no longer be compressed small enough to fit out the overwing exit?

[FlightDetent]

Originally Posted by Cosmos2

The A320 has slide rafts for wing exits so it's a different strategy.

Different strategy yes, different size and exit location indeed. But A320 does not have slide-rafts for wing exits.

FD (the un-real)

[hawk37]

Any thoughts that a ditching aircraft may not want to open the non overwing exits? Perhaps that could just let the water in, sink the aircraft faster. Thus the ERJ 145 says to only use the overwing exits in a water landing, not the normal exits.
Could Boeings & Airbusses float better, don't have to worry about flooding?