Will this cause any negative effect on health?

[kuobin]

We use ERJ-190 to fly domestic.all of our operating airport near sea level.When cruise at FL200. our cabin alt shown -200ft or -300ft .I wonder if this will this cause any negative effect on health?
I mean We are suffering a high pressure than sea level.Right?

[wiggy]

Interesting cabin alt figures...anyhow roughly speaking being at -300 feet would only add another 10 hectopascals to a sea level pressure, (e.g. If sea level was 1013 hpa then the cabin would be at 1023 hpa), the sort of pressure the body is regularly exposed to by a high pressure weather system (anticyclone). Personally can't see there's much to worry about.

[Bergerie1]

The people who live around the Dead Sea seem to do alright -1371 feet.

[wiggy]

Good point...

Must admit being a bit perplexed by the "negative" cabin alt figures - any ERJ operators able to shed any light on the cabin alt scheduling?

[Fursty Ferret]

Yes, increasing the cabin pressure adds structural rigidity to the fuselage.

[FE Hoppy]

Originally Posted by wiggy

Good point...

Must admit being a bit perplexed by the "negative" cabin alt figures - any ERJ operators able to shed any light on the cabin alt scheduling?

FL200 should give 6.7psid cabin alt 2800'.

However on short legs at light weights it could be different due to early change to cruise mode.

It will also depend on the cruise alt put into the FMS as this sets the initial cabin rate of climb.

Going the whole way with -200 to 300' looks like return to base mode to me which could be caused by a short descent before reaching 5000' AGL or 10000' absolute.

Something fishy.

[Check Airman]

Originally Posted by kuobin

I wonder if this will this cause any negative effect on health?
I mean We are suffering a high pressure than sea level.Right?

Not a doctor, but unless you're really trying to grow an extra 0.000000023mm, I doubt you will see any change.

If I'm not mistaken, you're looking at pressure altitude, which could vary more than that on a given day at the beach anyway. Furthermore, the standard pressure that you're concerned about is entirely arbitrary from a biological point of view.