Quote:
Originally Posted by Kurn, son of Mogh
Another question on this incident: The news said that a *Low Pressure* warning light came on, not just on the flight when this happened, but on 2 or 3 prior flights.
What is the SOP for troubleshooting such a warning light?
The only Low Pressure warnings on an aircraft are for low fuel pressure.
Low cabin pressure is triggered at a cabin altitude of 10,000' and will cause a
CABIN ALT warning message on the EICAS, an aural emergency alert, and a flashing red "attention getter" light (one light in front of each pilot; either pilot can silence the aural alert by pressing the the red warning light on the coaming panel).
If not rectified and the cabin continues climbing (i.e. pressure keeps decreasing), the passenger O2 masks will drop when the cabin reaches an altitude of 14,500'.
This situation is covered in the QRH (Quick Reference Handbook which contains checklists for emergency and abnormal situations) but is one of the emergencies that has memory items associated with it. The memory items are the first steps in the appropriate checklist (in this case, the
CABIN ALT checklist) but are required to be performed from memory before reaching for the QRH.
In our
CABIN ALT checklist, the only memory items are the first two steps:
DON OXYGEN MASKS
ESTABLISH CREW COMMUNICATIONS
With the O2 mask on, the pilots need to select the microphone in the mask for comms. Once the masks are on and good communication established, the QRH is consulted. This will driect the pilots to descend below 10,000' (terrain permitting). If terrain is higher than 10,000, we would have already briefed the quickest heading necessary to fly to lower terrain. This is done routinely when overflying high terrain.