Klaxon on BAC 1-11

[NigelC]

I usually set the cabin altitude at about 20% (6,600 ft for FL330) of the cruising level on pre-flight. Wind it down to destination airfield elevation at top of descent. Works fine for me.

NigeC

[crisso]

On my last recent flight with the BEA/BA Panel from a cold start, in addition to the above, I switched the safety valve below the pressure gauge setting, from open to normal (or was it closed?) and - the klaxon didn't subsequently go off. Presumably that is what one should do pre-flight/taxy-ing?

[NigelC]

Yup! If you look at the checklist, Safety valve needs to be open for engine start, and closed on the taxi checks. (DMs Checklist and the AA one). If you leave it open, as the aircraft pressurises, it just dumps the air overboard - end result - no pressurization

Nigel C

[forthbridge]

Yup! If you look at the checklist, Safety valve needs to be open for engine start, and closed on the taxi checks. (DMs Checklist and the AA one). If you leave it open, as the aircraft pressurises, it just dumps the air overboard - end result - no pressurization

[Paolo Lao]

I usually set the cabin altitude at about 20% (6,600 ft for FL330) of the cruising level on pre-flight. Wind it down to destination airfield elevation at top of descent. Works fine for me.

NigeC

thanks alot Nigel for this one, I'll try taking it to 36000 next time, with the correct setting of cab alt ofcourse

[NigelC]

thanks alot Nigel for this one, I'll try taking it to 36000 next time, with the correct setting of cab alt ofcourse

Max FL for the One-Eleven was FL350. The four 400 series aircraft we had at BIA (G-CBIA, G-AXMU, G-AXBB and G-AXOX) were the exception, as they were built for Gulf Air and had beefed up air systems. On sectors up to about an hour and a half (light fuel load, or further if light pax load), they could go up to FL370. Examples of this were flights such as LGW-GVA, LGW-ZRH, LGW-MUC.

Regards

Nigel C

[Paolo Lao]

Yes a its getting a bit slower in FL360, I had to descend back to 330, the cab alt works great now, the alarm with the yellow light is not bothering me anymore :flying:

regards
Pao ;-)