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Booglebox
30th Apr 2016, 21:44
People's Viennaline operate an Embraer 170, OE-LMK s/n 00150. I hear it has more powerful engines to enable it to operate more comfortably at Altenrhein, with the surrounding high terrain.
This higher power setting apparently means that the bleed air pressure is higher than normal, with an adverse effect on some galley equipment.
Can anybody confirm this - or even give specifics of the exact pressure the higher rated engines produce? Many thanks!

Piltdown Man
1st May 2016, 06:58
Engine power and bleed pressure should be unrelated. The system diagrams I have show that initially bleed air pressure is regulated by an HPRSOV (LP air is unregulated on supply) and an Engine Bleed Valve. This air is supplied, in very small quantities, to pressurise the aircraft's water system. The next valve is the Flow Control Valve that regulates the pressure of the air supplied to the packs. My experience shows that typically pressure stays in the low 50's but some aircraft have the occasional tendency to rapidly fluctuate between 15 and 70 psi for no reason. The latter is permanently sorted out by a visit to hospital but can normally be corrected in flight by turning on the anti-icing for a few minutes.

Poorly functioning equipment is an unfortunate fact of aircraft operations. When it happens it gets put in the Tech. log and the techies sort it out. In Embaer's case, repetitive problems like this are normally fixed by a software upgrade and handled by your Engineers working in concert with the manufacturer's support team. After all, that is what you pay them for.

PM

FE Hoppy
1st May 2016, 20:20
As Piltdown says. The Engine rating is not related to the bleed system pressure.

Booglebox
2nd May 2016, 19:53
Thansk very much to you both :)