Good evening, engineers,
in the current PSX versions the FMU keeps operating normally when the ARINC 429 signal of the related fuel flow data is invalid. I'm wondering whether this is plausible.
PSX can simulate an invalid 429 signal for the EICAS FF display.
(Situation > Malfunctions > Alerts: "Invalid display EGT/FF"; severe for EGT, non-severe for FF.)
When the EEC is in ALTN mode, I now like to limit the N1 to the amber line (and slightly above) instead of the red line, because I just learned the FMU is able to keep it below the red line even when in ALTN mode.
I also like to keep the effect of the N1 bars turning red under non-normal conditions. The invalid 429 signal of the FF might be a condition that disables the FMU to keep the amber limit.
Any opinions? :-)
Regards,
|-|ardy
Well, it looks like the FMU incorporates a mechanical protection (shaft speed related) that limits the fuel flow, independent of any electronic control inputs.
Sorry, no access to my Engineering notes at the moment. Stuck in Tokyo.... Interesting TAF for tonight.... Winds 70kts, gusting to 90kts :-*
Success with that ... we've been through too many hurricane drills lately and know too well how that disrupts life.
Hoppie
The news says the worst typhoon in 60+ years, and that Tokyo is basically locked down for the day. Stay safe!
Thanks. I was quite safely stuck in my hotel room. You basically couldn't go anywhere. Almost everything was shut down/closed except some mini-marts. The local trains stopped running ... and umbrellas were useless if you wanted to go anywhere by foot in the rain.
The winds at Haneda (RJTT) didn't quite reach their expected target. A mere 85Kts 😋 If a typhoon wasn't quite enough drama, while I was in my hotel room, a mini earthquake struck. The hotel swayed and rattled for a few seconds. No tsunami warnings issued.
https://www.jma.go.jp/en/quake/