NWA From United States of America, joined Jun 2001, 1200 posts, RR: 3 Posted (9 years 2 weeks 3 days 1 hour ago) and read 4434 times:
On my free time, I like to fly "ready for pushback 747-200" in Flight simulator, and one of the main features is the FFRATS. My question is, for anyone that has expirance on it, did you like it? Also, when its set to auto EPR and in TOD mode, it requires you to advance the throttles to a certin EPR, and then it will go to th EPR limit. My question is does the pilot advance the throttles fully and let it limit itself, or just to the point where the FFRATS takes over? Thanks.
23 victor, turn right heading 210, maintain 3000 till established, cleared ILS runwy 24.
Flymia From United States of America, joined Jun 2001, 6781 posts, RR: 6 Reply 1, posted (9 years 2 weeks 2 days 7 hours ago) and read 4351 times:
Well I cant answer any of your questions. Just wanted to added that I fly 747-200 Ready For Push Back all the time. Never got the Ffrats down great or the INS. Great add on. Glad to see someone else have it.
"It was just four of us on the flight deck, trying to do our job" (Captain Al Haynes)
Air2gxs From , joined Dec 1969, posts, RR: Reply 2, posted (9 years 2 weeks 2 days 5 hours ago) and read 4315 times:
FFRATS, for those who don't know is Full Flight Regime Auto Throttle System. Basically its a modern auto throttle.
In an FFRATS jumbo the flight crew pushes the throttle up until the auto-throttle takes over. The classics don't have throttle by wire (unless you count the cable as a wire). That means the throttle movement is a direct linkage/cable to the jet fuel control. If the pilot pushes the throttle to the stop (as he would on a modern throttle by wire, FADEC system) he runs the very real risk of over-boosting, over-temping or over-speeding the engine.
Air2gxs From , joined Dec 1969, posts, RR: Reply 4, posted (9 years 2 weeks 1 day 14 hours ago) and read 4275 times:
Yes, unlike "modern" (FADEC) airliners, the jet fuel control on a B747-200 (JT9D-7Q equipped) receives its input from a cable. The cable moves the spool valve inside the JFC. If the pilot pushes the throttle to the stops he will be demanding the JFC to give the maximum amount of fuel. This can, and will, easily over-boost, over-temp and/or over-speed the engine. So, he just pushes the throttle up until the auto-throttle system picks it up.
To clarify, on a FADEC engine there is no direct (cable) connection between the throttle and the fuel control. When the throttle is pushed to the stops, the EEC interpets that as a full power command and sends the appropiate commands to the fuel control.