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BAC 1-11: Engine handling - temp buttons on pedestral
Posted: 09 Oct 2008, 14:34
by Sebastian
1.
What do those temp-buttons on the pedestral exactly do? I recapitulated the manual, but I cannot find any information how these switches work and what they affect.
2.
Do all the variants in the package have the water-injection feature? How long can/should you use them? How much percent of power can you add with water-injection?
3.
I have nothing to hand that could give me a rule of thumb which power settings and cruise speeds I should use for a particular altitude.
Take-off: I use about 101 to 102 percent
Climb: I take the number from the tutorial which states that 94 percent should be right
Cruise: I try to reach 300 to 310 knots, that means something like 92 to 93 percent
What is the cruise speed in Mach which would be a much more reliable and comparable figure for cruise settings?
And once again, I wrote the same in my thread that covers all about the fuel calculation: I anyone owns or knows where to find some charts respectively further online-material, PLEASE CONTACT ME!
Re: BAC 1-11: Engine handling - temp buttons on pedestral
Posted: 09 Oct 2008, 14:55
by Garry Russell
The top temp limit the power settings to keep the engine temp within limits
Opening the throttle full will not give you 100 percent thrust but all the thrust you can have for take off without having to throttle back to keep the temp in limits.
Garry
Re: BAC 1-11: Engine handling - temp buttons on pedestral
Posted: 09 Oct 2008, 15:01
by forthbridge
The Top Temp Buttons 'simulate' restricitng the fuel flow to the engine thus keeping temperature at nominal levels (IE prevent overheating).
Can't answer specifically on Water Injection other than the time it is useable is limited by the amount of water carried on the 1-11 for this purpose - about enough for one takeoff IIRC. IIRC DM has coded it for TWO minutes of use... anyone?
Mach .70 - .73 is the desired cruise speed, with M.77 being max speed.
Throttle settings are beyond me - as long as the engines aren't cooking, I aim for best speed without overspeeding. Also depends what weather settings you use.
Re: BAC 1-11: Engine handling - temp buttons on pedestral
Posted: 09 Oct 2008, 15:52
by NigelC
Normal cruise for the 1-11 is M0.72. Climb at 290-300kts until that equals M0.72, then continue at M0.72. Likewise, the reverse on the descent. 87-88% in the cruise should give you this speed on the 500, a tad more on the earlier versions.
On take off, use the TSI's (Thrust Setting Index). When you click on the top of the gauge, the figure in the window will change. This figure is the required thrust setting for take off (say 153). On take off, if you open the throttles to hit 100 on this gauge, that means you have 100% of the required thrust index of 153, so for different conditions you will have a different thrust index, but you just still go for 100% of whatever the set index is. This was used as I recall on the 500 and the 475, earlier versions had a P7 gauge where you would have to hit the required number (i.e. no index number).
Nige
Re: BAC 1-11: Engine handling - temp buttons on pedestral
Posted: 10 Oct 2008, 09:05
by clavel9
NigelC wrote:Normal cruise for the 1-11 is M0.72. Climb at 290-300kts until that equals M0.72, then continue at M0.72. Likewise, the reverse on the descent. 87-88% in the cruise should give you this speed on the 500, a tad more on the earlier versions.
On take off, use the TSI's (Thrust Setting Index). When you click on the top of the gauge, the figure in the window will change. This figure is the required thrust setting for take off (say 153). On take off, if you open the throttles to hit 100 on this gauge, that means you have 100% of the required thrust index of 153, so for different conditions you will have a different thrust index, but you just still go for 100% of whatever the set index is. This was used as I recall on the 500 and the 475, earlier versions had a P7 gauge where you would have to hit the required number (i.e. no index number).
Nige
US 200's and some 475's with fitted with either EPR or P7 (absolute exhaust pressure) gauges in place of the more commonplace TSI. The performance manual would contain charts for target EPR or P7 readings required for takeoff depending on local temperature and pressure. These were used for "rated thrust" takeoff only. In practice, it seems most 1-11's were flown on the FF gauge: optimal cruise performance was obtained via monitoring specific fuel flow. Throttles were set to achieve this within operating temperature and N2 limits. I do have a performance manual with all this information but a friend has it and I probably won't have a chance to get it back for a month or so. I'll post again when I do.