EPR-Settings at low temps/pressure

[OneDownOne2Go 0]

Hi,1st i wanna thank all the ppl involved for the phantastic Tinmouse-addon that leaves most if not all commercial addons behind...I was flying alot with that tiny bird the last weeks, and it's plain fun to take her on the short hauls.But when I fly under cold/low hg (-06

[Bob Scott 7,743]

Remember that those EPR settings are the maximum EPR limit, and that max thrust available increases significantly with the increased air density at very low temps. At max power settings when it's cold, the plane is a rocket, especially at lower gross weights.The PDCS does not compute reduced EPR settings. In the happy circumstances of an excess thrust situation, you can always pull it back to whatever power setting gives acceptable climb performance. In a fully-automatic aircraft like the G-V, I don't typically fly lightweight climbs at max climb power, as they produce high climb rates and deck angles that are downright uncomfortable for the pax. I instead use VS mode and select ~3000 fpm and let the A/T use what power is necessary to maintain that kind of climb until at least passing 10,000 ft MSL. In a steam-driven cockpit like the B732, I do the same thing, but manually. I use the CWS to establish the desired VS with pitch angle, and control airspeed with power.RegardsBob ScottATP IMEL Gulfstream II-III-IV-VSantiago de Chile

[OneDownOne2Go 0]

Thx for tne fast reply.So basicly I thought the PDCS would be a lill smarter then it acutally is. Guess flying the modern birds with allmighty systems spoiled my expectations ;-)I did what u described as "work around", but it's nice to hear that it's something that is done in real aviation From the experience I got with the Tinmouse, I usually climb at 3.000fpm up to 10.000ft MSL, then go on with 2.000-2.500fpm until at FL 210, above FL210, I climb with 1.500fpm. Is that realistic, or what rates should I use instead?Best RegardsKai

[Bob Scott 7,743]

I think that you should be able to maintain a comfortable climb using computed EPR once you've passed 10,000 ft and have accelerated to climb schedule speed.RegardsBob ScottATP IMEL Gulfstream II-III-IV-VSantiago de Chile