Thrust Lapse Rate

[Port Strobe]

Hi there I was wondering if anyone could help me interpret this engine data provided in the link below please?

http://www.bh.com/companions/034074152X/appendices/data-b/table-4/default.htm

I'm interested in the Tay 651 on the far right side. I'm not sure how to interpret the thrust lapse rate with altitude since the units aren't provided. What I'm trying to do is be able to find the thrust output for a given altitude and speed so I'd need the thrust lapse rate to cover the variation with altitude but I'm not sure about how to cover the speed relationship. It needn't be exact, just an approximate one would do thanks. From my first inspection it would appear to impact severely though looking at the quoted figures for climb thrust and sea level static thrust. Could someone also explain the term flat rating please?

Thanks very much for your time

[IFixPlanes]

Hy Port Strobe.
There are 2 types of engine rating:Full rated and flat rated.
Normally your engine thrust is limited by the OAT. Theoretically you have more thrust at low OAT till you reach the EGT limit.
OTOH your thrust decrease linear by rising OAT.
Full rated engines normally are used by military. But the wear of the engine is extreme (who cares: government pays!? :yuk: )
Airlines normally use flat rated engines. That means you don´t use the max. possible thrust at low OAT.
The manufacturer define a OAT on whitch you have the maximal thrust regardless how low the OAT is.
The trust only decrease if OAT goes over the manufacturer define a OAT.
If you make a drawing of thrust versus OAT, you get a "flat" line at low OATs and voila "Flat rated"
But pictures says more than explanation in my non native language:
http://img219.exs.cx/img219/6478/fullvsflat7tp.th.jpg (http://img219.exs.cx/my.php?loc=img219&image=fullvsflat7tp.jpg)

HIH

Ingo

[Port Strobe]

IFP, thanks very much for the reply, your explaination is more than clear enough for me to understand. That just leaves the lapse rate part then if someone smarter-than-I could share their wisdom please I'd be most grateful :D

Thanks again

[barit1]

I'm not sure how to interpret the thrust lapse rate with altitude since the units aren't provided.

Why not go to the BH webmaster and ask what the units for thrust lapse rate are?

[Port Strobe]

Thanks barit1 that's a good suggestion but right now finding a link to contact someone is proving elusive :mad: I'll endevour to find one but if anyone does happen to know the answer do share please, you know what its like trying to get replies from some firms. Thanks again