RAT 5 I don't think you are missing much at all except that on some aircraft the climb thrust selection is done manually.
From my looong term memory, the B767 requires you to manually select the CLB thrust rating via some buttons on the centre instrument panel. Perhaps there is a company policy that the only choice is CLB or CLB 1. Therefore on the occasion where a large derate/ high assumed temperature is used, where CLB 2 would have given you a thrust reduction, CLB 1 gives you a thrust increase.
The B737 FMC selects the Climb Thrust rating automatically ie CLB, CLB 1, or CLB 2 depending on the T/O thrust setting and is indicated via the CDU. This can be over-ridden if required. In some cases if you think there will be low-level turbulence or whatever and you want to gain altitude ASAP you can select CLB, again via the CDU either on the ground or anytime below 15,000 ft while in flight.
It is also interesting to note that any reduction in T/O or CLB thrust from the full rating actually means you burn more fuel!! Something to keep in mind if you are low on fuel and diverting from a go-around. Obviously the extended life of the engine that results from the lower thrust settings out weighs the extra cost of fuel.
Also with regard to the B737 (and others I suppose), the difference between Max CLB thrust and Rating 1 climb thrust reduces at a gradual rate as you increase altitude, so that at 15,000 ft they are the same. So as you pass through 15,000 ft the "R-CLB" annunciation simply disappears as the difference between them is now zero.
Cheers.
Last edited by Blip; 19th Feb 2004 at 12:05.