Originally Posted by
Gillegan
One thing to keep in mind regarding the REC ALT is that the FMC only looks at the winds for the next 500 nm. In some cases, when strong headwinds are forecast beyond 500 nm, the FMC will recommend a step climb when in fact, it's more economical to remain at your current level. I've only seen this on ULH flights. Because of this, it's a good idea to correlate any FMC recommended step climbs with the computerized flight plan.
Recommend functions as if you are the only aircraft in the sky. I've seen it recommend a descent after hours of recommending a climb.