What is all this rubbish about airmanship, monitoring, rules, regulations etc.? Why complicate a simple procedure with all this guff? Single engine taxiing saves fuel. There are times when is makes sense and times when it doesn't; it should be left to our judgement. Unfortunately one airport, LHR, has decided unlaterally for reasons only known to themselves that they will prohibit the crossing of active runways by aircraft with "reduced engine running". So be it and I comply. As a result, I pollute the air at LHR with 200 Kgs of CO2 near enough every time I fly there. As a company, I reckon we unnecessarily waste nearly 2,000 Kgs of fuel every day at LHR whilst taxiing.
PM