makes an excellent point. There is a distinct difference between less safe
in this case. The line between the two is usually drawn by what we refer to as "Aircraft Limitations", in this case "Performance Limitations".
There was a similar discussion last month on the pros and cons of intersection departures:
In one of the longer posts towards the bottom I described a situation where I have done an intersection departure which was actually more safe
in performance terms than a (derated thrust) full-length departure (reaching V1 less far down the runway than doing a full-length takeoff).
In all cases the calculations are done in advance and performance data is checked to ensure that thrust setting, flap setting and V speeds are used which provide a safe margin in the event of a high speed abort, or high speed single engine continue.
The calculations for RTO do not take account of reverse thrust (which we would most certainly use) but do assume maximum braking and full speedbrake deployed.
put it, "everything can be made safer – but the cost increases…". An absolutely true statement. We could double the size of every runway in the world… and takeoffs would be safer
, we could fit EGPWS to every airliner in the world and flying would be safer
, we could install an ILS at every airport in the world and flying would be safer
. But a line has to be drawn (that line I was talking about before). It is based on a balance between economy and safety, and provided you stay on the right side of that line, all will be well.
The first line of our company standard operating procedures sums it up nicely:
"The crew members should co-ordinate their actions to ensure that the aircraft is operated safely
at all times."
Safely, and efficiently. In that order. In other words, provided we don’t risk the first, we must strive to achieve the second, at all times
The thinking these days is very much removed from the pilots duties simply being to get the aircraft from "A to B" safely. Today the crew are expected to take commercial considerations into account at every opportunity to achieve the most efficient trip between A and B. That involves derating takeoff thrust, tankering fuel in some cases, selecting and negotiating more optimum speeds, altitudes and routings wherever possible, etc, etc…
All the while, safety is never compromised, but efficiency is enhanced. Have no doubt that in the future, this will become the role of the pilots more and more.
Anyway this post became longer than I intended!
I used to love the smell of Jet-A in the morning...