When I used to be a real pilot (TWA) required us to increase power on the remaining engine (s) in the event of an engine failure after achieving V2 speed.
No problem there - the option to increase thrust to the rated limit (but not above) remains available. In your case the operator had so mandated - fine. However, that is a discretionary option adopted by the operator. There is NO regulatory or design standard mandatory requirement to do so. In the view of most of us, the potential hazards associated with pushing up the throttles in a high workload situation greatly outweigh the potential hazards of leaving them right where they are - given that the RTOW sums were based on that latter option.
They also taught at the school house that payload was predicated on reduced thrust with all engines operating and with takeoff power in the event of an engine failure.
I'm afraid that is just so much engineering nonsense on the part of your instructors -
(a) if you start the takeoff reduced thrust then there is no procedure available to base an RTOW on the pilot's manually increasing the throttle setting. Indeed, the design standards specifically preclude such action in terms of required pilot procedure.
(b) following on from (a) your instructors' statement would imply never going with reduced thrust
(c) the option to increase thrust is there - mainly, I suggest, as a comfort factor to the operating crews back in the early days of reduced thrust takeoffs - certainly, I recall Wal Stack was very empathetic to such concerns in the 60s.
However, I leave it to you to produce a rational engineering argument to rebut my heretical position ?
I would be on a fool's errand if I did not increase thrust on the remaining engine (s) rather than hope to clear that ridgeline 7 miles away by 35 feet.
Common misconception. As mutt observes, you are looking at the calculated critical net surface case which has little to do with the pilot's world. The aircraft in the real world will do substantially better approximating or exceeding the gross surface case (unless you are having a REALLY bad hair day in which case you might eat a tad into the gross to net margin. You should expect to be a LONG way above that seven mile ridgeline as you cross over even if the net calculation were based on a minimal clearance back in the office.
I recall, in AN, John Walsh and Roger G quoting something like 1:250,000 probability of a critical OEI failure case's getting down to the net path. While I suspect that that figure might have involved some poetic pilot training licence, it sort of gives you an idea of the relative values of gross and net surfaces so far as the pilot might be interested.
TWA also did not assess more than 300 feet each side of the takeoff flight path (beyond the airport boundary), which was another reason for advancing to takeoff power in the event of an engine failure.
I can only hope that that statement is an aberrant misconception. The takeoff flightpath obstacle trapezoid is considerably larger - perhaps you can cite the operating standard to which the operator matched its ops engineering calculations ? All jokes aside, though, the trapezoids are NOT overly generous and the pilot needs to apply extremely strict attention to flight path tracking in any obstacle critical escape. Indeed, there has been sufficient simulator studies over the years to show, quite clearly, that mistracking IS a very real concern in the event of an unbriefed takeoff failure.
Really .. if you only had escape protection to 100 yards, your buddies would have had severe near misses in the real world failure case with close in obstacles ... I suspect that the tale is in the league of OWT perpetuated in the classroom ? However, please do provide authoritative support and we will recant our heresy.
we should not advance any thrust levers until we go to MCT if using fixed derates
That raises a point in philosophical difference. Indeed the takeoff thrust can be less than the continued climb thrust. While this might be fine from an engineering standards point of view, I prefer Wal's approach with his QF buddies. He related a tale about a crew's complaining that the F/E had pushed up the throttles to achieve METO/MCP - after a few seconds' thought, he concurred and, thereafter, the minimum flex level was climb thrust.
Are you sure your full thrust Vmca is below your fully derated V2?
The mutts, OSs, and JTs of the world like to keep the Vmca bogeyman in the thought processes just so that the newchums end up with a rational respect for those low speed lines in the sand. However, the line pilot should adopt a pragmatic approach - Vmca, generally, is way below your V2 and not a major concern unless one mishandles the failure grossly.
including V2 which can vary by as much as 40kts
While I can't comment on the 40kts as that would be specific to your particular bird, there is no problem with V2 varying - perfectly normal. However, you don't bring V2 below V2min for the day.
deck angle would be limiting, thus we accepted a speed well over V2
Unless such is mandated in the AFM takeoff performance section, it will be an operator discretion matter.
However, for the takeoff failure case, the problem is not so much well after the liftoff (which is where you might have limited the rotation angle) but during the takeoff flare rotation (ie a V1 or VR failure point). Having done a reasonable amount of work on this point in sim exercises, the case of min weight, aft CG takeoff (with a half realistic sim dynamic model) is the stuff of horror for the pilot until he/she has had several goes to get on top of the gyrations.
The main problem is that most pilots NEVER get to see the sort of aircraft response in this scenario as it is not routinely looked at in endorsement and recurrency training. Certainly opened the eyes for a few of my sim folk in years gone by.
common sense said to accept a speed greater than V2
In the extreme case that might be embarrassing in the case of a late first/early second segment critical obstacle ?
please tell me how you accounted for CLEARWAYS in the DC9?
(if I might fill in the background reason for the question) .. being that the DC9 AFM only provided BFL takeoff data so clearway was irrelevant to the matter.
"Just climb straight ahead" was the party line
No problem with that philosophy. However, commercially, it doesn't make sense as there will be runway cases for which it is commercial stupidity when, say, a turning escape might provide a LOT more weight.
With an engine failure at V1 +1 knot it took 31 miles to reach 1,500 feet, afe.
Now, that's pretty good. For the DC9 a critical takeoff might be closer to 50 miles for similar conditions .... [Caveat - as before, we are talking net so the real world pilot observation is considerably better than that pessimistic scenario].
The airplane crashed into the first low ridge of mountains west of Runway 25.
We would probably need some more details to comment. However, if the circumstances were an engineering mistake, then one should identify it, fix it, and make sure it doesn't happen again ...
They had failed to account for that.
Again, we would need more details to comment specifically but our discussion should be predicated on a presumption of competent ops engineering folks doing the work ...
So, I became a bit jaded about performance and engineering
and, by the sound of things, perhaps with good reason. Now, if we can interest Centaurus in this discussion, he has some real terror anecdotes on the subject in his archives ...
circumstances seemed to indicate that they cooked the books
can't speak to your circumstances but some of Centaurus' anecdotes relate to precisely that problem ...
.. and, should you perceive that mutt and I are giving you a hard time, we aren't. However, the youngsters need to be exposed to the good and the bad - there is still far too much in the way of OWT on this subject in the Industry.
Well done on a, no doubt, successful flying career - now to fishing, drinking and other fine activities more appropriate to the senior group.