SFFP F700
Funny you should mention the paper trail work done on ZD576 just before the last trip did not have a 700 raised.
ShyTorque
I think the only way to establish how much reliance RAF pilots would put in such a system (CPLS) and what they used it for is to ask those who have used it in several theatres since 1995 sadly, it is input from these guys that is absent from this thread.
<<Any crew using a DME system, VFR or IFR, would not rush towards a landing point at 160 kts in the climb, which was as fast as a Chinook helicopter can go in straight and level flight, or probably in a slight descent.>>
For years now I have repeatedly reccommended anyone interested in this case to start with working through the Boeing document Mull of Kintyre -Analysis of Available Data (8-7D20-DS S-03 06, Enclosure 4 Dated: June 18,2002) available on the web: this is not the simulation but old fashioned distance/time calculations using the available data and the like even if you do not accept the results at face value, it gives you a framework with which to guide your own sums; such basic calculations are especially useful in this case as to have got to the position of waypoint change when it did, it would have had to have maintained its high cruise speed all the way and kept very much on the 027 track that is, there was no possibility of their having been going slow earlier in the route (eg near the yachtsman) perceptions of speed of unfamiliar a/c without their being very near to a familiar object can be very unreliable; on the final leg from the position of wpt change to impact, the author (Mitchel) calculated (using retreived data also) that they had started to slow down in terms of airspeed but this was masked by the increase in tailwind as they approached the landmass. Hopefully, this may lead you to a different understanding of the speed.
A further significant point from the above document is that the author concluded that there had not been a sustained climb of any great magnitude on this last leg and that the full collective found was probably the result of a last second manouevre as the engines had not had time to respond (spool up). We know that the engines had been matched in power and also not at full power together with the lighthouse keeper's testimony that there had been no discernible change in sound rather puts to bed the undemanded engine run up I suggest as I have said before, I thought the immediate action would be to pull up on the trust lever while you sort it out isn't it? (prevent overspeed of rotors?) And this could have been the hand of God that saved them didn't happen.
From my hypothesis and some chartwork, I estimate that they thought themselves about ½ mile further out than they were at wpt change when they turned right onto 035 if you have reduced thrust and are coasting in, a Chinook slows down pretty quick with drag alone I have asked this before but have never got a decent answer Starting at 135 kts TAS, what could you get down to in ½ mile if holding straight and level with minimum thrust balancing weight only (coasting/letting the speed wash off)?.