With the very greatest of respect, I actually know what I am talking about in these areas .
I know who you be and, indeed, I respect that background. However, I wasn't aware that you were in the certification expert club ?
This is not the same as a text book definition of Vmcg,
Generally, for any given certification, the final Design Standard detail required for this and that will be as frozen by the relevant Regulator.in conjunction with the applicant. Indeed, were that not the case, no certification would get anywhere .. As we are both aware, the bulk of the rules have changed and developed over the years in light of accident experience and Industry state of the art capabilities. .. which is as things should be, I suggest. Certainly, as we remind the new chums regularly in PPRuNe, the relevant Design Standards must be reviewed to have a beginning notion of what might have transpired during the workup of the particular Type/Model.
As to "stories" about special DCA "rules" that said a VH- registered aircraft has a Vmcg
I presume that we are talking about the narrow runway width program, going back now probably 30 years or more ? Certainly, I was involved on the Industry side with several of the aircraft which went through the early process. I have to say, the activities were a little eye-opening and suggested to me that the standard runway width protocols (ICAO) used previously were a tad average in their lack of any engineering or flight standards rigour. I, for one, am of the view that the local Regulatory approach had much merit .. certainly, I went from being a non-believer to being the devout little wide-eyed engineer during the programs.
While I was on the outside, looking in, as it were, I knew the folk involved with the workup very well. Indeed, a main aim of the test program was to see what the aircraft could, or could not, do in the Vmcg environment and limit the operation for narrow width runways to suit whatever capability might be disclosed during the flight test program. I still have some "interesting" videos of some of the work we did on the several aircraft with which I was involved.
that ensured it would stay on the runway in the most adverse crosswinds, I heard that quoted many years ago, but never found any proof.
'twas the case, indeed .. I was there. Eventually, the early requirements were codified somewhat in an appropriate CAAP along the way.
Indeed, I never came across anybody in DCA who would have had the background to conduct such tests
That's fine. However, I did, and there certainly was a small group of folk at the time who knew what was what and what they were doing. I knew several of the test pilots quite well (one had actually done my initial twin training some years prior albeit that a well-known Industry instructor signed it off ..).
It transpired that I ended up on the long lens video at the runway head for each set of tests ... and, in the way of understatement, those aircraft which were Vmcg challenged certainly tripped the light fantastic during the testing.
was quoted by Boeing as good to 7kt crosswind,--- straight from the FAA guide
I have little specific knowledge of the 707 certification (one of my regrets is that I didn't bid onto it with the AN freight program but them's the breaks).. The 7 kt probably relates to the BCAR rules at the time.
The same was (mostly) not true if it was a G-registered aircraft.
As I recall from reading this and that .. there were a couple of US aircraft which the Brits required to be reworked to account for the 0/7 kt difference ?
"Back in the day", at YMML on a cold and wet and windy (from the WSW) we used to see the "safety advantages" of applying a crosswind component to the Vmcg, when you had a Vmcg limited V1.
Indeed and I am totally in agreement with an operational hat on. However, Vmcg, ie the certification animal, remained the same as it is a certification animal and knows naught of the real world. What was occurring was an operational adjustment of the AFM numbers to account for real world reality in a conservative manner. No doubt, I suspect, Wal Stack's good offices were behind such things .. wonderful chap with a wonderful turn of phrase when telling a tale.
Such was the result of a certified Vmcg being a variable based on crosswind component.
Now, as suggested above, I don't have any specific 707 background. However, are you referring to the AFM data ? .. or company operations data ?
[Note - Without chasing up all the cert basis ins and outs, the CAR 4b generic words were a bit vague re Vmcg - .. air speed, shall be selected by the applicant, but it shall not be less than the minimum speed at which the controllability is demonstrated during the take-off run to be adequate to permit proceeding safely with the take-off, using normal piloting skill, when the critical engine is suddenly made inoperative]
It was remarkable, at times, how strongly OWTs and "conventional wisdom" would be defended, in the face of the facts.
One of the reasons a few of us push the anti-OWT barrow in PPRuNe.
Were you every involved with B727 -100/200 certification
Flew both, and adored the -100, but no specific exposure to the certification program. The -200 ? well I did get one absolute greaser out of the beast .. but only the one. Had many of the other sort, though ...