Some thoughts .. noting that I don't claim to have much in the way of specific knowledge of what went on in the real olden days ..
I have been trying to establish, out of idle curiosity, the history of the development of aircraft Performance Groups, particularly Perf “A”
A specifically British thing.
If you run some searches you will find the odd document of interest to this question .. eg
Chaplin's paper. I suspect that references to "Performance A" in the pilot fraternity refer more to the pilot licensing theory examinations rather than the certification airworthiness regulations.
I have seen a claim that Perf A originated with FAR25, which was first published in 1965
Can't speak authoritatively as to the commencing date, but I suspect somewhat before the mid-60s. I did my theory subjects around that time and, as I recall, references to Perf A in the British system were not new. As to the first Part 25 certification, that would take some research which I will leave to you .. you might start with the TCDS for a range of aircraft; the sheets will give you the certification basis for the Types involved.
What standard applied before that?
There was a range of standards developed prior to the jet age. A reference cited later in this post will give you a bit of a rundown on the specifics.
Clearly, at that stage, there were major differences between national authorities.
Indeed. In recent years the harmonisation of, especially, European and US standards has seen a more sensible life for the OEMs
When Perf A appeared, was it applied retrospectively to existing types?
Here you are thinking of BCAR Group A (if my memory hasn't atrophied too much), which was the heavy airworthiness regulations rather than Perf A, which related more to pilot theory exams. Perf A caused much head scratching and pencil and paper work in the graphs to get folks to the standard where they could pass the relevant exams.
As a general observation, rule changes are not retrospective as this, often, would kill the old Types which hadn't been designed with knowledge of the newer rule. So, for example, the 2 second ASD fudge factor in FAR 25 A/L 42 was not retrospective, so far as I am aware.
reductions imposed in the UK on the MGW of the DC-3
I have no knowledge of that exercise
Further queries on performance criteria for some RAF types.
I can't speak to the RAF but, based on comments from RAAF flyers of that era, I have the impression that the system was more on the basis of TLAR .. ie we got over the fence last week so it should still be OK this week.
for the A-W Argosy, similar conversations in which I was told that at times they operated to “military performance standards”
The RAF may well have operated to weights in excess of the civil requirements.
For this Type I had plenty of performance exposure, having looked after IPEC's performance for quite a few years. The Australian certification essentially rubber stamped the UK requirements. I would have to dig out some AFMs from the filing cabinets to check just what the UK basis was but the AFMs were bog standard Perf A data .. think FAR 25 in general. In fact, typical of many UK manuals, the performance charts were great to work with as they gave all the various limitations as separate information.
I gave him my copy of the "Final Report of the ICAO Standing Committee on Performance"
Indeed .. and, again, many thanks to my colleague zzuf for the donation. I had been hunting for a copy on and off for years. zzuf's copy comes from a line of well-regarded Australian airworthiness regulatory stalwarts, including his good self. Reading the names on the cover, I remain somewhat humbled in the presence of such august company.
Prior to the Standing Committee's report, things were a bit TLAR and simplistic in the performance arena.
The rapid developments post WW2 led ICAO to a desire to get ahead of the action and develop more appropriate Standards. The upshot was the development of the PAMC on Performance which applied a much more rigorous and statistically based rationale to aircraft performance.
If I recall correctly, the then-recently certificated F27 was the first Type to be (re-)certificated to the PAMC. Again some further information in later references.
A now deleted post included the statement "I've never heard of Perf A".
The post referred to was by IGh who chose to delete it for his own reasons. A pity, as the post was quite useful and, while I won't reinstate it out of deference to the poster, the main details were
(a) a link to
a paper by Wagenmakers, a quite experienced and influential airline performance guru back in those days.
(b) reference to
Wagenmaker's reference text
(c) some references to the Boeing performance engineering manual Jet Transport Performance Methods. This document, which has been revised over the years, is a basic engineering reference text for the subject and is used by Boeing for training courses for airline ops engineering folks. For those who wish to read a copy, you shouldn't have too much difficulty finding a download on the net.
He made a reference to one edition (which I don't have) with credits to Walt ? Walt presumably is Walter Blake, a fine chap (now well-retired) but still active in the Industry. Walt, as I recall, was the Boeing performance boss for some years and is a very knowledgeable performance engineer quite apart from being a very nice bloke.
To give you some idea of how the very early regs were made, I recall some commentary by a chap at a training course (also attended by zzuf as a CASA - or whatever name it was that week - observer). This chap, whose name I can't recall, had been a junior engineer in the US regulator at the time. He gave two examples
(a) light aircraft maximum stall speed. Finger in the wind figure of 70 mph picked as being a reasonable balance for OEM design and crashworthiness survival.
(b) 50 ft screen height for light aircraft. This was based on a Curtiss demo at a military parade ground. The parade ground was surrounded by trees of about 50 ft height .. seemed as good an idea as any for starters.
While things had to start somewhere, one sees the eventual need for developing rigorous analytical approaches cf the PAMC on Performance.