Keep in mind that Mike Williams website is very biased and heavily manipulating with information. The article he has written cherry picks between 109G data, selecting the worst for display, selecting planes with cannon gondolas and tropical equipment etc. and dismissing all conflicting information. All of the his 109vsSpit articles are showing the best Spitifire figures in some cases for experimental machines at the highest engine rating, while at the same time Bf 109s are never shown at high boost rating. German, Finnish and Soviet testing of 109G are equally dismissed if the dataset is good. In brief, if Mike Williams or his co-author Neil Stirling says something about the 109, or the 190 for that matter, you can be sure they have an agenda about it, and the opposite is true.
Now as for the 1,42ata rating, it was appearantly cleared in September/October 1943. Mankau/Patrick goes into great detail of the 605 development and problems. They last discussion they note about the Freigabe of Startleistung of the 605 is from September 1943, then the question did not rise again. Daimler Benz was to produce 1000 oil dearator sets in that month, which seems to be the final fix for the problems. The October 1943 Bf 109G Flugzeughandbuch note
no limitation for use 1.42ata.
It seems that the problem was partly partially solved at the start of 1943, where the Startdrehzahl (2800rpm) was cleared for operational use, but the MAP stayed at 1.3ata. German engine documention (the ACTUAL DB 605A manuals, not aircraft datasheets) also note no limitation for 1.42ata in November 1942.I presume they simply issued the same manual over and over (if you see the complete ones, you know this is true, ie. late 109G manuals have the obsolate text simply strike through with a pencil) with an ammendment that 1.42ata is now cleared, it's fairly typical for WW2 aircraft manuals, or it simply was this way because at the time of the preparation of the manual (if it's march 1944, probably they prepeared it a few months ago), there could still be some engines in service that did not have the neccesary mods for the higher boost. And, again, DB 605A's with MW50 injection were running at 1.7ata by April already, so I guess they wouldn't have troulbe running at 1.42ata by then.
Mike Williams was shown of these facts, which he continoues to ignore. Frankly he has so much discredited himself with those articles that I don't even see Spitfire fans qouting his articles. What he tries is to make it look like 1.42ata was not yet cleared even in 1944, using the manuals listing. That's nothing new, Mike and Neil does the same about EVERY german engine rating, they deny it all. They deny the DB 601Aa was used, they deny the special low altiude WEP of the DB 601 bein in use pre-1942
, they deny the DB 601N was used during the BoB, they deny 1.42ata was used in 1943, they deny the use of 1.98ata for the DB 605D. They were shown the evidence about it mulitple times, nothing changed. BTW it's curious why they didn't make a MkV vs. 109F comparison article, I guess they didn't find 'low enough' figures for the 109F.
Besides, it's not the aircraft manual that determines what boost it may use or not. There are loads of other documentation for that, the aircraft manual is just some general information, it's usually the Motorenkarte that tells the limitations, the individual specsheet of each engine, the Einbaumappe and the various engine related docs for mechanics.
And as for a bottom line for the article... the Germans were'nt probably much pressed about the issue. The 109G's performance was not too much different at 1.3ata (on which it could run for 30 minutes) and 1.42ata, and even at 1.3ata, it got plenty of it over the RAF Spitfire Vs it usually faced, given that the MkIXs were rare birds until the very end of 1943.
