The Falcon II sounds definately wrong for 1918 then, especially if only 250 were produced and RR had stopped production when the Falcon III cam online. There's something dodgy about the engine numbers and production rates somewhere, unless a lot of Biffs had Puma or Hispano engines (doubtful).

Unless someone can produce evidence otherwise 777 should be modelling the Falcon III as the RR Biff for 1918.

Puma engined Bristol was a complete failure, very unpredictable and actually dangerous for the crew, thus the hundreds of ordered aircraft of this breed were eventually cancelled and those produced saw little use during the war.
200 HP Hispano-Suiza and Wolseley Viper powered variations were tested, but eventually didn't came into mass production, due to poor performance, shortages and demand for those engines to be used with other planes, but mostly due to anticipation for 300 HP Hispano-Suiza F8b, but eventually Biffs with those engines installed entered mass production after the war ended.

There must be something strange about the RR production figures, nothing else makes sense.

It would be nice for 777 to confirm what version they're making and why, call me neurotic but I'm slightly concerned now.

I believe it's that those planes were constantly modified during the war. RR Bristol version could accept any modell of Falcon engine with no changes to the construction of the aircraft, thus it could be done even during repairs in line service. What this means is that aircraft, that had Falcon I or II in evidention, could have ended up with Falcon III installed in reality.
As for other engines, many of them were tested on F.2Bs in search for best solution (meaning thath the engine would give the plane satisfing performance and could be built in large numbers). Majority of Bristols, that were used as test beds for those research were rebuilt specimens from serial batches, initially powered by some RRs or Arabs.
Another thing is that post-war production aircraft were allso counted in the evidention and this means a whole lot of 300 HP Hispano-Suiza F8b powered modells built to be sold in large numbers (Poland itself bought over a hundred H-S and two RR powered Biffs).
These in my opinion are most important points, that could have made a difference in between the evidence data and reality.

BTW If over a half of production F.2Bs had other engines, than Falcons, why then vast majority of wartime iconographic documentation shows those with Rolls Royces? It's pretty unlogic, don't you think?

Then you probalby are amazed to find that example C4808 (Falcon II engine) claimed Albatros D.V destroyed April 2, 1918 and itself was shot down by 18 April, 1918 by Fokker Dr.I

Also B1119 (Hispano-Suiza) was at St.Omer aeroplane suply depot No.1 at December 27, 1917. So there definately were other engined planes aswell outside of Great Britain.

B1134 (Falcon II) was attached to No 35 squadron february 4, 1918. So it atleast falcons II were definately used in 1918.

I agree.

Why do 777 appear to be interested in the Falcon II then...?

wHat this thread is telling me is that there is quite a lot of confusion about the engines most in use, so would 777's guess be as good as that of the rest of us?

In june 1918 there were 6 fighter squadrons at front equipped with brisfit. If we calcualte that each had 24 planes (Full strenght), then any compination of Falcon engines is possible even when we take account losses. It really depends how fast Falcon III engines were made. Did it get faster at the end? Was production same whole time, etc. What is sure is that Falcon III production was not adequate tought.

And I'd guess, this squadrons had prioryty in acquiring Falcon III engined F.2Bs.

Sure, but if RR could only made example (Numbers are invented just to show point) 5 Falcon III engines at month and there were 20 new Brisfits without engine in a month, you really have to use 15 Falcon II engines if you want make them all operational.

But who would manufacture those Falcons II, if the production was halted after 250? It actually makes sense to stop the production of older version to try to boost production of the newer, more demanded one.

Which would mean 250 were produce already and available to use when Falcon III production started. So when Falcon III production was not enought they used Falcon II from the inventory to get some engine to produced brisfits. Now question is how much? We know total production of Falcons but how many and when those were issued is still mystery.

Divide it for usement between Bristols and Kangaroos (only six serial specimens used Mk. II, but that gives you 12 engines on start), multiply engine demand for a plane by a couple due to service replacemnt needs and you're out-of stock pretty quick. Soon enough you cane replace the engine by Mk. III or not at all. And 6 x 24 = 144 planes. I think this is a number, that RR production could eventually support.

Eventually, but when? Total number of produced Falcons are quite low compared to built brisfits.

Falcon II for sure was not atleast totally replaced in June as seen in that statement (17 of 18 were Falcon I/II). Falcon II were still used and other engines were desperately seeked. Infact it seems that most produce Brisfits in fall propaply were with Sunbeam Arab (atleast there were quite large numbers ordered/built with it) altought only realtively few were sended to western front before war ended.

Interesting thread. I still see no evidence at all that disproves the assertion that the Falcon III engine variant was indeed the most numerous. Much is being made of the supply problems of the Falcon III from Derby in 1918, (the circumstances/reason for which I am unfamiliar). but put simply, scarcity of supply at a given time does not equate to scarcity of frontline numbers at a given time. An aircraft (or anything) having component supply problems does not mean that previous aircraft built with that component simply vanish into the ether!

It would be interesting and relevant to know Brisfit attrition rates at this time, which I believe were initially quite high due to improper formation tactics being applied. When it was realised that the Falcon III equipped Brisfit could function very competently as a 2 seater fighter, it apparently performed very well indeed and was a respected foe.

Also bear in mind that orders are made in surplus where possible, the outcome of the war when Falcon III production began was still far from certain. The relatively small and skilled Derby RR workforce may have struggled to meet demand in 1918 for this reason (conjecture of course). It is rare for any fighter type to be fully deployed commensurate with production numbers, which as already stated did continue in the Biffs case till well after the war. Even the DR1 (production stopping/retired before wars end) of 300+ produced only 100-120 ever saw frontline service at one given time/peak numbers)

While it is beyond dispute that the Hispano/Puma variant numbers were substantial enough to be noteworthy, as far as I'm concerned they were 'curios' and exceptions to the rule. I am still seeing no evidence as to any prevalence on the front line. They were 'stop gaps'. Till then, and unless it can be proven with reliable sources, the Falcon III as stated in Mogsters find was the most common engine in use. Even the Shuttleworth collections Biff is Falcon III equipped, I have seen it with my own eyes (though from memory it did not see action in WWI, arriving slightly too late. Might be wrong on that though.)

I want the most common engine Biff to be modeled, and if its not the Falcon II (which it clearly is not given the 250 production number) and there is no evidence it was stop gap Hispanos and Pumas, then until proven otherwise it is indeed the Falcon III.

@Mig Hello. Interesting info about a Falcon II Biff being shot down in 1918, but in what does this prove regarding frontline numbers? I'd say not a lot. One swallow does not a Summer make.

We need info on Hispano/Puma variant numbers. In the absence of this, its undoubtedly the Falcon III.

Note that while I like the Biff I am far from an expert on it. Just my Ha'penny, much from sketchy memory and I want to know the truth as much as anyone else. Seems pretty clear cut to me atm though...Falcon III all the way.

I'd do some more research on it but its Shogun II demo day lol. I'll come back to this one and see whats up. Have fun.

It just to show Falcon II were in fronline units even then.



It is not that simple. We actually need to know montly how much Falcon III were produced. Total number of issued Falcon(all variants) engines were ~1630 at the end of 1918. 500 is Falcon I/II that leaves 1160 for Falcon III. Total of ~3100 Brisfits were issued end of 1918 so at best Falcon III could have only been in 1/3 of total planes. Now on fall 1918 huge number of Sunbean Arab engined Briftis were ordered/manufactured so it is likely that huge number of that ~3100 planes are actually Sunbeam Arab brisfits that never reached to fronlines.

Question is how fast Falcon III engines were produced and how fast Brisfits were produced? Was production stable or did it speed up end of 1918 determines what point it surprassed Falcon II engines, etc.

wouldnt a 4-blade propeller have bad influence of the vickers gun's fire rate ?

I wouldn't think so as they could regulate the interuptor mechanism to fire the gun 180 Deg of phase which is what it would be with a two bladed prop. I would think that would make the rate of fire exactly the same. Now if they could have synched it to fire between each prop-heck, that'd almost be like a mini-gun! HAH

Perhaps, for 777 to take notice of this data, it would be better to mention it on the RoF forum. I don't think Han and Viks frequent SimHQ as much these days and a lot of data this will be missed.

...this!