A question on the Bf-109

[Autothrottle]

Hello all,

Since Nigel has been tremendous in his Bf-109 contributions to this site, I was tempted to find out a little bit more about this simply deadly fighter. In export to other countries ( maybe Nigel can elaborate further) it was said that the average lifespan on a 109 airframe was about 100 to 200 combat hours. How is it then that some Air forces made their 109's last well into the 1950's?

Ive been perusing some of the Bf109 operational history chapters, this figure in flight hours was procured from Finnish Bf-109 records only. Other export nations' figures vary though.

Just thought it was cool to find out since Nigel has me inundated over which 109 to choose in the downloads section.

 

[hairyspin]

In peacetime the aircraft aren't flown to their limits on most sorties, so the stress life of the aircraft is not used up so quickly. Also aircraft last longer if no-one is shooting cannon shells at them...

 

[ndicki]

Which basically sums it up.

Obviously airframes are built carefully or less carefully, under the circumstances; and are of better or lower quality according to where and when they were built. And a number of 109 types continued to be produced, either new or out of stockpiled parts, after the war.

I was talking a while ago with Siggi Knoll, who owns Bf109G-4/6 Red 7; he told me that the best airframes available were Spanish-built, and he has accordingly used a Hispano airframe which has been carefully retrofitted with a G-series with DB605A engine and all the trimmings. The Spanish are hardly renowned for the quality of their engineering, but as they were built in peacetime, they used the correct grade of materials and good quality control. German-built aircraft were less well built, he said. I could feel he was rather upset about that, seeing as he is German!

Immediately following the war, the Hungarian, Romanian and Finnish air forces among others remained major users of the 109; interestingly, in the case of Hungary and Romania, they were unable to keep them in serious service for very long, probably owing to Soviet restrictions on parts availability and servicing. The Finns, whose reputation for careful maintenance is well known, were more successful. I'll let Rene give you the details there.

Czech Avia-built S-99 (G-10/14AS) aircraft were comparatively well built but had to be redesigned into the hopeless Jumo-211 engined S-199 when the stock of DB605AS engines was destroyed in a fire. While handling and actually even flying the appalling S-199 was challenging, the reliability of airframes was globally satisfactory. In any case, they only served for a few years plugging the gap. The Israelis, the only foreign user (what irony, though!) couldn't replace them quickly enough. But that's mainly as a result of the redesign, rather than of the original aircraft.

The worst of the lot apparently were Romanian IAR-built G-6 aircraft (Look for the modified gun blisters) which had a post-war availability rate well below that of the German-built ones in the Romanian Air Force. I have the figures somewhere but can't be bothered to look. You get the point, anyway.

 

[greycap.raf]

The Finns, whose reputation for careful maintenance is well known, were more successful. I'll let Rene give you the details there.

There aren't many details to give but I'd like to underline one thing in the maintenance of our MTs (as they were known, the Finnish Air Force uses a serial system in which a model is given such a code - Bf 109G was MT, Ju 88A was JK, F-18 is HN, you get the idea) and to give some perspective, MT-507 flew for the last time in March 1954 and it had arrived in summer 1944. So it had a life span of ten years but one has to remember that the war ended for us in autumn 1944... and so did the supply of spare parts. No engines, no propellers, no landing gear tyres. Nothing. What was needed had to be made and they still managed to keep several dozens of them airworthy for almost ten years. The flight time record for MTs belongs to MT-415 that managed an unbelievable 591 hours and 45 minutes. Built by Erla in early 1944. About a dozen examples (out of 159) broke the 300 hour limit and 200 hours is nothing special for those that survived the war.

 

[hairyspin]

I was talking a while ago with Siggi Knoll, who owns Bf109G-4/6 Red 7; he told me that the best airframes available were Spanish-built ... German-built aircraft were less well built, he said.

He shouldn't be ashamed of his countrymen's engineering, although standards did slip in the latter years due to lack of good workers, the extensive use of forced labour and the huge push to improve productivity. Peter Brothers tells of his first look at Arnim Faber's captured Fw190:-

"I clearly remember that you could put a penny on the aileron and it would push it down, and its opposite surface on the other wing up, until the coin finally slid off!"

There was certainly one Gustav not on your list. Assembled at Deurne in late 1944, by a volunteer team from 193 squadron, 2nd Tactical Air Force - an RAF Typhoon squadron! They had the engine running (started first kick!) and all the ground running checks done when the Powers That Be intervened and had the aircraft shipped back to the RAE at Farnborough. A previous CO was the only pilot from 193 to fly it, back in England.

 

[Autothrottle]

Well, Im glad to see so many 109 enthusiasts out there! However, which was ever the superior fighter? The 109 or the Spitfire?

I've noticed in the Sim, Nigels 109s seem to turn tighter than some variants of Spitfire. I got the shock of my life seeing one of Nigels 109's as an AI in my Spitfire. (Wrong choice at the time!) turn and disappear right from under me, and seemingly toys with you as you try to get a lock.

 

[ndicki]

Rene can explain this better, but we found that the existing FMs did not systematically allow for the physical strength of the pilot; don't forget that these were all "direct-control" systems - pull hard and hold hard, and you'll have greater elevator efficiency at high levels of stress than if you are a weakling who can't hold it there. That's what you're seeing. We think this is closer to the reality, but it does not actually alter the way the aircraft flies, from the point of view of pure physics.

As for turning more tightly than a Spit, I'd be surprised! But if you were using the player-flyable version rather than the AI (which is only that bit heavier in fact) then you have the age-old trouble of CFS not adding the weight of fuel, weapons and pilot to the AI's FM. Hence the trick with the AI pylon, which goes some way to compensating. But only some!

 

[ndicki]

He shouldn't be ashamed of his countrymen's engineering, although standards did slip in the latter years due to lack of good workers, the extensive use of forced labour and the huge push to improve productivity. Peter Brothers tells of his first look at Arnim Faber's captured Fw190:-

"I clearly remember that you could put a penny on the aileron and it would push it down, and its opposite surface on the other wing up, until the coin finally slid off!"

There was certainly one Gustav not on your list. Assembled at Deurne in late 1944, by a volunteer team from 193 squadron, 2nd Tactical Air Force - an RAF Typhoon squadron! They had the engine running (started first kick!) and all the ground running checks done when the Powers That Be intervened and had the aircraft shipped back to the RAE at Farnborough. A previous CO was the only pilot from 193 to fly it, back in England.

Got a picture somewhere... Just as the Germans had their Zircus Rosarius, so did we. No. 1426 (Enemy Aircraft) Flight, RAF. The "Rafwaffe" as it was called makes for a very interesting few hours study!

 

[greycap.raf]

However, which was ever the superior fighter? The 109 or the Spitfire?

Spitfire, and there's very little to argue in it as long as they're compared to contemporary versions which goes basically:

Bf 109E against Spitfire I/II - a very close match
Bf 109F against Spitfire V - another very close match
Bf 109G against Spitfire IX - Spitfire noticably better
Bf 109K against Spitfire XIV - Spitfire definitely superior.

The only real virtues of the Bf 109 series, especially in the later models, are its astonishing climb rate and very hard hitting weapons. Every Spitfire turns better than the Bf 109 of the same era and reaches a higher top speed. However, pit a Spitfire V against a Bf 109K and the Spitfire pilot is in quite a trouble before he makes his escape - if he even does.

We think this is closer to the reality, but it does not actually alter the way the aircraft flies, from the point of view of pure physics.

I indeed changed the elevator travel a bit for the G-10 after finding some info that the last versions (G-10 and K-4) had different elevator control linkages to give more stick travel and thus lighter stick forces as the weight continuously increased. The stick force per 1G was about 8 to 9 kg at high speed so pulling 8G would mean a force of 65-70 kg. I believe it's realistic as even I can pull well over 40 kg at the gym and my physical stature is tiny compared to the well trained fighter pilots.

The difference isn't very big, a "normal" G-6 or G-14 pulled into a turn from 300 mph peaks at slightly over 7G and settles into a sustained turn of around 6.5G before the speed bleeds off. The G-10 with its tweaked elevator travel peaks at slightly over 8G and settles into a turn of 7.2G or so - a difference of 0.7G which means 6 kg in real life units. It doesn't take much bodybuilding to reach such an increase. And I'll repeat what Nigel said, the actual physics weren't touched, only the amount the elevator can be moved at speed which is directly comparable to the strength of the pilot. Below 250 mph there's very little difference if any.

But yes, there's most definitely something very wrong if you're out turned by a '109G while you're flying a Spitfire.

 

[Autothrottle]

Any chance of uploading a Bf-109 H in the series Nigel?

 

[greycap.raf]

I'm not Nigel but I feel qualified enough to answer as the flight model, and half the research, would be my job and there's pretty much nothing certain known about the performance. Not to mention that the H model had a much longer wing, a new vertical tail, and God knows what else - no photos exist. We don't have such a 3D model, we don't have any chance to get the flight model right because we don't even know for certain which engine was used, so "no" is a very good guess at this point.

 

[ndicki]

As Rene says, you'd need first of all to know something about it! The answer is clearly "No" for all the reasons Rene gives above, particularly because we don't have the 3D model and will not be making a new one. We are strictly "aftermarket" in that sense, I'm afraid.

 

[Autothrottle]

Bummer.

Well off to fly the tried and tested 109's of the fleet then.