The wheel and landing debate.

[Sternjaeger]

I just think they should try and make the aircraft behave as close to the real thing as possible, which means reproducing the directional stability issues.

[falstaff]

...the coding for going round and round in circles, however, looks excellent....

Edited December 4, 2013 by falstaff

[Sternjaeger]

Just like the one for trolling, stronger than ever! ;-)

Edited December 4, 2013 by Sternjaeger

[Wind]

According to wiki, finnish airforce lost 5 me-109 during 43-45 due to accidents.

 

1. MT-223 = no exp

 

2. MT-243 = no exp

 

3+4 MT-236 + MT-242 = crashed during taxing.

 

5. MT-418 = mistake during takeoff.

 

6.Me-109 = CFIT during night.

 

 

Someone with data how many planes FaF had, could calculate and make up somekind of irrelevant statistic.

That 1500 deaths has to be total BS. Let alone if the main cause would have been something as relevant as

take off/landing charasteristics...

[Crump]

Once again the same topic.

 

The gear was given toe out to add stability.  Properly adjusted camber and toe out, the gear on the Bf-109 is no more dangerous than any other tail dragger.

 

The oleo struts are angled out and forward to dampen the suspension and soften the landing impact.  It is really a red herring looking at the landing gear design and trying to the reason the Bf-109 was less directionally stable but more longitudinally stable.

 

Just look at the CG relationship to the mains and you have the answer.

 

That 1500 deaths has to be total BS

 

 

It is just a number pulled from thin air to add drama for a TV show.  There is not any difference in wastage rates for Bf-109 or FW-190's.  The real reason for the rate of accidents in the German fighters was poorly trained inexperienced pilots fly state of the art high performance tail draggers landing under less than ideal conditions. 

The Bf-109 should be less directionally stable than an aircraft with a longer arm from the mains to the CG but more longitudinally stable to allow for better braking as well as prop strike resistance.  The tail draggers that are more directionally stable should be more prone to prop strikes (nosing over) and with less braking ability.

 

It should be modeled realistically, IMHO.

[JtD]

...That 1500 deaths has to be total BS...

From May 1940 to June 1944, the Luftwaffe lost ~5500 SE fighters to none combat causes.

[wastel]

I spoke with some Luftwaffe Veterans in the last years (Rall, Bob, Wolfrum...all RIP now) during the JG52 meetings.

They often said, that they had no problems with the "newbees" in the late war times.

They where all  able to fly the 109 without problems.

Their Problem was to fight and survive in the 109, whats an different story than just "flying".

 

The 109 was not hard to land an takeoff in their eyes if you just follow the rules for the plane.

An the new recruits knew the rules...but had no time to learn to fight.

 

109 was a just a plane..if you follow the rules, you have no problems.

 

Wastel

[Quax]

I spoke with 3 guys (JG 51 / one still living). The 109 was no problem to land. Most beginners accidents occured on take off. In the beginning of take off roll right brake had to be used carefully. 

Edited December 5, 2013 by Rama

[Sternjaeger]

Once again the same topic.

 

The gear was given toe out to add stability.  Properly adjusted camber and toe out, the gear on the Bf-109 is no more dangerous than any other tail dragger.

 

The oleo struts are angled out and forward to dampen the suspension and soften the landing impact.  It is really a red herring looking at the landing gear design and trying to the reason the Bf-109 was less directionally stable but more longitudinally stable.

 

Just look at the CG relationship to the mains and you have the answer.

 

 

It is just a number pulled from thin air to add drama for a TV show.  There is not any difference in wastage rates for Bf-109 or FW-190's.  The real reason for the rate of accidents in the German fighters was poorly trained inexperienced pilots fly state of the art high performance tail draggers landing under less than ideal conditions. 

The Bf-109 should be less directionally stable than an aircraft with a longer arm from the mains to the CG but more longitudinally stable to allow for better braking as well as prop strike resistance.  The tail draggers that are more directionally stable should be more prone to prop strikes (nosing over) and with less braking ability.

 

It should be modeled realistically, IMHO.

 

Crump, there's nothing humble (or right) in your opinion about this topic, as many of us have vastly demonstrated and professionals have confirmed as well. Please do not cause this post to be locked as well.

Edited December 5, 2013 by Sternjaeger

[=LD=dhyran]

I spoke with 3 guys (JG 51 / one still living). The 109 was no problem to land. Most beginners accidents occured on take off. In the beginning of take off roll right brake had to be used carefully. 

 

 

will second that, additional to add, if you read Steinhoffs Street of Mecina, they had often enough only a open field, a noun, but no airfield with real and well built runways!

[Karost]

Friends, I have some thing simple and easy.

 

Just Ask your self when "first time" you  take off and landing   for LaGG or bf-109 ( for IL2:BOS alpha version ) did you make  a save landing ? 

 

for me, my  first time... I break my gear and wing,  lucky that  alpha version did not model pilot injure 

 

I think Dev.Team  have this kind of data  while we test this sim.

Edited December 5, 2013 by Karost

[Crump]

 

Marv asked me to

send him a copy of my Luscombe newsletter that actually

recommended toe-out for tail-draggers. He had served as

an aircraft mechanic in the Army 741 Div. Air Section in

Korea, where he found that rigging the Army’s air-spotter

tail-draggers with a couple of degrees of toe-out made

them easier to handle during the transition between flight

and touch-down with the reduction in rudder authority

when power was reduced.

 

While toe out is considered stabilitzing in conventional gear,  there are many designs that are adjusted toe in.  What is important is that each landing gear design is unique to the specific aircraft and is a part of that system.  The manufacturer's instructions are the last word in how to properly adjust the gear.  Properly adjusted, the gear will roll straight.

 

 

As a sidebar, in conversation with Marv, he mentions

that the Cessna 180 Maintenance Manual

recommends a 1/16” toe-in. This is however,

with the empty aircraft sitting on its gear in a

hanger. Marv points out that with the additional

weight of people, fuel, and baggage, the gear

geometry is such that this toe-in effectively disappears to a

neutral or slight toe-out condition in actual conditions.

 

 

My suggestion

for practical application of the toein,

toe-out lessons imparted by this

article is to check and double check

the completed, installed landing

gear on your airplane to make sure

there is no treacherous toe-in. It

would do no harm to put in a little

toe-out.

 

 

http://www.biplaneforum.com/uploads/20111027_130115_200901_EAA_CHAP.pdf

 

I am not sure I agree with the authors declaration of "treacherous toe in" but I definitely agree with his earlier conclusion to follow the manufacturers instructions to the letter.  Some aircraft require a degree of toe in and others are adjusted to toe out.  When on the roll and loaded for flight, the desirable outcome in a conventional gear is some toe out.

 

I hope that helps to shed some light on the myths surrounding the Bf-109's "dangerous toe out landing gear" so often advanced in popular media.

Edited December 5, 2013 by Crump

[DD_bongodriver]

I hope that helps to shed some light on the myths surrounding the Bf-109's "dangerous toe out landing gear" so often advanced in popular media.

 

No, all it does is illustrate the desperation involved in constantly trying to surround the facts with the conspiracy theory it is all a myth, Messerschmitt's own test pilot confirmed it, history has reflected it, modern test pilots also confirmed it.

[Rigsby]

I get the feeling I am going to die more in this game landing then I am been shot down. I can just see my self now, big grin on my face with my first kill, but then taken of my face when i land in a heap.

[Crump]

Richie posted the video originally guys, about something else at 9 minutes in. I caught the bit about the wheels by luck.

 

If you look at the video, he claims it is the "toe in" of the Bf-109 that makes it squirrely.  It should be very squirrely if the plane had toe in.  It would also be completely out of adjustment and improperly set up as the aircraft had toe out not toe in.

[DD_bongodriver]

Anyway, we have a test pilot who actually flew it telling us that it was very unstable and an internet Walt who never has telling us it wasn't.

[Sternjaeger]

yep, he does say toe-in, but I think it's just a honest mistake (I've heard several people referring to toe as just toe-in), it's obvious the aircraft has toe-out (as visible in the video), and the characteristics he talks about are typical of toe-out. This is also described on the book talking about the restoration (which is a great read and I warmly recommend).

 

We're not saying that toe-out is an intrinsically unstable design when landed properly, we're saying that under certain situations (i.e. landing on one wheel only) it will be more challenging to control, because the toe-out will generate a tendency to swing which is much stronger than an aircraft with no toe adjustment. It's controllable, but it can be unexpected if you have no experience and make you lose directional control.

Edited December 5, 2013 by Sternjaeger

[Kurfurst]

Very interesting, thanks for posting this vid.

 

The number of 1.500 pilots killed in training in the 1st two years is staggering. Especially when you consider that during the early war Luftwaffe pilots still received quite a thorough training compared to the ever-shortening training programme from '43 onwards.

 

It's a pity though that the number is entirely baseless...

[DD_bongodriver]

It's a pity though that the number is entirely baseless...

 

One can assume it is based on the research of the individual who put the figure forward, no point being all indignant about it until there is proof of the contrary.

[Quax]

I spoke with some Luftwaffe Veterans in the last years (Rall, Bob, Wolfrum...all RIP now) during the JG52 meetings.

They often said, that they had no problems with the "newbees" in the late war times.

They where all  able to fly the 109 without problems.

Their Problem was to fight and survive in the 109, whats an different story than just "flying".

 

The 109 was not hard to land an takeoff in their eyes if you just follow the rules for the plane.

An the new recruits knew the rules...but had no time to learn to fight.

 

109 was a just a plane..if you follow the rules, you have no problems.

 

Wastel

 

 

I spoke with 3 guys (JG 51 / one still living). The 109 was no problem to land. 

 

They didn´t speak only for themselfs. It is the experience of hundreds of wartime pilots behind thier judgement

 

 

Anyway, we have a test pilot who actually flew it telling us that it was very unstable and an internet Walt who never has telling us it wasn't.

 

 

What is one test pilot against that ?   He actually flew it ? That´s great - but the others flew it several thousand times in far more difficult circumstances.

And BTW, Walter Eichhorn is a "test pilot" as well, and he never said anything like "very unstable". This is just nonsense. Why don´t you stop repeating that over and over again ?

 

 

 

http://www.clipwings.com/clip/101/Messerschmitt_BF_109_Display___Walter_Eichhorn

Edited December 5, 2013 by Quax

[AndyJWest]

According to Max Hastings, "5,327 officers and men were killed and a further 3,113 injured in RAF training accidents

1939–45". Which makes a claim of 1500 Luftwaffe pilots killed in training in two years seem less far-fetched. http://www.maxhastings.com/assets/Bomber-Command-171-210.pdf

[Sternjaeger]

oh for the love of Pete... 

 

 

Nobody is saying the Bf109 was an unstable aircraft design, the known flaws are:

 

1) rudder authority, and this is the reason why the made bigger rudders after a while.

2) peculiar landing gear geometry, with a characteristic toe-out of the wheels, which means that when landing on one wheel, there will be a tendency of the aircraft to swing, as demonstrated by simple physics and witnessed by many pilots, which will require prompt counteracting.

 

It's not a difficult machine, it's a tricky one.

[Crump]

bongodriver says:

 

Messerschmitt's own test pilot confirmed it,

 

Really!  Which one said it and when?  Sounds to me like rumor control repeated for dramatic effect on a history channel show.  So we should base "realism" on popular belief or conjecture and not science/engineering.

[Kurfurst]

One can assume it is based on the research of the individual who put the figure forward, no point being all indignant about it until there is proof of the contrary.

 

One can assume but then he'd be wrong with the assumption. I have seen otherwise credible books stating that the Spitfire I had only four machineguns, it was the IA that had eight. 

 

Olivier has posted some figures on the matter, and from a detailed list of 109 incidents totalling 26 000 (!) cases, there are only 1000 of that related to take off and landing accidents/incidents. Typically the aircraft was slightly damaged in these and being repairable. In in 1937 there were just 29 accidents, each resulting in injuries.

 

The 1500 killed pilot figure is pure BS. It has been found in a book that is a very generic essay on the air war and not a serious study. It has been put into the wikipedia article by some clown with an agenda, who regularly bashes Wiki 109 articles with stuff like this.

[Sternjaeger]

yeah, the "anti-109 illuminati" strike again... if memory serves you've got quite the bad record on the ol' wikipedia, mate.. 

 

I think it's not an entirely improbable figure, although of course it can be opened to some interpretation or wrong translation.

Edited December 5, 2013 by Sternjaeger

[Kurfurst]

oh for the love of Pete... 

 

 

Nobody is saying the Bf109 was an unstable aircraft design, the known flaws are:

 

1) rudder authority, and this is the reason why the made bigger rudders after a while.

2) peculiar landing gear geometry, with a characteristic toe-out of the wheels, which means that when landing on one wheel, there will be a tendency of the aircraft to swing, as demonstrated by simple physics and witnessed by many pilots, which will require prompt counteracting.

 

It's not a difficult machine, it's a tricky one.

 

I do not buy the toe-in story either. BTW Crumpp has made a good point with the reference about the cessna in loaded/unloaded stance. The only explanation of a toe in being at the culprit comes from a few (no doubt very established and experienced0 British pilots who had flown the restored, early production G-2 "Black Six". They fly it without a war load (guns, ammo etc.) so the plane is a lot lighter.

 

Unladen trucks also have their wheels tilting outwards but it becomes neutral when cargo is carried. They are designed that way. I am not saying for certain that its the same case in the 109 but it would certainly make sense.

[Crump]

 

5,327 officers and men were killed and a further 3,113 injured in RAF training accidents

 

 

Which includes bomber command as well as ALL types of aircraft......for the entire war.

 

Bombers have crews which significantly cuts down the number of A/C for the entire war. 

 

6 years of fighting for ALL types in all commands vs 2 years for one single design.

 

The 1500 still sounds just as made up for dramatic effect for a history channel entertainment show.

 

yep, he does say toe-in, but I think it's just a honest mistake

 

 

Honest mistake or not, it speaks directly to his technical knowledge of the landing gear design.  He might fly the airplane but her certainly did not design it or appear very knowledgeable about the engineering specifics of the landing gear design.

[Kurfurst]

yeah, the "anti-109 illuminati" strike again... if memory serves you've got quite the bad record on the ol' wikipedia, mate.. 

 

Hardly. I built the 109 articles there and many others. See the 109 article and decide if its bad quality or not. There is a single kid out there with a lots of spare time who largely spends his otherwise uneventful life trying to bash that plane and he tends to following and scheming against me and Crumpp on various discussion boards. Appearantly he has nothing better to do with his life.

 

Funniest part was that when he tried the same scheming/reporting/baiting on my very own discussion board against another member. 

Edited December 5, 2013 by VO101Kurfurst

[Sternjaeger]

I do not buy the toe-in story either. BTW Crumpp has made a good point with the reference about the cessna in loaded/unloaded stance. The only explanation of a toe in being at the culprit comes from a few (no doubt very established and experienced0 British pilots who had flown the restored, early production G-2 "Black Six". They fly it without a war load (guns, ammo etc.) so the plane is a lot lighter.

 

Unladen trucks also have their wheels tilting outwards but it becomes neutral when cargo is carried. They are designed that way. I am not saying for certain that its the same case in the 109 but it would certainly make sense.

 

you don't have to buy it because it's not for sale, it's a fact. 

 

Nobody is really paying attention to what Crump says here, using a Cessna as an example is the typical case of "I have no idea what I'm talking about, but I'll find all possible circumstantial evidence that proves me right". What he doesn't tell you is that, unlike the 109, the Cessna suspension system is not based on an oleo leg, which has a completely different response to a spring leaf one. Or the fact that comparing the way load affects a taildragger as compared to a tricycle is inappropriate. 

 

The geometry doesn't change with load, it stays the same, and so does the behaviour: the toe on your car will not affect stability in a different manner if it's just you or you and four passengers. 

[Sternjaeger]

Hardly. I built the 109 articles there and many others. See the 109 article and decide if its bad quality or not. There is a single kid out there with a lots of spare time who largely spends his otherwise uneventful life trying to bash that plane and he tends to following and scheming against me and Crumpp on various discussion boards. Appearantly he has nothing better to do with his life.

 

Funniest part was that when he tried the same scheming/reporting/baiting on my very own discussion board against another member. 

 

Fine. Wikipedia is an open thing, you know that, so everybody can read what's happening there.. this is OT and unrelated to the topic anyway, so apologies for bringing it up here. 

[Gort]

Once again the same topic.

 

The gear was given toe out to add stability.  Properly adjusted camber and toe out, the gear on the Bf-109 is no more dangerous than any other tail dragger.

 

.

You keep saying "properly adjusted". WTF does THAT mean? What are the "proper " toe settings for the bf109, and other aircraft you are familiar with? How typical is toe out on conventional geared aircraft?

 

Explain how tow out contributes to directional stability when both tires are on the ground, or when on,y one tire is touching, or the effects of unequal weight distribution vs tire side slip at the contact patch.

 

Don't cut and paste from online manuals, explain it.

[DD_bongodriver]

It has been put into the wikipedia article by some clown with an agenda, who regularly bashes Wiki 109 articles with stuff like this.

 

When I realised who just wrote this I pissed myself laughing

 

They didn´t speak only for themselfs. It is the experience of hundreds of wartime pilots behind thier judgement

 

 

 

 

What is one test pilot against that ?   He actually flew it ? That´s great - but the others flew it several thousand times in far more difficult circumstances.

And BTW, Walter Eichhorn is a "test pilot" as well, and he never said anything like "very unstable". This is just nonsense. Why don´t you stop repeating that over and over again ?

 

 

 

http://www.clipwings.com/clip/101/Messerschmitt_BF_109_Display___Walter_Eichhorn

 

Walter Eichhorn doesn't seem to have any comments documented at all, it would be interesting to read something he 'has' said on the subject but extensive searching turns up nothing, so in that absence the words of several test pilots and experienced warbird pilots who have flown it and made documented commentary is a reasonable source of fact.

 

Rob Erdos explains the situation well.

 

The geometry of the undercarriage is perhaps the most unusual feature of the Bf-109. A digression is in order to appreciate how its characteristics would manifest themselves during take-off or landing. Some sources claim that between 15-25% of the Bf-109s ever built were damaged or destroyed during take-off or landing accidents. I find this a remarkable figure for a combat aeroplane – especially one that served on the losing side of the war! Most contemporary histories of the Bf-109 attribute this to the narrow undercarriage track, however this misses the point. (The Spitfire’s undercarriage is just as narrow, and it doesn’t have any of the Bf-109’s quirks. It has its own quirks – but that’s another story.) Dr. Messerschmitt faced a challenge in the design of his first fighter. In the interest of simplifying transport and repair of the aeroplane, it was designed with the undercarriage attached to the fuselage, such that the wings could be completely removed with the aeroplane resting on its wheels. The undercarriage struts were attached to a complicated forging at the firewall aft of the engine mount. The narrow width of the fuselage structure necessitated installing the undercarriage legs splayed outwards. This feature became the aeroplane’s Achilles heel.

Imagine that you have a bicycle wheel in your hands. Roll the wheel with the axle parallel to the ground. It goes straight. Now roll the wheel such that the axle is not parallel to the ground. The wheel turns. Let’s return to the Bf-109. Both of the tires are mounted “crooked”, rolling with a camber angle of about 25°. Consequently both wheels want to turn inwards under the aeroplane. When the aeroplane is rolling with an equal download on both wheels, symmetry prevails; both wheels fight to a stand-off, and the aeroplane rolls straight. Now imagine that something causes the download on the wheels to momentarily become unequal. In that case the rolling friction of the tires becomes uneven and the turning tendency of the “heavy” tire asserts itself. What might do this? Well, crosswinds. Or torque from engine power. However, the most dangerous culprit is turning. With the aeroplane’s centre of gravity situated high above the tires, a swerve will set loose large centrifugal forces that cause the aeroplane to try to roll over the tires. This is true of any aeroplane, but in this scenario the unusual camber of the Bf-109’s tires creates strong directional instability, requiring a different type of control strategy for take-offs and landings. Tight heading control or aggressive tracking of the runway centerline can set off abrupt directional divergence. Better for the pilot to relax, merely dampen heading changes, and accept small heading errors. Funny, I didn’t feel relaxed.

[Kurfurst]

Fine. Wikipedia is an open thing, you know that, so everybody can read what's happening there.. this is OT and unrelated to the topic anyway, so apologies for bringing it up here. 

 

It is.

 

Whats the climb speed of the 109K BTW, got any good figures from Wiki perhaps?

 

When I realised who just wrote this I pissed myself laughing

 

Suit yourself, it fits you.

[Sternjaeger]

It is.

 

Whats the climb speed of the 109K BTW, got any good figures from Wiki perhaps?

 

nope, and to be brutally honest I think it's a sterile debate. The indicative figures given by makers are like the modern speeds and MPG figures given by car makers: they're meant to sell, and often don't correspond to the truth, especially because as it logs more hours, every aircraft develops its own peculiarities. I have flown in at least 15 different Cessna 172, and in my experience it was hard to find more than two aircraft that performed in exactly the same way throughout the whole flight envelope, since there are so many variables involved.. Hell, even in a basic aircraft like the Tiger Moth things are quite variable: I've flown 4 different ones and each of them had its own peculiarities!

Edited December 5, 2013 by Sternjaeger

[MiloMorai]

Hardly. I built the 109 articles there and many others. See the 109 article and decide if its bad quality or not.

 

Yes your contribution was so great you were blocked from making any other further contributions.

[Kurfurst]

nope, and to be brutally honest I think it's a sterile debate. The indicative figures given by makers are like the modern speeds and MPG figures given by car makers: they're meant to sell, and often don't correspond to the truth, especially because as it logs more hours, every aircraft develops its own peculiarities. I have logged hours in at least 15 different Cessna 172, and in my experience it was hard to find more than two aircraft that performed in exactly the same way throughout the whole flight envelope, since there are so many variables involved.. Hell, I've flown in four different Tiger Moths and each of them had its own speeds and behaviour!

 

Just answer my question please.

 

What does Wikipedia says about the 109Ks climb speed.

 

You brought up the subject, so please don't backpedal when it becomes uncomfortable.

Edited December 5, 2013 by VO101Kurfurst

[Sternjaeger]

Just answer my question please.

 

What does Wikipedia says about the 109Ks climb speed.

 

You brought up the subject, so please don't backpedal when it becomes uncomfortable.

 

"The Bf 109's outstanding rate of climb was superior to all Allied adversaries including the P-51D Mustang, Spitfire Mk. XIV and Hawker Tempest Mk. V." (still don't see what this has to do with the OP...)

Edited December 5, 2013 by Sternjaeger

[Crump]

 

You keep saying "properly adjusted". WTF does THAT mean?

 

 

Like every other aspect of aircraft maintenance, the type specific maintenance manual will list the propeller adjustment for wheel alignment. 

 

I guess they did not teach you about that as the former professional fighter pilot you claim to be, you just get in and fly without knowing why or how it happens right?

[DD_bongodriver]

Why the fixation on that one single piece of information?

[Kurfurst]

"The Bf 109's outstanding rate of climb was superior to all Allied adversaries including the P-51D Mustang, Spitfire Mk. XIV and Hawker Tempest Mk. V." (still don't see what this has to do with the OP...)

 

Thank you. I meant the Bf 109 variants article. The relevant section says:  

 

"The Rate of climb was 2,775 ft (850 m)/min.^[101]"

 

Two more questions if I may.

 

^{1. Do you think the above figure is anywhere near correct?}

2. Do you know who made this edit and to what purpose?

Edited December 5, 2013 by VO101Kurfurst