Bf 109 = hard to fly?

[GregP]

If I am not mistaken, the airspeed is in knots or Mach number, the fuel in pounds, the fuel flow in pounds per hour. There is nothing mysterious about the metric system ... it is just in different units. I am comfortable in either. When I rode and raced motorcycles, it was ALL metric.

The airplanes we work on are ALL SAE and, if they are not, we convert them that way if we restore them ourselves. That way, we only have one type of hardware to deal with. While I was working on our Zero, I only came across two metric bolts ... since I have metric tools from motorcycle racing, it wasn't an issue, just go get the correct wrench and you're back going again. In my toolbox I have both SAE and metric drill bits, taps, and dies. Of course, I have by FAR more SAE since almost everything is SAE. The only tools I am almost completely lacking in are Whitworth, BSC, and BSF. If I ever start working on Merlins on a regular basis, I'll take the plunge. Otherwise, I really have no use for them since I have no items that use Whitworth hardware.

 

[CobberKane]

By any reasonable measure (geddit?) the metric system is the easier and faster system to work with, which would explain why militaries and professions have generally been quicker to take it up than populations - the plebeians tend to be very conservative about changing anything to do with day to day life, even when it makes sense. I remember the howls of protest when NZ made the switch. Had the system been around a bit earlier, maybe the USA would have been first on the bandwagon, to go along with the decimal currency and Websters attempts to tidy up the English language.
Re the structural integrity of the 109, maybe that was a relative thing, compared to the Spitfire. I believe the Spit was regarded as exceptionally strong in aerobatics. Against a mid war P-38 for instance, which probably lacked the ability to push the 109 in violent manoeuvres and dives, it might have been a non- issue

 

[gumbyk]

The airplanes we work on are ALL SAE and, if they are not, we convert them that way if we restore them ourselves. That way, we only have one type of hardware to deal with.

You should try working on BK-117 helicopters - metric airframe, and SAE engines!

 

[GregP]

Hi Cobber,

The USA HAS decimal currency. Our money increments in units of 1, 5, and 10.

Most people I know are not resistant to the metric system and neither am I. But almost all of the hardware HERE except for imports is SAE. It'll be around a LONG time in the future, too. All I ask is that any machine item I get is ONE or the OTHER, and not a mixture. My 1979 Chevrolet truck was part metric and part SAE and it sucked for that reason. You had to memorize which fasteners were which. When you are changing a transmission, why should you have to stop and go get more tools? Terrible. I don't see the metric system as superior in any way since I am very comfortable in the SAE system .... just different units, with which I am also familiar. Again, just make it ONE or the OTHER.

The USA has one of the only airspaces freely-available to civilians in the world, and it is run in feet and knots. People come from all over the world to learn to fly HERE, and they learn in our units or don;t train here. Right at Chino we have students in fixed wing and rotary wing from China, Europe, the mid-East, Iceland, etc. So, I suppose if you want to learn to fly airliners, you'd best get used to feet and knots. Likewise if you wan to fly a WWII Allied aircraft, at least from the Western Allies. There aren't any original Spitfires with metric instruments.

In point of fact, it doesn't matter a bit what units the airspeed indicator is marked in. If you can fly target speeds and altitudes, you can get around in either system. If you cannot fly target airspeeds, you'll probably crash even in the metric system and a metric aircraft right about zero meters AGL.

The USA was one of the earliest signatories of the metric system and the US government has no difficulties making specifications metric. We just have not forced an internal change to it, but many here really don't cared either way as long as we don't MIX them in together. It sounds selfish for me to say, "I don't really care what the rest of the world does; I operate in the world in which I live and work." But asking me to convert to the system YOU use is saying exactly the same thing in reverse.

In here I'm sure you can use either system and we can pretty much all figure it out.

Let's not let this aviation forum degenerate into an argument over units or measurement systems! Please! Conversion is easy and, if not, learn. The conversions are widely available in references and the internet. I usually post in feet, mph, or knots because that's what I use and those were the units in use during WWII by the vast majority of the Allies, of which I am part. All the Allied performance charts are in mph or knots and all the altitudes are in feet. Perhaps the axis embraced the metric system at the time, but this IS a WWII forum.

Maritime speed was always in knots, even the metric-oriented Axis.

 

[gumbyk]

In point of fact, it doesn't matter a bit what units the airspeed indicator is marked in. If you can fly target speeds and altitudes, you can get around in either system. If you cannot fly target airspeeds, you'll probably crash even in the metric system and a metric aircraft right about zero meters AGL.

I can attest to that.
I fly three aircraft at the moment, with three different units to the ASI, two different units to the VSI, and differing units for pressure gauges.
You simply remember speeds, limits, etc as the numbers, forget the units.

I fact, the only standard between all three is the altimeter, and that's because it is required by law to be in feet, so the CJ-6 has had it changed.

Anyway, back on track...

The 109 was an aircraft of its time - lots of 'quirks' that some people could live with, and others hated.

I suspect that some of the wings coming off may have had something to do with 'rolling G', where using aileron at high G can unevenly load the wings, and have catastrophic consequences. Does anyone have any published info regarding the complete flight envelope?

 

[bobbysocks]

When I posted, the post above said 700 mph. OK, I'll buy 700 kph, but Bf 109 wings don't fall off. The 109 had its faults, but shedding wings wasn't one of them.

You can use whatever measurement system you like, it makes no difference to me whatsoever ... unless I'm building an airplane with SAE rivets and screws. Then I need the correct drill sizes for the rivets and screws, and those aren't metric. I suppose I COULD switch to metric rivets and screws ... but I'm working on other people's airplanes and they get to choose the fasteners we use.

Really, it makes no difference to me at all.

as long as it isnt whitworth. the us mechanics had a heck of a time when they got their first mustangs because the nuts and bolts on the RR were all whitworth. they borrowed tools from local garages and made some themselves.

 

[CobberKane]

Hi Cobber,

The USA HAS decimal currency. Our money increments in units of 1, 5, and 10.

Sorry, maybe I didn't make myself clear. What I meant was that in it's fairly early history the USA had showed itself to be progressive when the opportunity arose by adopting decimal currency and trying to iron out some of the weirder parts of written English (Noah Webster actually wanted to go much further than he did), so maybe if the metric system had been around at the right time your country might have grabbed that opportunity too. You don't gt the chance to create a new nation from the ground up al that often.
Incidentally, I have heard of on instance where an airliner ran out of fuel mid flight because the it was refuelled with x amount of litres in instead of x amount of gallons...

 

[Koopernic]

Hello,

Popularily, it's common to heard that the Bf 109 was a hard airplane to fly, specially in take offs and landings. However, given that there are so many myths about WWII in general, I'm wondering how the 109 was really evaluated under critical eyes at the time, both by the Luftwaffe and the Allies.

Someone has information about this to share?

Hello,

Popularily, it's common to heard that the Bf 109 was a hard airplane to fly, specially in take offs and landings. However, given that there are so many myths about WWII in general, I'm wondering how the 109 was really evaluated under critical eyes at the time, both by the Luftwaffe and the Allies.

Someone has information about this to share?

The Me 109 was actually a lot easier to fly than most of its contemporaries, though that needs some qualification. The aircraft had a long tail relative to its other surface areas and masses and so was very stable and extremely easy to recover from a spin. Better than allied fighters. It gave plenty of pre stall warning and when it did come there was no tendency to drop a wing or flip which could happen in a Spitfire, Mustang or Fw 190. The DW.520 was especially notorious in this area. That's thanks to the slats and that tail. Up to the Bf 109E the slats did have a slight tendency to deploy unevenly under intense manoeuvring but the effect was more annoying than anything. From the me 109F onwards the mechanism was changed and the issue went away and slat deployment hardly noticeable. Slats don't increase lift at the angle they deploy, they only increase the stall angle possible thereby indirectly increasing maximum lift. There is a slight alteration in pitching moment i.e. the wings centre of lift but not its actual lift so the aircraft isn't unsettled.

The Me 109 bad reputation for handling comes from the tendency of the aircraft to ground loop during takeoff and landing. This was eventually traced to one wing stalling ahead of the other when in the three point attitude (tail on ground) attitude due to prop circulation.

It was fixed by fitting and extended tail yoke that lifted the nose and improved another problem that caused accidents in piston engined aircraft, poor forward visibility. The Vaught Corsair had the same problem and it was fixed the same way, with a longer yoke.

The extended tail yoke is usually most associated with the hybrid interim Me 109G-10 of November 1944 but was standard on the Me 109K-4 of October 1944 in which it was also retractable. The yoke was just an interchangeable part and could be fitted to the Me 109G6, G14 as well and often was.

Other fixes for the ground loop issue before it was fully understood was a lockable yoke, which worked so long as not forgotten, and a taller tail. Nevertheless Me 109 had no worse a statistical record than other Luftwaffe aircraft in this regard suggesting that pilot training, sparse towards the end, was a partial issue.

Allied pilots testing Me 109 didn't like that they needed to trim it into a dive but never seem to have annoyed the Germans who probably had different pilots notes.

The Me 109 had a high dive speed. When the taller tail came in the rudder balancing horn was replaced by a balance tab. The rudder horn caused shock waves in a dive and was thought the cause of airframe breakup sand unrecovered dives. There are stories of Me 109 out diving P-51D. The all trimming tail plane apparently helped in dive recovery.

While it couldn't out turn a Spitfire (though some Luftwaffe pilots claim they could) they were a good match for most other allied aircraft especially at low/medium speed where the roll rate was good. When the new oversized super charger and MW-50 came in the improved Power to Weight ratio could make the aircraft a real challenge and I recall a P-51 pilot on the dogfights series saying he met an Me 109 that was no ordinary Me 109 that out turned his P-51D.

The Me 109 had a high climb rate and in particular a steep climb: one escape trick was to go in to a tight corkscrew climb. No allied aircraft could get inside its steepness or tightness.

My father, who was 13 in 1945, lived some 25 miles from Penemunde where the V1 and V2 were developed. He remembers Luftwaffe fighters repeatedly rising up to intercept allied bombers on their many raids. What amazed him was the steep climb angle. He never forgot that. He'd motion something greater than 45 degrees, over 60. I've always assumed they were Me 109 from his description.

The Luftwaffe was trying to get rid of the Me 109 but it was not so easy to do. Remarkable for an aircraft that predates the Hurricane. Even if they could make enough Fw 190 they couldn't afford to provide its high octane c3 fuel.

Its worth noting that the Fw 190 was regarded as having nice well harmonised handling during high speed manoeuvre , a gentle stall when landing with flaps out but nasty when stalling under manoeuvre. The Me 109 had less harmonised controls but if stalled or spun was very easy to recover. So when talking of good handling consider the context might be different.

 

[GregP]

Hi Cobber,

That's right. It was a Boeing (757 or 767, can't recall) going from Canada South. Dead stick landed during a car race at an old airport in Cleveland, Ohio. The caaptain was a recreational glider pilot and there was no published glide speed for the Boeing, so he decided something like 1.2 * Vx (it's been a few years since I read that report), and made it safely to the old airport.

Goes a LONG way to explaining that 200 means nothing without the units appended onto the end. I don't CARE if it is metric or SAE ro whatever, but I DO want to know the units.

 

[Greyman]

This is the one I had heard of; Gimli Glider - Wikipedia, the free encyclopedia

 

[CobberKane]

I don't CARE if it is metric or SAE ro whatever, but I DO want to know the units

I remember that during Basic I told my section leader, an SAS vet, that something or other was 200 west of whatever. He said: "Two hundred what? F#$%G LIZARDS!!??"

 

[Koopernic]

Hi Stona,

The Me 109F1 was rushed into production so some more unusual problems escaped detection. The aeroelastic structural problem was however fixed in subsequent models such as the 109F2. From Wiki: "Tests were also carried out to find out why the tails had failed, and it was found that at certain engine settings a high-frequency oscillation in the tailplane spar was overlapped by harmonic vibrations from the engine; the combined effect being enough to cause structural failure at the rear fuselage/fin attachment point. Initially two external stiffening plates were screwed onto the outer fuselage on each side, and later the entire structure was reinforced.[33]". There were some other issues I know of anecdotally: seizing of tail plane bearings at high altitude and structural failure due to rudder over balancing in high Mach dives.

You'll find the Hawker Typhoon had a similar possibly worse serious problem in the same location. It seems to have significantly affected RAF commitment to the type along with Sabre problems. The tempest was the long term solution.

Konrad Zuse developed a floating point digital computer using relay logic and programs stored on punch tape made from discarded newsreel tape. His machine was used to solve systems of differential equations used to analyse flutter at the DVL aerodynamics institute in WW2 Germany. He is regarded as the inventor of the digital computer by some, certainly a strong case. It was quite a new and difficult problem for everyone in WW2.

 

[pbehn]

I don't CARE if it is metric or SAE ro whatever, but I DO want to know the units

I remember that during Basic I told my section leader, an SAS vet, that something or other was 200 west of whatever. He said: "Two hundred what? F#$%G LIZARDS!!??"

If you dont get the units right this can happen.

The Mars Climate Orbiter (formerly the Mars Surveyor '98 Orbiter) was a 338 kilogram (750 lb) robotic space probe launched by NASA on December 11, 1998 to study the Martian climate, atmosphere, surface changes and to act as the communications relay in the Mars Surveyor '98 program, for Mars Polar Lander. However, on September 23, 1999, communication with the spacecraft was lost as the spacecraft went into orbital insertion, due to ground-based computer software which produced output in non-SI units of pound-seconds (lbf×s) instead of the metric units of newton-seconds (N×s) specified in the contract between NASA and Lockheed. The spacecraft encountered Mars on a trajectory that brought it too close to the planet, causing it to pass through the upper atmosphere and disintegrate.[1][2]

 

[stona]

Hi Stona,

The Me 109F1 was rushed into production so some more unusual problems escaped detection.

Indeed. I don't know that there was a problem with the wings of the Bf 109 F. I've never found any reference to a problem having to be fixed. I do know that there was a perception amongst Luftwaffe pilots, picked up very quickly by British Intelligence and the RAF, that there was. Whether real or not it had an effect on the way that the type was flown that was real.

Cheers

Steve

 

[Elmas]

A friend of mine did the last Pilot training in the '60s with piston engine fighters, here in my town, flying G-59 (that were metric) and Mustangs ( that were Imperial).

SE = Scuola Elmas

To avoid confusion all the instruments had to be painted on the glass with red stripes indicating danger if surpassed......

 

[gumbyk]

I don't CARE if it is metric or SAE ro whatever, but I DO want to know the units





If you dont get the units right this can happen.

The Mars Climate Orbiter (formerly the Mars Surveyor '98 Orbiter) was a 338 kilogram (750 lb) robotic space probe launched by NASA on December 11, 1998 to study the Martian climate, atmosphere, surface changes and to act as the communications relay in the Mars Surveyor '98 program, for Mars Polar Lander. However, on September 23, 1999, communication with the spacecraft was lost as the spacecraft went into orbital insertion, due to ground-based computer software which produced output in non-SI units of pound-seconds (lbf×s) instead of the metric units of newton-seconds (N×s) specified in the contract between NASA and Lockheed. The spacecraft encountered Mars on a trajectory that brought it too close to the planet, causing it to pass through the upper atmosphere and disintegrate.[1][2]

Or this:

Gimli Glider - Wikipedia, the free encyclopedia

Fuel loading was miscalculated due to a misunderstanding of the recently adopted metric system which replaced the imperial system.

 

[GregP]

That was the Boeing that was fueled with liters instead of gallons and dead-sticked at a Cleveland car race.

 

[gumbyk]

That was the Boeing that was fueled with liters instead of gallons and dead-sticked at a Cleveland car race.

That's the one.

Great piece of flying

 

[Milosh]

That was the Boeing that was fueled with liters instead of gallons and dead-sticked at a Cleveland car race.

Gimli is in Manitoba Canada, near Winnipeg.

 

[bobbysocks]

wow....those are some vintage old race cars....60s and real early 70s models.