View Full Version : interesting article

12-10-2005, 03:19 PM
don't know if this has already been posted before, but i found a wonderful article on rhe bf109. The variant being discussed is chiefly the 109 E-4. All about its flight characteristics. Many are modelled in the game too which is pleasing, though some are not.


I think articles such as these are very reliable. If a German plane has been captured and thoroughly tested in Allied hands they have no need to bias their oppinions in favour of the plane they are testing, (like manufacturers did) and they have a lot of experience with their own planes to compare it to.

For example when they say 'initial climb from a low speed is very steep' they would mean relative to an allied fighter.

12-10-2005, 03:28 PM
VERY interesting and in-depth article. Awesome find.

Everybody read through it. Plenty to learn here.

12-11-2005, 12:36 PM
Especially if you know all the information NOT included on that web page.

A comment on the tests made on the 109 E above, , WerkNr 1304:

Case: Bf.109E
RAF Royal Aircraft Establishment (RAE) Farnborough handling trials,Bf.109E Wn: 1304. http://www.geocities.com/capecanaveral/hangar/9378/flybf109.html
Messerschmitt Me (sic) 109 Handling and Manoeuvrability Tests, M.B. Morgan and D.E. Morris, Communicated by the Principal Director of Scientific Research - Air, Reports and Memoranda No. 2361, Great Britain, September 1940. (Probably also using data from RAE Jan 1941 testing).
Comparitive Trials between Me109E and British Fighter Aircraft, RAE (?), 14 August 1941
Here we have two interesting reports. They're actually a 1941 report from tests conducted in September of 1940 from an aircraft that was captured by the French in 1939 (see next chapter). At the time the tests were conducted in 1940, they didn't have oxygen bottles for the 109, so test could only be done at low to medium altitude, where they thought combat would take place anyway. At these altitudes the result was indeed that both the Spitfire and Hurricane could out-turn the Bf109, and this was reported to the squadrons, whose pilots would have reacted in combat according to this perceived strength. Later, well after the Battle was over, testing at higher, "combat" altitudes showed the opposite to be true at these heights.
There is even more confusion. The 109 tested is claimed to be "Me 109E-3 Werk-Nr 1304" which is documented to have been captured. However, there is some discrepency as to WerkNr 1304 actually being an Me109E-1. So what have they tested? E-1? E-3? E-4? Did they test one of the crash landed, damaged planes? So we got major confusion with the tested plane. Also, Bf 109 E-3 WNr. 1304 (RAF AE 479) was at one point crash landed, among other things, and it received a new tail section from a Bf 109 E-4 WNr. 1980.
Another problem is with the test itself, when compared to a Spitfire. Overall the accuracy of the test suffers from the fact that it was flown with a crash landed plane wirh a worn, several years old engine producing less power than usual. It was then flown against a brand new Spitfire with a 1940 engine. As shown by the test data, the turns were made in the 120mph range which is too slow for the 109 slats to be deployed, which doesn't compare the maximum turning abilities of each aircraft. Further inspection of the report will show that the test was conducted with the "Rotol" Spitfire. The Rotol Spitfire had a Merlin III engine, not the Merlin II. At 11,000 feet it had a climb rate of 2,905 ft/min, the turn test was conducted at 12,000ft. This test was conducted 19 March 1940. Now look at the other two Spitfires in the test. Their test date was in July 1939. The climb rate of the 1939 aircraft at 12,000 feet was only about 2,000ft/min vs the 2,900 ft/min of the Rotol aircraft. The Rotol aircraft is inconsistant with the performance of the aircraft in the field. The 109 was captured in 1939, therefore for an accurate representation to be made it should be compared to other 1939 aircraft. We are talking about taking 1940 technology and applying it to a 1939 matchup, taking an aircraft with 45 % more climb rate than aircraft available at the time the 109E was in service in 1939.
The 1940 report clearly states that the performance of the 1939 aircraft was not even near equal to that of the 1940 test (2100ft/min vs 2900 ft/min @ 10,000ft). The 109E matchup was done with the Spitfire employing 1940 technology, a constant speed propeller that was not in use in 1939. The matchup was also done with a Merlin III engine that was not available in 1939 aircraft. Also, it was done with a captured battle worn aircraft of questionable service against a brand new aircraft. The report does not state the maximum speed of the 109E by which one could gauge the relative engine horsepower output compared to other known DB601 engines. Also, it doesn't state a matchup between the 109E and Spitfire MkI employing a Merlin II engine and a standard propeller at the time, rather with the new 1940 constant speed propeller.
The French flew their test with the same Me 109 E-3 (E-1?). The test results are not available in English, but to author's knowledge their recorded performance numbers are higher than in the British tests. Since British tests do not give the used power setting, it is extremerely hard to find the truth between different test results.

References: Impossible to Follow? http://users.bigpond.net.au/mantis/FW/Bob/Best.htm The 109 tested is claimed to be "Me 109E-3 Werk-Nr 1304" which is documented to have been captured. http://www.luftwaffe-experten.co.uk/usa.html However, there is some discrepency as to WerkNr 1304 actually being an Me109E-1: http://www.ww2.dk/pictures.html Could this aircraft have been mixed up with other E-1's and E-3's captured and may have been damaged resulting in lower performannce: http://www.luftwaffe-experten.co.uk/allied.html

Case: French test report of the above aircraft, White 1, WerkNr 1304, AE479:
Read it here
This is the test of White 1, WerkNr 1304, AE479. It was captured in 1939 and tested by the French, where they made a couple dozen flights testing it against a D.520. During a high power climb test, the engine malfunctioned due to lack of proper oil and coolant. The aircraft was subsequently handed over to the British, who tested up until September of 1940 or after, nearly a year after it had been captured.
The important things to note are that the climb rates listed are based on averaging time to climb. There is also a second climb table near the very end of the report that appears to correct the original. I believe the second table reflects climb with the radiators in a different configuration. The French seem to have considered 1100 PS, 1.4 ata as the 5 minute setting. The climb table looks to have been compiled at that power setting. There is also a table of Vmax values along with the altitude, rpm and MAP for each speed. The one I found most interesting is 490 kph at 2500 meters, 2400 rpm and 1.26 ata ( 960 mm Hg ). I make that 990 PS, 282 mph Vmax at sealevel. But, my speed conversion from altitude to sea level could be wrong. If I grokked the comment after the last part of the report, they roasted the engine during testing. This is important to note, as the British tested later the same 109!
Or to make things yet more confusing, did the Brits test two different Emils? The Rolls-Royce speed tests were only done at partial power and with radiators open (or I'm missing the pages with full-power tests), but they conform well with the French speed tests at full power and with radiators open. The conclusion is that the French speed data, though not calibrated, is nevertheless correct (or even slightly low). In other words, the French top speed figure of 570 km/h for the Me 109E-3 is perfectly realistic. What's more, the French had an early DB601A with the low full throttle height, a late-model DB601A (which became available at some time between December 1939 and August 1940) would have given an even higher top speed due to the reduced air density at the higher full throttle height.
This French test was flown with open radiators up to 4000 meters, then gradually closing the radiators up to 8300 meters. At that time test had to be abandoned due to engine problems, as the engine malfunctioned. They related that to the temperature outside. The temperature was +6c on the ground and -17c at 5000m. The French considered it possible to make the climb radiators closed, which would enhance climb rate. Engine problem stems most likely from the French substitute oil and coolant, that had a lower calorific value which induced serious engine troubles.
Also note that the 109's leading edge slats may have been taped shut during these tests. Both the French and the British used this captured aircraft in mock dogfights to test the relative performance of the aircraft to the D.520 and the Spitfire. The French and British may have been so afraid of the slats, that they taped them shut so as not to interfere with their maneuvering during mock dogfights. Almost all jet aircraft today have leading edge slats to increase lift during takeoff and landing. Most military jets automatically regulate the use of slats during maneuvering. If these slats were operational on this particular 109, there would have been a marked change in the stall boundary when the wing camber changed due to deployment of the leading edge slats. This change is not present in the graph. The only conclusion that can be made is that the slats were not operational during testing. Without use of operational leading edge slats to increase lift at low speeds and high g's, the entire stall boundary curve on this graph is not representational of combat aircraft.
So the conclusion? The French data, supported by the Rolls-Royce data, suggests a top speed of 570 km/h (or above) at 1.2 ata. WEP is 1.3 ata. The French data is for an early-type DB601A with low full throttle height, while at the time of the Battle of Britain, the new type with increased full throttle height and accordingly increased top speed was available. The French data suggests a 482 km/h sea level speed. This is confirmed by the Me 109V15a (the Emil prototype) which achieved a sea level speed of 486 km/h @ 951 PS. (The DB601A-1 provides 990 PS at sea level at the 5 min rating.) The French climbed to 5000 m in 6:18 min with radiators fully open in an aircraft that probably wasn't cooling correctly

Source: http://www.virtualpilots.fi/feature/articles/109myths/

12-11-2005, 03:10 PM
So Grendel, the LW did not repair crashed landed a/c and put them back in sevice?

12-11-2005, 05:25 PM
Originally posted by luftluuver:
So Grendel, the LW did not repair crashed landed a/c and put them back in sevice?

A Bf109 repaired by the French/RAF was not the same as a Bf109 repaired by the LW.