otherhunmiketeams Posted January 31, 2020 Posted January 31, 2020 Hi Guys, Can't get MW50 to actuate over 6200m for the G14 and 6500m for the K4. Given all the caveats about overheating the engine, I've tried spawing in QMB at 6000m with low engine temps and giving it the beans. Both planes accelerate up to the stated heights(above) then the MW50 cuts out and the engine ATA's drop back to combat levels. Effectively this means I can't get either 109 over 500kph in level flight above 6200m or so. Am I not understanding the issue or is this a bug?
JuliMonkey Posted January 31, 2020 Posted January 31, 2020 3 minutes ago, otherhunmiketeams said: Hi Guys, Can't get MW50 to actuate over 6200m for the G14 and 6500m for the K4. Given all the caveats about overheating the engine, I've tried spawing in QMB at 6000m with low engine temps and giving it the beans. Both planes accelerate up to the stated heights(above) then the MW50 cuts out and the engine ATA's drop back to combat levels. Effectively this means I can't get either 109 over 500kph in level flight above 6200m or so. Am I not understanding the issue or is this a bug? This is historically accurate. MW50 wasn't effective above 6000m. 1
otherhunmiketeams Posted February 3, 2020 Author Posted February 3, 2020 If you're going to make a statement claiming historical accuracy then Imho you should at least provide some referential evidence. Info posted by Jason on this forum: The aircraft is equipped with MW-50 water-methanol mixture injection system that prevents the engine detonation in the emergency power mode. It engages automatically when the throttle is set to maximum, there is enough mixture for 25-30 minutes. However, the engine can work up to 10 minutes at this mode, wait for another 10 minutes at the combat mode before engaging the emergency mode again. Attention: running the engine at the emergency mode without the water-methanol mixture or at altitudes higher than 6 km is forbidden! A pilot can check the system using the injection pressure indicator on the left: its normal pressure is 0.6...0.7 atm, stop using it if the pressure is lower than 0.4 atm and switch the engine to combat mode. and DB-605DB engine: Maximum true air speed at sea level, engine mode - Emergency: 599 km/hMaximum true air speed at 7500 m, engine mode - Emergency: 702 km/h Maximum true air speed at sea level, engine mode - Combat: 543 km/h Maximum true air speed at 8000 m, engine mode - Combat: 684 km/h Would suggest otherwise. A cursory look through other historical material suggests the MW50 was a pilot operated system in this aircraft (K4) and using it above 6000m was seen as a waste of material rather than a danger to the engine. according to https://en.wikipedia.org/wiki/Messerschmitt_Bf_109_variants 'Using MW 50 and maximum boost the Bf 109 K-4 was the fastest 109 of World War II, reaching a maximum speed of 710 km/h (440 mph) at 7,500 m (24,600 ft) altitude.[108] Without MW 50 and using 1.80 ata the K-4 reached 670 km/h (416 mph) at 9,000 m (30,000 ft).[109]' Similar posts by Kurfurst.org and others give the same info. So going back to my original question, I still can't see why I'm not getting either MW50 or ATA's above combat rating over 6500m for either the 605DB or DC engine?
6FG_Big_Al Posted February 3, 2020 Posted February 3, 2020 On 1/31/2020 at 5:52 PM, otherhunmiketeams said: Effectively this means I can't get either 109 over 500kph in level flight above 6200m or so. Am I not understanding the issue or is this a bug? I think that you have given yourself the answer. Because the speed you have indicated here is that of your instruments, right? Because then this is IAS (indicated airspeed). 1 hour ago, otherhunmiketeams said: DB-605DB engine: Maximum true air speed at sea level, engine mode - Emergency: 599 km/hMaximum true air speed at 7500 m, engine mode - Emergency: 702 km/h Maximum true air speed at sea level, engine mode - Combat: 543 km/h Maximum true air speed at 8000 m, engine mode - Combat: 684 km/h And as you can see here these values are for the TAS (true airspeed), which in this case you can't read from your instrument needle so easily (except on the Me-262). The higher you fly, the more the TAS deviates from your IAS. So you can "only" read 500km/h in the instrument, but in reality you are over 700 km/h fast due to your altitude.
Recommended Posts