Low speed trim for JU88

NachtPiloten

Kurier auf Stube...pauke!
Staff member
Hello,

For folks attempting a bomber intercept a few facts (yes not fake news) should be made known. Most RAF bombers while capable of flying near 270 or so, usually cruised around 180-200 especially in stream to help avoiding accidents. This allowed the NJG to intercept fairly rapidly when they flew around 300 or so. BUT a too rapid approach and you over shot the target and well all things go bad. So, slow down and approach with patience. But when you do the JU88 and all faster planes handle a bit poorly at low speed unless you trim. So to help those eager to attack from behind and below (this was the tried and true NJG tactic to avoid that nasty rear gunner) and approach slowly you need to trim and practice some, well a lot. Try the following as a starting point. Set trim as follows 27.59 for elevator, 8.98 for aileron, and -1.99 for rudder (as per the z key function). Set throttle to 68 percent with rpm at 2400 at around 20k altitude. Should get you a speed of around 218-220. I tested this see video, not as an intercept but nice day time flying to get the numbers correct. Hands free flying was made. Night intercepts were not the zoom and boom like day combat, but think of a cat stalking its prey, slow sneaky, and with stealth. I'll get a proper night video up soon. Also, setting pitch for the guns. All forward firing guns about 2.5 degrees should do. Schrage cannon (R2 7JQK and C6 R4XM) need about -3 degrees. The Schrage guns are set to hit the target at about 100-150 meters when tracers cross the center of the cross hairs. They should be closer as most were really fired at 50-75 meters, close enough to reach out and touch. Hope this helps. The G1/6 will have all of this done when uploaded - I hope!

 
Great post Ted. Night intercepts have more in common with a precision instrument approach than they do with daylight air combat. One is all planning and precision, the other is dynamic and improvised. Power settings, aircraft configurations, and airspeeds are the key to predictability, which is exactly what is needed when hunting a target you cannot see.
 
Maybe transfer to projected knowledge base sticky?
Speeds in mph I assume?
 
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Ah validation - low speed attacks were not easy and required some skill well at least according to Wikipedia.

Using the Schräge Musik required precise timing and swift evasion; a fatally damaged bomber could fall on the night fighter if the fighter could not quickly turn away. The He 219 was particularly prone to this; its high wing loading left it at the edge of stalling speed when matching the Lancaster's cruising speed, and therefore quite unmaneuverable. The same was true to a lesser extent of other Luftwaffe types such as the Ju 88, which was considered quite a "hot ship" by its crews. This was also a problem during normal stern attacks at low closure rate, but it was even more exaggerated during Schräge Musik attacks, since the pilot could not even make use of the limited climb performance available at the edge of the flight envelope to avoid debris from the stricken target.

 
It would require a high engine power setting to make up for the increased drag, but I wonder if a notch of flaps would improve this situation.
 
Never read that being done but the pilots. I have read a abundance of diary accounts and not once did someone mention that tactic.
 
Yep, pure conjecture by me. There are a lot of good reasons why it may not have been feasible, which may quickly become apparent if one tried, or maybe not and it was just never done.
 
The only plane that might be able to use flaps would be the bf110 with the leading edge ones. Just need to know what speed they were rated for.
 
So, looking at https://www.lancaster-archive.com/lanc_dims_weight.htm and https://web.archive.org/web/20050206134455/http://takeoff.to/halifax as well as some ORBS, Lancs seemed to bomb from 20K-18K while I think Halifaxes max was 20K, so probably bombed around 17-19K; I check some Halifax Squadron ORBS.
Lanc cruising at these heights is as in link above, but seems nearer to, say 235 mph at 18-20K feet, Halifax, I would say 220-225 mph at 20K so maybe faster at 17,5K.

I'm assuming data is TAS, but if that can be achieved in certain high alt winds, I have no idea.

ORBS are not giving speeds that I can see; only altitudes.

This implies that Nachtjaeger (Nachtjäger) would have to match these speeds around 235-220 mph, not much slower. I will have to do some test missions with the bombers as well as the NJ to test this out; but others could try as well. Use AIradar fighter control at least, if not also radar.
 
It is likely, but not certain, that the speeds are true airspeed. They could also be indicated airspeed. I strongly doubt they are groundspeed, so the quoted speeds are not accounting for wind.

I suspect cruise speeds at lower altitudes would be slower, all else being equal.
 
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