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======Dive Bombing====== =====General===== ====Physical Principles==== The aiming point for the bomb release can be calculated, when you know some values. What you need is: * h = Release height above target (1200 m indicated height - 200 m target to sea level = 1000 m) * v = aircraft velocity * a = dive angle The general formula for a 90° dive is: * h=(g/2*t²)+v*t By a dive in an angle you have to seperate the horizontal and vertical speed components which results in: * v<sub>1</sub>=v*sin(a) * h=(g/2*t²)+v<sub>1</sub>*t * v<sub>2</sub>=v*cos(a) * s=v<sub>2</sub>*t Since we don't know the time but our height, we can convert the formula to * t=(-v<sub>1</sub>+√(v<sub>1</sub>²+2*g*h))/g With this calculated time we can calculate our horizontal component s. As an example: * v = 450 km/h = 125 m/s * h = 700 m * a = 60° Results in: * v<sub>1</sub> = 108,25 m/s * v<sub>2</sub> = 62,5 m/s * t = 5,23 s * s = 326,75 m With s and h we can now calculate our aim angle ε. * ε = atan(h/s) - α * ε = atan(700/326,75) - 60° = 4,98° This means you have to aim ~5° below the Revi-center. There are 3 points which also influence the aim angle ε. * The angle of incidence (aircraft specific, in case of Ju 87 and Ju 88 negligible low) * The back-drift of the bomb (see [[http://www.scribd.com/doc/100687050/L-Dv-8-5-Der-Bombenabwurf-Bombenwurftafeln|L.Dv. 8/5 aka L.Dv. 20/3]]) * Wind speed and wind direction ====Consideration of the back drift distance Δx==== You can also calculate the aim angle ε under the consideration of the back drift distance Δx. For this your formula is: * ε = 90 - α - tg φ * tg φ = Wurfweite(throw length)/Abwurfhöhe(release height) [tg φ = Δx/h] As example: * h = 950 m; v = 550 km/h; α = 50° * From [[http://www.scribd.com/doc/100687050/L-Dv-8-5-Der-Bombenabwurf-Bombenwurftafeln|L.Dv. 8/5 aka L.Dv. 20/3]] the throw-distance Δx = 640 m Results in: * tg φ = 640/950 = 0,675 = 34° * ε = 90° - 50° - 34° = 6° As experience value for the Ju 88 is at dive angles above 50° a value of 1° and below 50° a value of 1,5° to add (in the Ju 88 tables already considered), so for Ju 88 * ε = 7° For the usual dive angle and release heights the aim angles are arranged in the following tables. =====Ju 87 Dive Tables===== ====Aim Angle==== ^ **Aim Angle for Ju 87** ^^ | Release Height = 700 m | Release Height = 1000 m | | Dive Angle α = Aim Angle ε || | 60° = 4° | 60° = 5,5° | | 70° = 2° | 70° = 3,0° | | 80° = 1° | 80° = 1,5° | | Aim Angle For Dive Angle 90° = 0° || ====Wind Correction Angle==== ^ **Wind Correction Angle For Ju 87** ^^^^^^ | Dive Angle α | Wind Speed in km/h ||||| | | 10,8 | 18 | 36 | 54 | 72 | | 60° | 1,5° | 2° | 4,5° | 6,5° | 8,5° | | 70° | 1,5° | 2° | 4,5° | 6,5° | 9° | | 80° | 1,5° | 2° | 4,5° | 7° | 9° | =====Use Of The PC 1000 RS In Ju 87===== From L.Dv. T2332/5b (june 1941) **The use of PC-RS bombs is only carried out against battleships, aircraft carrier and heavy cruisers, but __not against bedrock emplacements__. The use of this special ammunition has to be made __only by specially trained groups.__** Shall the PC 1000 RS be dropped with the Ju 87, so the Pilot has to use the following table. The PC 1000 RS must not be dropped by **an angle of less than 60°**, to prevent bouncing and increase the impact. Also do not drop the PC 1000 RS **with the Ju 87 below 1200 m height**, to take advantage of the full impact power. **Attention! Because of self endangerment it is forbidden, at the use of the PC 1000 RS with the Ju 87** after the bomb release to dive further into the old direction or to dive steeper. **Delayed flare-out is forbidden.** The A/C has to flare-out simultaneously with the release of the PC 1000 RS. **By usage of PC 1000 RS is the ZSK generally to switch to "v.V."[full delay].** Release of the PC 1000 RS with swivelling Revi has to be done like the normal bomb attack according to the **guidelines** of the L.Dv. 20/2. The wind correction angles for the Revi are the same. Only the aim angles at still wind are changing and can be taken from following table: ====Aim Angle For PC 1000 RS And Ju 87==== ^ Dive angle ^ Release heights ^^| | ^ 1200 m ^ 1400 m ^ 1600 m | | 60° | 9,5° | 10° | 11° | | 70° | 5° | 5,5° | 6° | | 80° | 2,5° | 2,5° | 2,5° | **By wind change additionally the aim angle!** The change for a wind of 100 km/h amounts to: * 0,5° for 60° dive * 1,5° for 70° dive * 2° for 80° dive At tail wind increase the aim angle by this value, at up wind reduce. =====Ju 88 Dive Tables===== ====Aim Angle==== ^ **Aim Angle for Ju 88** ^^ | Release Height = 1000 m | Release Height = 1500 m | | Dive Angle α = Aim Angle ε || | 40° = 10° | 40° = 14° | | 50° = 7° | 50° = 11° | | 60° = 5° | 60° = 8° | | 70° = 3° | 70° = 6° | ====Wind Correction Angle==== For a dive-angle α = 50° and an indicated end-dive-speed of 550 km/h (average dive-speed ~ 430 km/h) accounts the wind-correction-angle for every 10 km/h wind-speed per 1°. At 30 km/h wind therefor 3°. =====Dive Bombing Against Swimming Targets (Ju 88)===== ====General==== The dive method is the same, also the wind correction. The Pilot has to value course and speed of the target and then select the point for the dive. **As an example:** * Attack against the wind : 50 km/h * Attack in longitudinal ship direction and movement direction * Ship: 120 m long, 30 m wide, speed 12sm **Carry out:** * Approach against the wind in longitudinal ship direction and movement direction. * Selecting the initial point of the dive (in our case 3000 m height). * Dive time and bomb fall time = 27 s * Drive of the ship at 12 sm = 155 m = 1¼ ship's length * Dive in 50° angle * from chart 1: 50° dive = 7° aim point * wind correction: 50 km/h = 5° * 7° + 5° = 12° corrected aim point (note: Revi in sketch is dejusted to 9°) * At 1400m the wind correction point must be at the bow of the ship * Pull the target into the corrected aim point (Not: lower edge of the Revi in sketch), release bomb and continue flare out. {{:shipdive.jpg?nolink|}} **General Instructions:** * At course change of the target turn in with aileron and at pull-in of the corrected aim point aim left or right, dependent on sense of rotation, of the bow. * By attacks with side wind in longitudinal ship direction, what is possible up to 50 sm/h, the initial point must be set sideward to luv * Attacks in wind direction are feasible as attacks against wind direction ====Prediction Table==== ^ Prediction mete for the initial dive point ||| ^ at height ^ speed of the ship || ^ ^ 25 sm ^ 30 sm | | 5000 m | 480 m | 560 m | | 4000 m | 390 m | 450 m | | 3000 m | 300 m | 350 m | ^ ship's lentgh: ^^ speed: | | battleships and aircraft carrier | 200-250 m | 25 sm | | cruisers | 150-180 m | 30 sm | | merchant ships | 100-150 m | 12-15 sm | =====Bf 109===== from D(luft)T.229/4 annex 2 (may 1942) Same aiming principle as Ju 87 but do not exceed the dive angle above **45°** (for the Bf 110 temporary). **Mortal danger for pilot!** (bomb can fall into the propeller circle) ====General==== ===Before the dive=== * Propeller to 9:30 * trim to +2° head heavy ===In the dive=== * Throttle to idle * Do not exceed a dive angle of **45°** * At angles above 65° the bomb drops within 0,5 sec into the propeller circle * Max. ram pressure near ground at release v<sub>a</sub> = **600 km/h** * Height difference, which at 9:30 propeller position until achieving of v<sub>a</sub> = 600 km/h near ground in different dive angles and 500 kg bomb load can be dived. ^ Dive angle ^ Height difference | | 20° | 3000 m | | 30° | 1800 m | | 45° | 1400 m | Note: height difference from initial dive point to release * Highest allowed dive speed v<sub>a</sub> = **650 km/h** in 1000 m height * Highest allowed flare out acceleration = **3,5g** * Results in smallest flare out radius of 950 m at 650 km/h * Lowest release height at 45° dive and 50 m ground clearance: 350 m ====Aim Angle==== * For v<sub>a</sub> = 600 km/h * Aiming angle at release | ^ Release height ^^| ^ Dive angle ^ 500 m ^ 700 m ^ 1000 m | | 20° | 8° | 11° | 14° | | 30° | 6° | 8° | 11° | | 45° | 4° | 6° | 7° | ====Wind Correction Angle==== ^ Dive angle ^| | 20° | for every 10 km/h up- or tail-wind ½° | | 30° | for every 10 km/h up- or tail-wind ¾° | | 45° | for every 10 km/h up- or tail-wind 1° | =====Bf 110===== In general the same as for the Bf 109. ===Before the dive=== * Propeller to 9:30 * Trim light head heavy ===In the dive=== * Throttle to idle * Do not exceed a dive angle of **45°** (temporary) * Highest allowed dive speed v<sub>a</sub> = **650 km/h** * Highest allowed flare out acceleration = **3,5g** * Results in smallest flare out radius of 950 m at 650 km/h * Lowest release height at 45° dive and 50 m ground clearance: 350 m
