NUCLEAR WEAPON DELIVERY WITH THE USE OF BOMBING TIMERS

Transcription

1 NUCLEAR WEAPON DELIVERY WITH THE USE OF BOMBING TIMERS Fig. 1 Dual Timer BTU (Bombing Timer Unit) As shown in Figure 1, the SIM SKUNK WORKS F-104 S model does have the dual bombing timers and systems necessary for the simulation of the release of a nuclear weapon. Here we will show you how to plan and conduct a simulated attack with nuclear weapons1 with the SIM SKUNK WORKS F-104 S. As we describe here applies to the final part of the attack-run, in an arc of time less than 30 seconds from the target, since the timer count limit is 30 seconds. Two timers were available, one called RUN-IN TIMER and the other RELEASE TIMER2, were used one or both depending on the type of release/burst that had been planned. Types of release were essentially two: LAYDOWN delivery: a direct attack at level flight and an altitude of about 200' AGL, release to a ground burst with a timer delay, in this case only run-in timer was used. (This type release was rarely planned) LADD (Low Angle Drogue Delivery) or RLADD (Radar Low Angle Drogue Delivery), the most used, consisted of a maneuver to release the weapon for an air burst, usually around 500 feet AGL, as shown in Fig.2. Both timers were used, the release could have been in any weather condition, day or night, even in IMC, in these cases we used the RLADD. 1 Historical note: in those days, the Cold War, obviously we were not using real nuclear weapons for training, even a simulacrum, instead MK-76 bomblets were used that weighed about 25 pounds and were dropped from SSU/21A dispenser stored on centerline rack, these bomblets reproduced very closely the kinematics of the real nuclear weapon, the B-61 model. Procedures and parameters of bomb release were identical to those real, and then the simulation was perfectly suitable under a training point of view. 2 Indeed, in the S version of the aircraft the timers provided were 3, there was also the EXTRA TIMER which was to serve to extend the time available with the run-in and then plan a third type of release that was Combined Visual and Radar LADD, ie: e was possible to plan on the ground and set the timers for both events, choosing in flight which of two events do. In practical situations EXTRA Timer was hardly ever used, often was not mounted on the aircraft. You get the same result by calculating two values of ground run-in timer for the two different types of release, choosing in flight the best value. Better yet often could match the TRP (Time Reference Point) to the RIP (Radar Identification Point) and then have only one value of run-in timer for both types of release. For these reasons, you will not find on the right side panel 's EXTRA TIMER, as it Flight manual provides as a possibility

2 Fig. 2 LADD EXPLANATION OF LADD MANOUVER Preconditions: DCU-9/A should be in the AIR or GND depending on the type of burst BTU on (pwr button pressed) RUN-IN timer set to the computed value RELEASE timer set to the computed value REMARKABLE POINTS (as in Fig. 2): 1. Start the time count over a point that can be either visually (TRP, Time Reference Point) or radar (RIP, Radar Identification Point) identified, pressing the drop bomb button. the RUN-IN TIMER start and you hears a tone in the headphones. 2. The RUN-IN TIMER ends and starts RELEASE TIMER, you will hear a tone in the headphones and the light SPL WEP (Special Weapon) on the front panel lights up, you start the LADD maneuver applying up to 3.5 G reaching about 35/40 degrees of pitch. 3. The bomb is released, you hear an intermittent tone in the headphones, and the light SPL WEP (Special Weapon) on front panel goes out, start the escape maneuver. 4. The airplane is tipped with a 1/2 barrel roll and pulled under the horizon. 5. Escape maneuver continues at very low altitude and high speed, not less than Mach 0.9. The nuclear weapon when dropped is dragged by a parachute and falls down almost vertical, the detonation occurs when it reaches the computed height, measured with a radar altimeter; detonation occurs at least 45" after release when the airplane should be at least 8NM out of burst area.

3 ATTACK RUN SEGMENTS (as in Fig. 2): R1: distance from the TRP/RIP at the beginning of LADD manouver (pull-up), R1 time is set into the RUN-IN TIMER R2: distance traveled by airplane to the ground during the pull-up maneuver R3: distance traveled by the bomb to the groundor burst after release from the aircraft, R2 + R3 time is set into the RELEASE TIMER TABLE 1 - ALREADY COMPUTED RELEASE TIMERS BASED ON BURST HEIGHT ALREBurst Release alt altheight (AGL) Timer R2+R3 gain R2+R3 gainburst Release alt alt 530 KIAS 600 KIAS Burst height (AGL) REL TIMER R2+R3 Alt gain R2+R3 Alt gain Fig. 3 Table for calculating the release timer The release timer is set according to the planned air burst altitude, the second column of Fig. 3 shows the values of RELEASE TIMER, function of burst altitude. The third and fifth columns shows the R2 + R3 distances calculated as a function of the release timer and release speed planned for the attack. R1 distance, needed to calculate the RUN-IN TIMER, is computed subtracting the R2 + R3 distance from the distance between TRP/RIP and the target,. The fourth and sixth column shows the altitude gain during pull-up manouver, function of speed and RELEASE timer, this value was used for a manual release without bombing timers.

4 TABLE 2 - DISTANCE CONVERSION CHART feet mt nm feet mt nm The table used to convert measurements, cross the row (from) and column (to) and read the multiplying factor. Example to convert from meters to feet: the factor is 3.28, so 3 = 3 meters x 3.28 = 9.84 feet. TABLE 3 - HEAD/TAIL WIND COMPUTATION TABLE Wind offset Range win component It is used to calculate the head/tail component of the wind during R1 and R2 attack RUN segments. Example: Attack run heading: 075 Wind: 030 /18kts Offset: = 45 The offset is less than 90 so is an head wind component, multiply factor is 0.707, component is 18 x = 12.7 kts headwind. Example: - Attack run heading: Wind 230 /22 kts - Offset: = 125 The offset is greater than 90, so is an tail wind component of = 35, multiply factor is 0.819, component is 22 x = 18.7 kts tailwind. TIP: Above table and computations become unecessary if you considering using the GSE (Ground Speed Error Readout) since it help to maintain ground speed regardless wind component. Most used attack speed were 530 kts or 600 kts, the relative speed in feet/sec second are: feet/sec to 530 kts feet/sec to 600 kts

5 SIMPLIFIED LADD MISSION PLANNING FORM TGT altitude TGT Temp Deg Kts 150 Approach wind Release wind TRP-TO-TGT distance Run in heading 310 RIP-TO-TGT distance NA Burst Height 500 APPROACH altitude 350 ALT gain 3846 BALLISTIC DATA TABLE Ground Speed R2+R3 Distance 530 RELEASE TIMER COMPUTATIONS TRP-TO-TGT distance R2+R3 Distance R1 distance RUN-IN TIMER = / = 13 Above a simplified version of LADD MISSION PLANNING FORM, it assumes that GSE is used, correct ground speed can be maintained regardless the wind. Attack speed is 530 GKTS. Calculated into the map the distance from the TRP/RIP-to-TGT = 18228' Find into the TABLE 3 the R2 + R3 distance and the RELEASE TIMER based on planned burst height = 6554' Obtain R1 distance with TRP/RIP-to-TGT distance minus R2+R3 = Divide R1 by and obtain RUN-IN TIMER = 13.0 secs.

6 To calculate the RUN-IN TIMER, you can also use the above ruler that is fine also for speeds other than standard 530/600 kias.

7 With calculated data is possible to fill the LADD MISSION DATA CARD above, ignoring the given Offset distance.