Rocket Interceptor – The Story

The German’s were pounding our island nation day and night. Our boys in the RAF were doing everything they could to beat them back but Germany didn’t appear to be loosing their resolve. Well neither were we!

rrdecalstksOn a small country farm a project was coming to fruition for a new type of interceptor that could help destroy the waves of attacking enemy bombers. Our foe had developed a similar concept in their Messerschmitt 163 Komet. A little rocket powered plane that would swoop up to strike the US Army Air Corps B-17 and B-24 heavy bombers. Fortunately Jeri wasn’t having much luck with them. Sure they were inflicting some losses but they too were being shot down as they transitioned to landing. Sitting ducks as they were.

Inside what appeared to be a typical barn, filled with hay in fact held a small aircraft fabrication shop. Sitting in the middle of the main floor was a little bat like aircraft. It had a rather unique configuration, that being it sported a canard in front of the nose. Similar to what Orville and Wilbur Wright used on their first aircraft.

The canard had downward pointing vertical fins with small rudders which worked with two more vertical fins in the mid section of each wing. The wings themselves were very short, blending into the short but robust fuselage. On the tips of each of the wings was a rather large fairing which enclosed two small sphere shaped fuel tanks. The fairing looks more as if it were a large volume tip tank as it were.

Inside the round cross section of the fuselage held another two spherical shaped tanks as well as three large cylinders, cockpit and armament. The armament consisted of a 20mm cannon and a .50 cal Browning heavy machine gun. The cannon was liberated from a heavily damaged Spitfire which crash landed on a nearby farm. The .50 caliber machine gun was craftily obtained from the US Army for evaluation.

The weapons pod had the capacity of 30 rounds for the cannon and 300 rounds for the machine gun. Room for more of each was provided for but this was sufficient for test purposes. The weapon barrels fired from the lower front section of the nose, just underneath the canard. This kept gases and muzzle flash out of the pilot’s line of sight.

Four rocket motors propelled this bat like craft. Two motors were mounted on each wing inside a fairing about mid wing on the aft side. The rocket motors were stacked one on top of the other. The two upper rocket motors were linked and operated together, as were the two lower ones. This setup reduced the chances of adverse yaw from a motor on one side not firing off at the same time as the other.

Inside the cockpit there were two levers to control the rocket motors. One lever for each set of motors was provided with a somewhat different setup compare to conventional aircraft. One lever was on top of the control box, the other below. The one on top controlled the upper motors while the one below controlled the lower motors. The two were tied together in such a way that when the upper throttle had hit maximum power it advanced the lower throttle to give more thrust. Each could be operated independently should one or the other motors fail.

Below the throttle quadrant where two T-handles, each connected to a purge valve. The yellow colored one released pressure inside of the wing tip mounted fuel tanks supplying the rockets with fuel. The other had a red handle; it dumped the oxidizer from the large tank in the fuselage which exited through ports just aft of the dorsal fairing running from the canopy aft towards the tail.

On the floor one each side of the pilot’s seat were two handles which charged/cleared the weapons. A newer system would be incorporated once testing proved the aircraft viable.
The landing gear were of tricycle configuration, a rearward retracting nose gear which retracted into a bay between the two weapon barrels and each main gear retracted outward into the lower wing.

Control of pitch was both controlled by the canard mounted on the nose and elevons mounted on the wings. These elevons controlled roll as well as pitch. They could also be made to droop while the landing gear was down to increase lift at low speeds. This was only possible while the landing gear are down and locked the two being mechanically linked to a “flaps” lever in the cockpit.

To assist stopping there was a drag chute housed inside the tail cone of the fuselage. The pilot released this chute at or just before touch down of the main gear during landing or it could be deployed in an emergency to recover from a flat spin. The trick was not to pull the release handle too far. Pulling the handle part way deployed the chute, pulling it all the way released the chute. Get over zealous with the handle and you could deploy the chute and release it at the same time.

All of the aircraft’s electrical needs were supplied by a pair of batteries. One in each wing just forward of the main spar close to the wing/fuselage mounts. This was augmented by a small air driven generator inside the lower aft fuselage. Air entered an intake and turned the turbine producing electricity. It was not effective below 45 mph indicated airspeed. Therefore electrical power must be conserved. A more complex system would be designed later if the program was successful.

The sights for the cannon and machine gun were of a fixed iron sight type. Plans for an electrical sight were canceled because the powers at the government office of procurement would not consider the possibility of supplying one to the program. The pilot simply would line up the crosshairs with a dot for the machine gun and a circle for the cannon to point the weapons at the target. Each gun was operated by a separate lever on the control stick. Both could not be fired simultaneously.

The aircraft was essentially ready for test trials, first would be a test firing of the rocket motors. The Germans were using some volatile fuel for there propellants. If the two parts used came together even in small amounts it yield a violent reaction. Not so with the fuel used on this project. The two alone would not ignite or explode; they needed a third element…an arc of electricity. Inside each motor was a double set of ignitors. If one failed the backup allowed the motor to burn. If it too failed then it shut down that system. So if one side of the upper motors failed to ignite, it would shut down the opposite side as well. This measure prevented adverse yaw induced by an unbalance of nonsymmetrical thrust.

The morning of the rocket motor test was perfect. Fog so thick you could barely see your hand in front of your face. Mother Nature was helping to cloak the project from prying eyes.

The test pilot for the program was a tall lanky lad name Peter Orville Pickering better known to his friends as “Pop”. Peter “Pop” Pickering had just returned from a stint in the United States test flying new lend lease aircraft to check them before they were to be ferried over to England. He had also been given the chance to see some of the work the Yanks were doing in some of their design testing.

Wheeling out the ship was quickly handled; several workmen pushed it out into the yard adjacent to the barn. What took the longest was securing the aircraft to a series of anchors with heavy steel cables. Once that was done to the project supervisor satisfaction, two Lorries emerged out of the fog, having been parked at two different nearby farms. Each contained one of the necessary propellants for the ship. First the fuel was pumped into the one of the tanks in each wing. Then the oxidizer was pumped into the fuselage tank. Just enough of each to allow the four motors to burn for four minutes, no more.

Before making contact with the aircraft Pop made sure to ground himself off by touching the grounding cable connected to the aircraft. One end was connected to rod buried into the ground the other clamped onto a metal tie down eyelet on the aircraft. He kept a bare hand in contact with the aircraft at all times while he climbed up a ladder affixed to the aircraft. Once situated in the seat, secured by the harnesses he closed the canopy and affixed his oxygen mask and lowered his goggles. There was no radio installed but there was an interphone connection between the aircraft and the test director who was inside the farm house.

“Okay when you’re ready, master power switch to ‘On’.” The Test Director said.
Pop reached up and lifted the guard covering the switch and then flipped the master switch to “On”. He could hear the instrument gyros starting to power and wind up. “Master switch is on.” He replied.

“Start your checklist.” The Test Director said.

Pop followed the checklist item by item announcing each step over the intercom as his did. With a hesitation he moved the lever that pressurized the propulsion system. A tank of compressed inert gas mounted inside the fuselage was connected by high pressure tubing to the fuel and oxidizer tanks. This filled the tanks with gas pressure forcing each component into the manifold that controlled the flow and mixture of each into the rocket motors. When there was no explosion or warnings he breathed a sigh of relief.

He was finally ready to  switch on the ignitors and ease the throttles forward to fire the rocket motors. He cracked open the upper throttle.

“Switching on ignitors!” He stated with both excitement and anticipation.
The ignitors could be heard clicking and the two opposing upper rocket motor blasted to life. The air was filled with a loud screaming sound which would only get louder as the motors were throttled up to full power.

Pop left the upper rocket motors on for about fifteen seconds then closed the throttle. Next he eased forward the lower throttle handle and the two opposing lower rocket motors barked to life. Again he let then fire for about fifteen seconds before shutting them down.

“Looked real impressive from out here, how was it inside?”
The Test Director asked.

“Jolly good I’d say. I’m ready to have a go at the next step.” Pop replied. With that he again opened the upper throttle slowly. The two motors barked to life sending a flame several feet in length behind the aircraft. The noise increased, sounding like several freight trains bearing down on to the farm. He kept advancing the throttles until the upper motors were at full power. Hesitating only briefly he kept advancing the lever until he felt the lower motors come to life. The little aircraft was straining against the resistance of the anchors. He pushed the throttle lever all the way to the stop. All four rocket motors were now at full power. Then suddenly there was silence. The fuel was exhausted.

“Switching off the ignitor circuit.”
Pop said over the intercom as he closed down the switch guard this turned the switch off.

“Open purge valve.” Stated the Test Director.

Pop reached down and turned a large round knob clockwise; this opened a dump valve which purged any remaining fuel and oxidizer from the entire system. It sounded like a short blast on a steam whistle. Satisfied and verified by the ground crew, Pop secured all of the levers and switches, double checking each before undoing his oxygen mask and disconnecting the intercom connection from his helmet.

A technician was on the ladder and slid open the canopy. He reached in to congratulate Pop with a handshake. The Test Director emerged into view and asked if Pop was ready to see if it would fly. Pop now standing in the cockpit replied. “I’m ready! All we need is this fog to lift.”

Continue on to Chapter Two.

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