This document is to provide detailed building plans, directions, and construction techniques for the Bomarc project.

The Bomarc missile is a Surface to Air Missile (SAM). It was used for defense of bomber attacks from 1962 to 1972, when it was removed from service. The Bomarc (Military designations of F-99, or IM-99, or CIM-99) was produced in two versions, the "A" version and the "B" version. At this time additional detailed information is being sought. The known differences include:

The "Bomarc Project" is an attempt to build the "B" version. It will use advanced controls, to launch, vertically, and glide to a safe recovery.

Paint scheme:

There were three painting formats on the Bomarc; they were the "Canadian", the "Gray" and the "Black". The chosen color schema will be the "Black" schema, but research is still being conducted in an attempt to find an accurate depiction of how the Bomarc was painted. Currently Boeing Archives has made some blue prints available, which are being used to guide construction of the Bomarc.

Scope of Project:

The current schedule is to have the vehicle ready to launch by LDRS, August 7-10, 1997. Ok, so I missed 1997. Maybe 1999 ??? Still working on it....(5/10/00)

Current plan(s) for flights and flight testing:

The first flights, (using twin J350 motors) will be entirely remote control. These flights will be used to train the on-board computer, and get data from the onboard sensors to determine if they will work properly. Once this data is obtained, the next step will be to launch the rocket, and have it recover using it's own glide capabilities. The next step is to place a larger motor in the rocket (up to a "L" class) to test the rocket under near full thrust, to the max ceiling waver at our local launch sight. (5,000 feet AGL) When the rocket has been tested to this height, it should then be ready for LDRS. The rocket will be launched from a "custom" launch pad, to (as near as possible) simulate the real Bomarc launch. It will be raised to vertical, released, then launched. Though most of the actions can be (will be) controlled by the on-board computer, the final "launch" command will come from a remote source.

Concerns and design specifications:

The design of the rocket is to have all of the control surfaces to be the same as the original Bomarc. This causes two unique problems. First, that the Bomarc uses a control mechanism that is different from most standard aircraft systems. Standard rudder/flaps/ alarons are usually on the trailing edge. The Bomarc uses the extended edges to perform the controlling functions. This causes two problems, the first since the controlling surfaces have a more aggressive angle of attack to the on coming air. The second problem deals with the mounting of the controlling surface. With standard controlling surfaces that use trailing edges, force is applied in a manor that the entire surface is hinged, and can in fact be connected with a "piano" type of hinge for greater strength. The Bomarc system uses a "rotation point" method. With this technique, the force is applied to only one hinge element. With up to 2000 lb. of force being applied to the rocket, I do not want in my design to have the controlling surface "drag" on the rudder/fin. Safety is also a paramount concern. Numerous backup and redundant systems will be in place, both in software, design of the rocket, and it's safe recovery. This will also stand true for the consideration of hybrid power of the rocket, if used. Hybrid power is VERY appealing, as a valve can be placed between the nitrous and the engine. Further, hybrid power has the ability to shift the CG of the rocket, when used with the Bomarc is actually a good thing, and would solve other issues (glide recovery) with the rocket. (Changing a "rocket" to a "glider" requires a change of CG vs. CP)

An additional question is:

Will the standard RC servo's be sufficient to control the primary control services under thrust, and/or on the glide return? Work is still progressing on this issue, and considering replacements if these do not work. Replacement of different motors with the servo's control mechanism used is a possibility.

Actual Construction:

The body tube will be constructed out of standard 7.6 body tube. Two lengths will be used, One will be 60 inches, and the other will be 30 inches. With a 30-inch nose cone, the rocket will be within one inch of being exactly on scale. A nose cone from Public Missiles will be purchased. This is due to the Bomarc nose cone is long and slender, and the Public Missiles have the best shape for this rocket. The runner down the spline of the rocket will be made from standard body tube. The Forward portion of the spline will house two sections, for the drogue parachute, and main parachute.

The fins will be constructed with 1/32 inch aircraft grade plywood, or 0.010 aircraft grade aluminum. (This may change with material availability) As this rocket will be modeled after the real Bomarc, all control surfaces will have two sheets of plywood, with some ribbing, as necessary to structural strength, and for the shape of the wing services. With the exception of the main wing (this may change), all other surfaces will utilize though the will construction, with epoxy being applied to both the inside, and outside areas, and to the motor tube (or other applicable surface).

Wings

The wings will be constructed out of 0.010 aluminum. Current plans are to have the wings bolt on the outside of the rocket as they do on the real Bomarc – but this may change to through the wall construction. The problem with "through the will construction" in this case is that it would interfere with the scramjets mounting. The wings will have edge controls, as does the real Bomarc. With edge controls comes a potential problem of binding. This will be solved using two techniques. The first will be the use of 1-inch aluminum tubing in the wing, on each side. The tubing will have two retaining areas for each wing, for the tube to rotate freely in. The real Bomarc has, towards the rear of the wing a "limiter /anti binder". Until or unless more detailed information were to become available (real blueprints of this area), the designers true function may never be known. In the scale version of the rocket, it will be used to keep the wing surfaces from binding. For the wing surface, three (or more?) links of a standard bicycle chain will be used. The bicycle chain moves freely in one axis, but it does not move in the other. This ability will aid in keeping the moving wing surface away from the stationary surface. The moving surface will be controlled with a standard RC type servo, in a near standard fashion.

Rudder

The rudder will be constructed of 1/32-inch, aircraft grade plywood. The control surface will have a 5/32-inch rod going up the center of the non-moving surface of the rudder. The rod will be housed in a aluminum tube (approx. 7/32 inch) to prevent binding, and the rod will be bent 90 degrees (inside the control area of the rudder) to facilitate more area to attach to the rod. The rudder will utilize an anti-binding/control limiting feature similar to the wing surface, but will be reduce to two links. The rudder will be mounted to the engine tube using though the wall construction. Epoxy will be applied to the engine tube, and to the body tube surfaces. The control of the rudder will be from a standard RC servo.

Ailerons

The alarons again will utilize the same construction techniques as the rudder. The exception is that the alarons will be controlled with a 1-inch aluminum tube. There will be six mounting points (two will be hinged) for the alarons. The other four mounting points will be mounted solidly inside the alarons. Currently information is not conclusive if the alarons have a limiting device or not. If needed, a limiting device will be added, and it will use a similar technique for limitation of movement of the control surface.

Scram jet standoffs

The scramjet standoffs, as they may be connected to fully functional scramjets, need to be securely mounted to the rocket. Current plans are to have the scram jet standoff's made from ½ inch (maybe thicker) (if available – aircraft grade) plywood. This will comprise the structural support mechanism. Outside of the ½-inch plywood will be 1/32-inch plywood, cosmetically mounting the scramjet to the body tube. Now for the fun part. The ½-inch plywood will start at the far side of the scram jet, go though the center scram jet tube, though the near side of the scram jet, though the body tube, mating to the far side of the main body tube. This will also form a "X" with both scramjets mounting, which will be securely fastened. The "cosmetic" 1/32 inch plywood will start on the far side of the center scram jet tube, though the near side of the center scram jet tube, thought the near side of the scram jet tube, though the body tube, stopping on the "X" in the center of the rocket. Each peace of plywood will have it's own hole cut thorough the tube to provide a larger surface to adhere to.

Scram jets

The intention for the scramjets is to be functional engines. They will be securely mounted to the main body tube. (See "Scram jet Standoffs") The scramjets will be made from standard body tubing. This will permit the mounting of up to 98MM motors in each tube. Each tube will be mounted at a slight angle – pointing towards the main body tube. (The exact angle has yet to be determined – but the angle placement will be as accurate as possible.) The angle will be checked experimentation. The only thing (currently) that cannot be simulated is the "taper" of the scramjet. The Bomarc scramjets have a taper, as instead of a "nose-cone" appearance. Unless a tapered body tube can be found, no attempt will be made simulate a tapered scram jet motor. The design of the scramjet will be to have a "center" tube, with a nose cone inside for cosmetic reasons. Air will be permitted to travel the length of the scram jet tube however. The first 12 inches (approximate based on total length of scramjet minus length of 98MM engine tube.) will be a 2-inch tube. Most of the tube (as stated above) will be "sliced" by the scramjet Standoff. The tail of the tube will be left "open" – more detail o n this later. This tube will have additional plywood (1/32?) centering "fins". (The function is to center the cosmetic portion of the tube inside the outside portion of the scramjet.) By looking down the center of the scramjet, one would see the center tube (with nose cone) four "minor" fins reaching to the outside scram jet tube. The rear of the tube will permit adapters to mount different (or same) sized of motor tube inside the 5.1-inch scramjet. These will be permitted to be replaceable – as follows. Each motor tube will be made with four fins that mate to the "upper" (or cosmetic) portion of the tube, using a tube adapter/coupler as necessary. Each of the four fins will be locked into position by four sets of "runners" located inside the 5.1 inch main portion of the scram jet tube. Four wood screws (more if necessary) located at the bottom will retain the motor in place, and keep it from falling out the aft end of the tube.

Spline/Recovery

The Spline will act as the main housing for the recovery system. The first 1-½ foot of length (not counting forward taper) will house the drogue parachute. The drogue parachute will be mounted to a lengthy elastic cord – attached thought to the "X" in the center of the rocket. Note that this may not be a direct route, as the spline starts at the top forward of the rocket, and the "X" would be near the center of the rocket. There will be a forward bulkhead (to house the electronics section) The shock cord would make use of this bulkhead, so as to not "zipper" the rocket. There would be a hole cut in the center (near the center) surrounded with a material (plastic) so the elastic cord would not bind on *any* surface, including the spline. The main parachute would be mounted directly above the "X" (maybe this should be reversed?) and would have an elastic cord going directly to the "X". The covering (or top) of the spline that covers the parachutes will be permitted to "fall away" thus opening the way for the correct parachute to come out. The cover will be "spring" loaded so that when the release mechanism is activated, it will "grab" the wind, and pull the parachute out. The release mechanism will be a solenoid; with a separate power supply form the RC/Computer portion of the rocket. Current plans are to have a "remove power – activate" system, but this has not been finalized. The computer (if installed) or RC will control activation of the parachutes. The locking "peg" will actually be three pegs, mounted to a modified "centering" ring, with the activation solenoid attached to, and moving the pegs as necessary. Activation will be pointing in a "up" direction; thus, the thrust of the rocket will not set off the "ejection charge." As an additional note, with the length of spline, more parachutes (one additional backup drogue parachute) could be added if deemed necessary.

CG/CP (and two additional motors)

CG/CP calculations of this rocket will be very difficult, as the rocket is not symmetrical. The rocket is based on the Bomarc build by both Estes (The old, original glider and non-glider versions), and NCR (Both glider and non-glider versions). Their position of CG will be maintained for flight. This may require a "drop-away" pod. If so, this pod will be strapped to the nose code of the rocket. With RC, this pod would be dropped (with it's own parachute) to permit the rocket to change to a glider. All data from the other manufactures will be included as to location of CP/CG. Math or simulator calculations will be tried, if a system can be found for non symmetrical CP.

Engine mounts

The primary engine mount will permit the use of one 98MM engine, and up to six 38MM engines. (Thus the rocket could see up to nine engines). The primary engines will have two aft centering rings, and one forward centering ring (or more accurately "bulkhead"). The six engines are mounted in a non-symmetrical pattern. This is to permit for the non-symmetric possibility of weight at launch. The forward bulkhead will be securely mounted, and reinforced to prevent the motor from traveling up the center of the rocket, and to permit the even distribution of thrust to the body of the rocket. The fins will be mounted "though the wall" to the engine tube, where permitted. For the 98MM tube, design considerations are in place for using a "open chamber" motor mount. If implemented, this design would transfer all of the thrust to the forward bulkhead. The forward bulkhead would then transfer the thrust to the other centering rings and main body tube. This would permit the removal of unnecessary engine tube, and yet permit more free and open access to the rear of the craft. (Only a consideration at this time.) All of the motors will all be retained by a positive means (NOT friction fit).

Electronics/Guidance control.

Electronics will be primarily thought RC style devices. They will be connected to a RC unit for initial flights, and eventually reach the point of self-guidance thought a computer-controlled mechanism. There will be a separate, backup power supply for the parachute mechanism. This will permit the parachute to be fired with loss or drainage of the primary system. At this time the design will be the use of "secondary power off, ejection will happen" system. This is TBD. If this system reaches full capabilities, the control commands will come from any or all of the following data sources: Accelerometers, Attitude indicators, Altimeter, GPS, Ring laser Gyro's, and a homing beacon (Laser?). These will aid in the accent and recovery of the rocket. The power supply will have redundancy in critical areas (recovery) such that if a "abort" button is pressed, the recovery system will still be active and able to function with total failure of the primary power supply. If there is a failure of the primary power supply, the computer will attempt to fire the recovery system. The voltage inverters chosen can (and will) provide a "bad power" signal to the computer system, permitting the computer to take corrective action if necessary. The actions are fire the recovery system, and if hybrid vent the fuel. The electronics section will have a "power on" switch, with a "remove before flight" flag attached. There will be LED indicators in report the status of the primary power, backup power, computer power and computer operational. The 5V line will have a one MFD capacitor to prolong the time necessary in case of failure. The computer will log data to a PCMCIA device (Currently an Intel Flash memory card). The computer will boot off a standard 3-½ inch floppy drive, which will house the operational software. If need, a 42mb PCMCIA hard drive can be substituted for the Flash memory card, for the logging of data. The hard drive is rated at 200G force.

Main Body/Nose Cone

The main body of the rocket will be constructed out of two 7.7-inch body tubes, one 60 inches in length, the other will be 30 inches in length. The nose cone will be purchased, and be an additional 30 inches in length, for a total length of 120 inches. Scale length for this rocket is 119 inches. Positive latching will be maintained between the sections of the body tube, and the nose cone, to keep the rocket from falling apart.

Radar Mounts

Cosmetic at this time only. They may house "laser" detectors at a future time, to aid in recover of the rocket, if needed.

Launch Pad:

The launch pad will be constructed as to as closely match the Bomarc launch control system, but without the hardened shell due to cost considerations. The rocket will be setup on the pad, in a horizontal position, raised to the vertical, and a count down initiated. When the "launch" button is pressed, a signal is sent to the on board computer, which will determine if the vehicle is to launch. (The computer maintains the final "go/no go" decision. Note that the computer WILL NOT be permitted to totally launch on it's own. It will only have the ability to shut down (over ride) the launch. The connections to the rocket will be done through small connectors located on the aft end of the scram jet standoff's. As the ignition takes place, these will not interfere with the rocket's ability to launch. (Also, they are cheap to replace if they are burned by the rocket blast.) The rocket launch pad will be modeled after a combination of the Hill AFB Bomarc / launcher that is on display, and the Plastic Revel model. As many functional parts that can be will be placed on the launch pad. These are to include, but not limited to:

1. Raise the rocket to the vertical position.
2. Release the two upper clamps holding the rocket.
3. Release the four lower clamps holding the rocket.

A signal will be passed to the rocket indicating that it is now in the vertical position. (Through the scram jet connectors.) In addition, 12v power source will aid in the life of the on board battery – and will continue to power the rocket. If Hybrid power is use, this "extra" power (current) will be used to activate the solenoid necessary to start the motor, again adding to battery life. The launch pad will have an LED to indicate that the connection with the rocket is good.

We would like to spotlight our Sponsors of the The Bomarc Project and give recognition to those who have assisted in this effort.

New sponsors of the Bomarc Project will be added as they contribute to the project.

HOME | SPONSORS