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HomeFlight Safety Officer

Flight Safety Officer (FSO)



Primary Responsibility

Ensure that the flyer has followed safety guidelines dealing with stability, construction, propulsion and recovery and that the rocket is safe to fly.

Reports to

Range Safety Officer

Qualifications

Level 2 or 3 Tripoli Member in good standing; knowledge of safe rocketry practices and Tripoli safety codes is required; experience in performing flight safety reviews is helpful

Job Description

Before a flier can proceed to the pads to launch their rocket, the rocket and the flier must pass a preliminary Flight Safety Review. The role of inspection is performed by the Flight Safety Officer (FSO). Obviously, this review/inspection has a subjective component. Experienced fliers known to the FSO may need minimal inspection. Novice fliers, or fliers that are attempting to acquire new skills (e.g. Clustering, Staging, Electronic recovery, etc.), should warrant closer inspection/review. If the FSO does not have experience with clustering, staging, electronic recovery, etc. the FSO should refer the flyer to a more experienced FSO or the RSO.

When the FSO is satisfied that the rocket is safe to be launched, the FSO initials the flight card and returns it to the flyer.

Requirements

The FSO must be at a certification level (or above) of the rocket that they are reviewing. If a flyer presents a rocket at a higher certification level than the certification level of the FSO, the FSO must obtain the help of another FSO with a higher certification level.

If the FSO is unfamiliar with an aspect of the rocket (e.g., staging, clusters, air starts, electronics), the FSO must obtain the help of another FSO with appropriate experience.

If the flight is unusual, the FSO must seek RSO review before the flier can proceed.

Checklist

Flyer

Does the flyer have credentials for the flight?

Does the flyer have a flight card? Verify that it is legible and indicates all of the pertinent flight data including but not limited to flyer name and member number, physical vehicle parameters, motor configuration, and recovery systems.

Is it a Certification Flight? Special attention should be given to flights that are indicated as Heads-up or Certification.

Is the flyer 18 years old or older? If yes, is the flier a member of NAR or Tripoli? If not, an adult who is not a member of NAR or Tripoli cannot launch any rocket at a Tripoli event, not even a model rocket.

Is the flyer younger than 18? If yes, is the flyer accompanied by a member of NAR or Tripoli? If not, arrange for a NAR or Tripoli member to supervise them.

Is the flyer who is younger than 18 a member of the Tripoli Mentoring Program (TMP) (ask for the membership card)? A member of the TMP may fly high power rockets (up to I) accompanied by a certified Senior Member. Otherwise, the flyer may enter the Model Rocket Area but may not leave the Model Rocket Area, other than to return across the flight line, even to recover a rocket. Model rockets that land in the High-Power Rocket Area must be recovered by an adult Tripoli or NAR member.

Is the flier certified to the impulse level being flown?

Rocket

Is the rocket stable? Find the CG (center of gravity) of the flight ready rocket (motors installed; recovery system packed) by finding the rocket balance point. Where is the CG relative to the leading edge of the fins? On a single staged rocket with only a rear set of fins the CG should typically be forward of the forward root edge of the fins. Canards, wings, forward swept fins, and strakes will require the CG to be further forward. Multi- staged rockets must be evaluated for each stage. Ask the flier to show the CP (center of pressure) location on the rocket (and less each stage for a staged rocket). Request to see the calculations if in doubt. The CG must be a least one body tube diameter forward of the CP in each flight phase. Hybrid powered rockets must be examined carefully for stability. Unlike most solid fueled rockets, the CG of a hybrid rocket may actually move aft during flight. The rearward CG shift may destabilize the rocket. To be conservative, determine the CG of a hybrid rocket with the solid fuel component in place but without the oxidizer loaded.

Examine all "slip-fits", e.g. nosecone or payload shoulder, which are intended to separate in flight. Turn the rocket nose down. It is unacceptable if the nosecone (or payload) can separate under their own weight. Check that the nosecone, if used as part of a payload section, is firmly installed (e.g. screws). The object is to prevent loss of the nosecone and the payload contents in flight.

Examine the launch lugs or rail buttons/guides. Are they firmly attached to the rocket without evidence of cracking in the joints? Are the guides adequately sized for the rocket? If using lugs, check the lugs for paint buildup or burrs inside the lug(s). Paint or burrs may cause binding on the launch rod.

Examine the fins. Are the fins mounted parallel to the roll axis of the rocket? Attempt to wiggle the fins at their tips. There should be no movement and minimal deflection. If the fins deflect is the fin material appropriate for the rocket? Laminated or built-up fins should be checked for delaminations. Examine the fin roots for cracks; minor "hairline" cracks may be acceptable if the fins are not loose or if the fins are mounted using "through the wall" construction. Check the fins for warpage; there should be little, if any, warpage.

Can the motor "fly through" the rocket? Push on the nozzle end of the motor. The motor should not move forward in its mount nor should the mount move within the rocket. Try to determine the type and quantity of adhesive used in construction. Any evidence of "hot melt" adhesives should make the rocket suspect. Motor mounts should typically be mounted with epoxy adhesives with a sufficient quantity to form fillets at the centering ring to body tube joints.

Motor and Retention

Is the motor certified?

If the motor is a research motor, is the flyer a Tripoli member certified at Level 2 or 3?

Is the motor a sugar motor? Ask what case was used (PVC is prohibited). If in doubt, ask to see the motor.

Ask the flyer if they have flown this particular rocket and motor combination. If they have, ask for the results of that flight. If not, ask if they have flown a similar rocket/motor combination and the outcome. Use the results of this line of questioning to determine into how much detail the remainder of the FSR will go. IMPORTANT: By no means does a response of “I’ve flown it just like this perfectly before” exempt the flyer from the remainder of the FSR.

Is the motor appropriate for the rocket?

Does it provide enough initial thrust to get the rocket going fast enough to be stable as it leaves the launcher? A good Rule of Thumb is 3:1 thrust to weight ratio. Take into account ground wind speed (i.e. needs higher ratio if windy).

Is the motor too large for the launch equipment (e.g. high thrust motor on ¼” rod) or the FAA CAO?

Examine the motor installation. Verify, if possible, that the motor is what the flight card indicates. If in doubt, ask that the motor be removed from the rocket. Pull on the motor to make sure it is firmly restrained in the rocket. If the motor is friction fitted then it should not move when strongly pulled. A positive means of motor retention, e.g. motor clip, bolted washers, is preferred. Verify that the motor cannot deflect the retention device and then eject. A wrap of tape around motor clip(s) to restrain them against the motor is suggested.

Recovery

Ask the flier if they are using the motor ejection charge. If they are, verify that they installed the black powder. Some motors rely on a tape disk to retain the powder in its cavity. It is suggested that the flier backup the paper disk with masking tape around the edge to prevent it from coming free.

If the rocket appears neglected or of marginal construction or the builder does not display good knowledge of rocket practices, ask to inspect the recovery system. Pull on the shock cord several times. The shock cord must not be cracked, cut, frayed, or burnt. Discoloration from ejection operation is typically not a problem. Make sure that the shock cord is securely mounted in the rocket. Make sure any knots in the recovery system will not loosen or slip. Recovery system hardware, including screw eyes and swivels, needs to be strong enough for recovery loads, mounted to solid structure as necessary, and all fasteners are tight. Inspect “quick links” to verify that they are not likely to pull apart under recover loads. Is parachute protection from the ejection charge adequate and nonflammable? Verify that the parachute is undamaged including no loose suspension lines and no tears or burns which may spread during recovery. Is non- flammable, bio-degradable (no fiberglass) wadding being used?

Does the booster section have a vent hole? Typically, a 1/8 to 3/16 inch hole is drilled in the booster section just behind the nosecone or payload shoulder area. This hole is intended to vent the rocket internal pressure to the outside. It is recommended practice on high performance (high altitude) rockets because it prevents the internal pressure from prematurely separating the nosecone or payload section.

Electronic Recovery

Ask if electronics are used in the rocket (e.g. for parachute deployment, staging). If the flier is inexperienced with Electronics, examine the electronics for items that may dislodge (e.g. ejection canister matches) or break during flight. Are heavy items, e.g. batteries, adequately supported to prevent coming loose from "g" loads. How did the flier verify the functionality of his electronics? When was the last time the electronics were checked? Are the batteries fresh? How has the flier verified its operation?

Does the flier expose himself to accidental discharge during arming/disarming the electronics?

Do the electronics indicate whether or not they are armed?

Does the flier have a checklist or reminder to arm the system prior to flight and disarm the system upon landing?

Make sure that the rocket does not use mercury switches or roller switches to initiate motor ignition.

Clusters

Make sure that the flier has not pre-inserted any of the HPR motor igniters. That needs to be done at the launch pad.

Look for any open holes between the motor mounting tubes. Are the holes sealed to prevent ejection charge gases from venting out?

If black powder and composite motors are mixed in a cluster are the composite motors the first to be ignited? Composite motors are harder to ignite than black powder.

If the flier expects to ignite a mixed combination of APCP motors, recognize that the larger motors take longer to come up to pressure. Does the rocket have sufficient power to safely fly with only the smaller motors operating?

Are the motors configured in such a way as to behave dangerously if one or more do not light (i.e. off-axis thrust)? If, for example, the cluster consists of two motors, inform the flier that the rocket needs to be on the pad so that the motors are aligned parallel to the flight line so that if only one motor lights, the rocket will not arc towards the flight line.

Ask the flier if the motor igniters for the cluster wired will be wired in parallel (not in series)? Check for shorts which may prevent igniter function.

Are the igniters "matched"? Igniters having different current requirements may not light at the same time. Igniters that light quickly may ignite their rocket motors prior to ignition of other motors.

Does the launcher ignition system have enough power to ignite all of the igniters that need to be lit on the pad?

If some of the motors are to be air started, make sure that the primary motor(s) are sufficient to safely power the rocket off the launch pad. Make sure that the electronics to initiate the air-start motors will only be armed once the rocket is on launch position. Make sure that the same electronics can and will be disarmed if the rocket needs to be removed or lowered from the launch pad.

Staging

Make sure that none of the HPR motor ignitors are installed until the rocket is at the launch pad.

Make sure that the rocket will be stable during its entire flight profile: Ask the flier to show the CP of the fully assembled rocket (i.e. all stages assembled). Ask the flier to show the CP of the rocket after each staging event.

Make sure the booster motor(s) have sufficient power to get the rocket stable.

Make sure that the electronics to control the staging motor ignition will only be armed once the rocket is on launch position. Make sure that the same electronics can and will be disarmed if the rocket needs to be removed or lower off the launch pad.

Ask the flier about the delay(s) that are used between staging events. Make sure that the delay is not so long as to happen if the rocket has arced over into an unsafe orientation. Ask to see flight simulation if there is a concern.

Ask the flier if the stages are expected to “drag separate” or is there a separation charge to initiate separation prior to sustainer ignition. Depending on the location of the staging electronics (sustainer vs. inter-stage coupler), premature separation could prevent sustainer motor ignition.

If the sustainer motor is used to initiate stage separation, check to make sure that the blast from the sustainer motor will not damage the booster’s ability to safety recover.

The upper stage(s) of HPR rockets must be using electronic recovery, and not rely on motor ejection.

If required, make sure that the staging electronics have a feature to inhibit staging events if the rockets flight profile does not follow expected behavior.