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									                             New South Wales
                            Rocketry Association

               Formal Certification Procedure

                  prepared by Mike Limpus and Tom Matley for the NSWRA Feb99




NSWRA formal certification procedure Feb 99                           Page1
Contents
CONTENTS ...................................................................................................................................................................... 2

GENERAL......................................................................................................................................................................... 3

MINIMUM REQUIREMENTS ...................................................................................................................................... 3

CERTIFICATION PROCESS AND DOCUMENTATION ......................................................................................... 3
   LEVEL 1 CERTIFICATION (H, 160.01-320.00 N-SEC) ........................................................................................................ 4
   LEVEL 1A CERTIFICATION (I, 320.01-640.00 N-SEC) ....................................................................................................... 4
   LEVEL 2 CERTIFICATION (J/K, 640.01-2560.00 N-SEC).................................................................................................... 5
   LEVEL 3 CERTIFICATION (L-O, 2560.01-40960.00 N-SEC)............................................................................................... 5
ADMINISTRATIVE ITEMS ........................................................................................................................................... 6

APPENDIX A - NSWRA HIGH POWER CERTIFICATION APPLICATION ........................................................ 7

APPENDIX B - HIGH POWER CERTIFICATION TEST.......................................................................................... 9
   ANSWERS ................................................................................................................................................................... 15
APPENDIX C - LEVEL 3 CERTIFICATION OFFICIAL PRE-FLIGHT CHECKLIST ...................................... 18
   1. GENERAL ................................................................................................................................................................ 18
   2. ROCKET REVIEW .................................................................................................................................................. 18




NSWRA formal certification procedure Feb 99                                                                                             Page2
General
The following NSWRA certification program will be in effect starting Feb 9, 1999.

HPR levels are:

 Level         Pre-requisites                  Flight Test              Priviledge
 1(H)           Attendance              Fly a H powered rocket        Buy and fly H
              HPR theory class           successfully 160.01-        motors 160.01-
                                                  320NS                  320NS
 1a(I)                 “                Fly a I powered rocket     Buy and fly I motors
                                         successfully 320.01-        320.01-640NS
                                                  640NS
2(J/K)              Pass                  Fly a J or K powered      Buy and fly J or K
            HPR certification test         rocket successfully       motors 640.01-
                                            640.01-2560NS                 2560NS
 3(L)                  “                Fly a L powered rocket        Buy and fly H
                                         successfully 2560.01-      motors 2560.01-
                                                40960NS                  40960NS
C,S,H        Cluster, staged or        Fly successfully relevant   Fly rockets relevant
(Complex)   hybrid endorsements                   Rocket             to endorsement
                 as required

Certification is performed by two NSWRA members (known as Certification officials), namely,
prefect1 (as defined below) and a member certified to at least the same level as the
certification level2 attempted.
A checklist is included with the certification documentation to standardise the physical
examination of the certification model.
A written examination is part of the J/K & L certification process. The test consists of 50
multiple choice questions; the passing grade is 95%. The questions will be basic "rocket
science" questions such as CP and CG relationships, motor designations, and the High power
safety code.
For L certification the flyer must submit a detailed submission for approval 1 month prior to
desired launch date

1
  Prefect: a person who has appropriate workcover licensing a minimum of twenty HPR flights
and preferably certification from one of the following organisations Tripoli, NAR, CAR
2
  If no member is currently certified at any given level another member may be nominated by
the prefect to validate certification.



Minimum Requirements
1. The individual seeking high power certification must be a minimum of 18 years old at the
   time of certification. A driver's license or birth certificate are acceptable proofs of age.
2. The individual must be a member in good standing with the New South Wales Rocketry
   Association (NSWRA) at the time of certification. Evidence of NSWRA membership will be
   requested prior to the certification attempt. Acceptable evidence of membership is the
   NSWRA membership card
3. Motors used for certification attempts must be currently certified either by the NSWRA or
   another testing organisation (e.g., Tripoli) with a recognised certification program.

Certification Process and Documentation
1. Certification may be accomplished at any launch where sufficient individuals meeting the
   requirements mentioned above are available.
2. CASA regulations requiring notification or waivers must be complied with.



NSWRA formal certification procedure Feb 99                                   Page3
3. The individual attempting certification must complete a NSWRA High Power Certification
   Application prior to their certification attempt. This sheet includes the individual's name,
   NSWRA number, and relevant model data.
4. If certification to a level other than H is desired, the individual must provide proof of
   previous certification(s). Proof of previous certification includes the high power certification
   card or a NSWRA membership card showing the current certification level.
5. The model will be subjected to a safety inspection prior to flight. The safety inspection form
   is on the back of the NSWRA High Power Certification Application.
6. During the safety inspection the modeller will be expected to answer oral technical questions
   related to the safety and construction of their model. The questions may include (but not
   limited to) identification of the model's center of gravity and center of pressure, methods
   used to determine model stability, and interpretation of the rocket motor's designation. The
   certification officials will initial (or check) the blocks indicating that model safety, motor
   certification, and the existence of a CASA waiver (if required) in effect were verified prior to
   flight.
7. The individual will fly their model.
8. The flight must be witnessed by the certification officials.
9. Stability, deployment of the recovery system, and safe recovery should be considered when
   evaluating safety of the flight.
10.Models experiencing a catastrophic failure of either the airframe, rocket motor and/or
   recovery system (e.g. shock cord separation) will not be considered as having a safe flight.
11.The model must be returned to the certification officials after flight. and be inspected to
   verify engine retention and for evidence of flight-induced damage.
12.The certification team will initial the blocks indicating that a safe flight was made and that
   the post-flight inspection was satisfactory.
13.The certification team will sign the certification sheet to indicate that the certification
   attempt was successfully completed.
14.Both the certification sheet and the certification card must be signed. The certification card
   and the certification sheet are normally returned to the certifying individual after the flight.
   At club launches or NSWRA sponsored activities the certification sheets may be retained by
   the event sponsors to be sent to NSWRA Headquarters as a group. In that event, only the
   certification card is returned to the certifying individual.
15.The certification sheet(s) is (are) returned to NSWRA Headquarters by the certified
   individual or the event sponsors.
16.No fees are required.
17.A new NSWRA membership card will not be issued showing the certification level until the
   normal member renewal cycle.
18.The certification card is valid until the end the NSWRA member's membership.
19.The card is recognised as proof of the certification level.
20.Falsification of data or statements by the certifying individual will result in revocation of the
   high power certification. Falsification of data or statements by the certification officials, can
   result in revocation of the team members' NSWRA memberships.


Level 1 certification (H, 160.01-320.00 N-sec)

 The modeller must demonstrate their ability to build and fly a rocket containing a H impulse
  class motor.
 Cluster or staged models used for certification may not contain over 320.00 Newton seconds
  total impulse and are subject to the flyer having the relevant endorsement.
 Single use or reloadable technology motors are permitted (no hybrids).
 The modeller must assemble the reloadable motor, if used, in the presence of a certification
  official.
 No written examination is required but flyer must have attended HPR Theory Class within 3
  months of certification flight.
 Certification at this level permits single motor (multiple with endorsement) rocket flights
  with motors having a maximum total impulse of 320.00 Newton seconds.


Level 1a certification (I, 320.01-640.00 N-sec)


NSWRA formal certification procedure Feb 99                                 Page4
 The modeller must demonstrate their ability to build and fly a rocket containing a H impulse
  class motor.
 Cluster or staged models used for certification may not contain over 640.00 Newton seconds
  total impulse and are subject to the flyer having the relevant endorsement.
 Single use or reloadable technology motors are permitted (no hybrids).
 The modeller must assemble the reloadable motor, if used, in the presence of a certification
  official.
 No written examination is required but flyer must have attended HPR Theory Class within 3
  months of certification flight.
 Certification at this level permits single motor (multiple with endorsement) rocket flights
  with motors having a maximum total impulse of 640.00 Newton seconds.


Level 2 certification (J/K, 640.01-2560.00 N-sec)

 The modeller must demonstrate their ability to build and fly a rocket containing a J or K
  impulse class motor.
 Cluster or staged models used for certification may not contain over 2560.00 Newton
  seconds total impulse and are subject to the flyer having the relevant endorsement.
 Single use, reloadable or hybrid technology motors are permitted.
 The modeller must assemble the reloadable or hybrid motor, if used, in the presence of a
  certification official.
 A written examination is required. The test consists of 50 multiple choice questions; the
  passing grade is 95%. The questions will be basic "rocket science" questions such as CP and
  CG relationships, motor designations, and the High power safety code.
 The test may be taken only once in a 30-day period.
 The test must be completed prior to the flight attempt.
 The flight attempt should be made as soon as reasonably and safely possible after
  successful test completion (the target is less than 1 week).
 Certification at this level permits single motor (multiple or Hybrid with endorsement) rocket
  flights with motors having a maximum total impulse of 2560 Newton seconds.

Level 3 certification (L-O, 2560.01-40960.00 N-sec)
 The flyer must submit a detailed submission to certification officials approval 1 month prior
  to desired launch date including:
       Drawings of the rocket showing airframe components, fins, bulkheads, longerons,
         adhesive joints, recovery system components, payloads, etc.
       A parts listing that includes material descriptions, adhesive types, screw sizes gauges,
         thickness’, etc.
       Schematics of recovery system electronics that show batteries, circuit designs, wiring
         diagrams, etc.
       Pre-flight checklist describing field assembly of the rocket, motor installation, recovery
         system preparation, launcher installation, system arming, etc.
  A pre-flight review checklist used by certification officials is contained in Appendix C
 Single engine, cluster, staged or hybrid models used for certification may not contain over
  10240.00 Newton seconds total impulse and are subject to the flyer having the relevant
  endorsement.
 Single use, reloadable or hybrid technology motors are permitted.
 The modeller must assemble the reloadable or hybrid motor, if used, in the presence of a
  certification official.
 Proof of successful completion of HPR certification test is required. A level J/K certificate or
  membership card is acceptable.
 Certification at this level permits single motor (multiple or Hybrid with endorsement) rocket
  flights with motors having a maximum total impulse of 40960 Newton seconds.




NSWRA formal certification procedure Feb 99                                Page5
Administrative items
 NSWRA members who are certified by other recognised rocketry bodies (eg Tripoli ) may
  apply for equivalent NSWRA certification by completing NSWRA High Power Certification
  Application and attaching proof of other certification.
 Tripoli, NAR & CAR certifications will be honoured at NSWRA launches. A current
  confirmation card is required as evidence of Tripoli high power certification at launches.
 A one year lapse of membership of NSWRA voids certification at any and all levels




NSWRA formal certification procedure Feb 99                              Page6
Appendix A - NSWRA High Power Certification Application
Applicant and motor Information (applicant to complete)
Date of application: _____/_____/_____
          Full Name:     ______________________________________________
           Birth date     _____/_____/_____
        Full Address:    __________________________________________________________
                         ________________________________________________________
Contact Ph Number         ________________

NSWRA Membership Number: ___________ expiry: _____/_____/_____ Level:____

Other certifications (if requesting equivalent cert from other organisation):
_________________________________________________________

Certification requested (tick one box only):
Level 1                Level 1a     Level 2       Level 3
                   Clustering Staging      Hybrid
Motor(s) used this for attempt_____________________
Motor Manufacturer______________________

I, _________________________________, certify that the above information is accurate. I
further certify that I am a member in good standing of the New South Wales Rocketry
Association, and that I am over the age of 18.

Signed:_______________________ date _____/_____/_____

Certification checklist (officials use only)
          Pre-flight                       Flight                                    Post-flight
Attended HPR Theory class Stable/safe flight                         Vehicle intact and no major
Passed HPR Test (Level 2+) Recovery system deployed                     damage evident.

CASA waiver available (if req) Safe recovery                         Motor(s) retained in airframe
Safety checklist complete (att)
Motor is certified
current NSWRA member
Certification Successful?
YES           NO - Reason:__________________________________________________
                   ______________________________________________________________
                   ____________________________________________________________

Certification Affidavit
We the undersigned being senior members of the New South Wales Rocketry Association
distinct from the applicant, have witnessed a demonstration by ________________________
NSWRA# __________ of skills relative to the building and safe operation of High Power
Rockets to the attempted level. Pursuant to this the NSWRA hereby certifies the applicant to
the following level:
Level 1                   Level 1a               Level 2                      Level 3
H, 160.01-320.00 NS         I, 320.01-640.00 NS     J/K, 640.01-2560.00 NS         L-O, 2560.01-40960.00 NS
                   Clustering               Staging         Hybrid
Name                                              NSWRA#        Level              Signature
_________________________________                 ________      ____               ________________
_________________________________                 ________      ____               ________________
                                                                        Cut along dotted line and retain as proof of
                                                                        certification
NSWRA formal certification procedure Feb 99                                        Page7
HPR Certification Application - checklist
Requirement                                                                                        A3   CO4
Is the nosecone or payload shoulder sufficiently tight to prevent premature separation? The
nosecone or payload should not wobble side to side. Is a vent hole required to relieve
pressure at high altitude? Is the body tube used sufficient to withstand anticipated flight
stress? Are screws and fasteners tight if used?
Are the launch lugs (if used) securely fastened and of an appropriate size for the model? Are
they aligned to prevent any binding?. Verify no cracking of adhesive joints. (taped on lugs
are not permitted)
On Cluster models are the spaces between motor tubes (or any unused motor tubes) filled
to prevent ejection pressure leakage? If mixing different size motors does ignition method
ensure safe lift off? (smaller motors are quicker to come up to pressure)
Is the motor selection sufficient to safely fly the model? (Use motor manufacturers
recommendations as a starting point, also consider model weight, design, and finish). Are all
motors NSWRA certified? Is ignitor selection and wiring appropriate for motor(s) used?
Do all motors have positive retention? Is the motor mount (MMT) assembly sufficient to
transfer thrust to airframe. Are adhesives used in MMT appropriate? (modeller to advise of
materials used)
If electronics are used, are all parts secured against expected g forces? Does the design
protect against inadvertent operation? (eg external arm/disarm switches and/or status
indicators). Does the modeller have a checklist or reminder (eg “remove before flight” tags)
to arm electronics prior to flight?
If R/C is used are appropriate frequencies used? Is antenna secure? Has system been
range tested?
Fins securely fastened and parallel to the rocket? Any warps present which may cause
erratic flight? Fin materials and adhesives used appropriate for the anticipated flight stresses
(modeller to advise of materials used)
Is the model stable? If stability is in doubt require modeller to show CP & CG locations and
method used to determine them (rule of thumb: CG should be 1 body diam in front of CG)
Verify that flight motors are used for CG determination and that if staged each stage is
stable in it’s own right.
Verify that model will not exceed CASA waiver. Modeller to inform of expected performance
parameters and method used to determine them. (eg similar models, tables or computer
simulation)
Inspect the recovery system. Verify that Parachute, shock cord and any hardware (swivels
etc.) are in good condition and sufficient to withstand expected deployment forces. Is the
shock cord securely attached to the airframe? Are any objects in the airframe likely to
impede deployment? Is parachute protection from ejection gasses sufficient?

3
     Applicant check off as appropriate
4
     Certification Official to check off as appropriate




NSWRA copy
Certification Affidavit
We the undersigned being senior members of the New South Wales Rocketry Association
distinct from the applicant, have witnessed a demonstration by ________________________
NSWRA# __________ of skills relative to the building and safe operation of High Power
Rockets to the attempted level. Pursuant to this the NSWRA hereby certifies the applicant to
the following level:
Level 1                      Level 1a                    Level 2                  Level 3
H, 160.01-320.00 NS            I, 320.01-640.00 NS          J/K, 640.01-2560.00 NS     L-O, 2560.01-40960.00 NS

Name                                                      NSWRA#        Level          Signature
_________________________________                         ________      ____           ________________
_________________________________                         ________      ____           ________________




NSWRA formal certification procedure Feb 99                                            Page8
Appendix B - High Power Certification Test
1) Which of Newton's Laws best describes the behaviour of a rocket motor?
                Newton's First Law: Every body continues in its state of rest or of uniform motion in a
                   straight line unless it is compelled to change that state by forces impressed upon it.
                Newton's Second Law: The rate of change of momentum is proportional to the force
                   impressed and is in the same direction as that force.
                Newton's Third Law: To every action there is always an equal and opposite reaction.
2) How does Newton's Third Law "To every action there is always an equal and opposite reaction" relate
to rocketry?
                That the blast deflector must be strong enough to push the rocket off the launch pad
                   at ignition.
                That a rocket flies because the rocket motor "pushes" the rocket in a direction
                   opposite of the exhaust jet.
                That the thrust of a rocket motor is proportional to the air density at the launch site.
3) What are the three forces acting upon a rocket during the course of its flight?
                Thrust, rocket diameter and finish.
                Nose cone shape, thrust and drag.
                Gravity, thrust and aerodynamic drag.
4) What are the major factors that determine the maximum altitude of a high power rocket in vertical
flight?
                Lift-off weight, propellant weight and motor thrust.
                Fin size, propellant weight and motor thrust.
                Motor thrust, weight and aerodynamic drag.
5) For an inherently stable rocket, what is the relationship of center of gravity (CG) to the center of
pressure (CP)?
                The CG must be behind the CP relative to the desired direction of flight.
                The CG must be forward of the CP relative to the desired direction of flight.
                The CG must be in front of the fins of a rocket.
6) A 4" diameter rocket with its motor is determined to have the center of gravity (CG) four inches
behind the center of pressure (CP). Is this a stable rocket?
                There is insufficient information to answer this question.
                No, the CP must be behind the CG for the rocket to be stable.
                Yes, the CP is one body diameter in front of the CG.
7) The center of pressure (CP) of a rocket is generally defined as:
                The balance point of the rocket without the motor.
                The total area of the fins, airframe and nose cone divided by two.
                The point at which aerodynamic lift on a rocket is centered.
8) What is the "rule-of-thumb" for a stable rocket?
                That the center of gravity is one body diameter in front of the center of pressure.
                That the center of gravity is at the same point as the center of pressure.
                There is no rule-of-thumb because there are too many variables.

NSWRA formal certification procedure Feb 99                                          Page9
9) When determining the center of gravity (CG) of a rocket with a heavier motor at the launch site, one
can:
                Install the motor, recovery system and payload and determine the balance point of
                   the rocket as it is ready for flight.
                Balance the rocket with an empty motor because that is the condition of the rocket
                   after motor burnout.
                It is not necessary to test for the center of gravity when using a more powerful motor
                   because it has more thrust.

10) What happens to the center of gravity (CG) of a rocket during a solid rocket motor's thrusting phase?
                The Center of gravity stays the same.
                The Center of gravity shifts forward.
                The center of gravity shifts aft.
11) How can a statically unstable rocket be made stable?
                Using a heavier motor.
                Adding weight to the nose.
                Making the rocket shorter.
12) What are three methods used to shift the center of gravity (CG) of a rocket forward?
                Add weight to the nose, make the rocket longer, install larger fins.
                Add weight to the nose, make the rocket longer, use a smaller (or lighter) motor.
                Add weight to the nose, make the rocket shorter, use a smaller (or lighter) motor.
13) What are three methods used to shift the center of pressure (CP) aft?
                Make the rocket shorter, use larger fins, increase the number of fins.
                Make the rocket shorter, use smaller fins, add weight to the nose.
                Make the rocket shorter n change the number of fins, use a longer launch rod,
14) What is the definition of coefficient of drag (Cd)?
                A dimensionless number that represents the effect of gravity and Mach number of the
                   rocket.
                A dimensionless number representing the rocket configuration, Mach number and
                   angle of attack.
                A dimensionless number that represents the friction of the launcher and launch
                   velocity.

15) What happens to the coefficient of drag (Cd) as the rocket approaches the speed of sound?
                The Cd decreases.
                The Cd stays the same.
                The Cd increases.
16) For a subsonic rocket, what major factors affect the coefficient of drag (Cd)?
                Motor thrust, body diameter, nosecone shape and fin shape.
                Speed, airframe dimensions, nosecone shape and fin shape.
                Gravity, airframe dimensions, nosecone shape and fin shape.




NSWRA formal certification procedure Feb 99                                          Page10
17) What effect does a boat tail have on a subsonic rocket's coefficient of drag (Cd)?
                No effect, a boat tail is only a cosmetic design feature.
                It increases the Cd by changing the airflow over the fins.
                It decreases the Cd by reducing the base drag.
18)The flight of a high power rocket can be separated into three portions; they are:
                Ignition, burnout and peak altitude.
                Powered flight, un-powered ascent and peak altitude.
                Powered flight, un-powered ascent and descent.
19) What is the thrust curve of a regressive motor burn?
                A regressive burn has a high initial thrust relative to the ending thrust of the motor.
                A regressive burn has a lower initial thrust relative to the ending thrust.
                The thrust curve is flat.
20) What is the thrust curve of a progressive motor?
                A progressive burn has a high initial thrust relative to the ending thrust of the motor.
                A progressive burn has a lower initial thrust relative to the ending thrust.
                The thrust curve is flat.
21) Why does a Bates grain have an essentially neutral thrust curve?
                Because core burning motors always have a regressive burn.
                Because the burn area of the motor remains relatively constant.
                Because the core in the motor grain has a uniform burn area over time.
22) What is the primary function of a motor liner and the O-ring seals in a solid rocket motor?
                To hold all of the parts in place prior to ignition of the rocket motor.
                To make the motor easier to clean if it is a reloadable motor.
                To keep the hot gasses of the motor from burning or melting the motor Case.
23) What is the most common oxidizer in commercially available high power composite solid rocket
motors?
                Ammonium Perchlorate.
                Ammonium Nitrate.
                Ammonium Chlorate.
24) What is NH4ClO4?
                Ammonium Perchlorate.
                Ammonium Nitrate.
                Ammonium Chlorate.
25) A small hole is typically recommended near the top, but below the nosecone or payload section, of a
high power rocket's booster section. Why?
                This hole allows excessive ejection charge pressures to vent to reduce shock cord
                   stress.
                The hole is used to give air pressure readings for on-board altimeters.
                The hole vents internal air pressure as the rocket gains altitude to prevent premature
                   separation.

26) What happens when changing to smaller or fewer injector orifices in an ideal hybrid rocket motor
(assume the oxidizer weight stays the same)?


NSWRA formal certification procedure Feb 99                                       Page11
                The total impulse decreases and the average thrust increases.
                The total impulse stays the same and the average thrust increases.
                The total impulse stays the same and the average thrust decreases.
27) What happens when changing to more or larger injector orifices in an ideal hybrid rocket motor
(assume the oxidizer weight stays the same)?
                The total impulse decreases and the average thrust increases.
                The total impulse stays the same and the average thrust increases.
                The total impulse stays the same and the average thrust decreases.
28) What is the oxidizer most commonly used in a commercial hybrid rocket motor?
                N2O
                N2O4
                NO2
29) What is the nominal tank pressure of a nitrous oxide hybrid motor at 25°c?
                100 psi
                750 psi
                1500 psi
30) Above what temperature does pressurised nitrous oxide change to a gas? (ie critical temperature)
                40°c
                25°c
                36°c
31) A rocket with a motor cluster consisting of a central composite motor and four black powder motors
using thermalite igniters or electric matches:
                will result in all motors starting about the same time.
                will result in the composite motor starting first followed by the black powder motors.
                will result in the black powder motors starting first followed by the central composite
                   motor.

32) What typically happens to a marginally stable rocket with a long hybrid motor during the thrusting
phase?
                Nothing.
                The rocket may become more stable.
                The rocket may become less stable.
33) In general terms, the specific impulse of a rocket motor is:
                The total thrust force of a motor throughout its action time.
                The total impulse divided by unit weight of propellant.
                Dependent on the diameter and length of the propellant grain.
34) In general terms, the total impulse of a rocket motor can be described as:
                The product of the average motor thrust and its burn time.
                The product of the propellant weight and its burn time.
                The product of the propellant weight and the motor thrust.
35) The average thrust of a rocket motor is 100 Newtons and the burn time is 4 seconds, what is the
total impulse?



NSWRA formal certification procedure Feb 99                                      Page12
                25 Newton-seconds
                400 Newton-seconds
                400 newtons
36) Which motor has a higher total impulse?
                J200
                J400
                K200
37) Which motor has a higher average thrust?
                J200
                J400
                K200
38) What is the difference between a J640 and a J320 high power rocket motor (assume full 1280
Newton-second J motors)?
                The J320 burns out twice as fast as the J640.
                There is no difference between the motors, the numbers are manufacturer reference
                   only.
                The J640 burns out twice as fast as the J320.
39) Which of the following has a total impulse in the J motor range?
                It = 600 Newton-seconds
                It = 1000 Newton-seconds
                It = 1290 Newton-seconds
40) What is a Newton?
                The amount of force required to accelerate one pound one foot per second per second.
                The amount of force required to accelerate one kg, one foot per second per second.
                The amount of force required to accelerate one kg, one meter per second per second.
41) What does the motor designation I220-8 mean?
                The motor is in the I impulse range with an average thrust of 220 Newtons and an 8
                   second delay from motor ignition.
                The motor is in the I impulse range, having a total impulse of 620 Newton-seconds
                   with an average thrust of 220 Newtons and an 8 second delay from motor burn-out.
                The motor is in the I impulse range with an average thrust of 220 Newtons and an 8
                   second ejection delay from motor burn-out.

42) What is the difference in kinetic energy between two identical rockets, one descending at 30 feet per
second, the other descending at 60 feet per second?
                Cannot be determined without the weight.
                Two times as much energy.
                Four times as much energy.




NSWRA formal certification procedure Feb 99                                      Page13
43) The equation for determining the energy of a moving body (such as a rocket) is:
                E = 1/2 mv2
                E = ma2
                E = mv3
44) What is the purpose of a launch rod, rail or tower?
                To keep the rocket pointing in the right direction prior to flight.
                To control the rocket's flight long enough to allow aerodynamic stability.
                Both a and b.
45) What is the purpose of a launch lug?
                To add drag to the rocket at launch.
                To guide the rocket along the launch rod or rail.
                Both a and b.
46) A rocket with a motor cluster consisting of a central composite 54mm J415 motor and four 29mm
G80 composite motors using thermalite igniters or electric matches:
                will result in all motors starting about the same time.
                will result in the J415 motor starting first followed by the G80's.
                will result in the G80's starting first followed by the J415.
47) What can happen if all the motors of a cluster do not ignite at launch?
                Nothing, the rocket is inherently stable.
                The rocket may not fly straight.
                The rocket will shred.
48) What is a shred?
                A failure of the rocket air frame during boost resulting in destruction of the rocket.
                A failure of the recovery system during boost.
                A failure of the motor causing early ejection.
49) What is a cato?
                A failure of the rocket resulting in failure of the air frame during boost.
                A failure of the recovery system during boost.
                A failure of the motor causing flight termination.
50) What is the primary requirement for a rocket motor ignitor?
                It must transfer sufficient heat to the propellant to assure ignition.
                It must produce hot, high velocity gasses to assure ignition.
                It must have a high resistance to be reliable.




NSWRA formal certification procedure Feb 99                                       Page14
ANSWERS
1) c. Newton's Third Law. Applying a force in one direction always results in an equal force in
the opposite direction.
2) b. The rocket motor's thrust causes the rocket to accelerate in the direction opposite the
motor's thrust. Thus a rocket motor pushes only on the rocket, not on the air or launch pad.
3) c. Gravity, thrust and drag are the forces acting on a rocket.
4) c. The motor thrust, weight and aerodynamic drag are the primary forces considered when
determining the altitude of a rocket. Please note that the weight of the rocket must consider
the lift-off weight and the weight at burn-out to be complete.
5) b. The center of pressure (CP) is where the aerodynamic lift, due to the rocket being at a
   non-zero angle of attack, is centered. For an aerodynamically stable rocket with the CP
   behind the center of gravity (CG)n the lift which is centered aft of the CG will create a
   corrective moment to return the rocket to zero degrees angle of attack. Conversely, if the CP
   is ahead of the CG the lift will attempt to turn the rocket around so that the CP will again be
   behind the CG. This resultant "tumbling" is characteristic of an unstable rocket.
6) b. The rocket is not stable because if the rocket rotated around its center of gravity (CG),
   the greater aerodynamic force forward of the CG would cause the rocket to rotate even
   farther, resulting in an unstable flight.
7) c. The center of pressure (CP) is the point on the rocket where the aerodynamic lift is
   centered, This means that aerodynamic lift, if the rocket is at a non-zero angle of attack,
   forward of this point is balanced by the aerodynamic lift aft of that point.
8) a. Keeping the center of gravity (CG) one body diameter in front of the center of pressure
   (CP) typically allows an adequate margin for rocket stability.
9) a. Measuring the center of gravity (CG) by balancing the rocket requires that the rocket be
   prepared as though ready for flight. It is especially important to check when using a heavier
   motor than previously flown.
10) b. As the propellant burns the motor gets lighter and thus moves the balance point or
  center of gravity (CG) forward, This is why a marginally stable rocket will "act squirrelly" at
  launch, then stabilise and fly straight.
11) b. Adding enough weight to the nose will shift the center of gravity (CG) forward of the
  center of pressure (CP).
12) b. Moving the CG forward requires judicious design changes. The following are given as
  "rules-of-thumb," n Adding weight to the nose moves the CG forward by counterbalancing
  the rocket. Think of the rocket as a lever' making the rocket longer shifts the CG forward by
  making the lever longer. Using a smaller (or lighter) motor reduces the weight aft thus
  shifting the CG forward.
13) a. Moving the CP aft requires judicious design changes. The following are given as "rules-
  of-thumb." increasing the total fin area will move the CP aft. This can be accomplished by
  increasing the area on each fin and/or increasing the number of fins. The CP can also be
  shifted aft by making the rocket shorter. This alone is generally not preferred because the
  CG is also shifted aft and CP/CG stability relationship may be compromised.
14) b. The coefficient of drag (Cd) is a number that is used in equations for calculating the
  aerodynamic performance of a rocket. Values that make up the Cd are the rocket
  configuration (nose cone shape, airframe diameter(s), transition sections, fin size and
  sharpen etc.), the rocket velocity as Mach number and the angle of attack.
15) c. The coefficient of drag (Cd) increases and can be greater than 1 as the rocket exceeds
  Mach 1.
16) b. As speed increases, the drag number changes. The length and diameter of the rocket
  factors into the total surface area, The nose cone shape effects the airflow over the front of
  the nose cone. The fin shape and fin area factor into the total surface area.
17) c. A boat tail reduces the drag for a subsonic rocket by reducing the base drag resulting
  from the discontinuity of the air flow as it leaves the end of the rocket.


NSWRA formal certification procedure Feb 99                                Page15
18) c. The three phases of flight of a high power rocket:
  (1) Powered flight - the period of time when the rocket motor is producing thrust against
  gravity and drag.
  (2) Un-powered ascent - the period after powered flight where the rockets momentum
  allows the rocket to coast to peak altitude and is effected by gravity and drag,
  (3) Descent - the return of the rocket to earth effected by gravity and drag.
19) a. As the regressive motor burns, the thrust decreases or regresses because the burning
  surface area of the propellant decreases. This is typical of slotted grains.
20) b. As the progressive motor burns, the thrust increases or progresses because the burning
  surface area of the propellant increases. This is typical of core burning motors.
21) b. As the motor burns from the core out, the ends of the grains are also burning making
  the grains shorter, This results in a relatively constant surface area.
22) c. The liner serves to keep the burning propellant (typically >5000°F) from touching the
  motor case (aluminum melts at 1075-F) while the O-rings seal the ends to keep the hot
  gasses where they belong, that is going out of the nozzle.
23) a. Ammonium Perchlorate is NH4CIO4 and is used in practically all modern solid rocket
  motors.
24) a. NH4CIO4 is the chemical formula for Ammonium Perchlorate.
25) c. Air pressure external to the rocket decreases as the rocket ascends. Trapped (higher)
  pressure within the rocket can prematurely separate the rocket. The hole vents this internal
  pressure to prevent separation. Note: The hole size is dependent on the size of the rocket
  and volume of air to be vented; larger airframes require larger holes. Use caution in locating
  the hole so the nose cone or payload coupler does not block the hole. Be sure to position the
  hole such a manner that ejection charge pressure is not vented before recovery system
  deployment.
26) c. Smaller or fewer injector orifices allows a lower average oxidizer flown reducing the
  average thrust. Since the same amount of oxidizer is being used, the total impulse remains
  the same.
27) b. Larger or more injector orifices allows a higher average oxidizer flow, increasing the
  average thrust. Since the same amount of oxidizer is being used, the total impulse remains
  the same.
28) a. N2O or nitrous oxide, also called NOX.
29) Nitrous Oxide liquefies at 750 psi at room temperature.
30) a. At 36°c the NOX has changed state to a supercritical gas.
31) c. black powder motors do not have a significant start up time and will ignite as soon as a
  flame front is encountered. Ammonium perchlorate-based composite motors require heat
  and pressure To start the combustion process and generally require at least a half-second
  before ignition occurs.
32) If the CG of the motor is forward of the CP of the rocket , As the CG of the hybrid motor
  shifts aft, so does the CG of the rocket which may result in an unstable flight.
33) b. specific impulse is a term used to define the efficiency of a rocket propellant and is the
  total impulse derived from a given mass of propellant.
34) a. Total impulse is the amount of thrust produced by a motor over its action time. For
  instance, a motor may produce 10 Newtons of thrust for 4 seconds resulting in a total
  impulse of 40 Newton-seconds.
35) b. Multiply the average thrust (100 Newtons) by the burn time (4 seconds) to get the total
  impulse of 400 newton-seconds.
36) c. The J motor has a range of 641 to 1280 Newton-seconds and the K motor has a total
  impulse range of 1281 to 2560 newton-seconds.
37) b. Even though the total impulse of the K motor is greater than the J motor, the J motor's
  average thrust is 400 Newton's versus the K motor's 200 Newtons.



NSWRA formal certification procedure Feb 99                                Page16
38) c. The burn time is determined by dividing the total impulse (J = 1280) by the average
  thrust of each motor. The burn time for the J640 is: 1280 Newton-seconds divided by 640
  Newtons = 2 seconds, and for the J320 is: 1280 Newton-seconds divided by 320 Newtons =
  4 seconds.
39) b. A J motor is in the range of 640.01 to 1280 Newton-seconds. Therefore, a 1000 Newton-
  second motor is a midrange J. The 600 Newton-second motor is an I motor and the 1290
  Newton-second motor is a K motor.
40) c. The newton is an international (metric) unit of force and is the force required to
  accelerate one kg (2.2 lbs) one meter (39 inches) per second per second.
41) This is an I motor with a total impulse range of 320.01 to 640 Newton-seconds, an average
  thrust of 220 Newton's and an ejection delay of 8 seconds from burn-out.
42) c. Energy is determined by the equation E = 1/2 mv2. From this it is important to note
  that for objects of the same mass. one moving twice as fast has four times the energy as
  the slower one.
43) a. Energy is determined by the equation E = 1/2 mv2. From this it is important to note
  that for objects of the same mass. one moving twice as fast has four times the energy as
  the slower one.
44) c. The purpose of the launch rod, rail or tower is to guide the rocket at the beginning of its
  flight to allow it to gain sufficient velocity for a stable flight. This is achieved when the air
  flowing over the rocket and its fins allows the rocket to correct its flight by forcing rotation
  around the rocket's center of gravity,
45) b. The launch lug attaches the rocket to the launch rod or rail allowing the rocket to be
  guided by the rod or rail at launch.
46) c. Composite (Ammonium Perchlorate) motors require heat and pressure to ignite. The
  motor core diameter is smaller in the 29mm G80 motors and heat and pressure is more
  concentrated resulting in faster ignition of the motors.
47) b. Not having ignition of ail clustered motors results in the thrust being unsymmetrical.
  This unbalanced thrust may force the rocket to fly in an unanticipated arc that will not
  achieve a vertical flight.
48) a. A shred happens when the rocket is improperly built or has a rocket motor too powerful
  for that particular rocket. The typical shred sequence is that the velocity of the rocket has
  increased to a point where airframe, fins or other structural parts cannot take the loads.
  When that part fails, it typically causes the rocket to become unstable resulting in the rapid
  destruction of the rocket.
49) c. A cato is short for catastrophic motor failure. This occurs when the nozzle, forward
  bulkhead or casing fails. The immediate result is abrupt termination of thrust which results
  in the rocket failing.
50) a. A motor ignitor must deliver sufficient heat to the propellant to get it ignited. This may
  be in the form of hot gas, hot burning particles, a hot wire or a combination of all three.




NSWRA formal certification procedure Feb 99                                 Page17
Appendix C - Level 3 Certification Official Pre-flight Checklist
This is the information that the Certification Official will be checking for in determining the
applicability of signing off on a level 3 certification review.

1. GENERAL
Is this member known to the Certification Official?
Does this member have the appropriate Certification Level or will this be a Certification Flight?
Does the proposed launch site and date have the appropriate recovery area and launch set-up
for this flight?
What are the mission goals?

2. ROCKET REVIEW

General
 Are there attachments to the Pre-Flight submission?
 Drawings: airframe; structures; payloads, etc. Schematics: avionics, ignition systems,
  payloads, etc.
 Performance calculations: Center of Pressure; Center of Gravity, motor type, altitude,
  velocity, etc.

Airframe
 Is the design generally suitable for the application?
 Is the airframe material suitable for this rocket?
 Is the fin material/attachment sound?
 Is the motor mount sound?
 Is the nosecone suitable?
 Is it a staged rocket?
 Is it a clustered motor rocket?
 What are the most probable airframe faults and corrective actions?
 What are the safety implications of an airframe failure?
 Are there any design change recommendations?

Recovery System
 Is the recovery system attachment secure/suitable?
 Does the recovery system have sufficient capacity for safe deployment?
 Does the recovery system have sufficient capacity for a safe descent?
 What is the deployment system?
 Are pyrotechnics involved?
 Are avionics involved?
 What are the most probable deployment system faults and corrective actions?
 What are the safety implications of a recovery system failure?
 Are there any design change recommendations?




NSWRA formal certification procedure Feb 99                                 Page18
Avionics Description
 Commercial or unique design?
 What are the functions of the avionics components?
 Are the avionics appropriate to the application?
 Do the avionics have flight safety implications?
 Are the avionics and inhibits accessible from outside the vehicle?
 Are there safeing/arming indicators?
 Are any of the systems redundant?
 What are the most probable avionics system faults and corrective actions?
 What are the safety implications of an avionics system failure?
 Are there any design change recommendations?

Motor
 Is the motor (or motors) suitable for the rocket?
 Are the motors Certified?
 Are the motors experimental?
 Is the motor ignition suitable?
 What are the most probable motor faults and corrective actions?
 What are the safety implications of a motor failure?
 Are there any design change recommendations?

Launcher
 Is the launcher suitable for the rocket?
 Is the launch lug, or rail guide suitable for the rocket?
 What will the launch angle be?
 Are there any special launch control requirements?
 What are the most probable faults with the launcher?
 What are the safety implications of a launcher failure?
 Are there any design change recommendations?

Performance
 How were the performance calculations done?
 Were the calculations done manually?
 Are the algorithms used correct?
 Were the calculations accomplished correctly?
 Was a computer used?
 What is the source of the software?
 Is the software suitable for this rocket?
 Are there printouts?
 Should the calculations be independently run?
 What are the safety implications of poor performance data?
 Are there any changes or recommendations?

Operations
 Is there a pre-flight checklist?
 Which operations does it cover?
 Are each the operations sufficiently documented?
 Are hazardous operations flagged?
 What are the safety implications of poor checklists?
 Are there any changes or recommendations?
 Action Items




NSWRA formal certification procedure Feb 99                            Page19

								
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