National Air Racing Group Unlimited Division
-From Thomas L. Camp, President: My August letter stated that implementation of this recommendation will improve safety for not only race fans but for our race pilots also. Our Rules Committee (Committee) considered this Safety Recommendation and concluded that we should require any aircraft owner/operator whose aircraft has undergone a major change or major alteration, as those terms are defined by the FAA, to provide Unlimited Division of the National Air-racing Group, Inc. (UDNAG) with copies of all relevant engineering evaluation data and flight demonstration materials and required analyses, plus provide the UDNAG with copies of all approvals by the FAA for any such change or alteration to the aircraft.
These requirements should apply only to aircraft that have undergone changes or alterations since their last participation in an air racing event. We had not determined whether implementation of this recommendation would require a change in the UDNAG rules; however we noted that, should a rules change be required, we would consider early adoption. Following a successful 2012 National Championship Air Race event, our Rules Committee decided the best way to address this Safety Recommendation was to completely rewrite Appendix C, Aircraft Specifications. That, of course, is a revision of our UDNAG Official Competition Rules and requires a vote of our members qualified to vote on rules changes.
On February 15, 2013, the Revised Appendix C was approved (March 1, 2013) with immediate implementation rather than on January 1, 2014 as provided under our bylaws. We believe that our Revised Appendix C goes further than the Board’s Safety Recommendation (A-12-9) and, therefore, the Board should be able to close this last and final issue. A copy of the Revised Appendix C is attached for review by the Board and its staff assigned to the accident investigation. We appreciate the opportunity to assist the NTSB with its final recommendation for the Unlimited Division.
UNLIMITED DIVISION OF THE NATIONAL AIR-RACING GROUP (UDNAG)
These Specifications are the only official and approved aircraft specifications of the UDNAG and are a specific part of the Official Competition Rules (OCR's) of the UDNAG. Failure to comply with these specifications will result in disqualification of pilot and/or aircraft from race competition. Disqualification will be implemented by the UDNAG Board of Directors upon recommendation of the UDNAG Technical Committee and/or the UDNAG Procedure Rules Committee.
I. GENERAL SPECIFICATIONS
A. Aircraft must have a current registration certificate and a certificate of airworthiness issued by the Federal Aviation Administration. All certification, registration and current airframe, engine and propeller maintenance records must accompany the aircraft and be available for inspection by the FAA, the UDNAG Technical Committee and the event organizer. The owner/operator is responsible for compliance with all FAA rules and regulations applicable to the UDNAG race aircraft.
B. UDNAG race aircraft must pass an inspection by the UDNAG Technical Committee at each racing event prior to practice, qualification or racing and at any other time during the racing event if deemed necessary by the event organizer or the UDNAG Technical Committee.
C. Aircraft must display an assigned racing number on each side of the fuselage or tail and on the lower surface of the right wing, with the number facing inboard. The numbers must be at least 30 inches high and in a highly contrasting color. A stroke width of two-and-one-half (2.5) inches (minimum) is recommended.
D. Aircraft must be flown by the pilot in the aircraft, (i.e., no remotely piloted aircraft).
E. The specifications set forth in this document may be temporarily changed at a race site for the duration of that event only by a unanimous vote of all members entered as pilots (or race qualified members if after qualification). Bylaws of the UDNAG, Article VII, Section 1, Paragraph (g).
F. For a member of the UDNAG to reserve and pay for a race number, that member must currently own an aircraft that he intends to race or must currently be building an aircraft that he intends to race, and that member must be able to prove either option to the UDNAG Board of Directors. If a new aircraft project is not completed in five years, the member looses the number for one year; if that number is not taken by another member within that year, then the member can reapply for that number if it can be proven that work is progressing on the project. If the holder of that race number has not entered and attempted to race the aircraft for which the number was obtained within the past five years (with respect to the date of passage of this added rule), the holder looses that number. That number will then be available for other owners with current aircraft to pay for and use. The number will be good for the entire calendar year in which it was paid and must be renewed yearly. The member will lose the number if it is not renewed by April 1 of each year. Numbers cannot be lent from member to member without approval of the UDNAG Board of Directors on a case-by-case basis.
II. ENGINE AND PROPELLER
A. All UDNAG race aircraft must be propeller-driven and powered by a reciprocating engine or engines. The propeller must be driven by the reciprocating engine. (Rotary engines are considered to be reciprocating.) No aerodynamic turbine, turboprop or rocket thrust devices may be used. Exhaust-driven superchargers are permitted.
B. There are no other restrictions on engines or engine modifications.
C. Propellers used may be those that have been previously used on production aircraft and may be used either in the stock configuration or in a shortened or trimmed configuration. New custom propellers made from components not used on production aircraft, whether using composite, synthetic, or any other materials may also be used, but flight test verification at anticipated race speeds and race power settings of that exact propeller must be provided to the UDNAG Board of Directors. The UDNAG Board of Directors may, if they deem it necessary, require the owner/operator to have the design and flight test data reviewed by qualified technical personnel for this purpose in a similar manner to which "Custom Built" aircraft designs are reviewed. The UDNAG race aircraft owner/operator will bear the costs of this review.
A. There are no restrictions on airframe modifications.
B. All UDNAG race aircraft and any major change or alteration thereto (FAR 21, Section 21.93, FAR 1.1 or FAR 91, Section 91.9 and any other applicable FARs) must be designed to accepted structural design criteria to meet the limiting load factors of +6.0 g and -3.0 g and must be capable of demonstrating these load factors if required by the UDNAG Technical Committee. Positive load factors will be verified by demonstration, and negative load factors may be verified by submission of computational methods and procedures, which must be available for review. Flight testing at anticipated race speeds and race power settings must be completed and documented by the UDNAG race aircraft owner/operator no less than 90 days before participation in an air racing event.
C. UDNAG race aircraft that are not modified versions of previously designed and built fighter aircraft and any previously designed and built UDNAG race aircraft that has had a major change or alteration incorporated since the last time the UDNAG race aircraft participated in an event sanctioned by the UDNAG will be designated as "Custom Built" aircraft. The UDNAG race aircraft will be required to meet certain design and test criteria to ensure its safe operation, above and beyond those criteria specified in the preceding sections. The design of any flight-worthy aircraft should, for the safety of the pilot and those on the ground, be substantiated by the proper computational analysis and receive approval from the FAA. The following criteria are considered essential to ensure that an aircraft is properly designed and adequately tested.
1. Structural load analysis for the +6.0 g and -3.0 g load factors, including consideration of design loads, limit loads, and ultimate loads, will be submitted. The ground rules and basic calculations for the structural load limits must be presented in a format that indicates the aircraft designer is familiar with and has used accepted aircraft design procedures and safety factors.
2. A flight flutter test analysis, test plan, and test results will be submitted to verify that the aircraft will safely operate within the structural limits and not be in the flutter region at anticipated race speeds and load factors within the anticipated race configuration flight envelope.
3. Weight and balance data for an empty and full UDNAG race aircraft will be submitted. Weight and balance documentation must include the forward and aft center-of-gravity (CG) limits for the UDNAG race aircraft in its actual race configuration.
4. The flight test plan and flight test results must be documented and submitted to verify safe operation of the UDNAG race aircraft within its flight envelope at anticipated race speeds and race power settings.
5. The items specified in 1 through 4 above will be made available by the UDNAG race aircraft owner/operator no less than 90 days before participation in an air racing event for review by the UDNAG Technical Committee to ascertain the validity and credibility of the submitted data. The UDNAG Board of Directors may require, upon recommendation of the UDNAG Technical Committee, impartial qualified personnel such as Registered Professional Engineers or people known to be experts in their fields, to review and comment on the data. The review will be made far enough in advance that appropriate modifications, recommended by the qualified experts, if necessary, can be implemented, tested and re-evaluated. The UDNAG race aircraft owner/operator will bear the costs of this review.
6. Evidence of FAA approval of items 1 through 5 above plus demonstrated compliance with any and all additional requirements or criteria as may be required or deemed applicable by the FAA or event organizer must be submitted by the UDNAG race aircraft owner/operator before participation in an air racing event.
IV. FUEL AND FUEL TANKS
A. Any type of fuel or additive may be used.
V. SAFETY AND EQUIPMENT
A. All UDNAG race aircraft must have an operable oxygen system, which must be used when practicing, qualifying and racing. Oxygen masks must be the “Military Type;” rebreather bag type masks are not permitted.
B. UDNAG race aircraft must have a seat belt and shoulder harness, which must be used when practicing, qualifying and racing.
C. UDNAG race aircraft must be equipped with a functioning two-way communication radio, which must be used when practicing, qualifying and racing. The radio must have transceiver tuned to race frequency at all times during a race. Pilot must use a second radio if he desires to communicate with his ground crew during a race.
D. It is recommended (but not required) that a UDNAG race aircraft be equipped with fire extinguishing systems for the cockpit and engine compartment.
E. UDNAG race aircraft weighing less than 5,000 pounds gross takeoff weight must have an aft facing light mounted in the aft fuselage or tail section of the aircraft that can be clearly seen from a distance of 3,000 feet, and this light must be on at all times when the aircraft is on the racecourse. This light is to warn on-coming aircraft that a low profile hard-to-spot aircraft is ahead. It is recommended that all UDNAG racing aircraft install such a light as a safety item. (Sometimes ground colors and aircraft colors are not quickly discernible when an aircraft is being approached from the rear at high speed in traffic).
F. All high-pressure gaseous storage bottles (above 500 psig) must be hydrostatically tested and certified every five years. Proof of certification within five years, as of the date of the inspection, must be presented to the UDNAG Technical Committee before a UDNAG race aircraft will be allowed on the racecourse.