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noneThis content refers to past CAFE Challenges. Learn about the 2011 CAFE Green Flight Challenge.


  Frequently Asked Questions


2008 PAV Challenge FAQ


Q: May my team have more than one pilot?

A: Each team must designate one primary pilot.  A team may submit a written request to permanently replace the primary pilot with an alternate pilot.  CAFE may honor that request at its discretion.  In case of a pilot substitution competition weight must be maintained.  All pilot paperwork must be received by by CAFE by July 8th.

Q: Can a registered entrant be granted an extension for providing the documentation required to compete?

A: CAFE is supportive of the contestant's desire to compete with the best chances of achieving their highest scores. Therefore, if the compliance with documenting the aircraft requires additional time, the Board has elected to grant a one week extension from the July 1 deadline. A written request for an extension will be granted an extension until July 8th.

Q: During the flight competition, will teams be allowed to test fly with the CAFE Noise Measurement System in order to pre-determine ideal Competition Power settings and flight speeds that do no exceed the MER noise limits?

A: Yes. Teams wishing to do so may make a test flight for this purpose.

Q: Why must teams pay a sizable registration fee to enter the NASA PAV Challenge?

A: CAFE is a non-profit organization that receives zero dollars from NASA. Registration fees are required in order to pay for the event insurance coverage and the facility expenses (rent, power, phone) at the CAFE Foundation. All of the CAFE Board members work purely as volunteers. Many have personally donated thousands of dollars to CAFE to meet its expenses. CAFE would prefer to not have to charge registration fees but could only do that if its expenses were fully met by sponsor contributions.

Q: Will the "Quietest LSA" prize be awarded if only one LSA enters the competition?

A: No.

Q: Can one person or entity be a member on more than team?

A: No.

Q: Can vehicles on different teams have the same owner?

A: Yes, as long as the owner is not a member on more than one team.

Q: What octane of mogas is acceptable?

A: Any mogas is acceptable for use in the competition. Their price shall be treated as being the same--$3.40 per gallon.

Q: Is prize money awarded to the owner of the PAV or the team leader?

A: Prizes are awarded to the team leader .

Q: Can two teams have the same person's name or company name?

A: No. Each team must have a different and distinct name.

Q: Can I modify my aircraft for the PAV Challenge?

A: All modifications must show written approval by the pertinent FAA authority in accordance with the FARs.  This may involve FAA FSDO or MIDO offices, DAR's, DER's, A&P's, and/or certified repairmen.

Q: Is there a minimum noise level required to compete in the PAV (GAT) Challenge?

A: Page 29 of the 2008 rules clearly states: Noise limit required is = 95 dBA Cabin Noise during all phases of High Power Flight Attempts. Also stated is that = 72 dBA measured 500 feet sideways on takeoff at brake release is required (78 dBA for VTOLs). The 72 dBA limit required applies throughout the takeoff run, though it is expected that the highest noise occurs at brake release.

Q: How does the CAFE Foundation perform its noise measurements?

A: The CAFE Foundation performs its various noise measurements based on the Challenge rules for each year.  Please review the rules for the year that you are interested in for the specifics of each measurement.  The CAFE Foundation uses the following test equipment to make the measurements:  

Sound Level Meter: Ivie IE-45 using the Ivie RTA software
Microphone: Ivie 1134   1/2 inch pressure response Type 1 measuring microphone including windscreen
Preamplifier: Ivie 6P
Preamplifier Cable: Ivie 45MC-25XLR 25 foot extension microphone cable
Calibrator: Ivie CAL200 Type 1   1/2 inch microphone calibrator


You can get specific information on these products at the following web site:  

Q: Is the 400 lb. useful load pilots and ballast?

A: See pages 14, 15 and 17 of the 2008 rules. PAYLOAD required is 200 lb per credited seat. (e.g. 400 lb for a 2 seat aircraft.) This includes the seat occupant (pilot or passenger) + ballast. It does NOT include fuel. Fuel is not PAYLOAD. Fuel is part of USEFUL load. Ballast may be used to take the place of passengers, as needed, at the discretion of the team. However, flight operations are expedited by having real live passengers fulfill the payload requirements. CAFE provides ballast in the form of sandbags and other dense containers, but will not provide passengers. If a 4-seat PAV cannot legally within FARs carry 200 lb per seat, (800 lb payload), but can carry say 750 lb payload, then it must be scored as having 3 seats and need only carry 3 x 200 = 600 lb payload in the competition. This affects its required MPGe in the Green Prize (see tables in rules Appendix).

Q: Will the Duct Tape that holds on the wing cuff damage my PAV?

A: The industrial strength Duct Tape used on the wing cuffs and applied to the wing by CAFE's team has generally not affected the PAV's paint or structure. We have had no complaints about this in our entire 20 years of performing this practice. The PAV's wings should be waxed before applying the tape to help assure that no paint damage occurs. The wing cuffs are only kept on for a short period of flight testing on a single day, unless a weather delay occurs. CAFE does not have experience in using the duct tape on fabric wings. Fabric winged PAVs will need to work with CAFE in advance of the event to devise a suitable alternative to the wing cuff.

Q: Why can't I use my GPS to obtain my score?

A: CAFE must control the measurements and readings by supplying and equipping each PAV with the its high accuracy flight data recording system. Teams are free to use their own GPS for information, but all official scoring is done by CAFE's equipment.

Q: Can a universal RAM mount already mounted permanently on the dash board serve as the camera mount or do I still need to make the camera mount as described on the web site?

A: Camera mount must be in a location that allows forward view of the instrument panel and a view that can monitor the cabin noise mic to assure no one tampers with it.

Q: Can you accurately measure very short takeoff distances?

A: Remember, takeoff distance is the distance necessary to clear a 50 foot obstacle, not merely the ground roll distance. Yes. CAFE has the necessary equipment to accurately measure this.

Q: In the Slowest Level Flight Speed contest, can the PAV use power?

A: Yes. The PAV must maintain its Slowest Level Flight Speed for 10 seconds and is allowed to use power during that run. The speed measured will be in Calibrated Airspeed, using CAFE's recording equipment while flying at Competition Weight.

Q: Is there a refund fee on the entry registration fee?

A: Yes. A $500 refund is offered to teams that submit all required documentation by June 15, 2008. (See Page 3 of rules). Teams not selected to compete will be refunded in full. Teams that are a no-show, are found cheating, are disqualified for any reason, are found to be non-airworthy, or fail the MERs and consequently get disqualified will NOT be refunded. To accord teams on the waiting list the greatest amount of time to prepare for the competition, and to fulfill other administrative needs, CAFE cannot refund any registration fees for teams that withdraw after having been accepted into the competition.

Q:  The GAT Challenge overlaps with Oshkosh AirVenture 2008. How can we attend both?

A:  The GAT Challenge will extend its team arrival/registration process to 8 PM on Sunday August 4 to accommodate those who have attended AirVenture.

Q:  Why must pilots have 500 hours in order to compete in the GAT Challenge?

A:  The GAT Challenge requires 500 hours in order to maintain a high standard of safety, satisfy underwriters' concerns and obtain the best possible performances from the air vehicles in the competition.

Q:  How do CAFE judges determine the eligibility to participate in the GAT Challenge for Federal employees or federally-funded innovations?

A:  The basic rule is that no unfair advantage will be allowed. Unfair would be a directly and substantially federally-funded competitive advantage that was not available or accessible to all prospective participants. Education and the knowledge gained from it are deemed to be accessible to all except in cases where the federal government and/or its contractee have kept it confidential or proprietary and not shared it in the public domain. Privately-developed, non-federally-funded knowledge and innovation are eligible to compete. CAFE makes every effort to post relevant and helpful information and educational materials in the CAFE Technology Library on the CAFE Website. In addition, the CAFE website offers an esteemed list of expert Team Consultants that are accessible to all teams on the website.

Q:  What about long wings that fold?

A:  The rules state that a wingspan of 44 feet is the maximum allowed. This requirement is due to the size limitation of the CAFE Flight Test Center's building and scales. Wingspans of longer than 44 feet must fold in order to become 44 feet or less in order to participate. The wing fold must be accomplished in 30 minutes or less and must be such as to enable an accurate c.g. of the aircraft to be determined when weighing with the wings in the folded position. The other limitations on dimensions for height and length are given in the rules.

Q:  Can non-US citizens participate?

A:  Non-US citizens cannot win prizes and cannot be Team Leaders. However, a tentative ruling has been made that they can be Team members on a team whose Team Leader is awarded a prize.

Q:  Can a team shoot for only 1 prize and not perform all the flight tests for other prizes?

A:  No. To win any prize, each team must perform all of the required flight attempts in the entire competition and fulfill the requirements given in the Prize Matrix in the rules.

Q:  What must I obtain from the FAA in order to participate in the GAT Challenge.

A:  Your team pilot must qualify and have a current valid pilot's license, BFR and medical. Your team vehicle must have an United States FAA Airworthiness Certificate that allows day VFR flight anywhere in the continuous 48 states, a current annual inspection, including valid and current transponder and pitot/static system inspection/approval, and a sign-off approval for any modifications that have been made for the flight competition. An additional FAA approval for flight with the wing cuffs and ÜberBarograph system will be necessary and can be obtained at the GAT Challenge on registration day.

Q:  Can our team wash and wax our team vehicle in between flight attempts to remove bugs, etc. Can we add oil as well as fuel and payload?

A:  Once the team vehicle has entered the competition, its design is frozen and it may not be modified in any way other than by washing, waxing, fueling, loading bona-fide payload (e.g. CAFE sandbags) or adding oil. Such servicing will be chaperoned by CAFE officials.

Q:  Will our team vehicle be accessible to the public, spectators, etc, during the competition?

A:  Once registered, all team vehicles will be impounded away from the public and spectators until the competition flight events are completed on August 9, 2008. On Sunday August 10, a Public Exposition Day will showcase all team vehicles and their scores to the public. At least one team member must be available to answer questions for the media and spectators that day.

Q:  Can LSA team pilots fly without an FAA medical certificate?

A:  Yes.  LSA team pilots must comply with FARs and that means they can fly with a driver's license and their own affirmation of health adequate to fly. LSA team pilots do not require an FAA medical certificate for the Challenge. However, they must meet the other pilot requirements of 10 hours in type and 500 hours total experience as pilot in command.

Q:  Can vehicles compete with 91 octane mogas, and what will be its price?

A:  91 octane mogas is ok to use, if it is approved for the vehicle's engine, and is unaltered from the service station's public retail pump. In the Green Prize scoring, it will be treated the same as mogas ($3.40 per gallon).

Q:  Please discuss the LSA speed limit of 120 kts (138 mph). Can LSAs get FAA waivers to go faster than 120 kts for the purposes of the GAT Challenge, and then revert to LSA status?

A:  This is a complex question. Fundamentally, all teams must comply with all FARs throughout their participation in the Challenge. The LSA speed limit is very strict. Special waivers to temporarily exceed the speed limit are not allowed. The speed limit is tied to propeller RPM.

Earl Lawrence of EAA, who has led the LSA standards process, supplied the following LSA regulations that must be followed by all LSA teams in the Challenge:

The FAR 1 definition states:

(2) A maximum airspeed in level flight with maximum continuous power (VH) of not more than 120 knots CAS under standard atmospheric conditions at sea level.

The FAA required that the consensus standard define Vh for SLSA.

ASTM standard F2245 defines Vh as:

3.2.33 VH—maximum speed in level flight with maximum continuous power (corrected for sea level standard conditions)

This cannot be taken alone it must also be looked at with the following other requirements:

4.3 Propeller Speed and Pitch Limits—Propeller configuration

shall not allow the engine to exceed safe operating limits

established by the engine manufacturer under normal conditions.

4.3.1 Maximum RPM shall not be exceeded with full

throttle during takeoff, climb, or flight at 0.9VH, and 110 %

maximum continuous RPM shall not be exceeded during a

glide at VNE with throttle closed.

4.4 Performance, General—All performance requirements

apply in standard ICAO atmosphere in still air conditions and

at sea level. Speeds shall be given in indicated (IAS) and

calibrated (CAS) airspeeds.


The above propeller speed and pitch regulations must be complied with  throughout the Challenge by all LSAs because they are an integral part of the LSA design specification. The specification requires either a fixed pitch or a ground-adjustable propeller. Propellers with in-flight pitch adjustment are not allowed on LSAs.

The CAS used will be the CAS recorded by CAFE's ÜberBarograph, not a GPS groundspeed or the instrument panel airspeed. Any LSA that is found or proven to have violated the above stated ASTM F2245 must be disqualified from the Challenge.

Note: Each LSA's CAS, RPM, manifold pressure, altitude and climb/descent rate will be recorded and documented on the CAFE BlueBox flight data system. If an LSA is shown by that data to have violated the above regulations, that LSA must be disqualified from the Challenge. Therefore, each LSA team will be given the opportunity to cautiously accelerate their LSA toward the 138 mph CAS and RPM limits by slowly increasing power settings in flight trials to pre-determine their CP (Competition Power). During the CP trial flight attempt, CAFE will communicate by radio to the team pilot about the LSA's official CAS, RPM and manifold pressure. A small CAFE LCD display in the cockpit will provide that same information to the pilot.

 In selecting ideal fixed pitch propellers for both low noise and performance, LSA teams are encouraged to carefully pretest their speed and RPM performances to help assure that they remain within the FARs during the competition. Once an LSAs CP is determined and approved by CAFE, that is the power setting that will be used by that particular LSA in its shortest takeoff flight attempt, its Community Noise flight attempt, the angle of climb attempt, the top speed attempt and any other max performance flight attempts. Obviously, a low CP will both reduce the LSA's noise and limit its performance.

Q:  On what basis can a team be disqualified, other than by vehicle performance that fails to meet the MERs?

A:  Under Team Agreement Section 3.1 "Overview", and Section 4.0 "Safety", and 6.0 "General Provision" 6.12 "Additional Rules", CAFE, its judges and test pilots are authorized and empowered to disqualify any team and/or its vehicle found to be "incompatible with the stated goals of the competition". This includes infractions not limited to the following:

  • Cheating of any kind including tampering with CAFE flight test equipment
  • Disturbing the event by unruly behavior
  • Presenting a vehicle deemed unsafe or un-airworthy
  • Unsafe flying
  • Tampering with another team's vehicle, crew or possessions
  • Failure to timely attend required briefings or comply with their instructions
  • Failure to comply with any additional rules 




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