Frequently
Asked Questions (FAQ)
2002 Competition Specific
Updated 25 September 2001
Please check the FAQ often during the competition. Please note that rules interpretation
questions are not answered by e-mail until after the entry date (when all
participant e-mail address are known), so that all teams will have equal access
to all rules information.
Payload Questions:
- Question: Are wing pods
for carrying the cargo permitted? Is removal of the pods for a different
mission flight a modification to the aircraft structure?
Answer: Wing pods may be used for carrying the payload. If used for any mission, they must be present for all missions. The pods may be removed to change payload. - Question: In the "Passenger Delivery"
section of the chart it states, "Balls must be a minimum of 2
directly abreast (no staggered rows), and single height." We have a
few questions about the loading configuration of the softballs.
Q1: does this allow for two balls stacked vertically instead of horizontally? Meaning two balls high and one wide.
Q2: More generally, is the "single height" a minimum, maximum, or a mandate?
Answer: Balls must be “only” a single row high (vertical) and “at least” two rows wide (spanwise-horizontal). They can be wider, but not higher. - Question: In the contest rules it says “softballs
must be loaded/unloaded individually." Does this entail that each ball must be loaded/unloaded by
hand? Or, can they
"individually" roll into the payload compartment of an aircraft
with some sort of ramp-mechanism or tube?
Answer: You may not use any type of “device” to load or unload the aircraft, either one that fly’s with the aircraft (the old “speed loader”) or a ground based loading device. You may use a box or container to carry the balls, but may not “pour” them into the aircraft from the container (or vise versa), they must be loaded “individually” by hand.
As an example, you can't put all the balls in a big tube, line the tube up with the aircraft, and pour them in. Similarly you can't make a box with a removable bottom that matches your payload bay, hold the box over the bay, and slide out the bottom to load all the balls at once. You also can’t “group” the balls together by any means (remember it says no tape, bolts, nylon socks etc to hold the balls together) and put all the balls in with one fell swoop. And finally, you can’t tip the aircraft up or over and just let all the balls rolls out into the box, they must be “removed” and moved to the box “individually”. - Question:
Does "...directly abreast (no staggered rows) and single
height..." mean the adjacent balls must touch each other?
Answer: No, they don’t need to touch, but they can’t overlap. - Question:
May we tip the aircraft to get the balls to a location where they can be
unloaded if we do not "pour" them into a container (for
unloading)?
Answer: The aircraft does not need to remain perfectly level when unloading, but the main gear must remain in contact with the ground. - Question:
For removing the payload, does the "individually" allow that
we are allowed to let the balls roll out of the aircraft into the hands of
the crew?
Answer: The balls must move from the aircraft to the “box” and vise versa by a crew member. They may roll around in the aircraft itself during loading, as long as they are adequately secure when the plane is loaded and ready for take-off.
Flight / Mission Questions
- Question: In the rules
examples, all the times are in round minutes. What accuracy will be used for determining flight times?
Answer: It’s just to make the rules document cases simple. We will record times to the accuracy possible, probably to nearest second. - Question: The rules
state the aircraft must have the wheels off the ground in 200 feet. Is
there any height requirement?
Answer: No, the rules are correct as stated. Aircraft must have ALL wheels off the ground by the 200 foot line, and they must remain off until the landing. Their is no "obstacle" height requirement for this year. - Question: Can the
battery pack be changed out or "topped off"
between sorties?
Answer: No. Only payload may be unloaded and reloaded. Batteries may not be recharged. - Question: Is there a
minimum altitude for flying the course?
Answer: No. Altitude must be high enough for safe flight as set by the discretion of the Contest Director. - Question: How are the
turns made, and is there a set turn radius?
Answer: The turns may not be initiated until the turn judge raises his flag (for the two 180 degree turns), but may then proceed to be any turn radius and rate the aircraft is capable of. The 360 degree turn can be initiated anytime the aircraft is on the "downwind" leg and also may be any turn radius and rate the aircraft is capable of. - Question: In the
rules, it says that the flight time lasts "...until the aircraft
comes to a complete stop on the runway past the starting line at the
completion of all laps..." then goes on to say "If the aircraft
rolls off the runway, the ground crew may retrieve the aircraft and return
it to the runway. In this case, the time ends when the ground crew returns
to the staging 'box' after placing the aircraft at the starting
line." So why would a crew go
get the aircraft if it runs off the runway? Wouldn't it be stopped? Are
you saying that if the plane rolls past the starting line and stops, then
the time stops, but if the plane rolls past the starting line and off the
runway, the crew must return it to the starting line?
Answer: If the airplane rolls off of the runway BEFORE reaching the starting line it must be returned to the runway to taxi or be carried to the starting line. If it rolls off of the runway PAST the starting line it must be returned to the runway (but not necessarily to the starting line). In either of these cases, time stops when the pit crew returns to the staging box. - Question: Is it safe
to assume that if the rules do not explicitly forbid something, it is
allowed?
Answer: The rules are intentionally designed to not impose too many limitations while allowing each team an equal chance. If something adheres to the "spirit" of the rules it is likely to be allowed. If you have any specific questions you would like clarified they may be addressed in a private e-mail to the contest administrator. Ideas will not be disclosed to other teams if they represent a legal and innovative approach. If it is deemed to be not legal, it may be added to this FAQ or posted to the other teams at the administrators discretion.
General Questions
- Question: Can there be
thrust vectoring via rotating the engine, nozzles, blown surfaces etc.?
Answer: Yes. Any of the above options is allowed, and may be varied during flight. However, "rotary wing" vehicles are not allowed, so you may need to consult the judges with your specific design and it's thrust levels to be sure it doesn't cross over the line into vertical flight capability. - Question: Do all of
the team members need to be student members of AIAA?
Answer: Since the DBF is part of the AIAA competitions sanctioned by the Student Activities Committee and the AIAA Foundation, all team members should be student members of the AIAA. - Question: What was the
maximum number of people that can make-up a team.
Answer: There is no specific limit on team size. It is up to the team itself to determine a size sufficient to meet the required tasks and small enough to remain manageable. It is expected most teams would fall in the 5 to 10 member size range, but this is only an estimated guideline.
There is a maximum size of the flight crew (pilot and assistant) and ground crew (3) for this years competition. Please see the RULES section for more details on the limitations on the flight and ground crews. - Question: Is it
necessary to list all team members on the entry.
Answer: Yes, we need to know all the team members to verify the under/upper classmen rule. - Question: What is
meant by "Upper and Under Classmen"
Answer: Upper Classmen are (for purposes of the contest) seniors and/or graduate students. Lower Classmen are Freshmen, Sophomores and Juniors. - Question: Is it
allowed to have/declare more then 1 pilot in a team (in case one of them
can not go to the contest, or simply have a back-up pilot)?
Answer: Yes, teams may register multiple pilots as long as each meets the requirements listed in the rules. - Question: Can we have
corporate sponsors? If so, can we put their logo on the UAV at any place
that pleases them?
Answer: Teams may solicit and accept sponsorship in the form of funds or materials and components from commercial organizations. All design, analysis and fabrication of the contest entry is the sole responsibility of the team members.
Sponsor and university decals or logos may be placed as desired. Teams should make sure that the final color scheme of the aircraft provides good visibility of the aircraft location and orientation for the pilot. - Question: What is COB
in the submission dates mean?
Answer: COB - Close of Business: data must ARRIVE by 5 PM local time at the specified location. - Question: The contest
day is graduation. Is there any possibility of moving the contest.
Answer: In selecting the contest date we have tried to minimize the conflicts with graduation, finals, mothers day,... We can't miss all possible conflicts as each university is on a slightly different schedule. Moving the date earlier would greatly increase the risk of unacceptable weather, and further shorten the time available to design and build the entries (which will seem VERY short by then). - Question: We were
wondering if it wouldn't be easier to just send an official representative
from the competition to our school, fly our plane, and take down the
score. Then compare with all the other schools competing(they'd probably
be on home turf as well), and make the final decision that way?
Answer: The single site -vs- fly-at-home issue was discussed much by the contest organizers prior to selecting the current contest structure for many of the same reasons you raised. We realize that it is difficult for students to obtain funds for fabricating an entry, even without the added costs of travel. In the end we selected the single-site format for mainly two reasons: (1) the single-site format will allow the teams to see each others entries and learn from each other and will add to the competitive fever always present when pitting your best efforts against others; and (2) the single site is the only way to assure a level playing field for all entries, as weather variations at multiple sites and days would inevitably help some entries and hinder others. - Question: At what wind
speed will the contest be called.
Answer: It will be up to each team to determine whether they want to fly or not. The contest will be called (and the rain date used) if the wind speed exceeds 30 mph for a period of time sufficient to prevent all teams who are ready to fly from being assigned a flight time slot. The 30 mph limit is consistent with normal AMA competitions and is required to retain our contest insurance coverage. - Question: Will a hard
runway be used?
Answer: We will select a site that provides a paved runway. Note that a "smooth" paved runway for manned aircraft may still seem "rough" for contest aircraft. - Question: Our team has
completed our design calculations and we have found a manufacturer that
carries wing components that will meet our design criteria. Can we
purchase components (i.e. foam cores and skins) to construct the wing for
our UAV, or are we required to build it from scratch?
Answer: You may use unassembled components such as wing cores providing they are integrated in a way that results in the final configuration being an original design. - Question: Does the
plane have to be an external propeller plane, or can it be a duct fan UAV?
Answer: Ducted fans are also legal if they use a commercial fan assembly. - Question: In terms of
propellers. Can they be any kind of Gas engine propeller if we wish? Or do
they have to be Electric motor propellers? And if we can only use electric
motor propellers, can we cut them? Basically, if we wish to, can we use
any kind of non-electric motor propellers if they are commercially
available?
Answer: Any commercial propeller for either gas or electric models may be used. Props may be cut to reduce their diameter but the blades may not be reduced in thickness (such as by sanding the airfoils to a new profile) or in chord (such as by trimming the trailing edges). - Question: What
constitutes "over the counter" batteries, and does this apply to
the battery pack or to the individual cells?
Answer: The "Over the Counter" refers to the individual cells. This is a change from the rule for the 1996/97 contest year. - Question: How is the
radio fail-safe described in the safety supplement to be implemented.
Answer: This is a feature available in many production RC radio systems. It is required that your radio system be able to provide this function. - Question: Can we
construct a composite can for an otherwise stock over the counter model
motor?
Does the motor controller have to be an over-the-counter controller?
Answer: The motor and/or controller must be an unmodified commercial product. The intent of this rule is to prevent excessive cost, and to provide all teams access to equal propulsion technology so they can concentrate on the aircraft aerodynamics and structural aspects. - Question: Do the wires
and connectors have to be commercially available?
Answer: Yes - Question: When you
check the CG, what kind of a point will you use? For example will it be
checked with fingers or dowels or something even sharper?
Answer: The CG check will be coincident with the structural verification test described in the Safety Requirements supplement to the basic rules. Specifically, two team members will be asked to pick the aircraft up by the wing tips using their hands (usually a clenched fist placed under the wing at the desired location works well). They will (gently) lift the aircraft at it's full contest weight by the wing tips at the marked axial CG location. - Question: Will the
payload be supplied by the team or the contest administration?
Answer: By the team. - Question: If battery
power fails can an immediate landing be made without making a complete lap
(question paraphrased by editor)
Answer: First priority is safety of personnel, followed by minimizing damage to equipment. If power fails unexpectedly the pilot will setup for as safe an emergency landing as possible. If the plane does not pass the downwind pylon that sortie's payload will not count, but any prior sorties will still be credited toward the overall score. - Question: Will there
be a maximum altitude, other than the visibility requirement?
Answer: There is no specific numerical altitude limit. It would be very difficult to enforce a rigorous altitude limit without altitude telemetry equipment on each aircraft which would be a significant expense burden. The contest flight judge will enforce maintaining a "safe" altitude for both personnel/ground and flight visibility reasons, and may order the pilot to descend if he feels the altitude is too high. In general, altitudes of 300 to 500 feet are probably nominal, and altitudes near 1000 feet are likely to have the judge order a decent. - Question: Is
information available about previous year designs and results?
Answer: A summary of characteristics for all the entries that competed in the last years contest will be available on the contest web site. Remember that the objective of the prior years contest was slightly different, so you will have to adapt the design data accordingly. (Prior year rules will also be maintained on the web site for reference.) - Question: Would we
ever have to make any vertical loops with the UAV?
Answer: No
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