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Jan 18, 2014, 09:23 AM
Registered User
propicts's Avatar
Discussion

F5J vs ALES


From what I have read in AMA and FAI. The only difference between the two for
contests, is the FAI requires that the launch altitude must be read and verified
after landing and all settings must be verified prior to launches. Where as in
in ALES, a ALS switch must be in AC set for the altitude to be used in contest.
Am I correct in this observation ?
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Jan 18, 2014, 09:57 AM
turn, turn, turn.
I think you have part of it right
Jan 18, 2014, 10:13 AM
Registered User
Lenny970's Avatar
Probably the biggest difference is that everybody launches to the same altitude with the ALES format, but in F5J each pilot chooses his own launch height.

Lenny
Jan 18, 2014, 10:14 AM
Registered User
jtlsf5's Avatar
In a simple sense, yes, those are the main differences. It is a bit more complicated than that.

ALES: Maximum launch altitude is specified with a maximum 30 second engine run. A limiter switch is used to shut down the motor when the plane reaches the specified altitude or 30 seconds, whichever occurs first. The maximum altitude, while specified, is not confirmed. Thus the possibility of an altitude overshoot via excess kinetic energy exists with no specific penalty.

F5J: There is no maximum launch altitude but there is a 30 second maximum motor run. Launch altitude must be measured and reported at 10 seconds after motor shut-off, this is the "F5J Altitude". Points are deducted from actual flight score as 0.5 points per meter of altitude up to 200 meters, plus 3 points per meter above 200 meters. Altitude gains due to stored kinetic launch energy beyond the reading of the F5J Altitude are forbidden.

Net result is I think of ALES as F5J-Light, same basic flight/landing tasks with somewhat simplified launch requirement, plus no incentive for taking the lowest possible launch.

JT
Jan 18, 2014, 10:22 AM
WINS - Winch In Nose Sailplane
jaizon's Avatar
JT, could you explain this sentence. "Altitude gains due to stored kinetic launch energy beyond the reading of the F5J Altitude are forbidden." I'm not sure I understand that. Thanks.

Preston
Jan 18, 2014, 10:39 AM
Registered User
jtlsf5's Avatar
Preston,

FAI F5J Rule 5.5.11.10e: Zooming is not allowed. It is defined as the storage of extra energy in the form of kinetic energy (speed), which is then converted into potential energy (height) after the height reading is made. Any model observed by the designated timekeeper or Contest Director, to be attempting any zooming techniques, after the period of 10 seconds has elapsed, will be penalized by deduction of 100 points from the round score.

OK, not strictly "forbidden", but severely penallized.

JT
Jan 18, 2014, 10:43 AM
Registered User
jtlsf5's Avatar
Here are the most current FAI rules covering electrics. F5J starts on page 33.

JT
Jan 18, 2014, 10:48 AM
Red Merle ALES VII SJ
Curtis Suter's Avatar
Can a model have any extra zoom left 10 seconds after motor shutdown?
Jan 18, 2014, 11:06 AM
1 revolution and throw!
Quote:
Originally Posted by Curtis Suter
Can a model have any extra zoom left 10 seconds after motor shutdown?
yes, i think so but it should be designed for it (f5b model?) it will give up far more in sink rate then what possibly could be gained by zooming , actually i don't think there should be a penalty , a "normal" f5j (or ales) thermal glider would not have enough speed left after 10 seconds to gain altitude i supose , if you create a plane for it well lets have it i'd say as i don't think there's anything to gain...
less room for discussion to make out wheter someone uses a power launch to get far upwind or for zooming...
Jan 18, 2014, 11:09 AM
E sailplane thermal hack
I think its possible from what I've seen of heavily ballasted slope racers
But then those aren't exactly thermal planes
Jan 18, 2014, 11:35 AM
Registered User
Larry Jolly's Avatar
Curtis, The answer is yes...If you rounded over at motor shut off in a shallow dive, and counted to 10, you could theoretically get some gain in altitude from the zoom bypassing the 10 second penalty period.. LJ
Jan 18, 2014, 11:47 AM
Registered User
jtlsf5's Avatar
+1 to LJ's comment. Certainly possible with some practice to develop a launch that exceeds the F5J altitude by continuing to develop energy (velocity) in a very shallow dive then convert just after the 10 second window.

JT
Jan 18, 2014, 12:42 PM
solastagia
kcaldwel's Avatar
Quote:
Originally Posted by Larry Jolly
Curtis, The answer is yes...If you rounded over at motor shut off in a shallow dive, and counted to 10, you could theoretically get some gain in altitude from the zoom bypassing the 10 second penalty period.. LJ
None of those zoom techniques would work for F5J. Your start altitude is the maximum altitude achieved from leaving the pilot's hand, to 10 seconds after motor shut-off.

Your higher altitude before the dive would be your start altitude.

"d) The launch altitude for scoring purposes shall be the maximum altitude recorded from
the moment the model leaves the launchers hand until 10 seconds after the motor is
stopped."

I doubt there is a plausible zoom scenario under the F5J rules. The rules eliminate all the ambiguity of the ALES rules, and add the challenge of trying to shut-off as low as possible. This adds points spread without spot crashing.

Kevin
Jan 18, 2014, 12:59 PM
Red Merle ALES VII SJ
Curtis Suter's Avatar
Kevin JT and Larry are superb respectable guys but I have to agree with you. In full scale if I were to pull power to idle, descend and just prior to 10 seconds complete a climb and level off I just can't imagine I'd be higher.

Interesting. I'm sure DonH who has extensive accurate data flight data could put this to rest.

Neat thread.
Curtis
Jan 18, 2014, 01:09 PM
solastagia
kcaldwel's Avatar
Curtis,

I think they misunderstood the F5J rules, thinking it was your altitude at 10 seconds after motor shut-off that mattered. It is actually your max altitude from launch up to 10 seconds after motor shut-off.

Any airplane that could possibly store enough kinetic energy to gain altitude 10 seconds after shutting the motor off, is not going to do well in the remaining 9 1/2 minutes.

I suppose an airplane that could accelerate under power to 300mph in level flight, and then pull-up after the 10 second period, might end up higher. Good luck with that.

Eventually ALES will have to evolve into F5J. If the slightly simpler ALES rules get more people flying e-sailplanes and soaring, then I guess this interim period will be well served.

Kevin


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