SEN 1634

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Category: Archive 2012
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Table of Contents - SEN 1634

  1. Watch out for the Birdmen
  2. From a Crow's POV
  3. Stone the Crows
  4. Bird calendar
  5. Stone the henge
  6. FFQ #43

Watch Out for the Birdmen

Dear all,

the report of EoB has started me thinking. Indeed recently Pelican's have escaped or at least have tried to escape from the famous 'Artis' zoo in the Netherlands:

http://www.nrc.nl/nieuws/2012/02/03/waarom-er-altijd-pelikanen-ontsnappen-uit-artis/

Ornithologists are still at a loss why these birds show such behavior. But in the light of EoB's findings, this throws a whole new light on the matter. Is it possible that our wind tunnel experiments have triggered this? When a LDA F1A being launched produces the sound signature only once every launch, in the wind tunnel the sound has been produced
a number of times in a time frame of a few seconds.  We used an 'open' wind tunnel and the events described in the article above coincided with our experiments (same date)!

Rather than banning LDA's from the field or limit their speed I suggest to tackle this problem on two fronts: first we should continue experimenting with turbulators to muffle the sound (medium term), second we should ban all ornithologists from our fields and all free flight sportsman should show some kind of proof at contest registration that they are not affiliated with the science of ornithology in any way (short term).


met vriendelijke groeten, with kind regards,

Allard van Wallene
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From a Crows POV

Respected Sir:

With reference to your recent note in SEN with regard to the noise generated by low-drag airfoil equipped F1As and the consequent impact on the meandering flight pattern of the brown pelican (pelicanus pelicanus Brownii), might I suggest an alternate solution to the one you bravely put forward in your treatise?  As an F1Q flier, I am only too aware of the angst and hostility attending the introduction of energy limiters to that event, and fear that the response from the F1A community, known for their pugnacious and aggressive behavior, will dwarf the furor seen in F1Q if we attempt to introduce velocity-limiters (or perhaps, noise-limiters) to that august group of gentlemen (sic.)

Eschewing the notion of requiring all said pelicans to fly wearing Bose noise-cancelling headphones, which would in itself probably violate an untold number of Federal regulations concerning these primitive creatures, may I suggest instead that each LDA-equipped F1A flier be required to have an assistant fly an identical airplane at every event, said assistant being required to closely observe the primary contestant (he or she being assisted) and to execute, at the moment of zoom launch by the primary, a simultaneous mooz launch in which the assisting airplane is towed into the ground at a speed commensurate with that of the primary aircraft, thereby (presumably) generating a sound wave exactly out of phase with that generated by the zoomed airplane, and thus rendering any atmospheric disturbances inaudible to the balloon-beaked intruders?  This will of course require some practice and may necessitate pro-pelican finals ahead of the regular Team Finals.

On further consideration, in recognition of the time of year, might it be possible that the birds you observed were in fact gooney birds, and not pelicans, in which case your point is moot, as these are not protected by Federal Law, being maritime animals?

Yours in Science,

Bernie Crowe.


Bird Calender

Roger,

Any relationship between Bird Strike and the publishing date?
Suspicious in Phoenix,
                                H

Stone the crows
Regarding the article concerning LDA models and the effect it has on birds, I think you are on to something here.
It perhaps explains the Storks and flocks of parrots that have been inundating Salisbury Plain in the UK recently.

regards, Peter Tribe


Stonehenge Cup

-12/13th May-Salisbury Plain, UK
A reminder that the closing date for pre-entry to the Stonehenge Cup to be held on Salisbury Plain is 20th April 2012.
Entry forms and further details for F1A, F1B, F1C, F1P and F1Q are available from Peter Tribe:-
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Tel +44(0)1225 862748
UK entries to include entry fee with the application; entry fees for competitors based outside of the UK may be paid on the day of the contest.
regards
Peter Tribe

FFQ #43

 Roger,
As in previous occasions, I'd appreciate if you publish this summary of the articles in our latest issue.

regards


Sergio Montes

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    In this issue of FFQ, the reader may find a wide range of articles to please most tastes. For those on the look of new developments, Volodymir Sychov's new F1C folder is one of great interest. Sychov has developed to a practical degree an F1C folder that folds the wing backwards, presenting a very slim cross section to the airflow. Because of the minimum span during the climb one could conceive that there might be stability problems and also transition problems after the very fast climb. Photos and comments of other F1C flyers in the article illustrate the degree to which such problems have been solved.
    An equally audacious problem in aerodynamics, solved to complete satisfaction, is presented by the diamond wing-planform F1G model of Michel Coviaux.  It also uses a central propeller and mixed conventional and foam construction, as in the Pousseur design from the same designer, seen in the previous issue of FFQ.
    Maurice Bodmer tells, in this first part of a two-part article, about his experiences flying tailless models (mainly "planks" ) in Switzerland  from the mid 1940's. Both gliders and power models are covered, and in the second part magnet-steered tailless F1E models will be considered.  Andrew Longhurst and Mike Segrave remember the tailless rubber specialist John Pool, the designer of the influential "Never Forget" series, who died recently. To round off the topic of tailless models, we are presenting the famous Cyrano II, a tailless P30 model by Barnaby Wainfain that won the 1984 P30 category in the USA Reno Nats.
    Paul Rossiter has conducted a careful comparison by field tests as well as theoretical calculations of the the advantages or lack of them of Variable Pitch and Constant Pitch propellers for F1B. The results are a little surprising, but seem to agree with what many specialists had been reporting in the last several years: the advantages of the VP propeller are much less clear-cut than previously assumed. It is most interesting to see the degree of care needed  for comparative tests like these, and also to see how the tests verify closely the theoretical calculations using software developed by the author.
    Andrew Longhurst reveals his philosophy of design and flying F1G models without VIT or other timer-operated functions, ie "functionless" F1Gs. Among the points of interest in his approach is the effect of  the wing surface texture, considered as a three-dimensional entity, and the lesser effect, according to him, of ultimate refinements in airfoil shape. Simplicity and reliability are held to be of paramount importance. Craig Limber shows how to improve the enjoyment and efficiency of contest flying by careful preparation  of models and ancillary equipment. It covers standardization (as far as possible) of model design in several categories. This allows him to use the same parts in various models; reliable winding procedures and equipment are discussed, as well as  electronic DT systems, spectator-proof winding stooges, etc.  There is a second part in next issue of FFQ.
    Slobodan Midic has developed a number of Low-Drag F1A airfoils and  two of them suitable for conventional wings and flapper wings are discussed in his article. Numerical data for these airfoils is obtained using XFoil. Full coordinates of these airfoils, together with their  thickness and camber data are included in the article. Chris Stoddart concludes his three-part article on Scaling for Similar performance, by considering the design of an electric-powered Ramrod  250 sq.in. model of similar performance to the original Thermal Hopper powered design/
    The history of the long-standing Croydon Club of England is told by Keith Miller and Don Thomson. The Club celebrated recently its 75th anniversary and can trace a very distinguished history of major awards and placings in important contests. Mickey Furman shows the indomitable spirit of the true competition flyer. This spirit was sorely tested by a series of calamities when Mickey flew from Israel to the Max-Men contest in California in 2006. The tale of the experiences of Furman in that opportunity will send shivers to anyone who still believes that "nothing can happen" in such occasions, but all ends in a very positive note.

Cover and index of this latest issue can be found in our website : www.freeflightquarterly.com/wordpress




..................
Roger Morrell