AIRCRAF T ENGINEERING 226 September , 1930 Some Laboratory Results and Flying Tests of a Novel Type of Control H E problem of low speed control, to which speeds and gave control through the stall when the An experienced pilot who has tried the aileron Professor Melvill Jones drew attention wing-flaps ceased to function. Subsequent modifi report s as follows :— some years ago, has now become so urgent cation s have been made by the inventor a t the full I have unfortunately only been able to test one in aeroplane dynamics as to give special interest to scale stage, while the Air Ministry has given the typ e of machine fitted with the "oyster " aileron, an y device promising tangible improvement on inventio n detailed attention. Further channel which was of a rather unconventional design, and, ordinar y wing-flap ailerons. Mr. Irving described work is understood to have shown it possible to when fitted with normal ailerons, was extremely in ou r June Number the advantage in this respect retai n static lateral control up to wing incidences heav y laterally. of adding wing-tip slots. Mr. K. N. Pearson's exceeding 30 deg. A "Gadfly " tested at Martle- This was, in a sense, an advantage as it made the rotar y ailerons, which dispense altogethe r wit h wing- sha m Heath is said to have given considerably more comparison between the two types of aileron all the flaps, appea r at the stage so far reached in develop climb when fitted with this control; one would more striking, and gave very good proof of the high men t to possess claims to consideration. expec t an interest in effects on efficiency which no degree of controllability given by the oyster. Mr. Pearson's scheme for lateral control is entirely Th e control required a little getting used to, novel. Just beyond each wing-tip is fitted an partl y owing to the mechanical operation which had approximatel y horizontal disc, a fraction of the th e bad habit of allowing the control stick to move chord in diameter, which can be oriented by the a t least half the distance of its travel before the pilot about its central vertical spindle pivoting in control began to operate. a bracket attached as an extension to the front I n consequence the oyster appeared to be some spar. The median section of the disc from "six wha t "snatchy " in operation, though this would to twelve o'clock," say, is tha t of a deeply cambered probabl y not be the case were the control made aerofoil right-way-up; from "nine to three more positive in its action. o'clock " the median section is similar, but upside- Only One oyste r operates a t a time; on a left hand down. Consequently the aileron lifts if it is turn , for example, the left hand oyster only moves, oriented to give "twelv e o'clock" as the direction an d vice versa. of flight, but at "thre e o'clock" it depresses the Eac h oyster is mounted on an eccentric shaft, wing-tip. The grading of section through the disc which allows it not only to rotate on its own axis, gives a floating aileron at about "half-past one" bu t to dip forward at the same time. if it is set a t an incidence suited to the upwash out I n the air, the oyster is remarkably efficient: side the wing-tip. control is still possible almost right down to the stalling point, but when approaching the stall the The useful orientation to produce rolling moment oysters, although still to a certain extent operative, is evidently less tha n 90 deg., and the first consider ar e inclined to "flick" ; thi s may possibly be due to atio n is whethe r a sufficient change of lift co-efficient th e mechanical difficulty referred to above, but in is available with such a surface. Some preliminary an y case is not a serious defect. test s were carried out on this point under Dr. Piercy a t East London College with encouraging results. Th e oyster has one very noticeable peculiarity: it Th e examples given in the figure were obtained is quite possible to dispense with the rudder alto wit h a 5-in. diameter rotary aileron maintained at gether in the air, and make good turns of any angle 4 deg. greater incidence—at zero aileron-yaw— by manipulation of the stick alone. tha n that of a half wing which was fixed to the Th e oyster, indeed, has so much power tha t it will doub t would bo caused by a modification of the side of a channel with its rounded wing-tip 1¼ in. overcome the rudder if the latter is misused in the wing-ti p vortex system. clear of the inner edge of the aileron. The air course of a turn. Certain advantages are apparent, varying greatly speed was 70 ft. per sec. It will be noticed that Should the machine for any reason be flying one wit h circumstances—operational in regard to from 30 deg. to 60 deg. aileron-yaw the interval of wing down, this can a t once be cured by the applica balancin g and whip ; structural in regard particu lift co-efficient is more than 2½ times as great with tion of a little bank on the opposite side, when no larl y to the rear spar. But the appeal of the device th e wing at 18 deg. incidence as with it at 2 deg. rudde r will be needed. mus t rest largely on the ever-prominent yawing I t is claimed from full scale tests, indeed, that the Th e machine will do all the usual aerobatics— momen t question. Measurements do not appear to differential lift increases as th e speed of the machine a loop, roll and spin—and behave in a perfectly be yet available for publication with recent forms decreases through a useful range. norma l manner as if fitted with ordinary ailerons. of rotary ailerons, but Mr. Pearson states from Th e only difference on the particular machine An aeroplane of well-known make was fitted, in flying experience that the rudder-bar may almost flown was that when fitted with standard ailerons additio n to its standard ailerons, with rotary be neglected in ordinary flying with their use and tha t they make it possible to turn out of a spin in i t was almost impossible to acrobat, owing to the ailerons of one-fifth their area, permitting the th e natural way without a preliminary nose dive. extrem e heaviness of the lateral control, but with alternativ e systems to be tested against one another If this is substantiated their comparatively light th e oysters fitted, it behaved like any normal durin g flight. It is claimed that the rotaries with weigh t may prove an attraction. aeroplane. 14 deg. movemen t proved nearly as stron g a t normal
Aircraft Engineering and Aerospace Technology – Emerald Publishing
Published: Sep 1, 1930
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera