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The Pearson Rotary Aileron

The Pearson Rotary Aileron 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 http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Aircraft Engineering and Aerospace Technology Emerald Publishing

The Pearson Rotary Aileron

Aircraft Engineering and Aerospace Technology , Volume 2 (9): 1 – Sep 1, 1930

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Publisher
Emerald Publishing
Copyright
Copyright © Emerald Group Publishing Limited
ISSN
0002-2667
DOI
10.1108/eb029311
Publisher site
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Abstract

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

Journal

Aircraft Engineering and Aerospace TechnologyEmerald Publishing

Published: Sep 1, 1930

There are no references for this article.