I would like to express my thanks to the Council of theRoyal Aeronautical Society for inviting me todeliver this lecture. I am very happy that thishonour has been extended to me: I am happy formyself, and also for my country, Barbados, one ofthe newest sovereign states, but one which hasevolved with the British Commonwealth. Ourrelationship has existed since 1625 and apart fromwhat I believe to be the first case of UDI in theBritish Colonial Empire in the Cromwell era, we havebeen stalwart members of the club.

In November 1966 Barbados became a sovereign state, thecolonial days were over. From here on we have been afull member of the British Commonwealth ofNations.

In their time few writings on the .subject of aviationcan have been as avidly read, as furiously debatedand as lovingly quoted, as have those signed“C.G.G.” The initials stand for Charles Grey Grey.Spelt with an “E”. Both times. My recollections areof a man with no special gifts in the way ofscientific ability or technical achievement 'who, inthe most advanced industry of his day, grew to astature when he became a figure of much concern toindustrialists and civil servants alike. He walkedand flew with dictators but, though very much a manof the right, never lost the common touch. Somebody,I think it was the late Roland Dangerfield, calledhim a “democratic old aristocrat”.

Sir William Hildred drew upon his personal experiencesuntil 1966 as Director General of the InternationalAir Transport Association.

That body worked closely with the International CivilAviation Organisation (ICAO)—the author, instigator,and watchdog of Annex 9 of the Chicago Conventionwhich dealt wholly with the subject of facilitation.Neither body had legislative power. ICAO could onlymake recommendations but these required the assentand action of Sovereign Governments before theybecame effective. The President of ICAO had said itwas the increase in passenger and cargo volume whichcreated the problem but Sir William ascribed a gooddeal of it to the entrenched conservatism ofGovernments and their operating agencies.

Annex 9 to the Convention on International CivilAviation is entitled “Facilitation” and in theforeword to the fifth edition there is what might betermed a definition of facilitation … “all practicalmeasures, through the issuance of specialregulations or otherwise, to facilitate or expeditenavigation by aircraft between the territories ofContracting States, and to prevent unnecessarydelays to aircraft, crews, passengers and cargo,especially in the administration of the lawsrelating to immigration, quarantine, customs andclearance”. I am here to give a shipper's view offacilitation and therefore, am concerned only withcargo. I hope my views are not coloured byexperiences I have had as crew or passenger whichtend to be much more personal and immediate.

I had intended to speak about passenger control, andcargo control is not really my subject.Nevertheless, in view of what has been said byprevious speakers, there are one or two points oncargo matters which perhaps I might make at thisstage. I should first of all say how admirably Ithink Mr. Leeper dealt with a number of the pointsraised by Sir Archibald Hope. I do not think hecould have put the general Customs point of view ina better way. I was not always sure whether thespeakers were referring to their experiences withthe UK Customs or with other countries’administrations and I think several of them didadmit that their criticisms were not levelledagainst the home customs.

Immigration control is an expression of nationalinterest. The objective is to ensure that, of allthose people who wish to come from abroad to workand settle here, we should accept only those whom itis in the national interest to accept. The processof selection must be operated in a way which doesnot delay or inconvenience the great generality oftravellers.

In more detail, the current objectives of the UKimmigration control are: —

1. (a) to prevent theentry of people who are personally unacceptable,for example, because of criminalrecord;

2. (b) toprotect and supplement the resident labourforce;

3. (c) toprevent immigration of a type, and on a scale,which might give rise to serious socialproblems.

The organisations involved in health facilitation are 3international ones, 1 national one and 1 localone.

The three international ones are:

(a) The World Health Organisation, an offshoot of theUnited Nations and before that the League ofNations. This body has headquarters at Geneva anddisseminates on a daily basis, world-wideinformation on epidemic diseases, thus keepingcountries fully informed of the current diseaseposition in other countries.

(b) The International Civil Aviation Organisation,which is a consortium of Government Agencies whichdraws up statutory regulations for the internationalcontrol of air travel including, among others,personnel and medical problems. Its objective is toimplement the Chicago Convention which, in turn, wasthe successor to the Paris Convention. It isobviously desirable that recommended practices ofmedical standards for pilots should be uniformthroughout the world. Sir Frederick Tymms was at onetime the UK representative.

(c) The International Air Transport Association, avoluntary organisation of air operators whichendeavours to regulate conditions among commerciallycompeting airlines. The medical committee, likeother committees, makes an annual report to theExecutive. Sir Wjlliam Hildred was its distinguishedchairman for many years.

The lecture I am going to give attempts to cover, inforty-five minutes a subject that really merits aseries of lectures. This, of course, displays afitting disregard for minor difficulties, of which,I am sure, the dauntless spirit of Sir George Cayleywould have approved.

The broad title permits consideration of all methods ofintelligence gathering from the air, including themore widely known optical photographic systems, andhas been deliberately selected for this purpose. Toavoid clumsy and longwinded definitions I willfrequently have recourse to the the use of “in”terms such as Sensor, Multi-Sensor, Exploitation,Environment and many others.

I Feel highly honoured at having been asked to deliverthis inaugural lecture as a prelude to the bi-annualseries of Memorial Lectures on the development ofCivil Aviation in South Africa. This lecture will bedevoted to the man—Major Allister MacintoshMiller.

Much has come about in the field of Civil Aviationsince the days I am going to speak about. Space andtime have been telescoped. Colossal strides havebeen made. In this hall tonight I see a number ofpersons who, like myself, are able to make thecomparison between the civil aircraft of vintage1919 and the civil aircraft of today.

Determination of the cross-sectional dimensions ofpanels of least weight typically follows theprocedure set out by D. J. Farrar in this JOURNAL 20years ago. Farrar made the assumption that forpanels of least weight the flexural and localinstability stresses were coincident. Using this heinvestigated the Z-section stringer-skin combinationand later, using the same method, E. J. Catchpolestudied the panel having unflanged integralstiffeners. In both cases the panel is treated as awide strut, i.e. the flexural buckling load wastaken to be the Euler buckling load, no accountbeing taken of the effect of edge restraint.

It is a well-known fact that buckling values forcolumns under dynamical loads are different fromthose under static loads. Meier, Gerard and Davidsonhave already investigated the dynamics of thebuckling of elastic columns theoretically andexperimentally, and Hoff discussed analyticalmethods in detail. However, solid viscosities areneglected in all these researches. Previously, theauthor obtained the relationships between dynamicload factors and solid viscosities, and it was foundthat their effects on dynamic load factors cannot beneglected. It will be interesting to investigate therelationships between solid viscosities and dynamicbuckling values.

The rectilinear flow of an incompressible viscous fluidalong a duct of uniform cross section due to anoscillating pressure gradient has been considered bya number of investigators. The duct of circularcross .section has been treated by Richardson andTyler and Sexl, the elliptic case by Khamrui, andthe rectangular case by Drake and Fan and Chao.Recently Jeng has discussed the importance of thistype of flow and has given a procedure forcalculating a numerical solution for a duct ofarbitrary cross-section. An interesting feature ofthese flows is that, at large frequencies when theflow is of boundary-layer type, the velocity at anyinstant has its maximum near the walls, the velocityovershooting its almost uniform distribution at thecentre of the duct.