(I suspect if you are a civvy you just got yourself a brownie point for finding your way to the right place to ask people who would know )
While awaiting the info you are after... I looked online to see what RCB meant (doh!) ..and found the following....
I know it's impossibly dated but for those of us without a clue ........ an interesting read I thought........ Extracts from a Manchester Guardian article of 16th October 1980
Leighton Park, Westbury, in Wiltshire, is the home of the Army's Regular Commissions Board. It is where, since the end of National Service, every boy or girl, man or woman, who wishes to become an officer in the British Army is assessed and accepted - or assessed and rejected.
The officers chosen to look out for the leaders of the future are the most assured group. They are all "high flyers" - a spell at Westbury is no sinecure - and their task is to recognsie their potential replicas. They themselves are selected for an RCB stint because they have shown an ability to relate to young people, to get best out of people in a short time, and to judge character. They are also chosen for their wide experience of the Army and its requirements, both in this country and abroad.
Even with these qualifications the officers know that they do not always make correct choices - Sandhurst, the Army's military academy, has its drop-outs and failures. But their self-assurance stems from the fact that they feel there is damn all they can do about such lapses. No system is perfect.
The Army's procedure for selecting potential officers has been spat upon and polished continuously since the Second World War when the first attempts to be scientific about selection were introduced. The procedure now shines like a toe cap, and the other services have formed commissions Boards along the same lines. Industry and commerce have aped a few principles. Even detractors admit that the Board is impressive. Detractors? Chiefly those who see something unpalatable about the number of public schoolboys among the officer class. Exact figures are not easy to find. MPs asking parliamentary questions have been fobbed off with evasive answers that figures are not "readily available".
In any given year, and bearing in mind that only about five per cent of children go to public school, the RAF selects around 17 per cent of its new officers from public schools; the Royal Navy around 28 per cent and the Army around 50 per cent.
To the Army the difference in figures is altogether explicable. They dismiss it in a much used slogan: "The other services man equipment and we equip men." In other words, the navy and the air force are seen as technical organisations where ability to acquire knowledge and pass examinations is of paramount importance. The Army still thinks it requires "a certain kind of person to lead men".
So how are officers chosen? When I first glimpsed the eight potential officers whose fortunes I was to follow for the three days, they were seated in a circle, suited and smoking. They were debating such subjects as whether or not the police should be armed and to what extent Western Europe should support Carter ... The topics were being tossed at them by a young major whose task was not to assess their political views, but merely to relax the group and give them a chance to get the measure of one another: who sat silently, who talked too much, but said little of value; who made sure the conversation didn't wander off the subject.
Apart from a tendency to sit on the edges of their chair, the eight seemed fairly relaxed. The pass rate has improved significantly since the introduction of the two-day RCB Briefing and is now around 45 per cent (out of 1,500). Of the eight I followed, four made the grade in the end. The discussion group was not the only chance the eight had to display their powers of verbal expression. Their final test was to be a five minute lecturette in which they talked on a subject of their choice. Much came inbetween. Written tests to assess innate intelligence; two essays to assess ability to lead, and in turn to be led - to be supportive; tests to discover physical fitness, practical ability and planning capacity.
In addition there were three one-on-one interviews which skilfully unravelled what a candidate had achieved measured against his opportunities, as well as discovering why he wanted to join the Army: "I have a horror of sitting behind a desk and becoming unfit"; "In need of a tight reign at the moment"; "Good fun and it will stand me in good stead for the future".
Perhaps oddly, nobody asked them their attitude to killing. "We'd get silly answers, wouldn't we? Anyway, we take it for granted that if they have the qualities to make an officer they will have no trouble sticking the knife in when the moment comes."
The planning exercise, although hideous at first glance, held all the fun of a management game - two trapped mountaineers who needed rescuing and half a dozen ways in which they could be reached and transported to hospital. The candidates had one and a half hours to write out their individual solutions and then they came together to agree a corporate solution. This showed who had a good idea, but was easily deflected; and who quickly saw that someone else had a good idea and took it on board. There were few surprises, but most candidates glossed over the sums involving time and distance.
The outdoor exercises proved more divisive. They are often more difficult than they appear and they are designed, above all, to test an individual's ability to cope with stress. The corporal blew it. He briefed his men well enough to start their task, but clearly did not know how to see it through. Rather than seek their help, he stood on the sidelines, yelling: "Come on gents, get on with it!" No. 53 fared little better. They both, as they say in the Army, had a "cool" problem. They had to be failed.
At the end of the 72 hours, the selecting officers fill in formidable which attempt to grade the personal characteristics of each candidate: coolness, sense of urgency, dominance, liveliness, initiative, determination, military compatibility, sense of responsibility, sense of awareness, quality of personal relations, range of personal relations and maturity.
Coolness is not at the head of the list without reason. Sandhurst, as they say, can cure many an inadequacy, but not an inability to cope with stress. "Many people," the Army argues, acquire way of coping with the social and technical requirements of their jobs when in familiar surroundings, but under conditions of stress more superficial attitudes give way to more deeply ingrained patterns, and with the degree of stress to which an army officer can be subjected at certain periods, it is particularly important that his basic personality pattern is appropriate.
The discussion on each candidate was extremely detailed throughout the 72 hours. The selecting officers met regularly to exchange notes and make interim judgements. This enables them to identify borderline candidates and to concentrate on observing them as the hours wear on. Safeguards are built into the system so that no officer has all the various reports to hand until the final session.
It is difficult to detect bias. The public school boys appear simply to provide what the Army wants. And, on my small sample, the comprehensive school boy was unassuming and had difficult in making his presence felt. On the face of it, this was not a good omen for life on the Army.
The Army will not lower its standards in order to fill places, and Westbury staunchly continues to maintain that they couldn't give a damn where a boy comes from. If he looks like making an adequate officer they will take him.
A more interesting question, perhaps, is what would the Army do if there were no public schools? And what is it about a public school education which give boys such assurance? If the comprehensive boy had gone to such a school would he have been more assertive? Or would the environment have made him even more retiring?
Re mental aptitude tests, I think the main one is the planning task (a while ago for me but I doubt that much has changed). You should be able to get samples of these from your sponsor Regt / Corps when you do your pre RCB. If you want them before then why not give them a ring and ask them. They will have a selection and may have some old ones that they don't use and are willing to give out The planning tasks are along the lines of "you and 5 students are stranded in Outer Arrseland after your MOD issue rolls royce breaks down. You are all hideously injured, you have nothing of any use (3 teaspoons of water, a rubber duck, a PRC349 and an ETH), you can crawl at 1 mph on metalled roads and 2 mph on tracks, but will need 1/2 a teaspoon of water every hour and a thai massage if you choose the northern route. You need to get a message to the british embassy in Plopplop etc etc etc. You have half an hour to come up with a plan and brief your team".
Practising doing speed / distance / time in your head while under a bit of pressure is very good preparation for these sorts of things. When I needed to do this for a later course I used to do it while driving - using every sign post, and while doing PT.
I 'broke' one of their mgt planning exercises once. Brought DS to silence as they tried to work out what was wrong with my plan.
Problem: Route 3 went past bandits and you had 3 casualties moving by stretcher with four people carrying but they had to stop after every 10 minutes carrying for 4 minutes rest but the bandits would attack if the caravan stopped moving for more than 3 minutes.
Solution: Took route 3 but rested every five minutes for two minutes thus achieving mandatory rest minimum in 14 minute peiod. But also achieving same rate of travel over ground and amking it to the rescue boat on time (I was also able to rotate the carriers as there were more than 12 and increase the time travelled over ground)
Stick that in your pipe and smoke it oh Education Major with an attitude. DS did have to sit in silence and then say things like "but you said this wouldn't happen unless you do this and I'd argue the point even though they knew they were wrong and arguing a losing position" - ho hum.