They are going to the test in Jones' van, but Walker has been using it to fulfil a blackmarket order for Warden Hodges, the greengrocer, and has half a ton of onions.
The test is supervised by Captain Ramsey, a tough, no-nonsense officer who berates the platoon for their shortcomings, particularly Pike, who is crying from his contact with the onions.
However, it does not go well for them as Wilson is so indifferent to the role-playing that it loses all effect, Jones attempts to throttle Ramsey when his back is turned (because he had told Jones he was going to be a Gestapo officer) and Wilson ruins Mainwaring's test by pointing out that Mainwaring wouldn't have to push anyone out of a declining hot-air balloon as he could wait for it to land on the ground for the excess passenger to step out.
Remembering Wilson's advice from before, the platoon grab her, knocking over her trolley and pulling her hair, believing it is a wig, to which she responds, "Oh, you're worse than the Regulars!"
The next exercise is to get each man over a tall electric fence in half an hour using only equipment provided to them (mostly wooden planks and oil drums).
Jones inevitably volunteers to be the first over the fence, and tries to get Walker to catapult him over, but in doing so they break the only decent long length of wood, thus dooming all other attempts to failure.