At 1642 GMT (1742 local time) a radio message from a member of the crew to Aerodrome Control at Belfast International Airport reported that ZD576 was "now lifting and departing". At 1643 GMT a further message to Approach Control at the airport reported that the aircraft was "outbound" on a course of 027 at low level. A request was made to the aircraft to report at the zone boundary which is approximately nine nautical miles from the airport. At 1646 GMT a member of the crew of the aircraft called up the RAF Strike Command Communications System to report the departure of the aircraft and request a listening watch. There was nothing abnormal about this call. Also at 1646:14 GMT a report was sent from the aircraft to Approach Control to the effect that it had reached the zone boundary and the report was repeated at 1646:24 GMT in response to a request by the airport control official. At 1655:14 GMT a message was received at the Scottish Air Traffic Control Centre (Military) at Prestwick in the following terms: "Scottish Military, Good afternoon this is F4J40" (which was the aircraft's callsign). Although the message was received at the Centre it was not acknowledged for reasons which are not known. The call was not repeated, but there was nothing about it to suggest an emergency or alarm.

  ZD576 was seen by Mrs Tylor at about 5.50 pm local time from her house in Carnlough, County Antrim. She saw it flying so low that she could see the trees on the other side of the glen beside her house above the aircraft. It flew towards the harbour at Carnlough and out to sea parallel to the coast at that point. At the time Carnlough was in sunshine but Mrs Tylor could not see the Mull of Kintyre as it was shrouded in mist. She thought that there was something unusual about the noise made by the aircraft, but the probable explanation for that is that it was a twin rotored helicopter rather than one of the single rotored helicopters which she was accustomed to seeing.

  The last persons to get a good view of ZD576 were Mr Holbrook and his friend Mr McLeod who were sailing in the former's yacht off the Mull of Kintyre. They had missed the tide to go round the Mull that evening and therefore spent about half an hour changing sails and the like about a quarter to half a mile due west of the lighthouse. There was cloud hugging the hillside about the lighthouse but Mr Holbrook could see the whole of the lighthouse itself. At about 5.30 pm local time they set off from the Mull in a south westerly direction and soon found themselves among some fishing boats which they had to manoeuvre around. At that stage Mr Holbrook estimated the visibility at sea level to be "certainly in excess of three miles and possibly five miles". Just after the end of the shipping forecast at 5.55 pm he saw ZD576 approaching from the direction of Northern Ireland. At that stage his yacht was about two miles to the south west or south of the lighthouse. He estimated the range of the aircraft from his yacht to be about a quarter of a mile and its height above sea level about 200 to 400 feet. He estimated this height in relation to the last vertical reference which he had had, namely the height of the lighthouse (the light of which is 299 feet above sea level). At the same time he could see the land mass of the Mull of Kintyre. He could not see the light itself but he could see the position of the lighthouse and a white wall to the south of it. He could also see the land mass of the island of Sanda to the east. The aircraft was in straight and level flight. He was asked about its speed as follows: "Q.—Can you give any impression of the speed of the aircraft in the sense of, did it appear to be gaining speed or slowing first of all? A.—I believe it was in level flight and I believe the speed was constant. Again, with the proviso that I only saw this aircraft for a few seconds and I am not an expert in these matters, but I would have estimated its speed to be something between 60 and 80 knots if I had to put a figure on it. Q.—I take it you accept that that is just, as you have said very fairly, your estimate of it? A.—Sure, but it was not moving any more rapidly . . . This is the first time I had seen a twin-rotor blade helicopter and it wasn't moving at an undue speed relative to a Sea King which would have been engaged in looking on the sea surface for example". Mr Holbrook saw the aircraft heading towards the Mull of Kintyre peninsula. He was asked in more detail about the visibility: "Q.—Now, as far as visibility on the Mull of Kintyre was concerned at that time, you told us you were able to make out the position of the Mull light by first the large wall of the buildings? A.—Just. Q.—What about the Mull itself above the lighthouse? A.—No. I recall the conditions of visibility at sea level as being fine, perhaps as much as five miles. I think at that point I could even see the Antrim coast so it might have been as much as six or seven miles. In the area of the Mull there was low cloud hugging the Mull and also the top of Sanda and I couldn't distinguish the top of the Mull. Q.—So you have a recollection of low cloud clinging on the top of Sanda island? A.—Yes, localised in the Kintyre Peninsula and Sanda. Q.—I don't want to put words into your mouth, but for how long had that cloud been clinging there? A.—That cloud had been there since . . . it is difficult to say, but certainly at the time I started to observe the Mull lighthouse when I was underneath it at 5 o'clock. There was definitely cloud cover not much above the position of the Mull lighthouse at that time. Q.—So, it certainly was not cloud cover that suddenly appeared by the time you saw the helicopter? A.—No, there was a ceiling of cloud so I couldn't see very much blue sky. It was definitely overcast but the general cloud cover, as distinct from this low cloud that was over the Mull and Sanda, I believe that cloud cover was really quite high. I couldn't estimate its height. Q.—But that is distinct from the cloud that is over the Mull of Kintyre and Sanda? A.—Yes."

  In cross-examination Mr Holbrook indicated that the wind had got up to about 25 to 30 knots by the time his yacht reached the lighthouse, and he recollected that it had moved more round to the west as it had got up. Later he said that it was gusting up to 35 knots. He was asked: "Q.—Then once the sail change had been completed you started on your course west generally or south? A.—South west. Q.—Were you aware of the lighthouse still being visible? A.—Yes. I continued to be aware of the lighthouse because of the manoeuvre we were having to do really quite rapidly to get round these boats and there was a check in the general direction I was going in". Later he volunteered: "If you are seeking to establish, do I believe the pilot could see the location of the Mull Lighthouse, yes, I believe he could". He was asked again about the aircraft's speed: "Q.—Your estimate of the speed of this helicopter, how was that done? A.—I was asked . . .How was that done? Probably the only reference I have to that is helicopter activity off Troon. The movement from moving to being stationary. Q.—So you had seen other helicopters flying around? A.—I know what 30 knots looks like in a boat so I would have been able to multiply that up and that is it. That is the limit of my understanding of speed. Q.—So you think it might have been between two or three times faster? A.—Yes, it was not moving at a helluva speed. It wasn't moving at a speed that have caused me to remark on it in any way at all in terms of moving very rapidly from A to B and that is what caused me to think maybe it was looking, that there was some sort of event and it was looking for somebody. I believe the remark I made was "I wonder if he is looking for somebody"." He was also asked about cloud levels again: "Q.—And you could see where land is by the fact the clouds were hugging it? A.—Yes, that is correct. Q.—You say there was also cloud generally over the sea, is that correct? A.—There was cloud. There was general cloud cover, but, I mean, not sunshine but sunlight was breaking through the cloud cover so it was quite light cloud cover. It was very nearly total cover but I couldn't estimate the height of that cover but it was high cloud. Q.—High cloud? A.—High cloud, yes. Q.—So it was higher say than the height of the top of the Mull for instance? A.—The general cloud cover as distinct from this low cloud which was localised over the land mass, yes".

  In the course of his cross-examination of H counsel for Boeing Helicopters put to him a statement which had been made by Mr Holbrook to the Board of Inquiry soon after the accident in which he had stated that, when he had seen the aircraft, the visibility had been about one mile and limited by haze. This statement was not put to Mr Holbrook when he gave evidence in these proceedings and his assertion that he could see the land mass of the Mull of Kintyre and the area of the lighthouse, if not the lighthouse itself, was not challenged. In these circumstances, and bearing in mind the details which he was able to give about what he could see both of the Mull itself and of the island of Sanda to the east, I think that the evidence which he gave to this inquiry should be preferred to the statement which he gave to the Board of Inquiry. But of course it should be borne in mind that, in speaking of the visibility, Mr Holbrook was referring to the visibility at sea level.

  The question also arises whether Mr Holbrook's estimate of the speed of the aircraft at between 60 to 80 knots was correct. In light of other evidence in the case I was at first inclined to think that he had seriously underestimated this speed. But on reflection I am not so sure about the matter. On the two occasions in particular on which he spoke of the aircraft's speed he was quite emphatic that it was not moving at an undue speed and I should have thought that, if it had been travelling at a speed of 150 knots or more (in other words, more or less double his own estimate), he might have noticed that. Besides, if the visibility was as good as he said to this inquiry that it was, it might indeed have been expected that the aircraft would have been reducing speed if I have understood correctly an answer given by H towards the end of his evidence when he said: "If the visibility was such that at two to three miles he (ie Mr Holbrook) could plainly see the Mull of Kintyre or the lighthouse I would have expected the crew to reduce speed and be below whatever the cloud base was, bearing in mind he said he saw the aircraft at between 200 and 400 feet". Such a reduction in speed would I think have been consistent with the crew having seen the land mass ahead and having slowed down in part because of the decreasing visibility and in part to give them time to consider what their next course of action should be. Clearly, if Mr Holbrook was right about the aircraft's speed, that would raise other difficulties. For example, it may be asked why the aircraft thereafter increased its speed again as it approached the initial impact point and why the assistant lighthouse keeper, Mr Murchie, did not hear any sound from the aircraft's engines or rotors consistent with an increase in speed. It is evident too that Mr Holbrook was mistaken about the direction of the wind when he saw the aircraft (although he did correctly recollect its force and also the fact that his yacht would have been beating into the wind) and so it is possible that he might have been mistaken as well about the aircraft's speed. For present purposes I do not think that it is necessary to reach a concluded view on this particular question.

  Mr Murchie was the first witness to give evidence at the Inquiry. He had a particular interest in helicopters. He was sitting in the living room of his house at the lighthouse at 5.55 pm when he heard the sound of a helicopter, which he knew to be the sound of a Chinook, approaching. He immediately went outside to the seaward (west) side of the lighthouse building and heard the aircraft's continued approach from the southwest. At that point he would have been standing at a point about 250 feet above sea level. He was asked about the visibility at the time: "Q.—What was the visibility like? A.—The visibility out to sea—it was just a dense wall of fog, roughly in the region of 20 metres, give or take a few metres either way . . . Q.—At that point did you have any idea as to how far out to sea the fog might have gone? A.—Absolutely none". As he listened to the aircraft approach the area of the lighthouse, it continued at what he felt to be cruising speed. At no time did he actually see the aircraft. He was asked how long he had heard it for: "Q.—You have told us you went out and stood and waited for the helicopter to approach. How long were you standing there before the helicopter as it were went past the building? A.—About two, two and a half minutes. Q.—As long as that? A.—Yes. Q.—Witnesses often estimate time inaccurately in certain situations. Do you mean really two to two and a half minutes? A.—Yes, I do. It was a reasonably quiet night, and I heard it approach from what I thought was a considerable distance. Q.—You have used the words "cruising speed"? A.—Yes. Q.—Did you detect any change in the speed of this helicopter? A—None whatever. Q.—If you are right that you were standing there for two to two and a half minutes and had heard it when you were still in the living room, you would presumably hear the helicopter many miles out to sea; is that right? A.—Yes, that is correct." Mr Murchie said of the weather that day that there "was a light southerly breeze, about seven to 10 knots". He described the sound of the aircraft disappearing temporarily behind the lighthouse buildings from where he was standing, and then he was asked: "Q.—What happened next? A.—I became very concerned at this point, because I knew within myself that he had not the altitude to clear the high ground to the rear of us. I immediately ran to the north west corner of the dwelling houses, which takes one into the drying green area of the dwelling houses, and after one turns inland you can get a view of the entire hillside. Just as I reached that point I heard what sounded like a dull thud, followed by a kind of whooshing, whishing, and within about a further three seconds or so there was total silence. I knew immediately what had happened . . . Q.—What did you believe had happened? A.—Oh, I knew the helicopter had crashed, yes. Q.—When you moved out to look up the hill as you describe were you able to see the top of the hill? A.—No, not at all . . . It was very patchy inland. Most of the top of the hill was entirely covered in fog but one could see a large rock jutting out from the cliff face. Q.—At what sort of distance away from you? A.—Oh, that would be in some cases two or three hundred metres. It was just sort of coming and going all the time, continually changing all the time, but at no time were we ever able to see the top of the hill. Q.—You described hearing a noise and you knew it was a crash. Did you at any stage see the helicopter or any sign of it? A.—Never at any time did I see the helicopter." Mr Murchie went up with the lighthouse keeper, Mr Lamont, to the crash site but it very quickly became apparent to them that there were no survivors of the accident to whom they could give assistance. Later, he confirmed that he had detected no change in the engine noises of the aircraft prior to the thud which he had described and that they had sounded perfectly normal to him. He was asked about his impression of the height of the aircraft: "Q.—Please say if you can't help with this but did you have an impression as to how high above you the helicopter was? A.—No, I am sorry, I couldn't speculate on that I am afraid. Q.—But you did have the impression it would not be high enough to clear the high ground behind the lighthouse, is that correct? A.—That is correct, yes. Q.—You have told us about engine noises and basically there being no change. From your observations did the helicopter at any time appear to change altitude from the time when you heard it out at sea? A.—No, I wouldn't think so. Q.—I mean, do you feel able to comment on that or is that something that you . . . ? A.— . . . I would have thought by following the sound of the helicopter it was maintaining the same altitude all along."

  In cross-examination Mr Murchie confirmed that he had heard no change in the sound of either the aircraft's engines or its rotor blades, though he was evidently familiar with the slapping sounds made by the latter, for example when an aircraft was slowing down or coming into land. He was asked again how long he had listened to the aircraft and he repeated that it had been for nearly two and a half minutes. That I found very surprising given the direction and speed of the wind out at sea and also the direction and speed of the aircraft's travel from northern Ireland. The aftercast prepared by the Meteorological Office for the area of the crash site at the time of the crash indicated that the direction and speed of the surface wind were respectively 170oT and 20 knots gusting to 30 knots. This direction broadly coincided with what had earlier been forecast and this speed coincided with what Mr Holbrook had reported. If the aircraft had been travelling generally from the south-west towards the lighthouse at a groundspeed of 150 knots it would have travelled in excess of five nautical miles during the time that Mr Murchie claimed to have been able to hear it. At least until it approached close under the lee of the land mass near the lighthouse (where the wind might have tended to come round more from the south), the wind would have all the time been tending to blow the sound of the aircraft diagonally away to the north-north-west from where Mr Murchie was standing. Moreover, if Mr Holbrook was right about the speed at which he saw the aircraft travelling (at which point, if Mr Murchie is to be believed, it would have been within range of his hearing), it is odd that Mr Murchie did not hear the aircraft accelerating again to the speed at which it appears to have been travelling in the last few seconds before the initial impact. Moreover, it may be asked why Mr Murchie did not hear the sound of the aircraft's final cyclic flare although he did hear "what sounded like a dull thud, followed by a kind of whooshing, whishing". It is possible that the presence of terrain between him and the initial impact point may have affected his hearing. But in all the circumstances it seems to me that there must be some doubt about the reliability of Mr Murchie's evidence as to what he heard of the aircraft, and for how long he heard it. Again, I do not think that it is necessary for present purposes to reach a concluded view on these matters.

  The lighthouse keeper Mr Lamont was returning in a Land Rover down the road to the lighthouse with his wife when he heard the aircraft passing overhead. He then saw a slight flash of light in his mirror. He was able to confirm how poor the visibility was on the road over the peninsula of Kintyre down to the lighthouse, but otherwise was unable to divulge any useful information about the circumstances of the accident. Similarly, Mr Ellacott the only other witness who was present at the scene of the accident and who gave evidence to the inquiry was unable to cast much light upon what had happened. He described how he and a friend had gone off the road to the lighthouse down a track looking for the remains of a deserted village and a wrecked World War II aircraft. He was asked what happened then: "Q—Did something then happen? A—Yes. We had been sitting for a while, because I was digging some quartz up—my brother collects minerals—and we had just started walking when all of a sudden there was a feeling of pressure all around, and warmth, which instinctively made you duck. There was a sound of helicopter blades for about three or four seconds, then a thud, and like things going up into the air from the ridge we had just walked from, and there was smoke and things flying up in the air and landing all around us". Shortly afterwards he confirmed that he had not heard any sounds of either the engines or the rotor blades of the aircraft before he had experienced the feeling of pressure and warmth. Given the evidence of Mr Murchie as to what he had heard of the aircraft's approach, it is perhaps surprising that Mr Ellacott heard nothing of this. This may be explained by his having been in a hollow or fold of the terrain as the aircraft approached or the noise of his excavations for quartz. But again it does raise a small question mark over the accuracy of Mr Murchie's evidence about the sound of the aircraft's approach.