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IN THE SUPREME COURT OF SOUTH AFRICA (APPELLATE DIVISION)

In the matter between:

CASE A
BATES & LLOYD AVIATION (PTY) LTD 1st Appellant
and
GORDON LANG & RICHARD ANTHONY LYONS 2nd Appellant

versus
THE AVIATION INSURANCE COMPANY Respondent
CASE B
BATES & LLOYD AVIATION (PTY) LTD Appellant

versus

THE AVIATION INSURANCE COMPANY Respondent

CORAM: TRENGOVE, NICHOLAS,, HEFER JJA, GALGUT et SMALBERGER AJJA

HEARD: 4 March 1985

DELIVERED:

JUDGMENT

NICHOLAS, JA

I

2 I agree with GALGUT AJA that the appeal should be upheld, and I agree with the form of order proposed by him. Since, however, my approach differs somewhat from his, I set out my reasons briefly.
At 7.48 a m on 4 April 1978 a Beechcraft Baron aircraft took off from Lanseria airport near Johannesburg. It. was piloted by George Bates ("the pilot") and carried two passengers. At 8.45 a m the aircraft flew over Pietersburg at a height of 9,500 feet above sea-level. Some time later, it was heard by one Dinani, an employee at the Louis Trichardt airfield, which was under heavy mist at the time, flying above him.

It
3 It was seenuat about 9.00 a m by Du Plessis, who was working at the farm Nebo, 1,5 kilometres North-West of the airfield, flying in a northerly direction at a height of some 200 feet above the ground. Shortly afterwards the aircraft crashed into the cloud-covered side of the Soutpansberg. The aircraft was totally destroyed, and the pilot and both passengers were killed.

Arising out of the accident, two actions were instituted: one (referred to as "CASE A") by the AVIATION INSURANCE COMPANY LIMITED ("the insurer") as plaintiff; the other (referred to as "CASE B") against the insurer as defendant. The trial of the two actions was

consolidated
4 consolidated. Both were decided in favour of the insurer by MYBURGH J sitting in the Transvaal Provincial Division.
The issues in the two cases are set out in the judgment of GALGUT AJA. Two of those issues were fundamental to the decision of both cases. They were (a) whether the accident was caused by the negligence of the pilot, and (b) whether the pilot committed breaches of the Air Navigation Regulations ("ANR") and the Rules of the Air Regulations ("Rules"). If both of those issues are decided against the insurer (the present respondent) the appellants are entitled to succeed in the appeal irrespective of the remaining issues.

In

5 In regard to (b), I agree with GALGUT AJA that the insurer did not discharge the onus of proving that there was any breach of ANR or Rules.

In regard to the issue of negligence, the onus was on the insurer.
In viewing the evidence and considering the probabilities, the trial Court had to regard the matter from the point of view of a reasonable, experienced pilot. Lacking the special knowledge and skill required to do that, the Court needed instruction by expert witnesses. This was provided by Col. Jandrell, who was called on behalf of the insurer, and Capt. Worthington, who was called on behalf of the appellants. Both were highly

qualified
6 qualified pilots with considerable experience in all branches of aviation. Their function was two-fold: to instruct the Court generally in connection with the piloting of aircraft, and to give opinion evidence on matters in which they were better qualified than the Court to draw inferences, by reason of their special knowledge and training.

Inference, it was observed by LORD WRIGHT in Caswell v Powell Duffryn Collieries Ltd (1939) 3 All E R 722 at 733) must be carefully distinguished from conjecture or speculation:

"There can be no inference unless there are objective facts from which to infer the other facts which it is sought to establish. In some cases the other facts can be inferred with as much practical

certainty

7

certainty as if they had been actually

observed. In other cases the inference

does not go beyond reasonable probability.

But if there are no positive proved facts

from which the inference can be made,

the method of inference fails and what

is left is mere speculation or conjecture."

(This passage has frequently been quoted by this Court.

See S v Essack 1974(1) SA 1 (A) at 16; A A Onderlinge As-

suransie Bpk v De Beer 1982(2) SA 603(A) at 620; Motor
Vehicle Assurance Fund v Dubuzane 1984(1) SA 700(A) at

706. Cp. R v Ndhlovu 1945 AD 369 at 386, R v Dhlumayo

1948(2) SA 677(A) at 678. )

From both inference and speculation must be distinguished hypothesis. This is a theory advanced in explanation of the facts in evidence as a basis for an

inference
8
inference. To be logically sound, it must be consis
tent with all the proved facts, and it must not postulate
facts which have not been proved. It may be advanced
by a legal representative or, where the subject is a tech
nical one, by an expert witness. The process of
reasoning by inference frequently includes consideration
of the various hypotheses which are open on the evidence
and in civil cases the selection from them, by balancing
probabilities, of that hypothesis which seems to be the
most natural and plausible (in the sense of acceptable,
credible or suitable). Cp. Ocean Accident and
Guarantee Corporation Ltd v Koch 1963(4) SA 147(A) at 159.
In the present case the only negligence which

could
9 could causally be connected with the crash would be negligence in the piloting of the aircraft from the time it arrived in the Louis Trichardt area until the accident. In that regard there is a paucity of facts, due to the death of those who were directly involved. The facts as they are known are set out in the judgment of GALGUT AJA. They include the weather conditions prevailing at the time as described by observers on the ground (although such observations are not always a safe guide to what could be seen by a pilot in the air): the facts relating to the passage of the aircraft as deposed by Du Plessis and Dinani; and the topography in the area.

The allegations relating to negligence are set

out

10

out in the insurer's particulars of claim in CASE A as

follows:

"7. The said crash was solely caused by the negligence of the pilot who was negligent in one or more or all of the following respects:

(a)	He failed to maintain a safe flight trajectory;
(b)	He failed to maintain a safe and/or the minimum permitted height above the ground;
(c)	He failed to divert away from adverse weather conditions;
(d)	He attempted a navigational flight when under the prevailing weather conditions it was dangerous and/or. reckless, and/or inadvisable and/or contrary to valid flying regulations for a pilot of his experience and qualifications so to do;
(e)	He entered instrument flying conditions when he was not qualified or competent so to do;
(f)	He failed to have due regard for the readings on the instruments of the aircraft;

(9)

11

(g) He failed to avoid a crash when by the exercise of reasonable and/or necessary care he could and should so have done."

The allegations in sub-paras (b), (d) and (e) are closely bound up with alleged breaches of the ANR and Rules. As appears from the judgment of GALGUT AJA the alleged breaches were not established, and these particulars of negligence were not proved. There was no evidence in regard to (f) and it can be disregarded.
The facts alleged in (a) and (c), and the fact alleged in (f) (that the pilot failed to avoid the crash), were established on the evidence. The question then is whether the proper inference from those facts is that the pilot was negligent. The submission of counsel for

the

12

the insurer was this:

"It is therefore submitted that the pilot on these facts did one of two things: he either saw the inclement weather ahead and, instead of diverting, flew into it, or (which seems more probable) he was flying IMC (Instrument Meteorological Conditions) for some time

and had lost his way

On either of these hypotheses, the pilot was negligent and his failure to turn left in the circumstances inexplicable."

The possibility that the pilot, seeing the inclement weather ahead, deliberately flew into it, can be discounted: he must have seen the cloud ahead and he must have known that it shrouded the Soutpansberg and it would have been suicidal for him to fly into it of set purpose.

That the pilot had been flying in IMC for some time, and that he had lost his way, are both improbable.

He

13 He was flying below the cloud base, and had presumably been doing so for some time. There is no evidence as to the weather conditions below the cloud base between Pietersburg and Louis Trichardt, but from the fact that the pilot arrived over the airfield "virtually on time" as Worthington said, it is probable that he had been flying with visual reference to the ground features which are described by GALGUT AJA. Worthington's expert evidence was that the only way for the pilot to have reached the airfield accurately was visual map-reading navigation. Apart from the fact that the airfield itself was covered with thick mist (which may have been a local "pool") and apart from the 'cloud covering

certain
14 certain hill-features, there was no evidence that the ground in the Louis Trichardt area was obscured by cloud or mist.
The. reason for the pilot's conduct in respects (a), (c) and (g) must therefore be sought elsewhere. The submission on behalf of the appellants is that it is to be found in the explanation given by Worthington.

It is mainly in regard to the status of that explanation that I diverge from the judgment of GALGUT AJA. In my view the explanation did not constitute proof of how the accident occurred. It was not possible on the evidence properly to draw any inference as to what the pilot actually did, or saw, or knew, or expected.

Worthington's
15 Worthington's explanation was no more than an hypothesis, a theory as to what might have happened. worthington himself recognized it as such: he was giving "a reconstruction of what probably occurred"; he was "only surmising", "supposing","trying to get a reasonable assessment of what the pilot might have done".

An attempt was made in cross-examination to get Jandrell to comment on Worthington's explanation. He refused to do so, saying, "I do not know what the pilot was doing"; "We do not know .... these are all hypothetical questions put to me". Consequently one does not know what flaws, if any, lurked in the explanation.

It

16 It is an hypothesis which was not based on fancy, but had a substantial foundation in fact. It was logically sound: it was consistent with all the facts (including the features that were shown, and those that were not shown! on the aeronautical chart on which the pilot was flying); and it did not postulate any facts not proved. It was consistent with no-negligence on the part of the pilot.

There was no onus on the appellants to prove the explanation. All they had to do was to show a balance of probability in favour of the view that the pilot acted without negligence. (See Arthur v Bezuidenhout and Mieny 1962(2) S A 566(A) at 575.) In view of the

fact
17 fact that the hypotheses advanced on behalf of the insurer are improbable, I think that the appellants did show such a balance. It follows that the insurer did not discharge the onus of proving that the crash was caused by the negligence of the pilot.

This conclusion makes it unnecessary to consider any of the other issues in the two cases, and I prefer not to express any opinion about them.

H C NICHOLAS, JA

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