The third contention is, I think, met by sec. 14 of the Commonwealth Crimes Act 1914-1932. Rule 64 of the First Schedule and reg. 135 (5) permit matters to be raised by way of defence which are, in my opinion, "excuses" within the meaning of sec. 14. The onus of proving such "excuses" rested, by virtue of sec. 14, on the applicant, and the evidence does not show that the onus was discharged.

I come now to the first contention, that rule 51(1) is invalid. This contention is founded on the view that there is a fatal disconformity between this rule and the relevant part of the Convention for the Regulation of Aerial Navigation signed in Paris on October 13th, 1919, which is the source of the power of the Commonwealth with respect to air navigation within a State: See R. v. Burgess; Ex parte Henry[27]. Rule 51(1) of the First Schedule provides that: "An aerodyne shall not, except when departing or landing, fly over an aerodrome at a lower height than 2,300 feet." An aerodrome is defined by reg. 5 as: "any definite ground ... used ... for the landing or departure of aircraft, and includes the landing area, neutral zone, and building area included within such ground."

It is clear that rule 51(1) of the First Schedule purports to carry into effect in Australia part of clause 39 of annex D of the Convention. This part of clause 39 provides that: "Subject to any special local regulations which may exist - (a) Flight over a landing area at a lower height than 700 metres is prohibited for aerodynes, save in the case of a departure or landing." It is stated in annex A that (in annexes A to G): "The expression landing area shall mean the part of an aerodrome reserved for departures and landings of aircraft." It is contended on behalf of the applicant that, because of the words "flight over a landing area" in clause 39 (a) of annex D of the Convention and the meaning given to the expression "landing area" in annex A, rule 51(1) of the First Schedule, in prohibiting flight over an "aerodrome" (as defined by reg. 5), and not merely over a "landing area," has failed to carry out or purported to go beyond the provision of the Convention. It appears that the applicant flew an aeroplane at a height lower than the prescribed height over the neutral zone at the Mascot aerodrome. If rule 51 (1) of the First Schedule is valid, he is liable for flying over any part of the aerodrome; whereas, if it is invalid, the prosecution has been instituted on a false basis.

The applicant's contention makes it necessary to consider whether rule 51 (1) of the First Schedule is in conformity with the terms of the relevant part or parts of clause 39 of annex D of the Convention. The opening words of clause 39, viz.: "Subject to any special local regulations which may exist," indicate that the clause is not meant to fetter in any way the power which any party to the Convention may have had prior to the Convention, or may later acquire, of making regulations relating to the subject matter dealt with in the clause. The clause provides an agreed regulation which should stand in the absence of the exercise of any such power. It could hardly be said that, vis-a-vis the other parties to the agreement, the Commonwealth would be violating any right in them arising from the agreement by enacting regulations (extending to intra-State flying) covering the same subject matter as is covered by clause 39, but entirely different in detailed provisions. But whether the introductory part of clause 39 authorizes the Commonwealth to make any local regulations of its own, which would have a different operation from the clause itself, does not require to be decided in this case, unless the narrower question whether rule 51 (1) of the First Schedule is in conformity with the particular terms of clause 39 (a) were answered in the applicant's favour. In my opinion, that question should be answered adversely to him. His contention is based on the use of the word "aerodrome" in rule 51 (1) and the expression "landing area" in clause 39 (a) of the Convention. The meaning attached to the expression "landing area" in annex A of the Convention is provided, in my opinion, as a definition which distinguishes for relevant purposes of the Convention that part of an aerodrome where aircraft may land from other parts of an aerodrome, namely, the neutral zone (if there be one) and the building area (if there be one). The definition aids the application of provisions which direct that acts be done to, or in respect of, that particular part of an aerodrome, which are not to be done to, or in respect of, the other parts. There are certain provisions, as, for example, the provisions relating to ground markings contained in sec. IIB of annex D, in which the definition is clearly relevant and useful. The expression "landing area" is used, however, in other provisions (of which clause 39 (a) is one) in which it is not clear, in my opinion, that only the particular limited part specifically known as "landing area" in relation to the whole area is referred to. In such provisions it may well be that, by a natural synechdoche, the reference to the part of the aerodrome known as the landing area, which is the largest and really distinguishing part, was intended to be a reference to the whole of the aerodrome. Such may be the case, for example, in clause 39 (b) of annex D, in which "every aerodyne flying outside a landing area at a distance of less than 2,000 metres from the nearest point of such area shall ... keep the landing area on its left." Such a view of this sub-clause seems to be strengthened by a consideration of it in conjunction with the next following clause (clause 40), which prohibits aerial acrobatics "at a distance of less than 4,000 metres from the nearest point of the perimeter of the aerodrome." It is hard to say with certainty that the parties intended the measurement of the prescribed distances to be made from a different line in each case, particularly as the prescribed distances are large and the intervening space between the two lines, where two exist, would be relatively negligible.

Conversely, in various provisions of the Convention (for example, clauses 35 (a), 43, 44 (a), 44 (c) and 44 (f), which relate to landing on or starting from an aerodrome) the word aerodrome is used where the expression "landing area" may have achieved greater literal accuracy. But although the word aerodrome is used in these provisions, it appears that they bear rather upon operations proper to a landing area; and to extract, for example, from the use of the word "aerodrome" in any of such provisions a licence to land on the neutral zone, because actually the word "aerodrome" which includes the neutral zone has been used, would be straining the intention of the provisions by meticulous literalism: See McDermott v. Owners of S.S. Tintoretto[28], per Lord Shaw of Dumfermline; Burns Philp & Co. Ltd. v. Myrhe[29].

Is it certain that the expression "landing area" in clause 39 (a) of annex D was used to describe a particular area of an aerodrome as distinguished from the whole aerodrome? It is difficult to see any reason for restricting the prohibition to the particular area and to leave the rest of the aerodrome free from it. On account of the proximity of these parts to the landing area itself (where on any particular aerodrome these parts have been marked off) and their smallness in comparison with it and the great speeds at which aircraft can and do fly, it is difficult to see that any reasonable purpose is served by reading the expression "landing area" in clause 39 (a) of annex D to mean an area less than the aerodrome. And if the true object of the clause is to achieve order and safety in the circumstances contemplated in the provision, rather does reason lie on the side of treating the reference to the delineated area as standing, by a natural usage of language, for the whole; for, indeed, the term "landing area" is expressive of the primary function of an aerodrome. Counsel for the respondents advanced a cogent argument in this regard, which I may express in this way: that, if the object of the clause is to avert danger to life and property, why should it be read as permitting flight over the building area and the neutral zone, where, owing to the presence of buildings, equipment and machines, and frequently many people - and sometimes large crowds - two aircraft, having collided and fallen, may cause extensive loss and tragedy, while forbidding it only over that open and clear area where there is no property and seldom any persons? If, of course, the expression "landing area" is absolutely rigid and cannot in reason refer to anything more than the delineated area in any context, then, whatever the consequences, it must be so interpreted; but, in my opinion, the expression has the rigidity of the definition only for relevant and useful purposes, and in the provision now being considered it can have a wider and quite reasonable connotation including all the area which makes up an aerodrome.

But in order to sustain the validity of the Commonwealth regulation it would be enough to show that there are reasonable grounds for doubting that the prohibition in clause 39 (a) of annex D was intended to be restricted to an area less than the aerodrome: See Shell Co. of Australia Ltd. v. Federal Commissioner of Taxation[30]. There is, in my opinion, as has been shown, at the least, such reasonable doubt. The appellant's contention, therefore, that rule 51 (1) of the First Schedule, upon which the prosecution was based, is invalid, should fail.

For these reasons I think that the appeal should be dismissed and the order nisi discharged.

Appeal dismissed. Order nisi discharged with costs.

Solicitor for the respondent, H. F. E. Whitlam, Commonwealth Crown Solicitor.

[1] [1936] HCA 52; (1936) 55 C.L.R. 608.

[2] [1936] HCA 52; (1936) 55 C.L.R. 608.

[3] (1936) 55 C.L.R., at pp. 645, 696.

[4] [1936] HCA 52; (1936) 55 C.L.R. 608.

[5] (1936) 55 C.L.R., at pp. 674, 684.

[6] (1936) 55 C.L.R., at pp. 659, 660.

[7] [1936] HCA 52; (1936) 55 C.L.R. 608.

[8] [1936] HCA 52; (1936) 55 C.L.R. 608.

[9] [1936] HCA 52; (1936) 55 C.L.R. 608.

[10] (1929) 73 Law. Ed. (U.S.) 287 [278 U.S. 235].

[11] [1935] USSC 107; (1935) 295 U.S. 330, at p. 361; [1935] USSC 107; 79 Law. Ed. 1468, at 1482 et seq.

[12] [1936] USSC 91; (1936) 298 U.S. 238, at p. 312; [1936] USSC 91; 80 Law. Ed. 1160, at p. 1189.

[13] [1930] HCA 52; (1930) 44 C.L.R. 319, at pp. 374, 386.

[14] [1931] HCA 1; (1931) 44 C.L.R. 492, at pp. 513, 529.

[15] [1932] HCA 12; (1932) 46 C.L.R. 246, at p. 259; cf. p. 272.

[16] (1936) 55 C.L.R., at p. 689; cf. pp. 655, 675.

[17] [1936] HCA 52; (1936) 55 C.L.R. 608.

[18] [1936] HCA 52; (1936) 55 C.L.R. 608.

[19] (1936) 55 C.L.R., at p. 646.

[20] (1936) 55 C.L.R., at p. 674.

[21] (1936) 55 C.L.R., at p. 688.

[22] [1936] HCA 52; (1936) 55 C.L.R. 608.

[23] [1937] HCA 60; (1937) 58 C.L.R. 146, at pp. 152, 153.

[24] [1925] HCA 25; (1925) 36 C.L.R. 410.

[25] [1930] HCA 52; (1930) 44 C.L.R. 319.

[26] (1936) 55 C.L.R., at pp. 689, 690, 695.

[27] [1936] HCA 52; (1936) 55 C.L.R. 608.

[29] [1934] HCA 31; (1934) 51 C.L.R. 463, at p. 471.

[30] (1931) A.C. 275; 44 C.L.R. 530.