“ I certainly do not favor exemption of interstate commerce from its 'just share of taxation.' But history shows that fair judgment as to what exactions are just to the passerby cannot be left to local opinion. When local authority is taxing its own, the taxed ones may be assumed to be able to protect themselves at the polls. No such sanction enforces fair dealing to the transient. In all ages and climes those who are settled in strategic localities have made the moving world pay dearly. This the commerce clause was designed to end in the United States. ”

“ Even if we could say on this record that Minnesota and it alone can be regarded as the 'home state', we have no assurance that in taxing planes operated by other and more complex business organizations, one state will have any greater claim to that designation than several others, and the court's opinion furnishes no test to guide in the choice among them, if choice has any relevance. Nor does it say that the power to tax vehicles of interstate transportation at the domicile or the 'home port' is exclusive. ”

“ There is difficulty in the application of this doctrine to air commerce, I grant. There is no statutory machinery for fixing the home port. If federal registration established statehood as it establishes nationality, the home port doctrine would be easy to apply. However, on the record before us it seems unquestioned that Minnesota is in an operational as well as in a domiciliary sense the home port of this fleet. On that doctrine Minnesota can tax the fleet, but its right to do so is exclusive, for no other state can acquire jurisdiction to tax merely because it provides a port of call. ”

“ It is no answer to suggest that the states other than Minnesota have not asserted their constitutional power to tax or that we do not know how or to what extent they have exercised it. The extent to which one state may constitutionally tax the instruments of interstate transportation does not depend on what other states may happen to do, but on what the taxing state has constitutional power to do. The jurisdiction of Minnesota to tax 'must be determined on a basis which is consistent with the like jurisdiction of other states.' Johnson Oil Refining Co. ”

“ The taxation of vehicles of interstate transportation in a business organized and conducted as is petitioner's is as capable of apportionment, and the insupportable multiple tax burden on interstate commerce is as readily avoided by apportionment of the tax, as in the case of the taxation of tangible and intangible property of railroads, railroad car supply companies, express companies, and the like which we have repeatedly held to be subject to the rule of apportionment. ”

“ Certainly today flight over a state either casually or on regular routes and schedules confers no jurisdiction to tax. Earlier ideas of a state's sovereignty over the air above it might argue for such a right to tax, but it is one of those cases where legal philosophy has to take account of the fact that the world does move. ”

“ It is true that it has been decided that property, even of a domestic corporation, cannot be taxed if it is permanently out of the State. * * * But it has not been decided, and it could not be decided, that a state may not tax its own corporations for all their property within the state during the tax year, even if every item of that property should be taken successively into another state for a day, a week, or six months, and then brought back. ”

“ North Dakota, for instance, in taxing the planes regularly landing within its borders, is not taxing rights originating in and safeguarded by Minnesota, or exercising any rights attributable to Minnesota. No reason appears why North Dakota should be denied the right to tax the planes to the extent that they are within its borders, or why, to that extent, Minnesota has any relationship to them sufficient either to enable it to tax them or to preclude North Dakota from taxing them. ”

“ Minnesota cannot justify its imposition of an undue proportion of the total tax burden which can be imposed on an interstate carrier by saying that other states have taken or may take less than their share of the tax. It is enough that the tax exposes petitioner to 'the risk of a multiple burden to which local commerce is not exposed. ”

“ Petitioner, a Minnesota corporation, is owner of a large number of airplanes which it uses exclusively in interstate transportation moving on regular schedules and over fixed routes extending through eight states between Chicago, Illinois and the Pacific coast, with the usual landing fields and maintenance bases at intermediate points, including Minneapolis and St. Paul, Minnesota. It is stipulated that on May 1, 1939, 14% of the total mileage of the prescribed interstate routes was in Minnesota and that 16% of the daily plane mileage of all petitioner's interstate planes was in that state. ”

“ Obviously interstate business bears no undue part of that burden if the personal property tax imposed on it by a given state is-like a tax on real estate located there-exclusive of all other property taxes imposed by other states, as is the case with the taxation of vessels, Old Dominion S.S.C.o. ”

“ No other State can claim to tax as the State of the legal domicile as well as the home State of the fleet, as a business fact. No other State is the State which gave Northwest the power to be as well as the power to function as Northwest functions in Minnesota ”

“ They do not sustain the tax on the ground that Minnesota, as the state of petitioner's domicile, has exclusive power to tax respondent's planes which pass in and out of Minnesota in performance of their interstate functions. ”

“ Aviation has added a new dimension to travel and to our ideas. The ancient idea that landlordism and sovereignty extend from the center of the world to the periphery of the universe has been modified. ”

“ Air as an element in which to navigate is even more inevitably federalized by the commerce clause than is navigable water. Local exactions and barriers to free transit in the air would neutralize its indifference to space and its conquest of time.
Congress has recognized the national responsibility for requlating air commerce. Federal control is intensive and exclusive. Planes do not wander about in the sky like vagrant clouds. ”

“ On May 1, 1939, the time fixed by Minnesota for assessing personal property subject to its tax (Minn.Stat.1941, § 273.01) , Northwest's scheduled route mileage in Minnesota was 14% of its total scheduled route mileage, and the scheduled plane mileage was 16% of that scheduled. It based its personal property tax return for 1939 on the number of planes in Minnesota on May 1, 1939. Thereupon the appropriate taxing authority of Minnesota assessed a tax against Northwest on the basis of the entire fleet coming into Minnesota. ”

“ It subjects a new and important industry to state tax burdens, essentially discriminatory in their effect on interstate commerce, to which other interstate carriers are not subject and which it was the very purpose of the commerce clause to avoid. ”

“ This principle was successively extended to the old means of transportation and communication, such as express companies and telegraph systems. But the doctrine of apportionment has neither in theory nor in practice been applied to tax units of interstate commerce visiting for fractional periods of the taxing year. (Thus, for instance, 'The coaches of the company * * * are daily passing from one end of the state to the other', in Pullman's Palace-Car Co. v. Pennsylvania, supra, 141 U.S. at page 20, 11 S.Ct. at page 877, 35 L.Ed. 613, citing the opinion of the court below in 107 Pa. 156, 160.) ”

“ It is plain then that for present purposes, and so far as the Fourteenth Amendment is concerned, respondent's airplanes, which are chattels regularly moving over fixed interstate routes, are subject in some measure to the taxing power of every state in which they regularly stop on their interstate mission. [6]
In some instances it may be that vehicles of transportation moving interstate are so sporadically and irregularly present in other states that they acquire no tax situs there, Hays v. ”

“ Paul, Minnesota, its airplane and engine overhauling base, at which the principal repairs to planes and engines are made, it also operates maintenance bases at Chicago, Illinois, Minneapolis, Minnesota, Fargo, North Dakota, Billings, Montana, and Spokane and Seattle, Washington, at which points it maintains crews of mechanics and maintenance equipment. It owns and leases hangars and office space at all of its stopping points, each of which are manned by its employees. On the tax day, May 1, 1939, petitioner's planes made no scheduled stop in St. ”

“ This figure was arrived at by using the ratio between Central's mileage outside of New York and its total mileage. The comptroller nevertheless ruled that all of Central's cars were taxable in New York, the State of domicile. On review of this ruling as applied in the first tax year involved, the New York Court of Appeals remitted the proceedings to the comptroller to determine whether any of the rolling stock was used exclusively out of the State. People ex rel. ”

“ Moreover, the difficulties of applying to aircraft a rule of taxation at a 'home port' are essentially those which have led, long since, to the abandonment of the idea by this Court as applied to vessels. Compare City of St. Louis v. Wiggins Ferry Co., supra; Ayer & Lord Tie Co. v. Kentucky, supra. While it appears from the present record that petitioner maintains at St. ”