This is the second appeal involving efforts of the Civil Aeronautics Board to fix mail-pay rates for the international operations of Chicago & Southern Airline (“C & S”), subsequently merged with Delta Air Lines (“Delta”), petitioner here.
Mail rates may include a subsidy based on need, 1 as well as compensation for services performed. The purpose of the subsidy is to promote the development of air transportation to the extent required by interstate commerce, the postal service and national defense. Mail rates are usually set prospectively, on the basis of estimated revenues and expenses. 2 When so established, mail-pay rates, like ordinary utility rates, run for an indefinite period, subject to reopening at any time. If, however, a carrier performs services during a period for which no final rate has been previously determined, the Board in setting rates for that past period need not “ignore the known fact[s] and compute the rate as though it were looking at the unknown future as of the date of the beginning of the period.” 3 Instead it may set such rates retrospectively on the basis of actual operating results. This method is, in effect, “cost plus” compensation. 4
The former appeal was from the Board’s order of October 18,1951, fixing new international rates on a prospective basis, effective December 16, 1950. At the time that order was entered, several years of actual operations had transpired under the then effective domestic rate. This experience revealed profits well in excess of those estimated when that rate was originally set on a prospective basis. The Board refused the Postmaster General’s request to “offset” these past excess domestic profits against the new international rate. The Postmaster General appealed. We sustained his position, set the order aside and remanded the case with directions “to determine and fix the rates in accordance with this opinion.” 5 The Supreme Court granted certiorari, and affirmed. 6
On remand, hearings were held to determine the amount of excess profits on the domestic division to be offset against the international mail rate. After hearings before the Examiner and shortly before oral argument to the Board, the Board sua sponte raised the additional question of whether the international rate itself, against which the set-off was to be applied, should be recomputed on a past-period basis. By that time, the international rate period commencing December 16, 1950 had been closed as of July 31, 1952, and complete figures based *639 upon actual operating experience were thus available for the full period. These figures disclosed a 36 percent rate of return — 26 percent more than was estimated. The Board decided, over sharp dissent, that under our remand its inquiry was not limited to the question appealed and that it was free, if not required, to redetermine the proper rate on the basis of actual operating results. Delta brought the present petition to review this action.
Petitioner challenges the Board’s power to reopen the entire rate question, and further contents that, even if the Board had the power, its exercise in this case was arbitrary and an abuse of discretion.
Underlying these contentions is Delta’s assertion that its merger with C & S, while the former appeal was pending, proceeded upon the assumption that the C & S international rate was final, subject only to a possible set-off; and that it is unfair for the Board to retroactively alter a situation upon which its stockholders, suppliers, financiers and the stock-purchasing public relied.
More specifically, the Board is said to have exceeded its power because (1) the issue of excess profits under the new international rate could have been, but was not, raised and tested upon the prior review, and (2) the mandate of this court, directing the Board “to determine and fix the rate in accordance with this opinion,” precluded the Board from considering, de novo, questions not dealt with in our opinion.
With respect to the first argument, it is true that by the time the international rate, effective as of December 16, 1950, was entered in October of 1951, the Board and the Postmaster had available operating figures for at least part of the already elapsed ten-month period of operation under this new rate. 7 But at the time the Postmaster filed his petition for review (March 1952), the international rate was still in effect for an indefinite period. Even if the early operating experience showed an excessive return, the Postmaster could have refrained from challenging the basic rate on the reasonable assumption that further operating experience might be less profitable, thus rendering the average rate for a longer period fair and reasonable.
Moreover we agree with the Board that, even if the Postmaster could, as a practical matter, have challenged the rate level upon the prior review, his failure to do so did not, by itself, estop or foreclose the Board from reconsidering the matter on remand in the light of subsequent events. See St. Joseph Stock Yards Co. v. United States, 1935,
Delta’s second argument, that our mandate denied the Board power to reconsider questions not raised on the first appeal, relies upon cases which hold that questions not raised upon appeal are foreclosed upon remand to a lower court ;
8
and, in particular, upon Arizona Grocery Co. v. Atchison, T. & S. F. Ry. Co., 1932,
The Board rejected these arguments on the authority of Federal Communications Comm. v. Pottsville Broadcasting Co., 1940,
We agree with the Commission that the principles underlying Pottsville are applicable here. Considerations of administrative flexibility apply to airline subsidy as well as licensing proceedings, for the Board, like the Federal Communications Commission, is required “at all times” to gauge its actions by the public interest standard. 9
Petitioner likens this case to an ordinary utility rate proceeding, and contends that the application of the non-finality principle of Pottsville in such proceedings would produce chaos. We cannot agree with the premise of this argument. “[Ujtility rates apply to a multitude of customers; the air-mail rate is paid by only one — the Government. Utility services must be paid for currently ; air-mail payments can be and are being paid in lump sums on account of items long past.” Transcontinental & Western Air v. Civil Aeronautics Board, 1949,
Nor do we agree with Delta’s claim that it emerged from the former review with a legitimate expectation that the rate would not be reopened. True, the Supreme Court has held that mail-pay rates, like railroad freight rates, once final, cannot be reopened. Transcontinental & Western Air v. Civil Aeronautics Board, supra; Arizona Grocery Co. v. Atchison, T. & S. F. Ry. Co., supra. Indeed the primary consequence of “finality” seems to be that the rate cannot be reopened. But here the rate order was not final. We set it aside and remanded the case to the Board for further proceedings. Rather than supporting Delta’s contention, we think that these cases support the view, at least by implication, that the Board has power to re-examine non-final rates. 11
*641
We do not suggest that Delta and its associates did not
in fact
rely upon the finality of the international rate. Like Pottsville, Delta may well be in a worse position than it would have, been if the Board had not erred in the first place. See Pottsville Broadcasting Co. v. Federal Communications Comm., 1939,
What we have said with respect to the Board’s power is sufficient to dispel petitioner’s claim that the Board abused its discretion in exercising that power. 12
One question remains for our consideration. The Board decided that, in recomputing the proper mail-pay rates for the period December 16, 1950 to July 31, 1952 on a past-period basis, it would adhere to its former determination that a 10 percent return is all that C & S needed, even though the return was recomputed on a past-period basis. Delta now attacks the Board’s original findings that 10 percent is a proper return on the grounds that this ultimate determination is not supported by subsidiary findings which rationally support the conclusion. We have carefully considered these contentions and find no basis for disturbing the Board’s findings. Its thorough and well-reasoned opinion on this phase of the ease renders further discussion by us unnecessary.
Affirmed.
Notes
. See § 406 of the Federal Aviation Act of 1958, 72 Stat. 763, 49 U.S.C.A. § 1376. This section formerly appeared as § 406 of the Civil Aeronautics Act of 1938, 52 Stat. 998. The repeal and reenactment did not effect any changes significant for present purposes.
. Transcontinental & Western Air v. Civil Aeronautics Board, 1949,
. Summerfield v. Civil Aeronautics Board, 1953,
. Transcontinental & Western Air v. Civil Aeronautics Board, supra,
. Summerfield v. Civil Aeronautics Board, 1953,
. Delta Air Lines v. Summerfield, 1954,
. The international rate here under review remained in effect until July 31, 1952, a total of 19% months.
. See, e. g., Sprague v. Ticonic Nat. Bank, 1939.
. Although § 406 of the Federal Aviation Act does not refer to the “public interest” as such, the Board is authorized to award subsidy mail pay in order to promote aviation to the extent required by interstate commerce, the postal service and national defense. 72 Stat. 763, 49 U.S.C.A. § 1376. These objectives, as well as the expenditure of Government funds, make public interest considerations implicit.
. The majority held in Transcontinental & Western that mail subsidy rates were to be likened to utility rates for the purpose of determining whether a final rate could be reopened. But we do not think that it is inconsistent with that holding to recognize the distinctions described by Mr. Justice Jackson for the purpose of determining whether the Pottsville doctrine applies to a wow-final mail rate.
. Petitioner also contends that the Board erred in offsetting, against the international rate, excess profits earned in the domestic division in periods subsequent to those mentioned in the former appeal. This contention must fail. Tie need of the carrier as a whole is the governing factor in setting mail-pay subsidies. Delta Air Lines v. Summerfield, 1954,
. Delta points out that, even if we find that the Board had discretion in the matter, the Board found itself compelled by the Supreme Court’s decision in West Ohio Gas Co. v. Public Utilities Comm., 1935,
