dissenting.
This court, in Aman v. FAA, 856 F.2d 946 (7th Cir.1988), reviewed the age 60 rule’s “tortured history,” majority op. at 319, established the appropriate “substantial evidence” standard of review, noted that while the FAA is theoretically empowered to grant exemptions from the rule, none has ever been granted, vacated the FAA’s order and remanded the case to the agency for further proceedings and the presentation of further evidence that no airline pilot older than age 59, regardless of physical condition and experience, is qualified to fly a plane seating more than thirty passengers.
When the FAA adopted its age 60 and out rule some thirty-one years ago, in 1959, it justified the rule by stating:
(a) “... that there is a progressive deterioration of certain important physiological and psychological functions with age, that significant medical defects attributable to the degenerative process occur at an increasing rate as age increases, and that sudden incapacity due to such medical defects becomes significantly more frequent in any group reaching age 60”
and
(b) “... that such incapacity, due primarily to heart attacks and strokes, cannot be predicted accurately as to any specific individual on the basis of presently available scientific tests and criteria ... [so that] any attempt to be selective in predicting which individuals are likely to suffer an incapacitating attack would be futile under the circumstances and would not be medically sound____”
24 Fed.Reg. 9767 (Dec. 5, 1959). At the same time, the FAA also found that:
Other factors, even less susceptible to precise measurement ... [also] must be considered. These relate to loss of ability to perform highly skilled tasks rapidly, to resist fatigue, to maintain physical stamina, to perform, effectively in a complex and stressful environment, to apply experience, judgment and reasoning rapidly to new, changing and emergency situations, and to learn new techniques, skills and procedures. The progressive loss of these abilities ... even though they may be significant in themselves prior to age 60 ... assume greater significance at the older ages when coupled with medical defects leading to increased risk of sudden incapacitation.
Id.
Since 1959, numerous pilots, approaching or having celebrated their sixtieth birthdays, have petitioned for individual exemptions from the FAA’s rigid enforcement of its age 60 and out rule. The agency, however, has never granted an exemption — to anyone, regardless of his or her physical qualifications or experience. Pilots with tens of thousands of hours of flight time and flawless records, and who pass every physical test with flying colors, suddenly are grounded on their sixtieth birthdays, even though the day before they were flying, without restrictions, and were acknowledged to be qualified and, ironically, are still deemed qualified to pilot planes with thirty passengers or less.
I
The FAA actually admits to a policy of uniformly denying all petitions for exemptions from the age 60 rule. It’s not that the FAA pretends that no person over the age of 59 could ever safely pilot a Part 121 flight. In fact, the agency concedes that some over-59 captains would do just fine. Denial of Exemption, issued May 26, 1989, p. 31; petitioners’ appendix at 31. Then why not grant exemptions to those pilots? Why does the FAA persist in refusing ever to exempt any pilot, no matter how able, from its 60 and out rule? And why does it refuse to issue meaningful standards and criteria for granting at least some exemp*324tions? Because, says the FAA, although many pilots 60 and over would make safe captains, there is simply no way to tell the safe ones from the dangerous ones in advance.
In support of this position, the FAA advances, today, in 1990, the same kinds of justifications it originally offered thirty-one years ago, in 1959. And in 1990, just as in 1959, these justifications are of two types. The first starts from the proposition that “some psychomotor, emotional, intellectual and physical attributes necessary for enhanced flight crew performance deteriorate with age,” Exemption Denial at 32, resulting in a “sharp decline in physical and cognitive performance after age 60,” id. at 30; adds that there is no reliable way of measuring (or even necessarily detecting) the extent of an aging pilot’s deterioration; and concludes that it is not scientifically possible to screen out safe 60-year-old pilots from dangerous ones without actually putting them up in the skies and letting them fly.
The FAA’s second longstanding justification begins with the observation that at age 60 skills are not only deteriorating but beginning to do so at an increasing and increasingly unpredictable rate; adds that the dangers of their deteriorating to the point of sudden incapacitation (in flight, presumably) is significantly greater at age 60 and beyond than it was before; and finishes, again, with the assertion that there is no reliable way to tell a safe 60-year-old pilot, who won’t suddenly collapse in flight, from a dangerous one, who will. “The aging process ... is largely unpredictable, and generally is not measurable____ [Tjhere are no generally applicable medical tests that can, at this time, adequately determine which individual pilots are subject to incapacitation secondary to either acute cardiovascular or neurological events or to more subtle conditions related to cognitive functioning.” Exemption Denial at 32.
II
Two years ago, in Aman, supra, the FAA, advancing both of its customary justifications, defended its original denial of many of the same petitions that are before us again on this appeal. At that time, this court partially upheld the logic of the FAA’s customary justifications, finding what the FAA itself has repeatedly held in connection with every request for an exemption since 1959, i.e., “substantial evidence [to] support[ ] ... rejection of the contention that the petitioners’ protocol, combined with existing methods of operational testing, would screen out all increased risks of incapacitation or undetected skill deterioration among pilots older than sixty.” 856 F.2d at 957 (emphasis added).1 The Aman panel, however, ultimately vacated the FAA’s denial and remanded for further proceedings, concluding that the FAA had “failed to set forth a sufficient factual or legal basis for its rejection of the petitioners’ claim that older pilots’ edge in experience offsets any undetected physical losses.” Id.
It is unclear to me just what the panel in Aman meant for the FAA to do on remand. Given the number and variety of tests that are available and commonly used to measure the physical and cognitive powers of pilots — flight simulator tests, vision and depth perception tests, hearing tests, stress tests, blood tests, psychological workups, X-rays, angiograms and EKGs — I find it difficult to believe that there are skills or physical or cognitive abilities which the FAA can identify as necessary for safe flying but for which it either cannot or does not reliably test all pilots, including 60-year-olds and regardless of whether they pilot flights with more than thirty passengers or other flights with fewer passengers. If it is true, however, that physical deterioration can’t be tested and measured accurately, as the panel in Aman found “substantial evidence” to show, then it baffles me how the FAA, on remand, was supposed to reconsider the relationship be*325tween physical skills and abilities, on the one hand, and experience on the other. For whether, if as a pilot grows older, experience lends an edge which offsets waning skills and abilities, necessarily depends on at least two things: (1) how much experience the pilot has and (2) how severely physical skills and abilities have “deteriorated.” And if one of those things can’t be reliably measured for risk, or even spotted — “[A] substantial body of medical opinion continues ‘to doubt the feasibility’ ” of measuring the “incremental risk associated with ... undetected deterioration of skills among pilots over sixty,” Aman, 856 F.2d at 954 (emphasis added) — then balancing an intangible like experience against undetectable or unmeasurable deterioration would be some trick. The same problem, of course, must have faced the FAA on remand in trying to weigh the benefits of experience against its asserted concern about the allegedly unpredictable risks of “sudden incapacitation.”
The more serious difficulty, however, with the FAA’s continuing reliance on “sudden incapacitation” — the specter of a pilot in the cockpit, of no matter what age, suddenly stricken by a heart attack or a stroke — hasn’t much to do with whether the incapacitated pilot, suddenly stricken, could by dint of experience avert a crash. At that point, the safety net obviously is not experience but the presence of one or two other qualified pilots in the cockpit. Instead, the troubling problem with the FAA’s “sudden incapacitation” justification is its premise. The panel in Aman found substantial evidence to support the FAA’s conclusion that current medical science cannot determine which pilots over 60 will be most vulnerable to sudden and incapacitating disability. But that should have been a follow-up inquiry, not the first one. The first inquiry should be whether there is substantial evidence, current and valid in 1990, to support the proposition that all pilots, age 60 and older, are significantly more prone to sudden medical catastrophe than other pilots. For the age 60 and out rule makes sense only if it screens for risks that are significantly higher for all 60-year-olds than for 30, 40 or 50-year-olds. Otherwise, the rule is simply an arbitrary, overly broad and outmoded presumption, smelling of age discrimination, about infirmities which do not uniformly afflict all pilots over 60 and should not be assumed to.
The panel in Aman also remanded with instructions to the FAA to “make sense” of its increasing willingness to issue “special certificates” to younger pilots with records of heart disease, drug abuse and alcoholism — which conditions, like aging, can be progressive — in the face of its stubborn refusal ever to grant exemptions from the age 60 rule. In response, the FAA has now explained that “present tests can predict the expected course of a known medical deficiency” such as heart disease or alcoholism “with sufficient accuracy to allow valid, individualized judgments” but that “the same accuracy is not possible when assessing the decrements associated with the aging process.” FAA Brief at 32. The FAA, however, has not offered any evidence to support this distinction between the special certificates it grants to younger pilots and its refusal even to promulgate meaningful regulations and criteria for age exemptions for older pilots, much less to grant an age exemption to an older pilot. And there is no citation, either in the FAA’s brief or its latest order, for the proposition that the symptoms of alcoholism, drug abuse and heart disease can be monitored more closely and reliably than the “decrements” of aging. We defer to agency expertise, where expertise has been demonstrated, but “deference should not be equated with a license to issue inconsistent determinations.” Aman, 856 F.2d 957. The pilots have plausibly alleged that the FAA’s distinctions and exemption practices are inconsistent. The FAA has only answered with unsupported and unconvincing assertions.
The majority acknowledges that “exactly how [the FAA’s asserted] distinction [between aging and other conditions] applies as a practical matter is not entirely clear to us,” majority op. at 321, but concludes that for present purposes, it will not require more of the FAA with respect to the con*326sistency of restoring stricken younger (59 and under) pilots (suffering from alcohol abuse, drug abuse, heart conditions) to duty while grounding other pilots, 60 and over, whose records and physical condition are, by contrast, impeccable.
Ill
The FAA’s record here is more than just “disappointing.” Aman, 856 F.2d at 949. The agency has relied on a seriously flawed Flight Time study even though, as the majority points out, “various experts, even some from the FAA, state that the study should not be relied on as determinative— or even probative on the question of the continued validity of the age sixty rule.” Majority op. at n. 1. In addition, as the majority also recognizes, “the FAA’s own study on its face may in some aspects be construed to support the petitioners’ claims____” Id. at 321. The FAA has also relied on evidence of automobile traffic accidents involving fatalities as related to age. But again, as the majority points out, “The connection between automobile drivers and pilots itself seems tenuous given the pilots’ training, demonstrated proficiency, medical fitness, etc.” and “attempts to relate nonparallel categories of automobile fatalities with aircraft accidents ” does not reflect “exposure.” Id. at 321.
The petitioners, as the majority also concedes, face a Catch-22, if the FAA and this court require them to prove, with statistics that reflect actual flight time in large passenger transport planes with more than thirty passengers, that they can fly those planes as safely as pilots who are not yet 60. For until at least one exemption has been granted, none of the petitioners are eligible to pilot such flights and consequently no such statistics can be compiled. It is possible that statistics might be available for petitioners’ flight time in the same large passenger aircraft but carrying thirty passengers or less or cargo. If such statistics are available, they have not been referred to by the FAA or the pilots.
In lieu of statistics, petitioners have presented impressive evidence of pilots on the brink of age 60 performing heroic deeds and saving lives where less experienced pilots might have failed. They have also presented what the majority concedes is “impressive expert opinion evidence” that at least some experienced pilots over age 60 are qualified to fly large commercial aircraft and may be even better qualified than younger, less experienced pilots. And, relying on figures from the National Transportation Safety Board, they have presented evidence that licensed pilots age 60 and older show a lower accident rate per 1,000 pilots than pilots in other age groups, although those statistics do not reflect the number of hours flown by members of each age group and we do not know, therefore, whether pilots age 60 and over fly more or fewer hours per year than pilots in other age groups.
The majority concludes, on the basis of the foregoing, that the FAA has presented “substantial evidence” in support of an absolute 60 and out rule, although it admits that it has seen “no compelling evidence that granting exemptions would increase the risk of accident____” Majority op. at 322. The majority also concludes that it has seen “no strong evidence that the experience of the 60-and-over pilot clearly overbears the danger of deterioration of piloting skills (or of sudden incapacitation) associated with the aging process.” Id.
Since the FAA has refused as a matter of policy to grant any exemptions, what the FAA and the majority are holding, in effect, is that every airline pilot, on his or her 60th birthday, and regardless of physical condition or experience, becomes a significantly greater safety hazard than before, even though, just one day before, he or she was FAA certified, qualified and safe. The evidence in this case does not warrant that conclusion. Nor does everyday, ordinary good old common sense.
IV
Rather than again urging the FAA to recognize the need for keeping up with advanced technologies and accommodating other points of view, I would vacate the FAA’s latest order and remand for action on three fronts.
*327I would remand, first, for consideration of the adoption of regulations establishing ascertainable and meaningful standards to govern the granting of at least some exemptions to the age 60 rule. The FAA.’s present regulations — which dangle the possibility of an exemption to a pilot who can show “why the exemption would not adversely affect safety” or why, at least, it “would provide a level of safety equal to that provided by the rule,” 14 C.F.R. § 11.25(5) — do not sufficiently guide the agency in exercising its discretion and do not begin to provide adequate notice to pilots about the kind of showing that would justify an exemption. Cf. Allison v. Block, 723 F.2d 631, 636-38 (8th Cir.1983) (requiring the development of substantive standards to guide discretion); Environmental Defense Fund, Inc. v. Ruckelshaus, 439 F.2d 584, 596-98 (D.C.Cir.1971); Holmes v. NYCHA, 398 F.2d 262, 264-65 (2d Cir.1968); 2 K. Davis, Administrative Law Treatise § 7.26 at 128-32 (2d ed. 1979). See also Morton v. Ruiz, 415 U.S. 199, 94 S.Ct. 1055, 39 L.Ed.2d 270 (1974). Moreover, in light of the agency’s policy of never granting age 60 exemptions, its present regulations are a fraud.
I would also remand for a showing, by current and substantial evidence, that all pilots age 60 and over are significantly more prone to “sudden incapacitation” than all pilots under 60. The agency should re-examine the relevant data and articulate a satisfactory explanation, rationally connected to the facts, for its ongoing reliance on “sudden incapacitation” and for drawing a line at age 60.
Finally, I would remand, yet again, for a reasoned and full explanation for treating requests for special medical certificates under 14 C.F.R. § 67.19 differently than petitions for exemptions from the age 60 and out rule. Cf. Airmark Corp. v. FAA, 758 F.2d 685, 691-95 (D.C.Cir.1985) (recognizing the caprice with which the FAA rules on exemptions in other areas). And in that connection, I would require the FAA to consider the possibility that obligating pilots 60 and older to undergo more frequent medical and skills examinations than other pilots — a technique the agency already uses to monitor the condition of pilots who have been granted “special issuances” under 14 C.F.R. § 67.19 — might provide enough accurate and up-to-the-minute information about a pilot’s health and skills to enable the agency to make individualized determinations about the risks of letting any particular captain, 60 or older, pilot a Part 121 flight, rather than arbitrarily and capriciously denying exemptions to all.
. I would point out in passing that the FAA does not assert that it screens out “all" risks of incapacitation in pilots of any age and that, in fact, from time to time pilots under age 60 have had physical problems in flight.