IRVING R. KAUFMAN, Chief Judge:

Although we affirmed appellants' convictions for attempted bank robbery, 18 U.S.C. § 2113(a), in open court, we believe that since the question is one likely to present itself to district courts not infrequently it is prudent to discuss briefly the perplexing problem of distinguishing "mere preparation" for the commission of a crime from an "attempt."

Since an understanding of the facts is critical to any consideration of inchoate crimes, we summarize the pertinent events culminating in the arrest. Rodney Campbell, a convicted bank robber, agreed to cooperate with the F.B.I. on January 12, 1976 in return for a grant of immunity from prosecution for four armed bank robberies in which he admittedly participated between June and September, 1975. Arrangements were made for Campbell to use an undercover Government vehicle, provided with a tape recorder and monitoring equipment, to assist the authorities in apprehending some of his former accomplices. Campbell consented to the tape recording of all conversations taking place in his car.

After reestablishing contact with individuals named Larry Peterson, Willie Young, and appellant Johnny Sellers, Campbell transported the men in his specially equipped vehicle as they reconnoitered several banks in Queens, New York. The group began actual preparations for a robbery on Wednesday, January 21, by stealing ski masks from a department store. Later that day Peterson and Young appropriated surgical gloves from a hospital while Sellers, a recent patient, engaged several nurses in conversation. Finally, Peterson purchased a hacksaw and roofing nails which, he told Campbell, he needed to "fix" a shotgun.

On January 22, Sellers, Peterson, Young and Campbell perfected their plan to rob a branch of the First National City Bank in Whitestone, Queens. Peterson, formerly a factory worker in the neighborhood, advised the group that on Fridays (in this instance, January 23) large amounts of money would be on hand to accommodate industrial employees in cashing their salary checks. Young entered the bank on Thursday afternoon to examine its internal physical structure and reported to his colleagues that the tellers' counters were of average height and security was thin. The participants agreed to recruit appellant Clarence Stallworth to drive the getaway car.

On Friday morning Stallworth joined Young and Sellers, to whom he handed a .38 calibre revolver, and assumed the role of driver. Peterson met his comrades, gave them a sawed-off shotgun and distributed other paraphernalia required for the crime. En route to the bank in Whitestone the occupants of the Government-owned auto-mobile covered their fingers with band-aids, their hands with surgical gloves and donned the ski masks. They prepared to destroy the vehicle after the robbery by stuffing gasoline-soaked newspapers under the seats.

The target bank was located in a small shopping center. As the car entered the parking lot, Sellers alighted and strolled past the bank several times, peering inside at each opportunity, as his accomplices circled the shopping center. At approximately 11 A.M., Stallworth stopped the vehicle directly in front of the bank. Sellers, who had stationed himself at an adjacent liquor store, started to approach the bank. Simultaneously, Campbell said, "let's go," and the occupants of the car reached for the doors. At this point, F.B.I. agents and New York City policemen, who had saturated the area as a result of intelligence acquired through the would-be robbers' monitored conversations, arrested the men without incident.

Appellants contend that their conduct, while admittedly sufficient to sustain a conspiracy conviction, punishable by a maximum of five years incarceration, will not support a judgment of attempted bank robbery, carrying a potential twenty-year prison term. They argue that their activities did not transcend a hypothetical fixed point on a spectrum of conduct culminating in the substantive offense of bank robbery. Thus, appellants assert they cannot be convicted of attempted bank robbery because they neither entered the bank nor brandished weapons. We reject this wooden logic. Attempt is a subtle concept that requires a rational and logically sound definition, one that enables society to punish malefactors who have unequivocally set out upon a criminal course without requiring law enforcement officers to delay until innocent bystanders are imperiled.

The classical elements of an attempt are intent to commit a crime, the execution of an overt act in furtherance of the intention, and a failure to consummate the crime. The Fifth Circuit in United States v. Mandujano, 499 F.2d 370 (5th Cir. 1974), cert. denied, 419 U.S. 1114, 95 S.Ct. 792, 42 L.Ed.2d 812 (1975), has properly derived from the writings of many distinguished jurists a two-tiered inquiry to determine whether given conduct constitutes an attempt. Initially, the defendant must have been acting with the kind of culpability otherwise required for the commission of the crime he is charged with attempting. Then, the defendant must have engaged in conduct which constitutes a substantial step toward commission of the crime, conduct strongly corroborative of the firmness of the defendant's criminal intent. Id., at 376-77. We note that the Fifth Circuit's analysis conforms closely to the sensible definition of an attempt proffered by the American Law Institute's Model Penal Code. See also ALI's treatment of "reconnoitering the place contemplated for the commission of the crime" and "possession . . . of materials to be employed in the commission of the crime, at or near the place contemplated for its commission, where such possession . . . serves no lawful purpose . . . " under the subtitle "Conduct Which May Be Held Substantial Step Under Subsection (1)(c)."

Application of the foregoing to the instant case emphasizes the importance of a rule encouraging early police intervention where a suspect is clearly bent on the commission of crime. The undisputed testimony of Campbell and Young established that appellants intended to execute a successful bank robbery. Moreover, Stallworth and Sellers, in furtherance of their plan, took substantial steps that strongly corroborated their criminal intent. They reconnoitered the bank, discussed (on tape) their plan of attack, armed themselves and stole ski masks and surgical gloves. The getaway car was carefully prepared for destruction. As Sellers moved ominously toward the bank and Campbell uttered a verbal signal to his accomplices, a bank robbery was in progress. A jury could properly find that preparation was long since completed. All that stood between appellants and success was a group of F.B.I. agents and police officers. Their timely intervention probably prevented not only a robbery but possible bloodshed in an area crowded with noontime shoppers.

We note in closing that federal courts have upheld convictions for attempted bank robbery without evidence of either an assault, United States v. Foster, 478 F.2d 1001 (7th Cir. 1973), or actual entry into the target bank, United States v. Bussey, 507 F.2d 1096 (9th Cir. 1974). Cases such as these, however, should not divert a court from consideration of the rational policies underlying the attempt doctrine. Because the conduct of Stallworth and Sellers constituted an attempted bank robbery, the convictions must be affirmed.