OPINION OF THE COURT
JAMES HUNTER, III, Circuit Judge.Appellant Donald Thomas Margraf appeals his conviction for attempting to carry a “concealed deadly or dangerous weapon” aboard a commercial aircraft in violation of 49 U.S.C. § 1472 (l) (1971). After waiving trial before the district court, he was tried before a magistrate pursuant to 18 U.S.C. § 3401 (1971), found guilty, and fined $100. He appealed his conviction to the district court pursuant to 18 U.S.C. § 3402 (1971), which affirmed, 347 F.Supp. 230. This court’s jurisdiction is predicated upon 28 U.S.C. § 1291.
Appellant was arrested at Philadelphia International Airport while attempting to board a flight to San Francisco, California. Airline employees had notified the Customs Security Officer at the boarding gate that appellant conformed to the “Hijacker Profile.” Consequently, as appellant passed through the magnetometer, a metal detection device placed at the gate, his reading on the meter was checked. Because it indicated the possible presence of a weapon on appellant, he was asked to step through the magnetometer again. A second positive reading resulted. The officer then detained appellant. The officer testified that he asked appellant if he were carrying “a knife, a weapon, or any other large metallic object.” 1 After appellant responded negatively to the officer’s inquiry, he was searched and a folding poeketknife seven and one-half inches in overall length with a three and one-quarter inch blade was discovered in his right front pocket.
The magistrate held that appellant had violated 49 U.S.C. § 1472(Z):
[W]hoever, while aboard an aircraft being operated by an air carier in air transportation, has on or about his person a concealed deadly or dangerous weapon, or whoever attempts to board such an aircraft while having on or about his person a concealed deadly or dangerous weapon, shall be fined not more than $1,000 or imprisoned not more than one year, or both-.
Appellant challenges this conviction on two grounds. He claims that it is necessary for the government to prove a specific intent to carry a “concealed deadly or dangerous weapon” onto a plane in order for a defendant to be convicted. In other words, it is not sufficient for the government to show that a defendant was boarding a plane with a concealed deadly weapon on his person; it must go further and show that the defendant was aware that his weapon was dangerous, and knowing this, still intended to carry the weapon aboard. Appellant’s second contention is that the poeketknife he was carrying could not be considered a “deadly or dangerous weapon.”
SPECIFIC INTENT
Congress added paragraphs (i) through (m) to § 1472 in 1961 in an attempt to combat airplane hijacking.
*710“The primary purpose of this legislation is to amend the Federal Aviation Act of 1958 so as to extend Federal criminal laws to certain acts committed on board aircraft — in particular, such acts as aircraft ‘hijacking’, murder, manslaughter, assault, maiming, carrying concealed deadly or dangerous weapons, and stealing personal property. .
“Recent events have demonstrated the urgent need for stronger Federal laws applicable to criminal acts committed aboard commercial and private aircraft.
“The provisions of this legislation, it will be noted, are based on the use of criminal sanctions as a deterrent to the commission of criminal acts.
“Broad, stringent legislation such as is proposed here, cannot, of course, prevent piracy of aircraft, but it is to be hoped that the enactment of laws providing stiff penalties for various crimes in air commerce will deter all except the hopelessly unbalanced from risking life and liberty in such undertakings.” H.R.Rep.No.958, 87th Cong., 1st Sess. (1961), 1961 U.S., U.S.Code Cong. & Admin.News 2563.
Although as written § 1472(Z) does not contain a specific intent requirement, appellant would have us read one into the statute. This we decline to do.
In Holdridge v. United States, 282 F. 2d 302, 310 (8th Cir. 1960), Justice (then Circuit Judge) Blackmun listed the factors to consider in whether a statute could be construed as not requiring a specific intent:
“ . . . where a federal criminal statute omits mention of intent and where it seems to involve what is basically a matter of policy, where the standard imposed is, under the circumstances, reasonable and adherence thereto properly expected of a person, where the penalty is relatively small, where conviction does not gravely besmirch, where the statutory crime is not one taken over from the common law, and where congressional purpose is supporting.”
The presence of these factors here plus the strong contrast between paragraph (Í) and 49 U.S.C. § 1472 (m) compel us to hold that paragraph (Z) does not contain a specific intent requirement. Paragraph (m) was passed by Congress at the same time as paragraph (Z). The fact that paragraph (m) contains an express intent requirement is particularly convincing evidence that Congress did not intend such a requirement for paragraph (Z). That the maximum penalties for violating paragraph (Z) are much less than those for violating paragraphs (i) and (j) is also an indication that no specific intent is necessary for a violation of paragraph (Z) 2
A person who boards a plane with a concealed deadly weapon need not intend to use it to be a hazard. The mere presence of a weapon on board a plane creates a hazard because it may be seized and used by a potential hijacker.
In view of the seriousness of the hijacking problem — both at the time of enactment and at the present3 — it is rea*711sonable to conclude that Congress meant paragraph (£) not to have a specific intent requirement. To include a specific intent requirement would be judicial legislation, and such inclusion could seriously hinder attempts at enforcing this statute.
The dissent contends that this case is governed by United States v. Freed, 401 U.S. 601, 91 S.Ct. 1112, 28 L.Ed.2d 356 (1971). In particular, it finds Justice Brennan’s concurrence in that case persuasive. Freed does not control this case. For each particular statute which we consider, we have to make a determination as to what Congress intended. As Justice Brennan pointed out, in Freed the court was considering amendments to a pre-existing statute. Cases decided under the pre-existing statute had held that a specific intent requirement was necessary to convict. The Court decided that Congress approved these cases in amending the statute. We have no similar case history before us here. Nor do we have any other indication that specific intent is necessary.
“DEADLY OR DANGEROUS WEAPON”
If, therefore, the pocketknife in this case can be described as a “concealed deadly or dangerous weapon,” it will be necessary to uphold appellant’s conviction.
The House Report accompanying paragraph (£) stated:
“Consideration was given to attempting to define the term ‘deadly or dangerous weapon’. However, this is not practicable. These terms have been used without definition in other provisions of Title 18, United States Code, and in many State Criminal laws.
The courts will determine in each case, as it arises, whether the weapon in question was deadly or dangerous.” H.R.Rep. No. 958, 87th Cong., 1st Sess. (1961), 1961 U.S.Code Cong, and Admin.News 2563, 2570.4
This case-by-case determination in turn depends on the entire context of the situation being considered.
“[W]hat in one context might not be a dangerous weapon in a- different context would be a dangerous weapon, giving consideration to the language and purpose of the specific statute involved, the nature, use or anticipated use of the ‘weapon’ involved and the consequences logically flowing from its use. See United States v. Barber, D.C.Del.1969, 297 F.Supp. 917, 922, 923, and cases cited therein; Baker v. United States, 5 Cir. 1969, 412 F.2d 1069; United States v. Brown, 9 Cir. 1969, 413 F.2d 878”. United States v. Ware, 315 F.Supp. 1333 (W.D.Okla. 1970).
Appellant contends that since his knife was found in a logical place, his pocket, and since there was no indication that he intended to use the knife in a threatening way, the finding of the magistrate that this was a deadly weapon cannot be upheld.
. [3] There are several factors present here which in view of the congressional intention to prevent potential weapons from being carried aboard planes lead us to uphold the determinations of the magistrate and of the district court that the knife in question was a “concealed deadly or dangerous weapon.”
First, the knife (open) was seven and one-half inches long, including blade and handle and its blade was three and one-quarter inches long.5 It was certainly *712capable of being used as a weapon. Second, in a boarding' situation it must be emphasized that administrative agents and courts have to act prospectively. They do not have the advantage of hindsight to see if a person with a knife used it in any threatening manner. Nor can one reasonably expect a hijacker to announce his plan so early. To adhere to appellant’s argument would give many prospective hijackers a free try at evading airport security measures.6 The dissent’s solution — to rewrite the statute to allow weapon carriers to go free but to permit the seizure of the weapons— would provide no deterrent to any prospective hijacker.
*711“The term ‘dangerous weapon’ includes all articles enumerated in section 14(a) of the Act of July 8, 1932 (47 Stat. 654, as amended: D.C.Code 22-3214(a) and also any device designed *712to expel or hurl a projectile capable of causing injury to persons or property, daggers, dirks, stillettoes, and knives having blades over three inches in length.” (Emphasis added). 40 U.S. C. § 193m (a) (3).
Third, there were signs at the airport warning people that to board a plane with a deadly weapon.is a crime. And fourth, when appellant’s knife triggered the magnetometer, he was asked by the officer present if he was carrying any knife, weapon, or other large metallic object, to which he responded “no.” While appellant may have considered his knife a tool and not a knife or deadly weapon, he still should have been aware that it could be used as a deadly weapon and that others could have classified it as a deadly weapon.
We do not intend, as the dissent would indicate to do, that the above statement will be used as a test of culpability. We are concerned about a situation in which a person carrying what anyone in the country would classify as a knife responds “no” to a question in which he was asked if he were carrying a knife.
Appellant’s answer was a circumstance which the fact finder could consider in determining whether the pocketknife was a deadly or dangerous weapon in this case. He did not have to credit the appellant’s contention that his knife was not a knife but a tool. This case involves more than a simple “walk-on” attempt that was stopped at the magnetometer. If the appellant had attempted to stab someone with the knife, there would have been no problem in consider-' ing it a deadly or dangerous weapon. But it is entirely unrealistic to think that any hijacker would commit himself this early or in this overt a fashion.
It is more difficult to determine prospectively whether a deadly or dangerous weapon is involved than it is to make that determination retrospectively. In contrasting the penalties in paragraphs (j) and (i), Congress provided for these difficulties. We would not think that knitting needles, etc., would normally be classified as deadly or dangerous, but there certainly could be situations in which they would be so classified.
Appellant also conjures up the specter of troops of boy scouts being hauled to jail as a result of this decision. We do not think that this will occur. As in the sentencing in this case, courts will have to balance the potential harm to innocent passengers with what could be an unknowing act by a defendant. This is precisely the kind of judicial determination that Congress envisioned in passing § 1472(1).
“ . . . Obviously, in order to jeopardize the lives and safety of the smallest number of people, the hijacker must be discovered when he is least dangerous to others and when he least expects confrontation with the police. In practical terms, this means while he is still on the ground and before ho has taken any overt action.
“Clearly, this would not be an easy objective to accomplish under the best of conditions. But amidst the rush and the congestion of many airports, this task is vastly complicated. Airport security officials have the awesome responsibility of ferreting out hijacking threats from among thousands of passengers while at the same time avoiding any undue disruption to this nation’s heavy flow of commercial air traffic. . ” United States v. Moreno, 475 F.2d 44, 49 (5th Cir., 1973).
*713The dissent also argues that if a specific intent requirement is not read into paragraph (Í), it is unconstitutional because it is overbroad or because it permits too much discretion in law enforcement officers. This contention was argued by the appellant before the magistrate, but not before the district court nor before us on appeal. We therefore do not find it necessary to decide it.7
The judgment of the district court will be affirmed.
. Appellant claims lie was asked only if lie were carrying any large metal objects. Although the magistrate did not make any specific finding on this point, on appeal the evidence and the inferences to be drawn from it must be taken in the light most favorable to the government. E. g., United States v. Goberman, 458 F.2d 226 (3d Cir. 1972). We must, as did the district court, credit the testimony of the officer.
. 49 U.S.C. § 1472 (i) imposes a minimum sentence of twenty years for air piracy. 49 U.S.C. § 1472(j) permits a maximum sentence of twenty years and a fine of $10,000 for interfering while on board an airplane with a flight crew member. If a deadly or dangerous weapon is used, life imprisonment may be imposed.
. As the Fifth Circuit recently stated in United States v. Moreno, 475 F.2d 44 at p. 48 (5th Cir., 1973) :
“ . . . Although the crime of air piracy exceeds all others in terms of the potential for great and immediate harm to others, its undesirable consequences are not limited to that fact. Among other things, it has been used as an avenue of escape for criminals, a means of extorting huge sums of money and as a device for carrying out numerous acts of political violence and terrorism. Perhaps most disturbing of all is the fact that aerial hijacking appears to be escalating in frequency. We’ do not think that it is unrealistic to say that the current situation has approached the crisis stage for law enforcement officials in this country.”
. As the dissent points out, this statement was made concerning paragraph (j) of the Act. But it was also specifically-made applicable to paragraph (l). H.R. Rep.No.958, 87th Cong., 1st Sess. (1961), 1961 U.S.Code Cong, and Admin.News 2563, 2575.
. While we do not adopt the following definition, it may be relevant to note how Congress defined the term “dangerous weapon” in prohibiting people from carrying one onto the grounds of the United States Capitol:
. The Fifth Circuit has recognized these difficulties in a different context:
. But the language of the Supreme Court in United States v. Petrillo, 332 U.S. 1, 7, 67 S.Ct. 1538, 1542, 91 L.Ed. 1877 (1947), could well be applicable:
“We think that the language Congress used provides an adequate warning as to what conduct falls under its ban, and marks boundaries sufficiently distinct for judges and juries fairly to administer the law in accordance with the will of Congress. That there may be marginal cases in which it is difficult to determine the side of the line on which a particular fact situation falls is no sufficient reason to hold the language too ambiguous to define a criminal offense.”
There are, it seems, two problems raised by the dissent. The first is whether the wording “deadly or dangerous” is over-broad. To this the above language may be applicable. The second is whether given that “deadly or dangerous” is capable of constitutional definition, are law enforcement officials unconstitutionally discriminating in their decisions as to whom to prosecute under the statute.
Our legal system relies to a large extent on the discretion of law enforcement officers and judges. There has been no allegation of discriminatory enforcement in this case. Nor do the figures cited by the dissent give us a sound basis for finding that to be the practice under this statute.