It IS unreasonable on multiple counts:
1. "Unreasonable" in the 4th Amendment referred to performing the search with no apparent reason to believe something would be found, and no indication that a crime was being committed. In practically all cases, there is absolutely no indication whatsoever that anyone entering the "sterile area" of an airport is associated with any past, present or future flight-related crime - it is, therefore, legally unreasonable to search them.
2. Considering the 2nd Amendment right to keep and bear arms ("...shall not be infringed", end of declaration), arbitrarily searching someone for something they have a right to is inherently unreasonable. See the latest "Emerson" and "DeCSS" court rulings for supporting legal views.
3. By your reasoning, random or pervasive searches anywhere else in society would be "reasonable" - but courts regularly deem far more "reasonable" searches unConstitutional. A guy wearing gang colors and obviously carrying a small heavy item in his pocket in a drug-dealing area cannot be searched for guns/drugs by police (despite obvious high probability of serious crimes past/present/future involved) and such a search, without corroborating evidence, would be ruled "unreasonable" - but an average person just stepping onto an airplane can be searched for just being there...this is "unreasonable" by any reasoning.
4. An otherwise baseless search performed to find items deemed "weapons" arbitrarily by an agency and not by explicit legislation is unreasonable. My right to be secure in my person & effects cannot reasonably be suspended/violated just because a faceless unelected burrowcrap, unaware of my existence, arbitrarily decided that I can't be trusted with a nail file.
5. The 4th Amendment REQUIRES that any search be predicated by probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized. Translation: a search may only be done upon a SPECIFIC person, with a SPECIFIC reason to believe crime-related items are possessed, with SWORN testimony to a judge, with SPECIFIC declaration of where the search will occur and what is expected to be found. Arbitrarily searching billions of passengers, especially when questionable items are RARELY found (and most of those otherwise legal without clear criminal intent), is almost as pure an example of "unreasonable search" as can be given.
Signs posted in the airport state that baggage will be checked and you will be asked to step through a metal-detector as part of airline safety procedures. Legally, by going to the airport, you are consenting to be subjected to these searches. Searches of everyone who enters an airport are not required, only those who seek to enter a concourse. Therefore the search is not random and arbitrary, therefore it is not unreasonable.
2. Considering the 2nd Amendment right to keep and bear arms ("...shall not be infringed", end of declaration), arbitrarily searching someone for something they have a right to is inherently unreasonable. See the latest "Emerson" and "DeCSS" court rulings for supporting legal views.
Yet the court has upheld (almost since the 2nd amendment was minted) the rights of cities and states to declare "Weapons Free" zones. Schools, airports, and other public areas are included under local statute.
3. By your reasoning, random or pervasive searches anywhere else in society would be "reasonable" - but courts regularly deem far more "reasonable" searches unConstitutional. A guy wearing gang colors and obviously carrying a small heavy item in his pocket in a drug-dealing area cannot be searched for guns/drugs by police (despite obvious high probability of serious crimes past/present/future involved) and such a search, without corroborating evidence, would be ruled "unreasonable" - but an average person just stepping onto an airplane can be searched for just being there...this is "unreasonable" by any reasoning.
No, As seen in paragraph 1, airport security is not arbitrary or non-consenual. Only people entering a concourse are searched, and even then in a non-invasive way. The rest of your argument is just "slippery-slope" claptrap. There is a compelling reason to have tight security at airports just as there is a compelling reason to have tight security at the White House.
4. An otherwise baseless search performed to find items deemed "weapons" arbitrarily by an agency and not by explicit legislation is unreasonable. My right to be secure in my person & effects cannot reasonably be suspended/violated just because a faceless unelected burrowcrap, unaware of my existence, arbitrarily decided that I can't be trusted with a nail file.
Rants against bureaucrats aside, the safety of all of the passengers on a given flight overrides your personal right to carry a handgun, rpg, knife, toothpick, fork, or salami sandwitch. I am a good citizen who has never been convicted of a crime, does this mean that I should be allowed to bring a pound of semtex into the Hoover Dam? No, and I would rightfully be arrested for criminal conduct if I tried to do so.
5. The 4th Amendment REQUIRES that any search be predicated by probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized. Translation: a search may only be done upon a SPECIFIC person, with a SPECIFIC reason to believe crime-related items are possessed, with SWORN testimony to a judge, with SPECIFIC declaration of where the search will occur and what is expected to be found. Arbitrarily searching billions of passengers, especially when questionable items are RARELY found (and most of those otherwise legal without clear criminal intent), is almost as pure an example of "unreasonable search" as can be given.</>
The need to ensure the smooth running and safety of airline travel provides the P.C. that the security officers require to scan each traveler comming onto a plane. I think that if there were a real legal leg to stand on the Supreme Court would've ruled against airport metal detectors and airline weapons bans a long time ago.