How many commercial jets fly international routes into the US?

Among the approx. 20,000 commercial jets in service worldwide, how many normally fly into the US? I'm not asking about flights or passenger. I'm investigating a security modification that would apply to all jets on international routes to the US.

I assume that airlines divide their fleets between those

Among the approx. 20,000 commercial jets in service worldwide, how many normally fly into the US? I'm not asking about flights or passenger. I'm investigating a security modification that would apply to all jets on international routes to the US.

I assume that airlines divide their fleets between those for regional travel and those for long-range, international travel.

I'll need to break down the number further, later, so I'd appreciate knowing your source. Thanks!
(Updated, based on the first 8 answers)

I'd like to estimate the market for phase 1 of a security modification to commercial jets. Deployment would be phased. Phase 1 would include jets flying scheduled routes to the US.

Selling or mandating the modification is a separate problem.
I'm not asking how

(Updated, based on the first 8 answers)

I'd like to estimate the market for phase 1 of a security modification to commercial jets. Deployment would be phased. Phase 1 would include jets flying scheduled routes to the US.

Selling or mandating the modification is a separate problem.
I'm not asking how many flights or passengers or unscheduled flights (e.g., for maintenance).

I'd appreciate knowing your source. Thanks!

Other answer:

williewipes:
Your question is pointless – aviation does not work like that.

First, airlines do not divide their fleet like that. While US based airlines may have specific types that are mainly used for long haul transoceanic flights, many international flights in the western hemisphere use the same planes as domestic routes, The 737 that flies Miami to Atlanta this week may be going to Mexico City next month. The 777 flying Denver to Maui today may be flying New York to Paris next year. And non-US airlines certainly would not be willing to divide their fleet.

Which brings up the next point: There is an international governing body for flight, the ICAO. Any such device would have to be approved by the ICAO. The US does not get to mandate special equipment.

And the last point: Airframes have a lifespan of decades, and many, if not most, aircraft will be flown by more than one operator in their life span. An Airbus leased to Virgin Air today may end up being used as a freighter in China at the end of it's operating life.

Joseph:
Airlines do have generally divide their fleets into aircraft that only fly into the US and ones that don't. A plane may fly to China or South Korea one day and to the US the next. Even the shorter range aircraft that do not normally operate to the US may end up in the US one day; they can get sold or leased to a US airline or may have to come to the US for maintenance or modifications.

Aircraft are highly mobile assets, so for all intents and purposes you should include the entire world fleet in your calculations.

flyingtiggeruk:
You will have to work around the world and go through each airline and count up the number of

B737, B747, B757, B767, B787
A300, A310, A320, A321, A330, A340, A350, A380
Emb 170, Emb175, Emb 190, Emb195
CRJ700, CRJ 900
An124, An225, Il76

they have.

Check the airlines that fly to JFK, EWR, ORD, LAX, SFO, SEA, DFW, MIA, MCO, ANC which should cover pretty much every airline that flies to the US

potatochip:
I think that is a really hard question to answer because sometimes airlines will have to rotate their aircraft by pulling it out for a maintenance check. Therefore a major airline such as British Airways who has a lot of 777 and 747 aircraft can easily have each one of them come into the U.S. sometime in its usage.
Thomas:
Well, the US regulates who can & who can't fly into the US, but the number is still HUGE, like over 4,000 flights a DAY…
Skinner:
Well, the US regulates who can & who can't fly into the US, but the number is still HUGE, like over 4,000 flights a DAY…
Abraham:
Well, the US regulates who can & who can't fly into the US, but the number is still HUGE, like over 4,000 flights a DAY…
rick29148:
Well, the US regulates who can & who can't fly into the US, but the number is still HUGE, like over 4,000 flights a DAY…