Hi Everyone !
These three letter codes APIS (advance passenger information system) how are the compared to TSA secure flight , is this system linked? , who checks them , are flyover flights lets say from LHR-MEX ( BA req API before flight ) ran through the U.S ?

APIS is a CBP database required for flights departing/arriving internationally. Commercial aviation has been, for quite some time, required to provide CBP with passenger name and travel document (ie Passport) information electronically a minimum of 60 minutes prior to departure and receive permission from the DHS/CBP to depart the country. In theory the CBP is matching the passenger/crew manifest to a secret terror watch list and will forbid the departure with the people who's names are on the list. Same with international arrivals.

In essence, the airline is required to transmit to CBP computers a list of who's on the aircraft (crew and pax) and get permission to depart from or return to the US. CBP will then decide if it will allow those passengers to freely travel across our border. I think this is part of the rationale requiring everyone to have a passport under the "Western Hemisphere Travel Initiative."

It is one more way that DHS and its subsidiary agencies can keep track of U.S. citizens and others who wish to leave or enter the country. It amounts to an exit visa.

This was extended to private aircraft about 2 years ago and requires internet access to file the inbound/outbound manifests of both passengers and pilots. The current procedure is to file the information electronically and wait until you receive an email message from CBP saying you can depart for a foreign airport or a US airport. CBP has used this information to detain at gunpoint at least one aircraft in southern California departing to or returning from Baja California. (See the Baja Pilots Assn. web site for more details on this).

DHS's CBP commercial web site here has more information and for private boats and airplanes, here. A password is required to look at the documents and CBP has posted that password on the site. I have not read these documents, but since I operate private seaplanes in/out of remote lakes in Canada, this program has been a nightmare for me personally. Last time I was at N53.56 W92.94, there was no internet service. Come to think of it, the four of us and fish were all that were there. Nappy has publicly stated she is planning to expand this to pleasure boats in the future. More information here.

As I understand it, SecureFlight data is a subset of APIS data (with the possible exception of redress number), so if you provide APIS data, you've provided SecureFlight data.

I believe any flight that passes through US airspace must provide it.

APIS has been for much longer; in fact, APIS was around before 9/11/01 though its use before then was voluntary. Sometime between 2002 and 2004 it was fully implimented for commercial air carriers. Since then it has been extended to more and more modes of transborder travel as you note.

That is one way to look at it.

Where can I find one of these pleasure boats?

Sort of-- the API data is sent through APIS to CBP whereas the SecureFlight data is sent to the TSA (to the TSC, I believe). The airlines might co-mingle the data in their internal systems but, as far as our government is concerned, they are two completely separate things.

Every flight that passes over US airspace is subject to SecureFlight-- I believe APIS is not part of the deal unless the flight arrives or departs from the US since it is for CBP.

I was indeed talking about the data items themselves, not their destinations, which are indeed different. Moreover, because of the timing of the entry of the data, I think it may actually be duplicated at the implementation level.

Well, funny thing is yesterday I had a flight LHR-MEX via a Gulfstream 650 as a navigator , pilot told me to call CBP to check if we need to send APIS over. The lady said NO! But we sent API information over to MEX ....