I know that it's possible for military aircraft to "intercept" a civilian or foreign aircraft (and I'm well aware of the US interception procedures), but why would they be doing it in the first place?
What does it actually prevent from occurring?
They can't remotely control the aircraft, so is there anything that they can do once they intercept it?
As far as I know, interception of civilian aircraft is done to assess a situation where the safe status of a flight is uncertain.
Intercepting the aircraft and watching the situation inside the cockpit and/or the cabin can help to assess whether there is a serious situation developing (and further actions can be taken, such as alerting emergency services on the ground, monitoring the flight path, continuing the interception procedure to try to improve the situation).
It's not about piloting the intercepted aircraft, but about assessing the status of the flight. I think it's just a matter of gaining some time if a hijacking occurs.
Military interception usually happens after failure to make the aircraft comply by other means (such as radio, light signals, flares). So, first and foremost it is one way to do visual communications, which is usually hard for the pilot to miss. The messages for follow (wide level turn), land (low pass, landing gear extended), and continue on course (climbing turn) are well established (possibly even internationally?) and all pilots should know them, and are probably enough to defuse most situations. Not to mention that you should try to establish radio communications on 121.5 if you're being intercepted.
I'd wager a guess that the most common cause for interception is that a pilot has strayed into restricted airspace without talking to anyone on the radio, without any malicious intent.
If the pilot ignores the messages, there's always the option of using force, if the risk to occupants and collateral on the ground is acceptable.
One large part of the reason to intercept any aircraft is to visually confirm the identity of the aircraft. While every other method of communication is valid in establishing the identity, only "eyes on" can unequivocally confirm the tail number and registration of the aircraft.
The most common reason for interception is that an aircraft is not communicating with ATC and is somewhere that they aren't supposed to be. Often times it turns out to be unintentional with the aircraft on a VFR flight (i.e. poor flight planning or deviating for weather) and straying into a restricted or prohibited area.
In these cases, the standard intercept signals (AIM 5-6-4) are designed to attract the pilot's attention and have them proceed out of the area. In addition to the "standard" signals, they can also drop flares in front of the airplane to really get their attention if needed.
In cases where the airplane still doesn't respond and the aircraft appears to be a threat to national security, the decision can be made by a few senior military and civilian officials to actually shoot down the aircraft.
For more detail, in the US section 5-6-2 of the AIM gives the following reasons that a civil aircraft may be intercepted by a military aircraft:
5-6-2. Interception Procedures
1. In conjunction with the FAA, Air Defense Sectors monitor air traffic and could order an intercept in the interest of national security or defense. Intercepts during peacetime operations are vastly different than those conducted under increased states of readiness. The interceptors may be fighters or rotary wing aircraft. The reasons for aircraft intercept include, but are not limited to:
(a) Identify an aircraft;
(b) Track an aircraft;
(c) Inspect an aircraft;
(d) Divert an aircraft;
(e) Establish communications with an aircraft.
Flightgear.org also has a good wiki on interception procedures that covers some of the common reasons that they are used (and includes all of the ones that I was going to include):
Reasons for interception in real life
While interception of civilian aircraft is a last resort, interception is often the only means available to identify an aircraft that have not filed a flight plan and/or have no transponder and can not be contacted. Apart from identification interception is as well often the only means to redirect an aircraft that is straying into limited airspace or is believed to be involved in illegal activities.
Visual identification of aircraft that can not otherwise be identified.
An aircraft may be intercepted and through visual signals or radio communication on emergency channels be requested to change route and possibly to land at an specific airport if an aircraft
- is straying away from a route,
- are entering a danger, restricted or prohibited area,
- are suspected to fly illegally or is smuggling goods or persons,
- enters a countries airspace without permit an fails to follow instructions to leave the airspace or land at a specific airport,
- enters a countries airspace at different positions or routes than permitted, or
- is a hazard to other aircraft
If you are on a heading, being vectored to intercept final on an instrument approach, and it appears that you will fly through the final approach without being cleared to intercept it, what should you do?
256 KEA" seems to terminate on either 27 DME KEA or RDL 187 ATV. But then what? There is a 20 DME ATV on the next leg that spoils everything. CD (or Course to DME) is not a specific route over the ground so the previous turn won't be able to intercept it. I could either omit the CD part or insert another CR (course to radial) before the CD leg but then I'm not doing what the map says, I improvise...I am building my own ATC simulator and for that purpose I need to include several instrument procedures. I have a problem with that particular one: My problem is on KEA transition, the leg between
I know that it's possible for military aircraft to "intercept" a civilian or foreign aircraft (and I'm well aware of the US interception procedures), but why would they be doing it in the first place? What does it actually prevent from occurring? They can't remotely control the aircraft, so is there anything that they can do once they intercept it?
I know that to be allowed to fly an aircraft as to be certified by an agency and that this one is not the same for European or American (for instance) aircrafts. What are the different steps that an aircraft designed to fly in Europe has to go through in order to be certified? Proof on the paper of some features? Ground tests (which one)? Flight tests (which one)?
The Soloy Dual Pac apparently allows two engines to rotate one propeller -- here's a picture of it on an Otter: Is this recognised as a centreline thrust twin engine aircraft, a "standard" twin engine aircraft or just an aircraft with a single engine for FAA certification? What about for pilot licensing?
After purchasing an aircraft, it takes the FAA a long time to issue RVSM approval for the new owner. During this time, under what conditions may an aircraft fly in RVSM airspace even though they aren't approved for it? What is the process to get ATC approval for such flights?
Aircraft certification is covered by 14 CFR 23 and 25, what parts cover aircraft engines?
Some "ILS or LOC" approaches have crossing restrictions that are shown before and/or after the final approach fix/glideslope intercept. Are these restrictions for the LOC only approach, or do they also apply when tracking the glideslope? As an example, KSFO ILS 28L and KSFO ILS 19L (see below) both have crossing restrictions before and after glideslope intercept. For the fixes after intercept though, notice that NEPIC does not have a '*' next to the crossing restriction (which means "LOC only") while ROGGE does:
FAR Part 91, Appendix G, Section 2 says: (c) Altitude-keeping equipment: All aircraft. To approve an aircraft group or a nongroup aircraft, the Administrator must find that the aircraft meets the following requirements: ... (2) The aircraft must be equipped with at least one automatic altitude control system that controls the aircraft altitude Note that it does not say that it must be engaged, or even operative. Simply "equipped", and also that this is to approve an aircraft for RVSM. From what I can find, there is no operational requirement for the autopilot
Old registrations had no expiration date, so a pilot could get in a plane that is owned by someone else and verify the airworthiness and registration by inspecting the documents. But that registration might be expired, and without going to the FAA site to verify it is active could find themselves flying an unregistered aircraft. Has the FAA addressed this situation since they started expiring registrations that didn't originally expire? What would the pilot's liability be in this situation?