Well, that that violates no freedoms. It would be a classic example of sixth freedom. An Anchorage – Vancouver – Seattle routing by a putative Canadian registered airline would absolutely be sixth freedom. Interestingly, I am pretty confident that no such routing exists.

The US has always been very tetchy about granting fifth or sixth freedom or cabotage (ie. eight or ninth freedom) rights of any kind. So Air Canada flying (for example) a sixth freedom Chicago – Toronto – Boston route is a non-starter as far as the US authorities are concerned.

Would an US airline flying Chicago-Toronto-Boston be acceptable? Or flying to other detached pieces of US with a stopover abroad, like Mainland – Bahamas – Puerto Rico, or Mainland to American Samoa with a landing on non-US soil?

And (on cabotage) although BA has a London Heathrow – Chicago – Houston and return daily routing (BA294/5), it has no traffic rights on Chicago to Houston and return, which necessarily means artificially constrained low load factors on those internal US sectors. It was this that put paid to the old BA Gatwick-Phoenix-San Diego service.

I have one recent example of the US rarely giving eighth freedom rights to a non-US carrier. That was an Icelandair flight on this recent Christmas Day which flew Orlando – Boston – Reykjavik (effectively combining the Sunday Orlando to Iceland flight with the Sunday Boston to Iceland flight). I am told, and it appeared to be confirmed in the various airline booking sytems and databases (eg. OAG) that this flight was available to be booked purely for the domestic US sector from Florida up to Boston (FI658 at 17.10 ex ORL on 25.12.05, arriving Boston Logan at 19.45).

Well, the examples of London-Chicago-Houston, London-Phoenix-San Diego, Keflavik-Boston-Orlando all have an internal sector – nonstop flight between airports both in the same countries. That is relatively easy to define as something requiring 8th, 9th or other freedoms.

But if Air Canada flies a flight between Toronto and Chicago and also a flight between Toronto and Boston, how to define whether it is just unrelated 3rd/4th freedom services between Canada and US or whether it is a continuous flight with a stopover which violates lack of some freedoms (which ones?)?

This is a very interesting query, and #6 gives the regulatory position absolutely spot-on. But I wonder whether some of the other comments are actually correct. In the days before electronic ticketing and we all used airline coupons, the classic ‘sixth freedom’ flights were those that took the passenger on a single coupon (and usually without change of plane) from Country A to Country C via the registered home State of the airline (Country B). There have been some celebrated examples: with Aer Lingus in the mid nineties from New York to Belfast (touching down in Shannon en route), with Aeroflot from London to Tokyo with a Moscow stop en route (which still exists today as the twice weekly SU581 LHR-SVO-NRT, which can still be ticketed on a single coupon though nowadays passengers do need to change planes in Moscow). Duo’s announcement, just before their eventual demise on 1 May 2004, of a proposed Berlin Tegel – Birmingham – Shannon routing would have been, if the carrier has not gone bankrupt, a good example of a ‘sixth freedom’ flight.

The timetables abound with some splendid modern examples. My favourite in the current winter schedules is TAROM Flight RO303 from Vienna to Munich every morning (Mon-Fri) at 11.10 am. This journey is a through flight (no need to deplane en route) with the routing: Vienna-Cluj-Sibiu-Munich. Just under seven hours on a ATR-42, and actually, for a Y-Class single, a few euros cheaper than the direct LH or OS flights.

This TAROM example features in the January issue of hidden europe magazine which is, as it happens, published today. To access the full article in pdf format click here or go to the hidden europe website (http://www.hiddeneurope.co.uk) and follow the link to the table of contents of the current issue. The article is entitled “flights of fancy”.

#4 suggests that CSA might have some sixth freedom flights. Not in the current timetables, as it happens, nor I am aware of any recent examples (assuming we are talking Czech Airlines here, and not China Southern Airlines!). But CSA (OK) do have some really interesting fifth freedom flights. They have a twice weekly flight from Dubai to Colombo (OK188) and a daily evening flight (except Sats) from Marseilles to Barcelona (OK696). Both originate in Prague.

That same article in hiddeneurope referred to above discusses and has a listing of interesting European fifth and sixth freedom flights in the present winter schedules. Some of my favourite fifth freedom flights nowadays are Berlin to Moscow with MIAT Mongolian, Oslo to Copenhagen with Pakistan International (on a 747), Zürich to Manchester with Singapore Airlines (also a 747, but really pricey), Frankfurt to Geneva with Saudi Arabian Airlines (75 mins and 300 miles on a 777!). When the Faroese carrier Atlantic Airways (RC) starts Shetland to London Stansted later this year that will be an example of an ‘eighth freedom’ flight. But that’s another story!

The right of a carrier to operate connecting flights (ie. Lufthansa flying a passenger from Detroit to Frankfurt and then onward with a connecting flight to Tel Aviv) has been relatively unfettered, and has, I believe, not generally been seen as an expression of sixth freedom rights. That Lufthansa example (cited by #3 above) is replicated across the world: anyone flying from a UK airport with KLM to Amsterdam and then on with KLM to a third country for example. In the days before electronic ticketing and we all used airline coupons these were flights that required two coupons, so less truly an expression of sixth freedom rights that my Aer Lingus, Aeroflot, Duo and TAROM examples above.

Hope these few thoughts help. What a complex subject! I’m sure folk will leap in and correct if I’ve not got details absolutely right.

Ah, that´s interesting! But the official regulations stated in #6 are hard to understand when considered closer.

What precisely is the definition of 6th freedom?

Is it the existence of a single flight coupon that completes violation of the lack of the 6th Freedom? If yes, what constitutes an e-ticket that would violate the lack of 6th Freedom?

Or is it absence of deplaning? How does it compare with 2nd freedom? That is, is an aircraft making a 2nd freedom technical stop required to keep all passengers indoors and not let any of them out, even to stay in the airport transit zone until reembarking?

Or is it the use of the same craft? If yes, does 3rd/4th Freedom and lack of 6th mean that any aircraft used for 3rd/4th Freedom service must then be grounded in its home state until the next flight, even in case of once weekly flights?

Also, how does 6th Freedom compare with 8th and 9th? What is the legal status of flight starting and ending in the same country, with a stop in a foreign country?

No. it doesn’t need to be defined because it is not a Freedom recognised or mentioned in Air Service Agreements, which are held centrally by ICAO.

But then does not any airline having any 3rd and 4th freedom rights to more than one country also automatically hold all the 6th freedom rights between those countries through the home country?

Defining 6th freedom

Surely the 6th freedom must be particularly precisely defined when it is NOT granted (though 3rd and 4th are)?

Large aircraft are still sensitive to wakes. I remember seeing a few pictures of 707’s and DC-8’s who had engines removed by the wakes of similar aircraft they were following. Sure, the dangers for a 747 are different than a C152 but there are still risks.

Isn’t only the 753 considered a Heavy aircraft? I believe I have also heard the Heavy callsign for 739’s as well but I could be mistaken. I know there was an attempt to get the 737NG’s recategorized as the wakes off their new wings packed quite a punch when compared to the previous 737’s. I know the few times I’ve gotten rocked rather hard by a previous airplanes wake it was reported as a 738 or 739.

Well, somehow the ordinary Heavies are thought to be less sensitive. Light aircraft are allowed to get 6 miles behind a Heavy, Medium aircraft are allowed to get closer inside the wake, to 5 miles, and Heavies are allowed to get to 4 miles behind another Heavy.

Can it be proven by testing that all Heavies whether a 767-200 or 747-400 are safe to fly less than 5 miles behind another Heavy, like a 747-400?

Exactly how many miles behind the 747-400 was the Airbus 300 when wrecked?

Can it be argued that the VLA might be safe less than 4 miles behind a Heavy, the way it sounds accepted that Heavies are safe at less than 5-6 miles behind a Heavy?

The impact of a Wake Vortex Encounter is dependend on:
– aircraft’s span
– inertia
– airspeed
– mass
The higher inertia will reduce the effects of rolling. The size will maybe result in encountering both vortices at the same time. Generally I think the effect is neglitible.

@Bmused55: Be aware about the preliminary status of the ICAO-recommendation. The seperation categories by ICAO are outdated and not appropriate at all. The understanding of wake vortex generation is limited. We will see a totally new approach developing over the next years. After being threatened by ICAO with the increased seperation, Airbus is doing research in order to prove that A380 will have only slightly increased vortex. Additionally, the A380’s climb performance will enable it to clear the airspace faster than a B747.
This research was not conducted before because nobody was really interested. The (sorry to say it this hard) propaganda of Boeing, that A380 will nullify its slot-advantage, is embarassing for such an old company. I actually believe that they have no idea what kind of vortices their own aircraft produce.

Just to add: Category heavy starts at 136 tons (including everything from a A310 to a B747-400). A B757 is actually rated as “heavy”, too, because it produces such strong vortices. Taking the ICAO-seperation as proven fact is scientificly not valid.

Has Boeing ever tried to prove that a B757 does not produce such strong vortices and is not heavy?

Also, how sensitive is a B757 to the wake vortices of B747? Or of another B757?