Instrument IFR route (off airway)

[StatorVane]

Hi,

Is it possible to fly under IFR to airports not serviced by navaids or situated on or nearby airways? For example, could we take off in VFR from our private strip and fly to another private strip when a proportion of the flight will be in IMC? If so, how would this be filed with ATC - would we just put in a direct route or would we need to plan to use the airways system. If the airways system takes us on an inefficient route can we mix and match those portions that would be useful and are we allowed to "create" our own waypoints (GPS or VOR/DME) and use these in the plan?

I have not flown for years and believe it or not I have an FAA IR and should be able to answer all these questions myself but I'm ashamed to say I can't. Perhaps you guys would be obliging as I'm on a mission to retrain and get back into the air!

Many thanks

[ab33t]

File a combo flight plan , with the , begining and end being VFR and the enroute section to be IFR . This is done all the time

[IO540]

If you are asking internationally, it is a good question...

The answer is country dependent.

In the UK, and most of Europe, you can file an "I" flight plan to/from an airport with no instrument approach (IAP).

In some countries (I think Spain is one but I can't remember) you would have to file a "Y" flight plan if you are going to one of their non-IAP airports, if you want Eurocontrol to accept the flight plan (and you cannot fly unless they accept it).

The actual process for going to such an airfield would be according to how much ATC down there give a damn. With a Y plan you are supposed to formally cancel IFR and proceed VFR.

In practice, flying internationally, the problem does not arise much because much of the time you need Customs, and most Customs airports have an IAP.

However taking this

For example, could we take off in VFR from our private strip and fly to another private strip when a proportion of the flight will be in IMC?

in a strictly UK context, nobody cares because UK allows IFR in Class G non-radio, so you don't need to file anything. The change VFR to IFR (some cloud) to VFR is purely inside your head.

[ab33t]

Sorry , I meant to say that you cannot mix and match any way you like to get into the system you will need to establish the entry and exit point that are compliant with the IFR system , ie you cannot enter the IFR system from any point there are pre defined entry points . Saying that, the flight plan is just to get you in the system once in flight the ATC will then route you in a combination of either to suite their traffice flow and or to give you the shortest route.

[IO540]

you cannot enter the IFR system from any point there are pre defined entry points

You've got me a bit confused.

Departing a "farm strip" (Class G), for an international or other Eurocontrol IFR flight, one files the flight plan, gets airborne, calls up the regional FIS unit (London Information usually) and they give you a provisional airways clearance (which, them being non-radar etc, will be a squawk and the IFR controlling authority frequency - usually London Control). Then you change to London Control and they will clear you to enter CAS in the climb on a track to some waypoint which they will give you. This could be anywhere where it suits them.

[ShyTorque]

Here's one UK based scenario.

An aircraft takes off from private land into Class G airspace. No flight plan required, no R/T call to be made.

The aircraft continues under IFR and IMC, remaining in class G towards its destination airfield. At some point near the airfield it will enter controlled airspace. The pilot calls the appropriate ATC unit in advance, obtains an IFR clearance to enter the airspace and is given direct routing to the approach.

What ATC service, if any, the pilot obtains en route is up to the individual.

All perfectly legal, although it might not always work in practice. Other things like destination PPR and obtaining a slot might be needed.

[IO540]

One might not get clearance to enter CAS - VFR or IFR.

One does potentially need PPR - VFR or IFR.

Slots? They are issued by Eurocontrol. If one say departed a farm strip and flew to Bournemouth (Class D) would they issue a slot? I have never come across that. The flight never went anywhere near Eurocontrol. Bournemouth is PPR (and so are most UK airports of that type) and the PPR is your permission to go there. Of course ATC could refuse but that would be very rare.

If OTOH one departed from a strip, and tried to get an IFR clearance into Class A (UK), that is different. IME one is unlikely to get it unless a flight plan has been filed and - unlike Class D - this cannot be done with a radio call. And if you file an IFR flight plan, airways levels, then Eurocontrol might issue a slot and quite often do.

[mm_flynn]

Hi,
I have not flown for years and believe it or not I have an FAA IR and should be able to answer all these questions myself but I'm ashamed to say I can't. Perhaps you guys would be obliging as I'm on a mission to retrain and get back into the air!

Many thanks
If you are an FAA pilot (rather than a UK pilot who got an FAA IR years ago) I strongly suggest some experience flights over here with an IMC/IR instructor. The UK system is quite different from the US - there are things which are totally illegal in the US that are normal practice here and normal practice US things which don't really exist over here. Flying in most other parts of Developed Europe is much more like North American flying.

Within several European countries you can file and fly 'informal IFR' which allows pretty much arbitrary routes from a-b (and in the UK you don't generally file any flightplan for these), this almost never work across FIR boarders - you really need to be 'in the system' which means something the Eurocontrol computer considers within its remit. It is only these plans (to my knowledge) that are included in flow control planning and hence potentially subject to departure slots.

[S-Works]

This is something I day very frequently. I operate from a private strip well outside CAS. One example is that I fly on a very regular basis to the CI. I file an IFR flight plan with a ZZZZ for departure and then airways to the CI. London info are my first call when airborne and they negotiate my airways join which is generally at the point I defined in my flight plan but can be as IO540 pointed out pretty much anywhere that please ATC.

On the way back I do the same thing and am asked by ATC where I intend to leave CAS. There is an airways intersection at FL100 almost straight above the field EBOTO and tell them that I will be leaving by descent in this direction. It then gives me a chance on a weekday to get a Radar service from my local RAF unit who when required will give me a cloud break for a scud run back to base or will accept me as a diversion if I am unable to get in (only needed once in the last 5 years).

I tend to do virtually all of my IFR flying in the airways even when the routing looks longer at first planning as I like to try and get above the weather and a lot of the time this is invariably in CAS altitudes. It is also a lot easier when single pilot IFR when you are on a radar service and the separation is provided for you, transits don't have to be negotiated etc. So even when flying long distance between uncontrolled fields I will use the airways. When flying over seas pretty much all of my flying is done IFR as it makes life so much easier and you never run the risk of busting CAS!!!

[ShyTorque]

The original poster said "off airway".

IO540, Re class A, it can be done with a radio call and no written FP provided a PPR is requested in advance by phone. An SVFR clearance is the expected way to join (pilot's discretion to safely and legally break cloud) but on a few occasions where the weather was deemed on arrival to be below limits for SVFR I have been vectored for an ILS.

One might not get clearance to enter CAS - VFR or IFR.

Hardly ever occurs in my experience, but I do always have an alternate route in mind.

[S-Works]

The original poster said "off airway".

No he did not, go and read it again. He asked about mixing and matching........

If the airways system takes us on an inefficient route can we mix and match those portions that would be useful and are we allowed to "create" our own waypoints (GPS or VOR/DME) and use these in the plan?

[ShyTorque]

Title was: Instrument IFR route (off airway)

[IO540]

Re class A, it can be done with a radio call and no written FP provided a PPR is requested in advance by phone.

However, you later mention SVFR which is possible only if the Class A reaches the ground e.g. Heathrow, Jersey, etc. That I don't doubt, otherwise nobody could fly to Jersey etc without an IR :)

What would be news to me would be a pop-up clearance (no Eurocontrol flight plan filed) into Class A, followed by a sizeable enroute flight from say the UK to say Italy, or even s. coast to Scotland.

This topic has come up on various forums and it always makes a lot of heat with UK ATCOs being unhappy about it, but from private ATCO comments it appears that UK ATC has no practical way to generate an IFR flight plan on the fly. Other n. European countries can do it, and the USA does it routinely. I once flew from Split (Croatia) to the UK and about halfway it became apparent that my FP had vanished from the system. Somewhere between Switzerland and France they generated a new one, with very little fuss, all while I was flying along in roughly the right direction at FL140... But on the few occassions I have tried a pop-up clearance into UK Class A (from a non-FP VFR flight, or even a flight-planned IFR flight which was filed below CAS) I was never successful and on the last occassion I had Manchester quite deliberately frustrate me. However, the ability to do this may vary around the UK.

[ShyTorque]

IO540,

Every time I have flown into LHR (been doing so quite a few times in the last 9 years) I have been given an arrival slot time when making the PPR. On one occasion we were warned by the handling agent that our company had been "awarded" a "slot time violation", for reasons outside our control.

[Droopystop]

However, you later mention SVFR which is possible only if the Class A reaches the ground e.g. Heathrow, Jersey, etc. That I don't doubt, otherwise nobody could fly to Jersey etc without an IR

IO540

Not sure what you mean by this - I regularly get SVFR in class D airspace. Basically allows non IFR access to CAS (of any type) below normal VFR weather limits or at night. Is it different between fixed wing and helicopters?

[spekesoftly]

Not sure what you mean by this .....

SVFR flights in the UK are only permitted in Control Zones - either Class A or Class D. If you wish to enter or transit a portion of Controlled Airspace where the base starts above the surface, by definition it is not a Control Zone, and SVFR is not an option.

[Vone Rotate]

Could anyone recommend some reading on these types of scenario's?

[mm_flynn]

Could anyone recommend some reading on these types of scenario's?

The detail discussion on SVFR is documented in 'all good airlaw books' (and the ANO). For real life fixed wing IFR operations, PPLIR has a good book available, back issues of a newsletter and an active forum (PPL/IR Europe (http://www.pplir.com)).

[englishal]

Basically allows non IFR access to CAS (of any type) below normal VFR weather limits or at night. Is it different between fixed wing and helicopters?
How can UK SVFR allow access below normal VFR weather minima, when for UK one requires 10km / 3000m (if instrument qual held) vis for SVFR?

I agree it is arse about face, in the USA SVFR can be used in weather down to 1 statute mile (less for helicopters).

[palou89]

Hi,

Is it possible to fly under IFR to airports not serviced by navaids or situated on or nearby airways? For example, could we take off in VFR from our private strip and fly to another private strip when a proportion of the flight will be in IMC? If so, how would this be filed with ATC - would we just put in a direct route or would we need to plan to use the airways system. If the airways system takes us on an inefficient route can we mix and match those portions that would be useful and are we allowed to "create" our own waypoints (GPS or VOR/DME) and use these in the plan?

I have not flown for years and believe it or not I have an FAA IR and should be able to answer all these questions myself but I'm ashamed to say I can't. Perhaps you guys would be obliging as I'm on a mission to retrain and get back into the air!

Many thanksYes you can fly on an IFR flight plan to an uncontrolled airfield not serviced by anynavaid or situated nearby airways.

Now depending on what kind of airpace you will be flying will make a difference here. You can legally fly in IMC in class G airspace (off route), but you could also be flying off route in class E airspace (in FL ussually starts at 1200ft agl). So in order to conduct your IFR flight in IMC you would have to dodge all the airways by flying through class G airspace. (I dont quite remember if you need to file a flight plan for this kind of flight as ATC has no authorithy nor responsibility over you in class G airspace).

If you want to stay away from the airway system, you could file a direct IFR flightplan, even if VFR on the grass strip. After takeoff stablish contact with appropriate atc facility and get your clearence. Here is where they might not want you flying direct (going across airways), and may issue you an airway based route. Then you can simply terminate your IFR flight whenever you want as long as you are above VFR wx minimums and not in class A airspace.

You have some decent information about this on the AIM 5-1-8

[bookworm]

How can UK SVFR allow access below normal VFR weather minima, when for UK one requires 10km / 3000m (if instrument qual held) vis for SVFR?

Instrument rated pilots have no such minimum vis. Minima for ATC to issue SVFR clearances for departures vary a little between airports I think, but usually can be issued down to 1800 m met vis and 600 ft ceiling. There is no requirement for a SVFR flight to maintain a particular flight visibility, just clear of clouds.

But even 3000m is "below normal VFR weather minima".

[Vone Rotate]

This subject has got me reading up and improving my knowledge on this subject.

One thing I have found which is confusing me a bit is the requirements for filing a flight plan. One of them states IFR flight.

So on my understanding of that any IFR flight requires a flight plan to be filed? I prepare to be corrected:}

[Islander2]

So on my understanding of that any IFR flight requires a flight plan to be filed?
Varies from country to country.

If you are referring to the UK, it isn't true that any IFR flight requires a flight plan. See ENR 1.10 in the UK AIP. IFR flight OCAS doesn't, and some IFR flight in CAS requires only an abbreviated flight plan obtained by telephone prior to take-off or by RT in flight.

[IO540]

There is a vast difference in replies one is going to get here, according to which country (most people here are in the UK, but not all, and this needs to be absolutely understood otherwise some advice will be way off), and according to whether one is filing IFR within the UK, IFR for a trans-European flight, whether one has an IR, etc.

The OP (original poster) has to detail where he stands papers-wise, where he flies, and only then one can do a useful reply.

For example flying "IFR" in UK Class G (crudely speaking, getting airborne and drilling a hole in a cloud, which as it happens I have been doing tonight while renewing my FAA 3+3 night passenger currency) is completely different to flying "IFR" from UK to Germany.

The air is the same of course (though the national CAAs would differ on that one, because they invented air) but one flies under vastly different constraints due to ATC, airspace, procedures, etc.

Taking the "purest" form of IFR, international IFR is pretty similar to US IFR. The main differences are that the flight plan is ICAO rather than the very brief US national format, and some terminology differs. Then in Europe you have the bizzare Eurocontrol routing issues but there is a software tool (http://flightplanpro.eu/Home.html) for that now. Apart from these things, a US pilot will be able to fly in Europe OK.

[IO540]

Presumably it "has" to work that way otherwise somebody flying into the USA would not be able to.

The really big differences are in VFR flight. Europena pilots just cannot believe that in the USA one can fly VFR up to 17999ft (Class A base is 18000ft) and gets easy transits through most controlled airspace, etc. Class D transits are with just 2-way radio contact (no explicit clearance needed).

A US pilot (IR holder) who does an IFR flight in Europe will first hit the Eurocontrol routing system. After he has found a way through that, the flight is pretty well as he might expect. He does need to stick to reasonably high levels for it to work; in the USA this is formalised in the way the airway MEAs are shown on the chart but in Europe this is more vague.

The fun bit is if he cancels IFR; then he needs to know the airspace, and all the other stuff.

[travisholland]

The vast majority of European FIRS allow off airway routing, so off airways, or IFR to airports not served by airways or nav-aids is no issue at all.

A friend of mine in Austria goes into eastern europe a lot where many FIRS don't allow off airway (CFMU REPLY: MAX DCT (0) NM IS EXCEEDED...) and he just files to a nearby IFR airport and then diverts when he gets close. Works great for him. He does the ZZZZ in the ADES when he can, but his backup is the above.

In Western Europe I have never found an airport I couldn't file to, although many airports are coded no IFR operations and you have to file a composite flight plan.

www.EuroFPL.eu is the magic for routing, as you can easily see from their 30,000 route validated database what the common routes are into and out of airports, as well as access the Eurocontrol auto-routing tool that was recently released. It makes Europe IFR route-finding as easy as USA. Free flight plan filing, routing, weather briefing, flight tracking and flight notifications. It is just too cool!

Travis Holland

[Sciolistes]

StatorVane,

Under standard ICAO procedures is it certainly possible to fly under IFR to airports not serviced by navaids or situated on or nearby airways? For example, could we take off in VFR from our private strip and fly to another private strip when a proportion of the flight will be in IMC? If so, how would this be filed with ATC - would we just put in a direct route or would we need to plan to use the airways system.
Yes. You simply file the flight plan as an IFR flight with your required routing. You will receive and ATC clearance from, for example London Control, via the FISO/AG at your local strip or you simply call to get the clearance if no ATS. The clearance will contain your initial routing, altitude and contact frequency on departure. Once you have established contact after departure you're off. When you arrive at your destination, if you are under radar control, ATC will vector you and request you report visual, if not visual they will continue to vector you to your alternate or re-sequence you. If visual you will be handed over or cleared own navigation. If there is nobody to hand you over to you'll probably be given an appropriate FIS frequency.
If the airways system takes us on an inefficient route can we mix and match those portions that would be useful and are we allowed to "create" our own waypoints (GPS or VOR/DME) and use these in the plan?
I'm not sure how complex you can get before the flight plan is rejected. The UK AIS publishes a standard routing document which shows the preferred routing to and from ATS airfields that join/depart airways. The ICAO flight plan provides the means to specify radials and distances from navaids, etc and I have certainly done this, but the routing remained simple and didn't not mix'n'match airways. Personally I would keep the complexity in the flight plan to a minimum and either stick to airways or offroute (one or the other) and then ask for appropriate shortcuts when in the air.

I have not flown for years and believe it or not I have an FAA IR and should be able to answer all these questions myself but I'm ashamed to say I can't. Perhaps you guys would be obliging as I'm on a mission to retrain and get back into the air!
Fortunately I did my IR from a non-instrument airfield which meant many IFR flights beginning and ending with visual departures and arrivals with off airway IFR flights. I'm now based in Asia and I also ferry company aircraft to our maintenance facility in Singapore which is a VFR airfield, the procedure out here is no different from what I experienced in the UK.

[SergeD]

In France one can get off the airway but ATC dont (wont) let you if there is a military zone there, and there are many of those in between the airways!

[StatorVane]

Hi Guys,

Thanks for the response, I have found this very useful. Just to state my position I was generally talking about the UK system and I appreciate there are differences levied by different states.

When I wrote this I had in mind a number of scenarios. One, as I mentioned, was private site to private site where some part of the flight encountered IMC. The Class G airspace thing has answered that.

Could I give you another random scenario? If I said we'll fly from EGBM (Tatenhill) to EGTP (Peranporth) and mostly under IMC/IFR could anyone talk me through how you would approach the planning and chosen routing under IFR? In particular:


would you utilize airways (none apparently useful)?
would you route direct (maybe throw a waypoint in to steer around Bristol)?
how would you handle the final stages around Newquay (avoid or go through)?
Would you file a flightplan beforehand or whilst airborne?Finally, and possibly a very silly question, if ATC come back with a routing which is not what we asked for, and furthermore rendered the flight "inefficient" from our point of view and not worth doing can we renegotiate or re-file?

Many thanks guys. I appreciate this becoming a lesson in its own right but I'm finding this very useful and despite dusting off several "instrument" books I jsut haven't got my answers. By the way, can anyone recommend a good read on this theme, with scenarios? Perhaps I've already asked enough for one post...? :=

[IO540]

As with nearly all flights around the UK, you can fly that in Class G, non-radio. There is no need to complicate it any further :)

Just draw it on the VFR chart and fly it with a GPS; that's what I've been doing since I got my PPL and I haven't hit anything yet.

For backup, plan the route on navaids so you have a backup for the GPS. Or, if VMC and sight of surface is assured, you can practice goode olde map reading (the Brits beat the Germans with that in WW1 and did it again in WW2 so it has to be good).

If you want to transit a bit of Class D, call up the frequency shown on the chart for a transit, say 20nm/10mins before you get to the boundary. A lot of the time they will let you but sometimes they won't so you need a Plan B which is a dogleg :)

If you want to do it as a Eurocontrol IFR (called "airways" by many) flight, generally in controlled airspace which in the UK will generally be Class A, then you need this FPP routing tool (http://flightplanpro.eu/Download.html) and have a play. Without this, it gets awfully messy because you have to dig out the standard route documents and build a lot of understanding of the system, and the resulting routes will be hugely sub-optimal in distance terms.

If you post a pair of ICAO airport identifiers, people here can have a go at different routes.

I use FPP with a min level of F100, max of F180, and preferred of F140. That gives the best routings around Europe, generally. There are cases where setting the min to F070-090 gives a better result in some places. Above F140 there is no improvement anywhere except the Alps and similar - until you get to F200 (upper airways) but you need a place actually capable of flying up there; I can do F200 but not fuel efficiently. It is readily apparent that oxygen is handy...

The Eurocontrol routings work less than well at sub-oxygen levels, but the bigger issue is that at most airway MEAs you will be in IMC if there is any IMC, and much of the year the temp will be below 0C, so the name of the game is to climb above it and fly the enroute bit in sunshine.

[tmmorris]

I generally plan to VOR-hop using GPS as the main tool but tuning in the beacons as a backup in case the GPS fails (very rare but it has happened). Occasionally I include an NDB as a backup though they are pretty much useless.

Not sure exactly how I'm going to do that when they turn off most of the VORs, but there you go...

As IO540 has said you want to plan to transit class D but have a plan B in case of refusal. Don't forget you can often go higher (icing permitting) to avoid class D rather than going round - I sometimes go over the Brize zone, for example, though they rarely refuse a transit.

Tim

(edited to add - our club rules require a radar service at all times when IMC, though that isn't always feasible if you are on one and get dumped to a new frequency who won't provide. But it's a good policy to aim for.)

[IO540]

our club rules require a radar service at all times when IMCHave you asked for the data on which they base that policy?

There are no known collisions in UK airspace in IMC, since WW2.

Actually IMHO this is an appalling and ridiculous restriction which if really obeyed would make Class G IFR flight around the UK impractical. Most of the time in the UK one either cannot get a radar service, or the one which one does get is useless "due to controller workload". And even at the best of times some traffic is not reported. Most people think that a TS amounts to a formal radar separation but it's nothing of the sort; it is at the controller's discretion whether to make the call or not. And to top it all, the majority of reported traffic is nontransponding so nobody knows where (vertically) to look for it (but when one does spot it it is usually way down below).

[ShyTorque]

IO540,

It seems sensible airmanship to use whatever radar service is available. I always do so where possible even if I then treat the efficacy of the service with guarded suspicion.

It's becoming more difficult to obtain though.... the UK LARS system is gradually being disbanded by stealth.

[IO540]

I agree; I always call up a radar service.

What I didn't get is a club rule which bans IMC without one. If I was flying alone I would obviously ignore such a rule, but if flying with a passenger, somebody might spill the beans and I might be risking eviction. That rule is totally nuts; imagine an instrument rated pilot, flying in IMC, and having his RS terminated. What is he supposed to do??? It's bonkers.

From a mid-air risk management POV a better (and equally hilarious) rule would be to ban flight on any sunny Sunday that was preceeded by 1 week or more of non-VFR weather, to any non-ATC airfield :) In fact I would just ban all flight to Wellesbourne and Stapleford at weekends :)

Much more sensibly though, banning enroute flight below 1500ft would, on the basis of UK VMC midair data, virtually eliminate the enroute risk. That is what I do.

[Chilli Monster]

Could I give you another random scenario? If I said we'll fly from EGBM (Tatenhill) to EGTP (Peranporth) and mostly under IMC/IFR could anyone talk me through how you would approach the planning and chosen routing under IFR? In particular:

•would you utilize airways (none apparently useful)?

No

•would you route direct (maybe throw a waypoint in to steer around Bristol)?

EGBM - TELBA - TALGA - EGTP

•how would you handle the final stages around Newquay (avoid or go through)?

Go through - they don't have any CAS, plus you'd be doing them a favour as they can deconflict you from any inbound / outbound traffic

•Would you file a flightplan beforehand or whilst airborne?

Wouldn't bother - no need to file, only advisory due to the terrain / water you'd be crossing.

Finally, and possibly a very silly question, if ATC come back with a routing which is not what we asked for, and furthermore rendered the flight "inefficient" from our point of view and not worth doing can we renegotiate or re-file?

That isn't a consideration because the route above is wholly within class 'G' airspace - you're responsible for planning the route, you're responsible for flying it, you're responsible for following. Nothing to do with ATC. The above example if you're looking for an answer to that question is actually a poor one, as ATC are only responsible for / and likely to give you, a reroute within class 'A' airspace or within the route structure that requires a CFMU Flight Plan to be filed so as to enter it.

Top tip though - you get routes within that type of airspace for a reason, and if you try re-negociating over the R/T, especially within a busy environment, you might just find yourself leaving that airspace just to get you out of ATC's hair.

By the way, can anyone recommend a good read on this theme, with scenarios? Perhaps I've already asked enough for one post...?

Rather than sitting down wth a book I'd suggest sitting down and talking to somebody who does this sort of thing often and is in current practice - you'll learn a lot more and, more importantly, will actually (hopefully) understand the environment you're operating in.

[tmmorris]

I have to admit to treating it as an 'aspiration' in New Labour speak... i.e. I will always ask for a radar service and wouldn't depart into IMC without one (but then the home field will provide it :-) ) but if I get dumped en route and can't get a radar service I don't immediately declare a Mayday!

In that respect the rule is a bit meaningless.

Tim

[12Watt Tim]

A quick piece of advice, slightly contrary to other answers here. One very fraught flight (the police put a TRA on the airspace I needed just before I took off; I was informed at the threshold) when I was inexperienced in joining the airways out of an uncontrolled airfield I called London Information for clearance. It took a while which was a real nuisance. London Control said I would have been better to call the nearest LARS unit (airfield ATS offering a radar service), they would have obtained my clearance more quickly. If you are unsure you could even phone the nearest LARS airfield beforehand to ask them what they expect, air-traffic assistants are generally helpful.

In France and Germany I have found that the radio operator will generally pass on a message from the nearest radar unit with departure instructions, squawk and frequency.