What does 'Maintain present heading and altitude' actually mean?

, ,

Approaching a large airport on an IFR flight. As I get near the airport it says ‘Maintain present heading and altitude. Expect vectors blah approach, SXG’.

So I turn off NAV, lock in the heading and wait and wait and wait. I then ask ‘Request Vector to Next Waypoint’ and it gives me a different heading - though I’m not sure to where.

What is it actually asking me to do?

Don’t turn off NAV. All that means is stay on course, whatever current course NAV is taking you, but start Loading the Approach ATC assigned you into the GPS.

That way when ATC says “You are xx Miles from Destination Y. Cleared RNAV runway 28 via STOKY transition. Cleared to STOKY.” Acknowledge the Approach, then all you have to do is go into the GPS and Activate the Approach, and the GPS will start guiding you to the first point in the Approach pattern to Landing.

5 Likes

Its a nonsense call. Maintain present heading does happen every once in a while in real life, usually for separation purposes or to leave the instrument arrival and receive vectors for approach. But the phrase “maintaining present heading and altitude” during approach clearance is nonsense.

There is no meaning to “maintain present altitude”, what are you supposed to do during climb or descent? Hit altitude hold and level off 5169.25 ft? When already in level flight you will of course maintain present cleared altitude without further clearance anyway so no need to call “maintain present altitude”.

The only scenario I can think of is the following:

When cleared for approach you are automatically cleared to descent in accordance with the published procedure, it could happen that you are cleared to follow the approach procedure but not cleared to descent in accordance with the procedure yet. In such case ATC would clear you for approach but to maintain present altitude, the phrase “present altitude” is never used in RTF however, the cleared altitude is mentioned. Example:

”KLM123, cleared ILS approach runway 27 via SPL, maintain altitude 5000 ft”

6 Likes

How is that going to work?

If you‘re cleared for an approach, ILS or visual or whatever you cannot maintain a certain altitude. The approach clearance forces a vertical movement, otherwise it‘s not an approach clearance. Wouldn‘t such a constraint come with a „until 12DME“ or so so that you don‘t descend to the 2700‘ too early? (or whatever the FAF is at RW27)

1 Like

@Ephedrin87 They may sometimes not want you to descend yet (with the understanding that descent clearance will be issued in due time, or that your intercept point is sufficiently far out that you can maintain that altitude until establishing on the ILS), but normally you might expect they’d clear you for the localiser initially in that case… clearance for the ILS would normally imply the ability to descend with the procedure, but a specific instruction to maintain an altitude would over rule it until intercepting the ILS. AMS in particular have parallel approaches and multiple landing and T/O runways active at any given time so may interfere more than others.

Into Gatwick 26L for example there’s a very specific case, which is that the platform (2000’) for the ILS is lower than the noise box further out which came later, normally necessitating a 3000’ platform. As they haven’t cleared you down to the platform altitude yet if they simply cleared you for the ILS you would technically be allowed to descend down to the platform altitude and thus bust the noise area underneath you… that gave birth to a very specific terminology that I’ve only really come across in LGW - “cleared to intercept the localiser 26L and descend with the glide slope” rather than the more typical “Cleared ILS 26L”, the inference being that you must maintain the 3000ft you would currently be cleared to until intercepting the glidepath. Why after all these years they haven’t just changed the procedure platform to 3000’ and allowed their controllers to go back to just saying cleared ILS 26L is another question entirely. Elsewhere this terminology is rare and you’d just be told cleared for the ILS, maintain xxxx’ with the understanding that you will intercept from that altitude.

Well the standard instrument arrival ends at the IAF, the part between the IAF to the FAF-FAP is part of the approach, you might be confused with the final-approach segment.

The intermediate approach between the IAF and FAF-FAP could be complex with multiple step-downs, reversals etc. In my example the approach starts overhead the airport and then goes to a locater (IF), procedure turn after which the final approach is intercepted. No idea if this procedure still exists though, we used this one often in the simulator when I was an instructor.

Visual approach is another example indeed, cleared to proceed own navigation to the runway but not yet cleared to descent all the way.

In any case “maintain present altitude” is not a phrase used, at least according ICAO phraseology.

2 Likes

Some good replies here if the OP was asking about real life. But I’m sure his question was related to what it means in the sim.

1 Like

This is something UKish though, I have heard this before. Think it must have been Glasgow or Edinburgh…

1 Like

we like to be different

When I attempted the first time I left NAV on and I got all the way to landing without ATC ever giving me the clearance to land - though they did complain when I began to descend.

I restarted and instead waited, regularly asking the ATC for an updated vector. It appeared to be making me do a very wide circle. After about 10 minutes it finally told me to contact airport tower who gave me the magic ‘Cleared RNAV blah’. The airport is a major one so I’m wondering if what ATC is actually doing is saying that it isn’t ready for me to land yet and to keep flying until they are ready.

Is it meant to direct me to some sort of holding pattern? When I’ve been a passenger in a commercial jet and the airport has been busy we’ve circled the airport and when I’ve looked out the window I’ve seen a string of planes following what appears to be the exact same route making me think it’s predefined.

Just as in real life, it doesn’t mean anything.

Its simple and easy, when flying under IFR, ATC guides you and tells you what to do. You don’t have to enter a holding if not being specifically asked to do so. You certainly don’t gave to ask for the next vector when being radar vectored. Vectors are broken in MSFS, don’t request an approach with vectors is the only work around I think?

IFR flying is one of the hardest types of flying, simply because it is covered by so many more rules. Knowing the rules is the tricky part especially when flying internationally.

So let’s discuss an IAP (Instrument Approach Procedure.) There are basically two major ways ATC can normally get you on the approach. They can RADAR VECTOR you or they can CLEAR you to a: transition, IAF (Initial Approach Fix), or IF (Initial Fix) on approaches without an IAF.

When RADAR VECTORING that is when we would normally expect that ATC is going to assign us a HEADING and ALTITUDE to fly. Since they are taking you to the approach it is mostly in their hands, however, don’t let this fool you. As the PIC (Pilot in Command) you are still the final responsibility for the safe operation of your aircraft, not ATC. If they give you a bad vector or a bad altitude and you collide with something, ultimately it is the PIC who failed to maintain terrain clearance. So while being vectored this is not the time to let down your guard, you need to follow along on charts and double-check your clearances. TAWS (Terrain Avoidance and Warning Systems) really helps to backup the pilot here. (Unlike the old day where a moving map was our finger moving across a paper map.)

When they clear me to a fix then I expect they will tell me how to get to that fix. I can proceed direct if I am RNAV/RNP enabled, join a radial or bearing, continue via a STAR, or maybe even my flight plan if they will take me to a fix that joins the approach. Once I join the approach then unless restricted by ATC then I expect that I will fly the courses or track and altitudes published. That includes PT (Procedure Turns) or HILO (Hold in Lieu of Procedure Turns) unless I am on a segment of the procedure that specifically states NO PT. So sometimes based on the IAP I in fact may fly a PT or HILO, but generally not the Missed Approach (MA) Holding unless I execute the missed approach procedure. (Be careful sometimes a missed approach holding procedure will be at the FAF and sort of look like a HILO.)

MAINTAIN simply means that maintain a cleared altitude or heading. It is rarely used with current and should never be given by ATC when an aircraft is maneuvering. i.e. Maintain a current heading is fine when an aircraft is already on a VECTOR or assigned heading, but not OK when the aircraft has not been already assigned some heading. The same with altitudes, I should be at an altitude or given CLIMB and MAINTAIN or DESCEND and MAINTAIN. If ATC needs me to stop climbing or descending then should issue specific clearance to stop my maneuvering.

MSFS AI ATC tries hard but is ultimately limited. Again there are lots of rules and lots of situations. The reality is it really does take a human to properly interpret and control an aircraft. Remember always it is the Pilot in Command that is ultimately responsible for the safe operation of an aircraft, not Air Traffic Control. Don’t surrender the safety of your airplane (or virtual airplane) to ATC, especially not AI ATC. I often ignore MSFS AI ATC when flying an approach, because of its severe limitations. I keep myself under pilot nav and fly the whole procedure as published. Of course, then there are significant limitations of the avionics systems as well to contend with.

4 Likes

“Maintain present heading and altitude” in FAA terminology means “fly straight and level, stop turning, stop changing altitudes, stop following IFR course until told to resume.”

As other have mentioned, it is not being used properly by ATC in MSFS. What they mean to say is “proceed on course, maintain own navigation to transition fix.”

2 Likes

A lot of ATC will get revamped because WT is ripping out the legacy Flight Planning logic and replace it with the ARINC compliant model inside CJ4 and NXi today. ATC doesn’t understand all those leg types so both will be updated by WT team. Clearance/Departure for example doesn’t assign a SID or Approach doesn’t assign a STAR because ATC isn’t coded correctly for those leg types.

For now in the sim, use a chart or an EFB, evaluate whether the approach makes sense and accept or request a new one. Once agreed upon, Load the Approach. When cleared to the Approach, Activate it. Until then, do not deviate from the plotted leg assuming you’re in on Autopilot and following a plan.

Yeah, people need to understand that in-sim ATC has absolutely no connection with reality…

2 Likes

Unfortunately yes…

Do you have a reference to that from FAA Order 7110.65? I’d be interested in reading the parameters under which ATC should assign that. Thank you.

1 Like

Yes, there’s a minimal resemblance to actual ATC. I get maintain heading and altitude while decending to an assigned altitude and heading in the sim. It does not make sense and ATC rarely says it, unless they think there’s some confusion or say youve meandered off the alt and hdg. If they think it works for them, they may issue a new instruction to maintain present hdg and alt. Expect after you land to maybe get a request to call ATC to discuss the meandering.

It’s not needed for ATC to give you an altitude and heading and then later repeat maintain heading and altitude. Its implied in he first instruction.

For anyone not flying in FAA-land, I wrote a Mod to transform the MSFS phraseology into ICAO phraseology, I have removed the option for vectors entirely as MSFS does not currently give vectors. Also this “maintain present heading and altitude” is gone.