Pilot Discussion With a Global Perspective
By Matthias Schwab 1390507
#520021 Hi everyone :)

I would like to fly IFR in a vintage propliner on VATSIM. But while planning a flight, I always end up with the same problem. All those fancy SIDs and STARs are designed for fast climbing and even faster descending turboprops or jets, which the DC-6 just isn't able to handle. :oops:

For example the LUNIP 4L RNAV arrival at ENGM. At one waypoint (GM414) throughout the STAR you have to be at FL110, and after only 27.4 NM you should be at 3500 feet for the ILS RWY01L. :shock: Thats 7500 feet to descend in 27.4 NM. In the DC-6 I'm able to achieve a maximum descent-rate of 500 feet per minute with about 200 KIAS (without destroying the engines). This means, that I need about 50 NM to descent from FL110 to 3500 feet, and I need an additional 10 NM in level flight to slow down from 200 KIAS to 170 KIAS for extending flaps/gear. So no way to comply with the published STAR. :lol:

What should I do? Fly circles in the holding pattern at INSUV until I'm low and slow enough for the ILS approach, or can I state something in the remarks of the flightplan that I'm not able to comply with the SID/STAR height and speed restrictions?

Thanks in advance! 8)
Regards Matthias Schwab
By Morten Jelle 1012739
#520025 As far as I know, the DC-6 is not RNAV capable - so in that case you will not be able to fly the RNAV STARS/SIDs. In your case, I'd inform ATC and let them know, that you are unable to comply with the restrictions. In such case, there may be another procedure to follow, or the ATC will give you vectors and altitude clearances.
By Johan Grauers 1113891
#520027 Can you fly a 3 degree glidepath?

If not you can't fly most ILS approaches as they tend to have a 3deg glidepath. Most non-precision approaches also seem to aim around the 3deg mark.

If you can, then can you configure your aircraft in a config which allows this earlier? The descent listed in the OP is just below 3deg mark so if you can fly an ILS I would've thought you could manage that descent too?


Regardless though, don't accept a clearnce you can't fly and ask for an alternative, but I have to admit that if you can't fly an ILS or a non-precision 3deg approach you might struggle to end up with an IFR approach apart from a visual, and even then you would have to fly it very wide to allow the descent.
By Matthias Schwab 1390507
#520029
Morten Jelle 1012739 wrote:As far as I know, the DC-6 is not RNAV capable - so in that case you will not be able to fly the RNAV STARS/SIDs. In your case, I'd inform ATC and let them know, that you are unable to comply with the restrictions. In such case, there may be another procedure to follow, or the ATC will give you vectors and altitude clearances.


I got a GTN650 installed, which is RNAV-capable, and can be coupled to the autopilot for LNAV.

A 3° ILS approach is no problem with the six. The problem is the STAR that should get you from the last fix of the route to the IAF, which demands a descend-rate of more than 500 feet per minute, and with no room to slow down in level flight to set the plane up for the approach.

I also wonder how a small GA piston aircraft is flying in and out of a major airport while being in IFR condition. :?: Will it be vectored by ATC? And what waypoints do they file in their flight plan, as they're defenetly not able to fly a SID or STAR? :|
By Josh Glottmann 1275389
#520035 US here, but see if there are any prop arrivals. It may be a better option to use a non-RNAV arrival (if available) as they tend to be less geared towards jets (and may have more flexible restrictions).
I would advise the controller that you will be unable 5000 at INSUV and may require further vectors for descent.
By Lindsey Wiebe 1101951
#520037 GA would file the last enroute fix from the IFR enroute chart then to destination. ATC would then assign an approach; in RL ATC would go by the equipment code and assign as appropriate, we're on VATSIM so hit and miss if the equipment code is referenced or not (and whether the pilot put the correct in to begin with). Best bet is to put in the comments that NO RNAV, only VOR/ILS equipped.

As for the DC6 I think you are missing a step in the preparation for the approach. I've never flown one so can't help you but Buffalo Air in North West Territories in Canada flies several and I'm pretty sure they are using RNAV approaches and do it just fine. I would review the docs with the plane and in particular the approach segment preparation. As well search on YouTube for people doing tutorials or just a full flight in the DC6. It's certainly a cool looking and very capable aircraft. I'm sure once you get it figured out it will be immensely rewarding making a full flight in the old girl.
By Matthias Schwab 1390507
#520052 Thanks for your replies. I also got a tip via PM which was very helpful.

For the LUNIP 4L at ENGM I'm going to try the following:
- Enter the STAR vie LUNIP at FL120,
- Try to slow down to about 170 KIAS in level flight between LUNIP and DEVKU,
- As soon as possible (below 174 KIAS), drop the flaps to 20° for additional drag,
- When additional drag is required while descending after GM414, drop the gear,
- Look at what height I end up at INSUV. :lol:

If I'm too high, I will try to slow down even more before starting the descent, maybe 150 KIAS or even 130 KIAS (which is described in the planes manual as base-speed).

I also wonder what the additional numbers on the STAR-charts are for? For example also the LUNIP 4L, where the fix GM416 is stated "at FL110", but above the line of the leg to the next fix and just below the legs distance, there is the number "5000". Is that the minimum safety altitude to stay clear of terrain and/or obstacles? Why is it there, when you have to be way above that anyway? Btw, I use Navigraph charts.
By Dace Nicmane 1313735
#520053
Matthias Schwab 1390507 wrote:Try to slow down to about 170 KIAS in level flight between LUNIP and DEVKU

This might not be the best idea, since you'll be holding up traffic behind you. Once again, there's nothing wrong with being vectored. The STAR is there for convenience, but if it causes more inconvenience instead, don't fly it. If ATC is online, they'll decide how to sequence you, so just advise them of your capabilities and leave it up to them. The portion from GM416 to 414 is there for sequencing only anyway, so they may put you there for your descent while clearing faster traffic direct INSUV, or they may take you off the STAR and somewhere else altogether. If you want to be different, just be different, if not, take a 737 and fly like everyone else. :mrgreen: ATC is more flexible than you think.
By Simon Kelsey 810049
#520055
Matthias Schwab 1390507 wrote:I also wonder what the additional numbers on the STAR-charts are for? For example also the LUNIP 4L, where the fix GM416 is stated "at FL110", but above the line of the leg to the next fix and just below the legs distance, there is the number "5000". Is that the minimum safety altitude to stay clear of terrain and/or obstacles? Why is it there, when you have to be way above that anyway? Btw, I use Navigraph charts.


Yes, that's correct. It's there for your additional information and situational awareness: what if you had a problem which meant you couldn't maintain FL110, for example? Wouldn't it be nice to know that you're not going to end up on the side of a mountain if you don't make the restriction? Remember the assumption with all instrument procedures is that you may be flying them in IMC where you can't see out of the window. Note also that the chart says that your actual descent clearance will be by ATC, which may differ from the levels published on the chart: again, ATC in theory could clear you to descend to 4000ft when you're still inbound LUNIP, in which case it's good to know that you can't descend below 5000ft until after GM114.

As you have correctly identified, the procedure is (unsurprisingly) designed for modern jet traffic. As such, if you don't fit the speed/descent profile of other traffic using the arrival, there is little point in you flying it: SIDs and STARs exist to make life easier for ATC and cut down on RT traffic. If you are slow/and or low compared to other traffic, as Dace the easiest thing for ATC is likely to be to vector you out of the way and sequence you in that way.

I also wonder how a small GA piston aircraft is flying in and out of a major airport while being in IFR condition. :?: Will it be vectored by ATC? And what waypoints do they file in their flight plan, as they're defenetly not able to fly a SID or STAR?


To fly IFR in most of Europe these days you have to be at the very least BRNAV capable if you want to fly airways anyway, and in any event there's no reason why an IFR-equipped light aircraft could not fly at least a conventional-nav SID.

However, as mentioned above, it is about making the traffic flow work and if you are mixing it with the big boys then you will likely be routed to stay out of their way, which will very likely mean a non-standard clearance and/or vectors.

You can file whatever you want, but ATC may well have other plans :lol:.

In terms of increasing your rate of descent (which is essentially what you are asking) the answer is to get more drag on the aircraft by extending the gear etc.
By Matthias Schwab 1390507
#520067 Thanks for you explanations! So I'm going to comply as good as possible with the SIDs and STARs, and wherever I run into a SID or STAR the DC-6 isn't able to handle, I'll inform ATC about it (if there is one online). I'm also considering on flying at a lower altitude than published on the charts when no ATC is online, so I'm not going to "block" another approaching aircraft.