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Visual vs. ILS approach

Posted: Tue Jul 07, 2020 2:25 pm
by IFlyVeryLittle
I live within view of KSRQ and I've noticed something with the addition of several airlines in the last year. Far more than other airlines, Allegiant arrivals seem to fly a very short, curving approach to runway 32. Without supporting data, I would say nearly all the other airlines routinely fly a much longer final approach under exactly the same weather conditions. Im guessing this is a visual approach vs. an ILS approach, but is this something that Allegiant is known for? And for what purpose? Thanks.

Re: Visual vs. ILS approach

Posted: Tue Jul 07, 2020 2:41 pm
by airtran737
IFlyVeryLittle wrote:
I live within view of KSRQ and I've noticed something with the addition of several airlines in the last year. Far more than other airlines, Allegiant arrivals seem to fly a very short, curving approach to runway 32. Without supporting data, I would say nearly all the other airlines routinely fly a much longer final approach under exactly the same weather conditions. Im guessing this is a visual approach vs. an ILS approach, but is this something that Allegiant is known for? And for what purpose? Thanks.


It sounds like a visual approach. Given the option between a visual and an ILS, most of us are going to take the visual and back it up in the box with the ILS. Why do we do this? Because sometimes we actually like to fly the airplane rather than just spinning the heading bug and arming approach mode. Additionally, flying a visual approach is quicker than being vectored for an ILS. Sometimes I need to pee after a long flight, and an extra three minutes not flying spells relief for my full bladder.

Re: Visual vs. ILS approach

Posted: Tue Jul 07, 2020 2:46 pm
by CFM565A1
airtran737 wrote:
IFlyVeryLittle wrote:
I live within view of KSRQ and I've noticed something with the addition of several airlines in the last year. Far more than other airlines, Allegiant arrivals seem to fly a very short, curving approach to runway 32. Without supporting data, I would say nearly all the other airlines routinely fly a much longer final approach under exactly the same weather conditions. Im guessing this is a visual approach vs. an ILS approach, but is this something that Allegiant is known for? And for what purpose? Thanks.


It sounds like a visual approach. Given the option between a visual and an ILS, most of us are going to take the visual and back it up in the box with the ILS. Why do we do this? Because sometimes we actually like to fly the airplane rather than just spinning the heading bug and arming approach mode. Additionally, flying a visual approach is quicker than being vectored for an ILS. Sometimes I need to pee after a long flight, and an extra three minutes not flying spells relief for my full bladder.


Not to mention, at least for me, how tiring it is to do a full briefing for an ILS leg after leg. Nothing like keeping it simple when it’s safe to do so.

Re: Visual vs. ILS approach

Posted: Tue Jul 07, 2020 2:54 pm
by mcg
Ok, so a really dumb follow up question: Is a visual approach truly 'visual' in the sense the pilot sees the airport and runway and simply flies there, or is there a system of electronic navigation 'landmarks' (for lack of a better term) that are used to navigate to the runway? Thanks in advance.

Re: Visual vs. ILS approach

Posted: Tue Jul 07, 2020 3:07 pm
by sadde
It’s truly visual, but almost always backed up by some form lateral and vertical guidance (usually an ILS).

Re: Visual vs. ILS approach

Posted: Tue Jul 07, 2020 4:23 pm
by CFM565A1
mcg wrote:
Ok, so a really dumb follow up question: Is a visual approach truly 'visual' in the sense the pilot sees the airport and runway and simply flies there, or is there a system of electronic navigation 'landmarks' (for lack of a better term) that are used to navigate to the runway? Thanks in advance.


Also depends on the place you’re going... for example my Dash 8 days going into smaller Canadian airports, I would just join a circuit pattern once I had the field in sight... I’d shut off the flight directors completely from top of final descent and just hand fly. Wouldn’t do that going into busy airports like YYZ/YVR/YUL.

Re: Visual vs. ILS approach

Posted: Tue Jul 07, 2020 9:40 pm
by GalaxyFlyer
The “visual” is a fancy name for how we learned to land in the traffic pattern prior to solo. Look at airport, figure out the active runway, point airplane at the right spot and land. It’s not a mystery, but some are never comfortable with doing so.

Re: Visual vs. ILS approach

Posted: Tue Jul 07, 2020 11:53 pm
by Starlionblue
mcg wrote:
Ok, so a really dumb follow up question: Is a visual approach truly 'visual' in the sense the pilot sees the airport and runway and simply flies there, or is there a system of electronic navigation 'landmarks' (for lack of a better term) that are used to navigate to the runway? Thanks in advance.


A visual approach requires you to be visual for the entire approach. Otherwise you can't do a visual approach. However, the approach doesn't necessarily start from way out. The control will vector you to a certain location, or direct you to a waypoint, and from there clear you for the visual.

So yes, there are "landmarks", in the form of waypoints.

Re: Visual vs. ILS approach

Posted: Wed Jul 08, 2020 9:41 am
by GoSteelers
To add a few tidbits...

Although a visual approach, it is still a IFR procedure. And the aircraft doesn’t necessarily have to actually have the field in sight. If the aircraft has the preceding aircraft in sight, he can be instructed to follow the traffic and cleared a visual approach. And there are special approaches where the aircraft is required to fly over waypoints and meet restrictions even though on a visual approach. At one of my previous facilities, JetBlue developed an approach called the RNAV-Visual. The aircraft had to report the airport in sight but for noise abatement purposes he still had altitudes and a profile to fly.

Re: Visual vs. ILS approach

Posted: Wed Jul 08, 2020 1:01 pm
by Woodreau
A visual approach has nothing to do with automation. It can be flown with or without automation.

Most approaches are visual approaches 99% of the time, even the ones who are flying that “longer final approach.” The only way you’ll know is if you listen to the approach frequency and hear what the controller clears the flight to do.

Even though we are expecting to fly a visual approach, we will still do the full approach briefing, briefing the underlying ILS, LOC, RNAV, or RNAV Visual approach procedure to ensure we land on the correct runway and airport. As there are more than a few historical cases (I can think of four examples) where crews cleared for a visual approach have landed at the wrong airport. We also brief the published missed approach procedure and add that if we are cleared for the visual approach instead of the underlying instrument procedure, our go around procedure will be tower instructions and in absence of tower instructions the go around altitude will be 1500 AGL and either left or right traffic to remain in the traffic pattern.

Sometimes weather will be clear and a million, but we won’t get cleared for the visual. For example, Landing on the 19s in Las Vegas, we’ll be cleared for the RNAV Visual 19L/R, automation is off, we’re hand flying but we have to watch and follow the box sequence the waypoints to get us to the runway.

Being cleared for the visual 26 at Las Vegas, I’ve joined the visual 26 on a 20 mile straight in final outside PRINO and I’ve also joined the visual 26 rolling out of a 120 degree turn at RELIN 5 miles out.

It just depends on where the plane is In relation to the airport and runway and what you have to do to get the plane there when you’re cleared for the visual approach.

Re: Visual vs. ILS approach

Posted: Wed Jul 08, 2020 2:38 pm
by IAHFLYR
GoSteelers wrote:
To add a few tidbits...

Although a visual approach, it is still a IFR procedure. And the aircraft doesn’t necessarily have to actually have the field in sight. If the aircraft has the preceding aircraft in sight, he can be instructed to follow the traffic and cleared a visual approach. And there are special approaches where the aircraft is required to fly over waypoints and meet restrictions even though on a visual approach. At one of my previous facilities, JetBlue developed an approach called the RNAV-Visual. The aircraft had to report the airport in sight but for noise abatement purposes he still had altitudes and a profile to fly.


You nailed it. Charted visuals exist at a number of ATC facilities though my previous facility did not have any of them. It was either airport in sight or preceding aircraft as you refer.

As for SRQ, have to listen to the frequency to find out exactly what the OP is addressing, but my guess is they are simply flying a shorter approach for whatever reason.

Re: Visual vs. ILS approach

Posted: Wed Jul 08, 2020 4:58 pm
by FLALEFTY
Some visual approaches are very specific and strict as an ILS approach. A good example is the River Visual into DCA's RWY 19:

https://flightaware.com/resources/airpo ... RWY+19/pdf

Re: Visual vs. ILS approach

Posted: Wed Jul 08, 2020 9:51 pm
by mcg
Thanks for the interesting responses. One follow up, assuming good weather, are most approaches to busy (for example DEN or ORD) visual approaches? Thanks in advance.

Re: Visual vs. ILS approach

Posted: Wed Jul 08, 2020 10:26 pm
by N1120A
As some have mentioned, visual approaches take many forms. Most, particularly in the GA setting, are literally normal VFR style approaches. If approach vectors you there, you're usually going on a base of some sort. If the airport has an operating tower, the tower will basically tell you what they want, or communicate it to approach and they will tell you. For example, if you get a visual approach into KSMO (usually to Runway 3 - they want you on an instrument to 21), SCT will tell you which way to make traffic for the runway. Airplanes of all types going into KBUR that are on a visual for Runway 8 will basically be expected to follow the Burbank localizer and cross Van Nuys airport (BUDDE if you are on the ILS) at or above 3000' to protect the traffic pattern there. Most modern GPS boxes will provide visual approach guidance, as do modern airline FMS systems. Basically, they use GPS to calculate a proper glidepath and provide an infinite extended centerline. They can also set up a virtual fix a defined distance from the runway numbers.

Re: Visual vs. ILS approach

Posted: Wed Jul 08, 2020 10:31 pm
by N1120A
mcg wrote:
Thanks for the interesting responses. One follow up, assuming good weather, are most approaches to busy (for example DEN or ORD) visual approaches? Thanks in advance.


Actually, the busier an approach control is, the more often they want people on a visual. That way, their separation requirements go down.

Re: Visual vs. ILS approach

Posted: Thu Jul 09, 2020 2:49 am
by zeke
mcg wrote:
Ok, so a really dumb follow up question: Is a visual approach truly 'visual' in the sense the pilot sees the airport and runway and simply flies there, or is there a system of electronic navigation 'landmarks' (for lack of a better term) that are used to navigate to the runway? Thanks in advance.



There are 3 types of visual approaches, first being when an iFR aircraft does not complete some or all of and instrument approach and lands with reference to terrain, then there is is the visual procedural approach like the DCA RIVER for RWY 19 chart above, a series of landmarks are strictly followed to landing, then there is the visual guidance approach which can either with ground based aids like the LDA into HND, or RNAV like the RNP AR into JFK. The RNAV visuals basically have waypoints that can be flown by the aircraft until quite low.

GoSteelers wrote:
And the aircraft doesn’t necessarily have to actually have the field in sight. If the aircraft has the preceding aircraft in sight, he can be instructed to follow the traffic and cleared a visual approach. And there are special approaches where the aircraft is required to fly over waypoints and meet restrictions even though on a visual approach. At one of my previous facilities, JetBlue developed an approach called the RNAV-Visual. The aircraft had to report the airport in sight but for noise abatement purposes he still had altitudes and a profile to fly.


While correct in not needing to have airport in sight, it is a requirement to have terrain in sight. I am not aware of any Part 129 carrier that is permitted to follow the preceding aircraft with no other reference. ICAO does not permit this.

JetBlue did not invent the RNAV visual, they are widely used, many started off as overlays of other visual procedural or LDA style approaches to give final guidance. You might mean JetBlue around 2010 paid MITRE Corp for the development of a custom RNAV visual chart approach in JFK, which many airlines and EMS have for specific airports/heliports/hospitals around the world. Alaska Airlines has been flying them since the mid 1990s.

Re: Visual vs. ILS approach

Posted: Thu Jul 09, 2020 3:11 am
by e38
Quoting zeke (Reply 16), “ . . . it is a requirement to have terrain in sight.”

zeke, I’m not sure that applies in the United States for domestic operations.

Many times an air traffic controller has pointed out other aircraft to me, something like “traffic you are following is at one o’clock 4 miles, report the airport or traffic in sight.”

And when we did, either the field or the traffic, we were cleared for the visual approach, without making any reference to terrain.

e38

Re: Visual vs. ILS approach

Posted: Thu Jul 09, 2020 3:31 am
by zeke
e38 wrote:

zeke, I’m not sure that applies in the United States for domestic operations.

Many times an air traffic controller has pointed out other aircraft to me, something like “traffic you are following is at one o’clock 4 miles, report the airport or traffic in sight.”

And when we did, either the field or the traffic, we were cleared for the visual approach, without making any reference to terrain.

e38


From ICAO Doc 4444, PANS ATM

"Visual approach. An approach by an IFR flight when either part or all of an instrument approach procedure is not completed and the approach is executed in visual reference to terrain."

Re: Visual vs. ILS approach

Posted: Thu Jul 09, 2020 6:25 am
by mmo
In the US, at least, you could always get cleared for a "contact approach". As long as the traffic proceeding you are insight you can take that clearance. Although you never have to accept a visual. I do remember "fly to rule" times where we always took an ILS. But, that's another story!!

Re: Visual vs. ILS approach

Posted: Thu Jul 09, 2020 9:39 am
by GoSteelers
zeke wrote:
mcg wrote:
Ok, so a really dumb follow up question: Is a visual approach truly 'visual' in the sense the pilot sees the airport and runway and simply flies there, or is there a system of electronic navigation 'landmarks' (for lack of a better term) that are used to navigate to the runway? Thanks in advance.



There are 3 types of visual approaches, first being when an iFR aircraft does not complete some or all of and instrument approach and lands with reference to terrain, then there is is the visual procedural approach like the DCA RIVER for RWY 19 chart above, a series of landmarks are strictly followed to landing, then there is the visual guidance approach which can either with ground based aids like the LDA into HND, or RNAV like the RNP AR into JFK. The RNAV visuals basically have waypoints that can be flown by the aircraft until quite low.

GoSteelers wrote:
And the aircraft doesn’t necessarily have to actually have the field in sight. If the aircraft has the preceding aircraft in sight, he can be instructed to follow the traffic and cleared a visual approach. And there are special approaches where the aircraft is required to fly over waypoints and meet restrictions even though on a visual approach. At one of my previous facilities, JetBlue developed an approach called the RNAV-Visual. The aircraft had to report the airport in sight but for noise abatement purposes he still had altitudes and a profile to fly.


While correct in not needing to have airport in sight, it is a requirement to have terrain in sight. I am not aware of any Part 129 carrier that is permitted to follow the preceding aircraft with no other reference. ICAO does not permit this.

JetBlue did not invent the RNAV visual, they are widely used, many started off as overlays of other visual procedural or LDA style approaches to give final guidance. You might mean JetBlue around 2010 paid MITRE Corp for the development of a custom RNAV visual chart approach in JFK, which many airlines and EMS have for specific airports/heliports/hospitals around the world. Alaska Airlines has been flying them since the mid 1990s.


I’m sure your pilot rules are different, but from a controller point of view, I don’t have to say anything about terrain on a visual approach. When you accept a visual approach clearance, whether with the field of the preceding aircraft in sight, it is your responsibility for obstruction clearance. Matter of fact, there a lot of situations where our radar “computer” thinks you are too low or descending too fast and we get a “low altitude alert”.

As far as JetBlue, I’m sure there are numerous other airports but as I stated I gave one example that I was specifically familiar with. I didn’t say they invented it. And yes, JetBlue came to our facility, helped design the approach, flew test approaches and were the ONLY authorized users of the RNAV-Visual for years.

Re: Visual vs. ILS approach

Posted: Thu Jul 09, 2020 1:39 pm
by GalaxyFlyer
FAA definition,

a. A visual approach is conducted on an IFR flight plan and authorizes a pilot to proceed visually and clear of clouds to the airport. The pilot must have either the airport or the preceding identified aircraft in sight. This approach must be authorized and controlled by the appropriate air traffic control facility. Reported weather at the airport must have a ceiling at or above 1,000 feet and visibility 3 miles or greater. ATC may authorize this type approach when it will be operationally beneficial. Visual approaches are an IFR procedure conducted under IFR in visual meteorological conditions. Cloud clearance requirements of 14 CFR Section 91.155 are not applicable, unless required by operation specifications.

Re: Visual vs. ILS approach

Posted: Thu Jul 09, 2020 2:38 pm
by mcg
Thanks so much for all of the responses. Yet another dumb follow up question: when flying an instrument approach, are the pilots eyes focused only on the instruments inside the airplane? Thanks again.

Re: Visual vs. ILS approach

Posted: Thu Jul 09, 2020 3:02 pm
by GalaxyFlyer
If IMC, yes; if VMC a mix of both inside and outside. As the clouds break in IMC, one brings the visual picture in as part of the scan.

Re: Visual vs. ILS approach

Posted: Thu Jul 09, 2020 3:32 pm
by mmo
Nothing like the Crow Bar approach going into JFK. Once past LGA a quick slam dunk and you're there. Lots of fun!!

Re: Visual vs. ILS approach

Posted: Thu Jul 09, 2020 3:45 pm
by GalaxyFlyer
Or the LGA 31 visual from the Tanks

Re: Visual vs. ILS approach

Posted: Thu Jul 09, 2020 8:47 pm
by IAHFLYR
N1120A wrote:
Actually, the busier an approach control is, the more often they want people on a visual. That way, their separation requirements go down.


Once the pilot acknowledges the visual approach clearance ATC has no further separation requirement from that point on until the tower runway separation requirements come into play. If you want to run up the guy you're followings butt go ahead, but if you go around don't blame me the approach controller for that operation. :bouncy:

Re: Visual vs. ILS approach

Posted: Thu Jul 09, 2020 8:55 pm
by IAHFLYR
GalaxyFlyer wrote:
FAA definition,

a. A visual approach is conducted on an IFR flight plan and authorizes a pilot to proceed visually and clear of clouds to the airport. The pilot must have either the airport or the preceding identified aircraft in sight. This approach must be authorized and controlled by the appropriate air traffic control facility. Reported weather at the airport must have a ceiling at or above 1,000 feet and visibility 3 miles or greater. ATC may authorize this type approach when it will be operationally beneficial. Visual approaches are an IFR procedure conducted under IFR in visual meteorological conditions. Cloud clearance requirements of 14 CFR Section 91.155 are not applicable, unless required by operation specifications.


And this from the FAA Controller Handbook....FAA JO 7110.65, Para 4-7-1 and 4-7-2.

7-4-1 VISUAL APPROACH
A visual approach is an ATC authorization for an aircraft on an IFR flight plan to proceed visually and clear of clouds to the airport of intended landing. A visual approach is not a standard instrument approach procedure and has no missed approach segment. An aircraft unable to complete a landing from a visual approach must be handled as any go-around and appropriate IFR separation must be provided until the aircraft lands or the pilot cancels their IFR flight plan.

At airports with an operating control tower, aircraft executing a go-around may be instructed to enter the traffic pattern for landing and an altitude assignment is not required. The pilot is expected to climb to pattern altitude and is required to maintain terrain and obstruction clearance. ATC must maintain applicable separation from other aircraft.
At airports without an operating control tower, aircraft executing a go-around are expected to complete a landing as soon as possible or contact ATC for further clearance. ATC must maintain separation from other IFR aircraft.

7-4-2 VECTORS FOR VISUAL APPROACH
A vector for a visual approach may be initiated if the reported ceiling at the airport of intended landing is at least 500 feet above the MVA/MIA and the visibility is 3 miles or greater. At airports without weather reporting service there must be reasonable assurance (e.g. area weather reports, PIREPs, etc.) that descent and flight to the airport can be made visually, and the pilot must be informed that weather information is not available.

There are some other paragraphs after 7-4-2 in the order that need to be met as well during specific type of operations. Well worth a read as the ATC world is one that was very fun as well as quite a number of regs to follow depending a number of condtions.

Re: Visual vs. ILS approach

Posted: Fri Jul 10, 2020 1:10 am
by Starlionblue
mcg wrote:
Thanks so much for all of the responses. Yet another dumb follow up question: when flying an instrument approach, are the pilots eyes focused only on the instruments inside the airplane? Thanks again.


As mentioned above, it is a mix.

Assuming VMC, from around 1000- 1500feet, you'll look up periodically and ensure the runway "looks right", so to speak. Correct perspective and alignment. The extended centerline should "go through your body", as the saying goes.

From around 500 feet, you'll look outside more often, focusing on the aimpoint, while still keeping up your instrument scan. The closer you get to the ground, the more you look outside. From around 100 feet, you stop looking at the instruments, and only look outside. At this time you also move your visual focus from the aimpoint to the far end of the runway. This allows you to gauge the flare and alignment.

Remember there is a pilot monitoring. Even if you don't have the instruments in view at all times, he or she will periodically call out speed and rate of descent, as well as any exceedances such as excessive glideslope or localiser deviation. From 100 feet you also have the automated radio altitude callouts.

If the cloud deck is low, you simply keep up the instrument scan until you break out.