FLYING ON INSTRUMENTS

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Peter Armstrong
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Re: FLYING ON INSTRUMENTS

Post by Peter Armstrong » Mon Apr 22, 2019 3:09 am

VISIBILITY

It is recommended that to continue a circling approach there should be a visibility of at least 2,000 metres, assuming a pattern speed of 100 kt or less. (Faster aeroplanes with a greater turning radius and requiring manoeuvring area may need greater visibility – about 200 metres for each additional 10 kt).

The precise visibility is impossible to measure in flight, but you can estimate it, and must feel confident and comfortable that sufficient visibility exists for safe visual manoeuvring. Ideally, keep the runway in sight at all times.

If at any time during the visual manoeuvring for a circling approach you feel uncomfortable for any reason (such as a lowering cloud base, decreasing visibility, heavy rain or hail, turbulence, windshear, or if you lose visual contact, etc.,) execute a missed approach.
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Re: FLYING ON INSTRUMENTS

Post by Chris Brettrager » Mon Apr 22, 2019 12:41 pm

Peter Armstrong wrote:
Mon Apr 22, 2019 3:09 am
VISIBILITY

It is recommended that to continue a circling approach there should be a visibility of at least 2,000 metres, assuming a pattern speed of 100 kt or less. (Faster aeroplanes with a greater turning radius and requiring manoeuvring area may need greater visibility – about 200 metres for each additional 10 kt).

The precise visibility is impossible to measure in flight, but you can estimate it, and must feel confident and comfortable that sufficient visibility exists for safe visual manoeuvring. Ideally, keep the runway in sight at all times.

If at any time during the visual manoeuvring for a circling approach you feel uncomfortable for any reason (such as a lowering cloud base, decreasing visibility, heavy rain or hail, turbulence, windshear, or if you lose visual contact, etc.,) execute a missed approach.
The circling minimums for every approach are published at the bottom TERPS section of the chart, they are not estimated and are unique to each airport's approach procedure, take into account all known obstacles and each category of aircraft A-D.

Image

The first number is the decision height in MSL, the second is the visibility required in miles. The rest are not normally used. If you don't have the reported visibility required in miles, then you can't be cleared or execute the approach and intend to circle.

Cheers
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Re: FLYING ON INSTRUMENTS

Post by Frank Miller » Mon Apr 22, 2019 3:43 pm

One more addition for US requirements for circling approaches......executing a missed approach is not a matter of judgment only (or being “comfortable”). You can, of course, execute a missed approach at any time if you believe it is necessary for the safe operation of the aircraft and conduct of the flight. But it is required under US rules
[w]henever an identifiable part of the airport is not distinctly visible to the pilot during a circling maneuver at or above MDA, unless the inability to see an identifiable part of the airport results only from a normal bank of the aircraft during the circling approach.
Once you are past the MAP or below MDA, you must execute a missed approach if, at any time, at least one of the relevant visual references for the intended runway is not distinctly visible and identifiable to the pilot (e.g. runway lights, runway markings, VASI/PAPI, various lights).

See 14 CFR Section 91.175 Takeoff and Landing under IFR. See para (c)(3) for the list of relevant visual references.

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Re: FLYING ON INSTRUMENTS

Post by Peter Armstrong » Mon Apr 22, 2019 11:14 pm

Thanks guys - these are to be future subjects under respective headings.

ALL contributions are welcome, thank you

Peter
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Re: FLYING ON INSTRUMENTS

Post by Chris Brettrager » Tue Apr 23, 2019 12:32 am

Peter Armstrong wrote:
Mon Apr 22, 2019 11:14 pm
Thanks guys - these are to be future subjects under respective headings.

ALL contributions are welcome, thank you

Peter
:nyd:
The Don - I've been here for too long...
"He who stands a top the mountain for everyone to see, does not lead. He who finds a way to move the mountain, he is the one who leads." - Christian Brettrager

Peter Armstrong
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Re: FLYING ON INSTRUMENTS

Post by Peter Armstrong » Tue Apr 23, 2019 8:28 am

Pilots are versatile and international in their travels

Ok! On social media some of you have approached me with interest in flying around the world. But, my knowledge is restricted to Europe and USA. Therefore, I will try and incorporate some “international” feel for those of you that would like to be more versatile.

With this in mind, I will try and embrace some concepts of techniques, other than the USA/FAA requirements. I think that knowing differing techniques can only enhance your enjoyment of this pastime.
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Re: FLYING ON INSTRUMENTS

Post by Peter Armstrong » Tue Apr 23, 2019 9:06 am

The Visual Manoeuvring (Circling) Area

The visual manoeuvring area (or circling area) is the area around an aerodrome in which obstacle clearance has been considered by the state authority for aircraft having to manoeuvre visually before landing. To avoid penalising slower and more manoeuvrable aircraft (which require less manoeuvring area than faster aeroplanes), different categories based on maximum speed for circling have been devised (See post above in this thread).
Most training aeroplanes have a maximum speed for circling of less than 100kt (known as Category A for visual manoeuvring purposes), and the circling area considered for obstacle clearance for such aeroplanes can be considered as a radii from the runway thresholds in some countries. Example, in the UK this is 1.68 nm. For aeroplanes with a maximum speed for circling between 100 and 135 kt, the radii are increased to 2.66 nm.

Obstacle Clearance in the Visual Manoeuvring (Circling) Area

Once the state authority has established its circling area, obstacles within this area are surveyed and a safety margin added to ensure clearance from these obstacles. A visual manoeuvring (circling) obstacle clearance height, VM(C) OCH, is then determined for each category of aircraft.
For Category A aeroplanes, the circling area has a radius of 1.68nm and maximum circling speed 100 kt. The safety margin for visual manoeuvring in the circling area is a minimum of 300ft above obstacles.
If, for example, the highest obstacle in the circling area is a tower 290 ft aal, then the visual manoeuvring obstacle clearance height, VM(C) OCH, is (290 + 300) = 590 ft aal.
If there are no specific obstacles, then 100ft is allowed for the growth of trees, etc., and the 300ft safety margin added to this to give a lowest permissible VM(C) OCH at any aerodrome of (100 + 300) = 400 ft aal.
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Re: FLYING ON INSTRUMENTS

Post by Frank Miller » Tue Apr 23, 2019 2:50 pm

Peter, you are welcome to continue posting as you have, but please do continue to note where you are referencing ICAO or other non-FAA standards.

VATSIM Seattle simulates US procedures and our training program and competencies are based solely on FAA procedures and standards. For aircraft operating in ZSE airspace, pilots and controllers should familiarize themselves with FAA procedures and phraseology and adhere to them unless given express prior authorization from the ZSE ATM.

With respect to the specific subject of “circle to land” procedures/requirements, there are differences between the FAA and ICAO standards. See, e.g., https://www.skybrary.aero/index.php/Cir ... _US_TERPS.

The money quote from the source cited in the link above:
In summary, circling procedures based on US TERPS calculations afford considerably lower safety margins than those based on ICAO PANS-OPS. It is therefore essential that pilots understand these differences and are aware of the basis of calculations for all airfields at which they intend to operate, including alternates.
In my view, this topic is a step beyond what we train and expect our S3 controllers to master, but for those controllers who wish to “deep dive” and for pilots flying in US and other airspace applying US TERPS standards (e.g. Canada), it is important to recognize the differences from ICAO or other non-FAA standards and procedures.

Fly safe!

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Re: FLYING ON INSTRUMENTS

Post by Peter Armstrong » Wed Apr 24, 2019 3:10 am

Sorry Frank – no disrespect intended

This thread is strictly for pilots only (not ATC) – as per the titles and contents (looking at instruments and gauges in cockpits etc.,) and any ATC topics are best suited in Notams/General/SOPs and Policies and Training/Continuing Education Forums.

The 18704 views so far recorded on these Flying on Instruments and Instrument Flying are mostly from pilots around the world. 60% of my pilot base when I am controlling are from outside USA.

However, I will – as you request – give indications of differences between FAA and other “States”, which I do attempt to do on those very rare occasions.

ATC example posts:-
GENERAL – a sample of some recent posts
• Raise your anchor
• Now you see me – now you don’t
• Sample comms
• Your own personal chat box
• Little reminders
• Alias files
• Wake up call
• The black arrow
• Wajt ASDE-X looks like
• Information is valuable
• Searching your alias file
• Sharing controller techniques
• Some little controlling tips
• DOT commands
• Research subjects


Best regards

Peter
Last edited by Peter Armstrong on Wed Apr 24, 2019 11:29 am, edited 1 time in total.
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Re: FLYING ON INSTRUMENTS

Post by Chris Brettrager » Wed Apr 24, 2019 6:59 am

:nyd: :teach:
The Don - I've been here for too long...
"He who stands a top the mountain for everyone to see, does not lead. He who finds a way to move the mountain, he is the one who leads." - Christian Brettrager

Peter Armstrong
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Re: FLYING ON INSTRUMENTS

Post by Peter Armstrong » Wed Apr 24, 2019 10:31 am

Night flying at an aerodrome

Night flying involves a mixture of visual and instrument flying skills. The take-off run at night, for instance, is made with visual reference to the runway. But shortly after take-off, there may be no visible features at all to be seen, and transferring your attention from outside the cockpit to the instruments in the cockpit at or before that time is essential. In contrast, by day and in good weather conditions your attention can remain outside the cockpit.

Adaptation of the Eyes to Darkness

Your eyes are very important when flying, and they should always be looked after. However, at night there are some special considerations regarding your vision. Since your attention during night flying will be both inside and outside the cockpit, care should be taken to ensure that eyes can function at near maximum efficiency. It takes the eyes some minutes to adapt to a dark environment, as most of us have experienced when walking into a darkened cinema, stumbling across other patrons in an attempt to find an empty seat.

The rate at which the eyes adapt to darkness depends to a large extent on the contrast between the brightness of light previously experienced, and the degree of darkness of the new environment.

While bright lighting within the previous minutes has the strongest effect, that experienced for some period within the previous few hours will also have an effect. Bright lighting, therefore, is best avoided prior to night flying. Generally, this is difficult to achieve, since flight planning in a well-lit room and pre-flight inspection with a strong torch or on a well-lit tarmac will almost always be necessary. The best that can be achieved in many cases is to dim the cockpit lighting prior to taxying, and to avoid looking at bright lights during those few minutes prior to take-off.

This may be useful in RW flying. However, it can be adapted within the virtual world by making adaptions to your place of “pastime” by increasing/decreasing and adjusting/dimming lighting scenarios and opening/closing drapes etc., to allow/restrict natural lighting into your virtual environment.
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Re: FLYING ON INSTRUMENTS

Post by Peter Armstrong » Thu Apr 25, 2019 2:42 am

Night vision can also be affected by lack of oxygen, so ensure that you use your (virtual) oxygen system when flying above 10000 ft amsl. On a more mundane level, avoid cigarette smoke in the cockpit at night, since it will displace oxygen in your blood to some extent, and consequently reduce your night vision by an amount comparable to an extra 5000 ft in altitude. In the long term, a good diet containing foods with Vitamin A and C can improve night vision.

Since bright lights will impair your outside vision at night, it is good airmanship to keep the cockpit lighting at a reasonably low level, but not so low that you cannot see your charts, or find the fuel selector!

There are some occasions, however, when bright cockpit lighting can help preserve your vision. This can occur on an instrument flight, for instance, if flying in the vicinity of electrical storms. Nearby lightning flashes can temporarily degrade your dark adaptation and your vision, particularly if it is in contrast to a dim cockpit. Bright lighting in the cockpit can minimise this effect and, although your external vision will not be as good as with dim cockpit lighting, you will avoid being temporarily blinded by the lightning flashes.

Note that flying near electrical storms is not recommended. They should be avoided by at least 10 miles and, if you are not an instrument-rated pilot in a suitably equipped aeroplane, then perhaps you should stay on the ground at night if there are storms around.
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Re: FLYING ON INSTRUMENTS

Post by Peter Armstrong » Fri Apr 26, 2019 2:51 am

Instrument flying at night and/or in low visibility conditions


Aerodrome Lighting

Description

The majority of airports have some type of lighting to identify and mark taxiways and runways and to control movements of aircraft and vehicles. The variety and type of lighting systems depends on the volume and complexity of operations at a given airport. Airport lighting is standardized so that airports use the same light colors for runways and taxiways.

Control of Airport Lighting

Airport lighting is controlled by air traffic controllers (ATCOs) at towered airports. At non-towered airports, the lights may be on a timer, or where a Flight Service Station (FSS) is located at an airport, the FSS personnel may control the lighting. A pilot may request various light systems be turned on or off and also request a specified intensity, if available, from ATC or FSS personnel. At selected non-towered airports, an ARCAL (Aircraft Radio Control of Aerodrome Lighting) system is installed. This system allows the pilot to control the lighting by using the aircraft radio. This is done by selecting a specified frequency and clicking the radio microphone a specified number of times within a specified time period (for example, 7 "clicks" within 5 seconds on frequency 121.7).

Taxiway Lights

Omnidirectional taxiway lights outline the edges of the taxiway and are blue in color. At many airports, these edge lights may have variable intensity settings that may be adjusted by an air traffic controller when deemed necessary or when requested by the pilot. Some airports also have taxiway centerline lights that are green in color.

Light Colours and Their Meanings at Runway Entrances

RED lights ahead of an aircraft or vehicle mean: it is unsafe to proceed beyond the RED lights. This is the case regardless of whether the lights are fixed, alternating or flashing and is independent of an ATC clearance. RED means stop.

AMBER lights are used to convey a similar but less distinct message. They indicate that a potential hazard exists beyond the lights, but that in conjunction with an appropriate ATC clearance it will be safe to proceed.

GREEN lights are often used to indicate the route to be followed by an aircraft or vehicle, particularly at night or in periods of reduced visibility. In all cases green lights are a routing aid and must only be followed in conjunction with an ATC clearance.

Approach Light Systems

Approach light systems are primarily intended to provide a means to transition from instrument flight to visual flight for landing. The system configuration depends on whether the runway is a precision or nonprecision instrument runway. Some systems include sequenced flashing lights, which appear to the pilot as a ball of light traveling toward the runway at high speed. Approach lights can also aid pilots operating under Visual Flight Rules (VFR) at night.

Visual Glideslope Indicators

Visual glideslope indicators provide the pilot with glidepath information that can be used for day or night approaches. By maintaining the proper glidepath as indicated by the system, a pilot should have adequate obstacle clearance and should touch down within a specified portion of the runway:

Runway Lighting

There are various lights that identify parts of the runway complex.

Lights Protecting the Runway

Lights on runways and at runway holding points have been developed to deliver warnings and status indications to pilots and manoeuvring area vehicle drivers.

Requirement

All runways licensed for night use must have lighting which at least defines the extent of the runway. This is referred to as Edge Lighting, Threshold Lighting and Runway End Lighting. Other types of lighting may also be provided.
ICAO guidance requires that runway lighting shall not be operated if a runway is not in use for landing, take-off or taxiing purposes, unless such operation is required for runway inspection or maintenance purposes. ATC are required to use whatever means are available to them to ensure that they are aware of any lighting system unserviceability so that appropriate notification action can be taken.

Minimum Runway Lighting

• Runway Edge Lights are omni-directional and are located along or just beyond the edges of the area declared for use as the runway as defined by edge markings and are white subject to certain specific exceptions. The area defined may not necessarily be the maximum width of the paved runway surface. The lights may be either elevated or embedded in the surface. If a landing threshold is displaced, but the pre-landing threshold area is available for take off, then the edge lights between the beginning of the runway surface and the displaced threshold will be split so as to show red up to the landing threshold whilst still showing white after that point. If a runway ‘starter extension’ is provided which is narrower than its associated runway, then blue edge lighting may be used to mark its edges.
• Runway Threshold Lights are provided in a line along the landing threshold at the touchdown end of a runway and define the beginning of the declared Landing Distances. They are green and can only be seen from the approach.
• Runway End Lights are provided in a line along the end of the runway available for use. They are red and can only be seen in the direction of runway use.

Supplementary Runway Lighting

Various other forms of runway lighting may also be provided, especially if the runway is used for aircraft movements in less than Instrument Landing System (ILS) Cat 1conditions, which require both Low Visibility Procedures (LVP) and, in most cases, specific forms of additional lighting.
• Runway Exit taxiways may be indicated by substitution of one or two of the white runway edge lights with blue ones.
• Stopway Lighting may be used to show the extent of a stopway beyond the designated end of a runway. Red unidirectional edge lights visible only in the direction of runway use are provided at intervals until a further transverse line which marks` the end of the stopway.
• Runway Centreline Lighting may be provided in which case it will extend for the full length of the runway, It will be white except in the event that colour coding is provided in order to indicate the approaching end of the runway. Such colour coded centreline lighting consists of alternating red and white lights beginning at 900 metres from the runway end and these change to continuous red lights for the last 300 metres of the runway.
• Touchdown Zone (TDZ) Lighting must be provided on runways available for use in low visibility conditions so as to provide enhanced identification of the touchdown area. The method of provision is specified in ICAO Annex14 Volume 1 ‘Aerodrome Design and Operations’ and the lighting must extend from the landing threshold for either 900 metres or to the midpoint of the runway, whichever is the least.
• Rapid Exit Taxiway Indicator Lights (RETILs) may be provided to indicate the distance to go to the nearest rapid exit taxiway. In low visibility conditions, RETILs provide useful situational awareness cues to assist in appropriate rates of deceleration and to allow flight crew to concentrate on keeping the aircraft on the runway centre line during the landing roll. They usually consist of six yellow lights adjacent to the runway centreline, configured as a three - two - one sequence spaced 100 metres apart with the single light positioned at 100 metres from the start of the turn for the rapid exit taxiway.
• Caution Zone Lighting may be provided on ILS-equipped runways which do not have centreline lighting. It is provided by replacing the usual white edge lights with yellow` ones for the lesser of the last 600 metres or last one third of the lighted runway length available to provide a visual warning the approaching runway end.
• Landing Threshold Wing Bars, which are green but may take various detail forms, are sometimes provided if it is considered that the threshold needs accentuating.

Lighting Intensity

It must be possible to adjust the intensity of runway lighting so as to be suitable for the full range of horizontal visibility and ambient light in which use of the runway is intended. It must also be compatible with the intensity set for the nearest section of the approach lighting system, when such a system is also provided. Flight crew can be expected to request ATC to adjust runway lighting intensity in order to ensure that, for their particular case, it is of sufficient intensity to be useful but not so bright as to hinder overall visual clarity. Whilst automatic or careful manual control of lighting intensity based upon the degree of available natural light will produce a generally acceptable lighting intensity, the intensity preferred by a particular crew may differ because of variation in pilot eye height above the runway surface (broadly proportional to aircraft size) or because of the effect of the reflective properties of moisture particles when forward visibility is restricted.

Information on Runway Lighting at an Airport

A detailed description of the runway lighting system at each licensed airport must be provided in the State AIPs. It must include details, including colour, intensity and extent, of:
• the runway threshold lights and any wing bars
• the runway edge lights
• the runway end lights and any wing bars
• any runway touchdown zone lights
• any runway centre line lights
• any stopway lights
Equivalent information will be found on aerodrome charts in proprietary ‘Flight Guides’ provided by aircraft operators for flight deck use.



Airport Beacon

In the United States, airport beacons are used to help pilots identify an airport at night. The beacons are operated from dusk till dawn. Sometimes they are turned on if the ceiling is less than 1,000 feet and/or the ground visibility is less than 3 statute miles (Visual Flight Rules (VFR) minimums). However, there is no requirement for this, so a pilot has the responsibility of determining if the weather meets VFR requirements. The beacon has a vertical light distribution to make it most effective from 1–10° above the horizon, although it can be seen well above or below this spread. The beacon may be an omnidirectional capacitor-discharge device, or it may rotate at a constant speed, which produces the visual effect of flashes at regular intervals. The combination of light colors from an airport beacon indicates the type of airport. Some of the most common beacons are:
• Flashing white and green for civilian land airports;
• Flashing white and yellow for a water airport;
• Flashing white, yellow, and green for a heliport; and
• Two quick white flashes alternating with a green flash identifying a military airport.




Visual Approach Slope Indicator Systems (VASIS)

Description

A visual approach slope indicator system is a system consisting of four light units situated on the left side of the runway in the form of two wing bars referred to as the upwind and downwind wing bars. The aircraft is on slope if the upwind bar shows red and the downwind bar shows white, too high if both bars show white, and too low if both bars show red. Some aerodromes serving large aircraft have three-bar VASIS, which provide two visual glide paths (GP) to the same runway.

The main systems in use are the:
• AT-VASIS: abbreviated T visual approach slope indicator system
• T-VASIS : Visual Approach Slope Indicator System which can be installed flush with the runway pavement surface to provide approach guidance to that runway. A T-VASIS installation will span a large area on each side of the runway centreline extending along it from just beyond the runway threshold for approximately 500 metres
• PAPI: precision approach path indicator
• APAPI: abbreviated precision approach path indicator

Precision Approach Path Indicator


A precision approach path indicator (PAPI) uses lights similar to the VASI system except they are installed as four lights in a single row, normally on the left side of the runway. However, depending upon the runway / taxiway configuration, the PAPI can be located on the right. . An aircraft is on the appropriate glide path when two of the lights are red and two are white. Three red lights indicate that the aircraft is below and four red lights indicate that the aircraft is well below the nominal flight path. Conversely, three white lights indicate that the aircraft is above and four white lights indicate that the aircraft is well above the flight path.

There are other, less common approach slope indicator systems.

A tri-color system consists of a single light unit projecting a three-color visual approach path. Below the glidepath is indicated by red, on the glidepath is indicated by green, and above the glidepath is indicated by amber. When descending below the glidepath, there is a small area of dark amber. Pilots should not mistake this area for an “above the glidepath” indication.

Pulsating visual approach slope indicators normally consist of a single light unit projecting a two-color visual approach path into the final approach area of the runway upon which the indicator is installed. The on glidepath indication is a steady white light. The slightly below glidepath indication is a steady red light. If the aircraft descends further below the glidepath, the red light starts to pulsate. The above glidepath indication is a pulsating white light. The pulsating rate increases as the aircraft gets further above or below the desired glideslope.
The useful range of these systems is about four miles during the day and up to ten miles at night.
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Re: FLYING ON INSTRUMENTS

Post by Justin Alderman » Fri Apr 26, 2019 9:32 pm

Peter Armstrong wrote:
Thu Apr 25, 2019 2:42 am
Night vision can also be affected by lack of oxygen, so ensure that you use your (virtual) oxygen system when flying above 10000 ft amsl. On a more mundane level, avoid cigarette smoke in the cockpit at night, since it will displace oxygen in your blood to some extent, and consequently reduce your night vision by an amount comparable to an extra 5000 ft in altitude. In the long term, a good diet containing foods with Vitamin A and C can improve night vision.

Wait what? Where is this stuff being copied from? Must be some pre 1980's thing? :? :?

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Re: FLYING ON INSTRUMENTS

Post by Peter Armstrong » Sat Apr 27, 2019 12:39 am

.
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