Airport signs

[ethanhopkin14]

Are the short signs along taxiways and he active runways at airports written in FHWA Highway Gothic font? I was looking at it today and it sure looks like it. I know those signs are standardized so it should be the same regardless of airport.

[SignGeek101]

Are the short signs along taxiways and he active runways at airports written in FHWA Highway Gothic font? I was looking at it today and it sure looks like it. I know those signs are standardized so it should be the same regardless of airport.

I noticed that also. Looks like series D. Not just in North America though; I've seen it in Asia.

[PHLBOS]

FAA Advisory Circular #150-5340-18F: Standards For Airport Sign Systems

While the Advisory Circular (AC for short) doesn't call out the font for its aircraft guidance signage per say (it only calls such out for ground vehicle signage (MUTCD Series B font for example)); the examples certainly shows that the lettering and numerals to be mostly Series D.

[roadman]

FAA Advisory Circular #150-5340-18F: Standards For Airport Sign Systems

While the Advisory Circular (AC for short) doesn't call out the font for its aircraft guidance signage per say (it only calls such out for ground vehicle signage (MUTCD Series B font for example)); the examples certainly shows that the lettering and numerals to be mostly Series D.

Seeing the "Do Not Proceed Contact ATC" tab reminded me of the field trip our fifth grade class took to Logan Airport in 1973.  After the Director of Aviation spoke to us and we viewed a couple of films, we were loaded into a couple of buses for a tour of the tarmac.  At that time, the outer perimeter road intersected one of the principal runway pairs at grade.  Vehicle traffic was controlled by the tower with a set of traffic lights on each side, and there were very large signs that read 'AIRCRAFT HAVE RIGHT OF WAY'.

Not sure when it happened, but at some point afterwards the perimeter road was reconfigured so that it passed through the runway threshold instead of intersecting with the runways themselves.

[formulanone]

If you go Shreveport Regional Airport, you can see some of these signs up close, but behind some plexiglass...I recall they were located after the security check-in area. My guess is that they changed the signs once the runway headings were changed (which periodically happens).

[SignGeek101]

Looks like a modified / pseudo Highway Gothic Series E. Seen at Toronto Pearson International Airport last summer.

[vtk]

If you go Shreveport Regional Airport, you can see some of these signs up close, but behind some plexiglass...I recall they were located after the security check-in area. My guess is that they changed the signs once the runway headings were changed (which periodically happens).

Are those retroreflective? I thought they were all internally illuminated...

[formulanone]

Are those retroreflective? I thought they were all internally illuminated...

They are, which I wasn't expecting. The signs are typically illuminated, but they never appear to be back-lit during  daylight hours.

[PHLBOS]

Looks like a modified / pseudo Highway Gothic Series E. Seen at Toronto Pearson International Airport last summer.

Exterior signs at the actual terminal gates are not covered in the fore-mentioned AC and can vary a bit more in colorschemes and font.  The exterior gate signs at PHL, for example, feature white elongated Arial(?) Bold font on a dark brown background.

[realjd]

There are a few of them on display on the sidewalk near the DOT offices in DC:
https://www.google.com/maps/place/305+M+St+SE,+Washington,+DC+20003/@38.876433,-77.001993,3a,27.1y,172.17h,87.18t/data=!3m4!1e1!3m2!1sMpxvdVWZuDTyhNrQfHkk4g!2e0!4m2!3m1!1s0x89b7b9d186c33875:0xfc79d1c3c93b207d!6m1!1e1

[Scott5114]

In case anyone was wondering, the yellow is directional signage and black is what we would call an assurance marker. Each taxiway carries a letter designation, but that's not pronounced "L", it's "Lima".

[roadman]

Save a major reconstruction project, I can't see how runway headings at your average airport would change all that often.

[US81]

In case anyone was wondering, the yellow is directional signage and black is what we would call an assurance marker. Each taxiway carries a letter designation, but that's not pronounced "L", it's "Lima".

Like the Peruvian city, not like the bean.        But I'm sure we all knew that. 

[vtk]

Save a major reconstruction project, I can't see how runway headings at your average airport would change all that often.

Runway numbers are based on magnetic compass headings, which are subject to drift over time.  USGS topos indicate the difference between true and magnetic north, and the rate of change of that difference, for example +0.4°/year.  A change of that amount would cause one runway out of 25 to change numbers, if the runway headings are assumed to have uniform distribution.

[PHLBOS]

Runway numbers are based on magnetic compass headings, which are subject to drift over time.  USGS topos indicate the difference between true and magnetic north, and the rate of change of that difference, for example +0.4°/year.  A change of that amount would cause one runway out of 25 to change numbers, if the runway headings are assumed to have uniform distribution.

There was a plan not too long ago to redesignate all the runways at BWI by 1 (not sure '+' or '-') but was shelved.

If PHL indeed goes ahead with building another east-west runway to the south (per its CEP (Capacity Enhancement Plan)); the existing Runway 9R-27L (which is presently slated to be extended) would be redesignated as Runway 9C-27C and the new runway would be the new 9R-27L.

[jeffandnicole]

Save a major reconstruction project, I can't see how runway headings at your average airport would change all that often.

Runway numbers are based on magnetic compass headings, which are subject to drift over time.  USGS topos indicate the difference between true and magnetic north, and the rate of change of that difference, for example +0.4°/year.  A change of that amount would cause one runway out of 25 to change numbers, if the runway headings are assumed to have uniform distribution.

Does this drift occur both ways, so that it averages out over the years?  I would imagine if (using your example) the drift is as much as 0.4 degrees, it's only a decade because we're talking quite a difference in compass directions.

[Big John]

Headings have some leeway and are allowed to be 1 away.  This also accounts when airports have several (>3) parallel runways.  For example ATL's runways would have a natural 9/27.  But theyare listed as 8L/26R, 8R/26L, 9L/27R, 9R/27R and 10/28.

[vtk]

Save a major reconstruction project, I can't see how runway headings at your average airport would change all that often.

Runway numbers are based on magnetic compass headings, which are subject to drift over time.  USGS topos indicate the difference between true and magnetic north, and the rate of change of that difference, for example +0.4°/year.  A change of that amount would cause one runway out of 25 to change numbers, if the runway headings are assumed to have uniform distribution.

Does this drift occur both ways, so that it averages out over the years?  I would imagine if (using your example) the drift is as much as 0.4 degrees, it's only a decade because we're talking quite a difference in compass directions.

Certainly, but the time scales are long.  I think it may drift one way for decades before it swings back again.  As the next magnetic inversion draws near, the variations will become more chaotic, but now we're talking many centuries...