Hi everyone, Marines.
I noticed while exploring on Google Earth that on most Air Force bases across the USA that there are huge X markers near the runways at various points. I can't figure out a pattern, so I was wondering what exactly are they for? some sort of Parachute markers, or distance practice markers for the pilots to drop loads? How are they used exactly for an approach? Because I've never seen them at any commercial airports. At high-resolution areas like Langley, VA you can even see a B-52. and at Patrick, FL, there are a few very old models of B-52s with the propeller engines...I think Model 462, not sure.
Thank you.
Syzygyone
04-15-08, 10:04 AM
I think Big X's on runways indicates the runway is CLOSED to traffic. It can be temporary or permanent. There are LOTS of X's out there but there might be some other designation I am not aware of.
Hope that helps a bit.
Here's a sample picture on an old abandoned WWII base.
http://www.airfields-freeman.com/FL/Ellis_FL_48_rw.jpg
Ed Palmer
04-15-08, 10:30 AM
I think Big X's on runways indicates the runway is CLOSED to traffic. It can be temporary or permanent. There are LOTS of X's out there but there might be some other designation I am not aware of.
Hope that helps a bit.
Here's a sample picture on an old abandoned WWII base.
http://www.airfields-freeman.com/FL/Ellis_FL_48_rw.jpg
No the X at the end of the runway means CRASH HERE
Ed Palmer
04-15-08, 11:01 AM
HERE IS WHAT YOU WANT TO KNOW
8/31/99 AC 150/5340-1H
17
40. MARKING AND LIGHTING OF
PERMANENTLY CLOSED RUNWAYS AND
TAXIWAYS. For runways and taxiways that have
been permanently closed, the lighting circuits are
disconnected. The runway threshold, runway
designation and touchdown zone markings are
obliterated and solid, not striated, yellow X’s are
placed at each end and at 1,000-foot (300 m)
intervals. If the closed runway intersects an open
runway, X’s should be placed on the closed runway
on both sides of the open runway. For taxiways, a
yellow X is placed on the closed taxiway at each
entrance. The X’s shown in Figures 20a and 20c
are normally used, but the X’s shown in Figures
20b and 20d are more readily seen from aircraft on
final approach and may be used.
41. TEMPORARILY CLOSED RUNWAYS
AND TAXIWAYS. The following procedures are
to be followed when it is necessary to temporarily
close a runway or a taxiway:
a. When it is necessary to provide a visual
indication that a runway is temporarily closed, X’s
are placed only at each end of the runway on top of
the runway designation markings or just off the
runway end when required by construction activity.
The X’s are yellow in color and conform to the
dimensions specified in Figure 20. Since the X’s
are temporary, they are usually made of some
easily removable material, such as plywood or
fabric rather than painted on the pavement surface.
Any materials used for temporary X’s should
provide a solid appearance. Since these X’s will
usually be placed over white runway markings,
their visibility can be enhanced by a 6 (15 cm)
black border.
b. A raised-lighted X may be placed on each
runway end in lieu of the markings described in
paragraph 41a to indicate the runway is closed.
The X is to be located within 250 feet (75 m) of the
runway end. Normally the raised-lighted X would
be located on the runway; however, it may be
located in the safety area on the extended runway
centerline.
c. Temporarily closed taxiways are usually
treated as hazardous areas (see paragraph 48).
However, as an alternative, a yellow X conforming
to the dimensions in Figure 20 may be installed at
each entrance to the taxiway.
d. If the runway or taxiway will be closed
during the nighttime, the runway and taxiway
lights will normally be disconnected so that they
can not be illuminated unless such illumination is
needed to perform maintenance operations on or
adjacent to the runway, e.g., snow removal.
NOTE: The airport operator is responsible for
determining the need for a visual indication that a
runway or taxiway is closed and for determining
the safest place to put the X. In making this
determination, the airport operator should consider
such things as the reason for the closure, duration
of the closure, airfield configuration, and the
existence and hours of operation of the airport
traffic control tower.
42. CONVERTING A RUNWAY TO A
TAXIWAY. The following actions are necessary
to close a runway permanently and convert the
pavement to a taxiway.
a. If the pavement is to be used as a taxiway,
then all runway markings including the runway
designation numbers are to be obliterated. The
centerline is to be painted yellow. Any edge lights
should be blue. For those runways that have
centerline lights, it may be appropriate to leave
them in operation and change the lens color to
green. Aircraft should not be permitted to land on
or takeoff from a taxiway.
b. X’s are used to indicate that a runway or
taxiway is closed to aircraft. Consequently, it is
improper to place X’s on a runway if it is intended
to be used as a taxiway.
c. The holding position lines must be
removed and appropriate signs installed to indicate
the existence of a taxiway.
43. INTERMITTENT USE OF A TAXIWAY
AS A RUNWAY. The following actions are
necessary for the intermittent use of a taxiway as a
runway: There are several things that must be
considered to achieve the proper markings and
signage. A piece of pavement cannot be marked as
both a taxiway and a runway at the same time -
that is, it can not have a yellow centerline and
white designation numbers. (NOTE: On airports
subject to National Environmental Policy Act
requirements, a proposal to use a taxiway as a
runway should include a review of the
environmental consequences of such an action.)
a. If the pavement is to be used as a runway
during the day, it should be painted, at a minimum,
AC 150/5340-1H 8/31/99
18
with visual runway markings, i.e., white
designation numbers and a white centerline.
Further, if it used as a runway at night and is to be
lighted, it should have lighting conforming to
AC 150/5340-24.
b. If the pavement is to be used ONLY as a
taxiway at night, blue lights conforming to
A.C.150/5340-24 should be used.
c. In either case, the Airport Layout Plan, as
well as other appropriate documents, must be
updated to indicate the presence of the runway. If
the runway is to be used ONLY as a taxiway at
night and blue edge lights have been installed, then
the runway is to be listed as unlighted along with
an appropriate annotation in the Airport/Facility
Directory (A/FD) and the Airport Master Record
(FAA Form 5010) indicating the runway is closed
to nighttime operations and that blue lights are
provided for taxiing aircraft.
d. Since the pavement is now considered a
runway, any taxiway intersecting the designated
runway must have appropriate holding position
markings and signs placed in accordance with
AC 150/5340-1 and AC 150/5340-18.
44. CLOSED/ABANDONED AIRPORTS.
When all runways are closed temporarily, the
runways are marked as in paragraph 41, and the
airport beacon is turned off. When an airport is
abandoned and all runways are closed
permanently, the runways are marked as in
paragraph 40, the airport beacon is disconnected,
and an X is placed in the segmented circle or at a
central location if no segmented circle exists.
45. HELIPORT MARKING. Information on the
marking for heliports is contained in
AC 150/5390-2, Heliport Design.
46. VERTIPORT MARKING. Information on
the marking for vertiports is contained in
AC 150/5390-3, Vertiport Design.
47. MARKING FOR ARRESTING GEAR.
Information on the marking for arresting gear is
contained in AC 150/5220-9, Aircraft Arresting
Gear for Joint Civil/Military Airports.
48. HAZARDOUS AREAS. Marking of
hazardous areas, in which no part of an aircraft
may enter, are marked in accordance with
AC 150/5370-2, Airport Safety During
Construction.
CHAPTER 2. (RESERVED) MARKINGS FOR LARGE AIRCRAFT PARKING
POSITIONS.
CHAPTER 3. (RESERVED) MARKINGS FOR UNPAVED RUNWAYS.