View source for Pave Spike

{{Short description|Targeting pod}}
{{refimprove|date=September 2007}}
[[File:Pave Spike targeting pod on display.jpg|thumb|200px|AN/ASQ-153 Pave Spike]]
The [[Westinghouse Electric Corporation|Westinghouse]] '''AN/ASQ-153\AN/AVQ-23 Pave Spike''' is an electro-optical [[laser designator]] [[targeting pod]] used to direct [[laser-guided bomb]]s (LGBs) to target in daylight, visual conditions. It contained a laser [[gun harmonisation|boresight]]ed to a [[television camera]], which displayed its image on a cockpit screen.

==Development==
Pave Spike was developed to replace the earlier [[Pave Knife]] laser designator used by [[USAF]] [[F-4D/E Phantom II]] which was bulky, slowing the F-4 and restricting maneuverability while occupying one of the weapons pylons on the F-4. Pave Spike was much smaller, the 144-inch-long (3.66 m), 420-lb (209&nbsp;kg) pod was designed for carriage on the left, forward [[AIM-7 Sparrow]] missile station of the F-4. Because it was smaller and nestled into the semi-submerged AIM-7 station, it did not restrict F-4 speed or maneuverability, nor did it occupy a precious weapons pylon. The F-4 still had three AIM-7 stations in which it could carry the usual radar-guided missiles. Pave Spike, like Pave Knife, had a clear dome nose through which a television camera viewed the target area, and through which the laser could fire to designate the target. The entire nose assembly [[Gimbal|gimbaled]] to look throughout the hemisphere below the jet.<ref name=Anderegg>{{cite book|last=Anderegg|first=C.|title=Sierra Hotel: flying Air Force fighters in the decade after Vietnam|publisher=Air Force History and Museums Program|year=2001|url=https://media.defense.gov/2010/Sep/29/2001329786/-1/-1/0/AFD-100929-043.pdf|archive-url=https://web.archive.org/web/20190301182349/https://media.defense.gov/2010/Sep/29/2001329786/-1/-1/0/AFD-100929-043.pdf|url-status=dead|archive-date=March 1, 2019|isbn=9781508674009}}{{PD-notice}}</ref>{{rp|129}}
[[File:F-4E 51st TFW with Pave Spike and GBU-12s 1982.JPEG|thumb|right|Pave Spike carried on an F-4E]]
By 1976 the F–4 Fighter Weapons School squadron, the [[414th Combat Training Squadron|414th Fighter Weapons Squadron]] at [[Nellis Air Force Base]], was flying its F-4E fighters with the new Pave Spike pod and learning how to employ the system throughout its performance envelope. The pod was on the leading edge of technology for the day and had several operating modes and bombing options.<ref name=Anderegg/>{{rp|129}}

The system offered the crew three options to acquire, or see, the target in the pod's television picture. In the most basic mode, the pod looked straight ahead, at the same location as the pilot's [[pipper]] on his gunsight. The pilot pointed the gunsight at the target, the [[Weapon systems officer]] (WSO) saw it in the TV picture, and, after taking command of the pod, tracked the target with his radar control handle. This mode was called 12-acquire or 12-vis because the pod looked at the visual point at the jet's 12 o'clock. A second acquisition mode was 9-acquire, or 9-vis. In this mode, the pod looked directly left of the aircraft at 9 o'clock. This mode enabled the crew to point the pod at the target before they rolled in on the attack if the target was on the left side of the airplane. The third mode, weapons release computer system acquire, was at once the most useful and the most difficult to use because of its complexity. During their mission planning, the crew measured the distance between a point that was easy to find and their intended target. As they approached the target, the crew could fly over the preplanned point, whereupon the WSO pushed a button that commanded the pod to look directly at the target over the premeasured distance.<ref name=Anderegg/>{{rp|130}}

All of these modes were particularly useful if the crews planned to fly at low altitude to the target, then pop up to higher altitudes to drop their LGB. In fact, a proficient crew might plan to use all three, each one as a backup for the other, during the attack. As the attackers zipped toward the target, they would plan to have the target offset to their left side. First, they would fly over a known point and insert the weapons release computer system (WRCS) offsets to slave the pod toward the target. Then, at a specific distance from the target, the pilot would select full [[afterburner]] and start a 20- or 30-degree climb, while visually scanning out the left side for the target. If the WRCS acquire worked perfectly, then the WSO would see the target in the picture. If not, and the pilot saw the target visually, he would tell the WSO to put the pod in 9-acquire to find the target. If that worked, fine, but if it did not, then the pilot would start a left roll in and put his pipper on the target, after telling the WSO to change acquisition modes again to the 12-acquire option.<ref name=Anderegg/>{{rp|130}}

For low altitude attacks crews adopted a 10-degree [[Toss bombing|loft]], {{convert|2|mi}} from the target. With the pod in 12-acquire, the crew flew directly at the target at very low altitude. As soon as the WSO saw the target in his TV, he took command of the pod and started lasing the target. A cockpit indicator displayed exact laser range to the target, and, at precisely two miles from the target, the pilot depressed the release button and pulled sharply up. The computer would then release the bomb at 10 degrees of climb. The whole pull-up and release process took only two seconds. Immediately after the bomb came off, the pilot would start a [[g-force|6-g]] turn away from the target and back to low altitude, while the WSO lased the target until the bomb hit.<ref name=Anderegg/>{{rp|132}}

In December 1978 the 414th Fighter Weapons Squadron got the opportunity to demonstrate how the Pave Spike pod and the new 500-pound [[GBU-12 Paveway II]] could perform at low altitude. The Air Force hosted a precision-guided munitions firepower demonstration for the [[United States Secretary of Defense|secretary of defense]] to showcase improvements in precision munitions. The squadron successfully destroyed a fuel tank partially filled with expired jet fuel with four LGBs in a low-altitude loft attack.<ref name=Anderegg/>{{rp|133}} By the end of the 1970s Pave Spike tactics and systems were a mature part of the F-4 fleet.<ref name=Anderegg/>{{rp|142}}

Even though Pave Spike was a good system, it was suited for use only during periods of good visibility during the daytime. At night, in haze, or in bad weather, the pod was virtually useless.<ref name=Anderegg/>{{rp|133}}

==Service==
156 examples of the original '''AN/ASQ-153''' were used from [[1974 in aviation|1974]] through [[1989 in aviation|1989]]. 

In 1979, the [[Royal Air Force]] acquired a number of the simplified '''AN/AVQ-23E''' pods for their [[Blackburn Buccaneer]]s. Twelve aircraft equipped with the pod were deployed to Saudi Arabia for the [[Gulf War]] to initially perform laser designation for other RAF aircraft <ref>{{cite web|url=http://www.raf.mod.uk/gulf/spiker.html|title=Pave Spike in Granby - System background|date=2004-10-09|archiveurl=https://web.archive.org/web/20110606203517/http://www.raf.mod.uk/gulf/spiker.html|archivedate=2011-06-06|accessdate=2015-12-07}}</ref> Later in the air campaign, these aircraft would carry laser-designated bombs themselves.

The pod is now obsolete, and is being phased out in favour of newer systems like [[LANTIRN]] and [[AN/ASQ-228 ATFLIR]].

The [[National Museum of the United States Air Force]] holds a Pave Spike in its collection.<ref>{{cite web |title=AN/AVQ-23 Pave Spike |url=https://www.nationalmuseum.af.mil/Visit/Museum-Exhibits/Fact-Sheets/Display/Article/195741/anavq-23-pave-spike/ |publisher=National Museum of the United States Air Force |access-date=7 December 2024}}</ref>

==References==
{{reflist}}

==See Also==
{{Portal|Electronics|Aviation}}
*[[List of military electronics of the United States]]

==External links==
{{commonscat|ASQ-153 Pave Spike}}
*{{webarchive |date=2012-12-12 |url=https://archive.today/20121212203007/http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=1010 |title=AN/AVQ-23 PAVE SPIKE at National Museum of the US Air Force}}

{{PAVE US}}

[[Category:Targeting pods]]
[[Category:Equipment of the United States Air Force]]
[[Category:Military electronics of the United States]]
[[Category:Military equipment introduced in the 1970s]]