Defensive Electronic Countermeasures circa 1962

The Fan Song Radar, a typical radar set for the era, provides guidance for the SA-2 Guideline surface to air missile.

The Fan Song Radar, a typical radar set for the era, provides guidance for the SA-2 Guideline surface to air missile.

Defensive Electronic Countermeasures are a subset of Electronic Countermeasures used by attack aircraft to disrupt enemy search and fire control radars.

The video below details the general fucntions, specifications, use and components of the following defensice ECM systems (circa 1962):

The AN/ALQ-35 is a target repeater consists of a tuner, pulse generator, transmitter, and control panel working in concert to display multiple false positives on the enemy’s radar scopes. The unit receives the incoming enemy pulse, amplifies it greatly, repeats it, and sends them back with random delays.

The AN/ALQ-41 and 51 are track breakers are designed to break enemy lock-on and to give false information. It provides simultaneous protection against pulse ranging, FM-CW, conical, and monopulse radar in different ways, based on each method’s angle and range.

The AN/ALQ-51 is a deceptive track breaker to counter S-band fire control radars which employ pulse ranging, frequency modulating carrier wave pulse, and conical scan.  It is also designed to cause proximity fuses on the SA-2 SAMs to detonate prematurely or be duded so they did not detonate at all.

AN/A.LQ-51 operator console from the F-4 Phantom

AN/A.LQ-51 operator console from the F-4 Phantom

The AN/ALQ-55 is comm disrupter that operates in the 100-210MHz band. It distinguishes the threatening enemy communication bands from those of beacons and civilians, evaluates them, and jams them with a signal that’s non-continuous, which helps avoid detection.

The systems were found in attack aircraft at the time. Early models of the A-6 Intruder, A-3 Skywarrior and the A-5 Vigilante.

The video provides an interesting view on just how advanced ECM in the US Navy was at the time. While in concept the operation of modern systems has changed little over the years, the speed with which modern ECM systems process signals has increased as operating flexibllity over a wider range of frequencies to counter a number of OPFOR IADS.

Leave a comment


Those who know, know.



by | May 22, 2015 · 6:23 pm

Breaking: First Flight of Sikorsky’s S-97 Raider

Sikorsky Aircraft's S-97 Raider helicopter achieved successful first flight at the Sikorsky Development Flight Center in West Palm Beach, Florida, May 22, 2015.

Sikorsky Aircraft’s S-97 Raider helicopter achieved successful first flight at the Sikorsky Development Flight Center in West Palm Beach, Florida, May 22, 2015.

From PR Newswire:

WEST PALM BEACH, Fla., May 22, 2015 /PRNewswire/ — Sikorsky Aircraft Corp., a United Technologies Corp. subsidiary (NYSE:UTX), today announced the successful first flight of the S-97 RAIDER™ helicopter, a rigid coaxial rotor prototype designed to demonstrate a game-changing combination of maneuverability, hover ability, range, speed, endurance and survivability. The first flight was conducted at Sikorsky’s Development Flight Center (DFC) where the two-prototype RAIDER™ helicopter test program is based.

The S-97, developed from Sikorsky’s X-2 technology demonstrator, was started in 2010 oringally as a response the replace the Army’s OH-58D armed scout helicopter through the Armed Aerial Scout (AAS) program. Now the first military customer is aimed to the Army’s Special Operation Command replace the M-6M Little Bird helicopter. The aircraft is also intended as a possible armed escort for the USMC’s MV-22 and the USAF’s CV-22 Osprey. Some civilian some are seen as well.

This inflight view of Sikorsky's X-2 Technology Demonstrator provides an interesting conparison with the S-97 Raider.

This inflight view of Sikorsky’s X-2 Technology Demonstrator provides an interesting conparison with the S-97 Raider.

The S-97 features an all-composite fuselage, variable speed coaxial main rotors, pusher propellor to the rear and modern digital cockpit displays. The S-97 is a fly-by-wire aircraft featuring actuators to cancel out aircraft shaking. The Raider is powered by the GE YT706 turboshaft (the same engine used on the UH-60M Black Hawk). This is an interim powerplant until the Improved Turbine Engine Program provides power to production aircraft. Expected performance will be a range of 340 miles, a maximum speed of 276 mph, a max cruise speed of 253 mph and a max ceiling of 10,000ft. Gross weight is 11,000lbs. The Raider prototype has space for but is not fitted with weapons or sensors.


Sikorsky uploaded the first flight video:



22 May 1968, Loss of USS Scorpion SS-589


On 27 May 1968, for the second time in just over five years, the United States Navy announced the disappearance of a modern nuclear attack submarine.  The Skipjack-class SSN, USS Scorpion, disappeared on 22 May as she transited near the Azores.

589 sail

The cause of the loss of Scorpion continues to be a subject of fierce debate.  The recorded acoustic signature of the event has been analyzed extensively, and expert opinion is divided regarding what the SOSUS data points to.  Several recent books have addressed the subject, positing that the Soviets had targeted Scorpion and sank her with assistance from ASW helicopters, and intelligence gained from the capture of USS Pueblo (AGER-2) and the John Walker spy ring.  Other theories included a battery fire which caused a Mk 37 torpedo to detonate in the tube in the torpedo room, or an inadvertent launch of a Mk 37 which came back and struck Scorpion.  Other analysis points to a possible explosion of hydrogen gas, built up to unsafe levels during a charge of batteries, that doomed Scorpion.

Much has been made of the abbreviation of her overhaul and the postponement of the SUBSAFE work (initiated in the wake of the loss of Thresher, SSN-593, in April of 1963) by the CNO, and the tagging out of the Emergency Main Ballast Tank system.   However, there seems little that points to any neglected maintenance or repair being responsible for the loss of the boat.

Regardless of the cause of the loss of Scorpion, the submarine carried 99 US Navy sailors to their deaths.  Her loss should stand as a reminder that plying the sea is a dangerous occupation, and that there is a a cost in lives for vigilance and readiness for war, even a Cold War.   It should also serve as a warning, that a Navy without sufficient ships and sailors to meet mission requirements in peace must compromise that readiness and vigilance, which has a far higher price in the unforgiving occupation of war at sea.



Opinion: USS Samuel B Roberts Should Take Barry’s Place at the Washington Navy Yard – USNI News

The U.S. Navy has a brief window of opportunity to ensure that a warship continues to grace Washington’s waterfront for another generation.

For more than three decades, the destroyer USS Barry has sat pierside at the Washington Navy Yard, berthed in the Anacostia River across the street from the Navy’s main museum.

Uncounted busloads of Washington students, not to mention visitors of every other stripe, have tramped across her steel decks and peered at gun turrets that laid down covering fire for Marines going ashore in Vietnam. In recent years, the opening of Nationals Park and the Anacostia Riverwalk Trail have brought the old warship to a new peak of visibility and accessibility.

via Opinion: USS Samuel B Roberts Should Take Barry’s Place at the Washington Navy Yard – USNI News.

From what Byron told me, USS Samuel B. Roberts is decommissioning today.

The name Samuel B. Roberts, both as the epitome of a fighting sailor, and as the namesake of multiple fighting ships, is a proud one, and the Navy  should take Mr. Peniston’s suggestion very seriously. Most of the costs associated with such a suggestion would be sunk costs anyway. That is, virtually every cost associated with turning the Sammy B into a museum ship would be incurred simply in the process of preparing her for scrapping.

We intend to write more about the Sammy B., and her predecessor, in the coming months.

Leave a comment


Boy Scouts ban water-gun fights | New York Post

It’s going be some doggone days of summer.

Boy Scouts everywhere will no longer be able to partake in the summer childhood pastime of squirt guns and water balloon fights.

A blog post by Bryan Wendall, an Eagle Scout and editor at various Scouting publications, reminded Scout leaders that new policies now prohibit the use of water guns and water balloons.

The ban is detailed inside the “2015 Boy Scouts of America National Shooting Sports Manual,” which regards water guns as firearms.

via Boy Scouts ban water-gun fights | New York Post.

Firearms safety is all well and good, but this is obviously a case of taking a good idea to its illogical extreme.

Of course, I don’t really know how rampant watergun fights were in the Boy Scouts in recent years. But I do know they’d have been aghast is the water fights we had in Sea Scouts (a division of the BSA).

The SES Whidby didn’t have any squirt guns. What it did have was four 1-1/2″ fire hoses, and the big old Hercules diesel fire pump.

Whenever we found ourselves cruising in company with another Scout ship, we would have a good natured water fight. And by good natured, I mean you could knock a man off his feet at about 100 feet with one hose.

And if you made the mistake of towing your ships rowboat behind you, we’d flood that thing in a heartbeat.



X-37B Launch Video, and A Co-author quoted in the New York Times

Yesterday the Air Force hush-hush X-37B space plane successfully launched from Cape Canaveral.

In addition to whatever the Air Force has the X-37B doing, they allowed NASA to piggy-back an experiment aboard.

NASA is also taking advantage of this X-37B flight to test how almost 100 materials react to the harsh conditions of space, like the barrage of radiation and swings of temperature the craft will experience while passing between the day and night sides of the Earth for at least 200 days.

“It’s just sitting there and letting the environment hit it,” said Miria Finckenor, a materials engineer at NASA’s Marshall Space Flight Center in Huntsville, Ala. She is the principal investigator for the experiment, which is housed in the space plane’s cargo bay.

The materials to be tested include thermal coatings to keep spacecraft components within a certain range of temperatures, clear materials under consideration for lighter windows on NASA’s Orion crew capsule and ink to make sure that markings on parts do not fade away.

NASA previously tested more than 4,000 samples outside the International Space Station, but it is difficult to carve out time during spacewalks to set up and retrieve the experiments. “This opportunity presented itself, and we just needed to take advantage of it,” Ms. Finckenor said.

I’m just a simple grunt. Would you believe that I actually know three, count ‘em, three honest to goodness rocket scientists?


Filed under NASA, space