Fighting in the Electromagnetic Spectrum: U.S. Navy and Marine Corps Electronic Warfare Aircraft, Operations, and Equipment

By Thomas Wildenberg

Naval warfare was confined for centuries to surface combat, or undersea clashes. In the twentieth century aerial warfare became the third domain and shortly thereafter, the electromagnetic spectrum also appeared. Until now, little has been written about this important aspect of military conflict on the high seas. In Fighting in the Electromagnetic Spectrum author Thomas Wildenberg provides the first book covering these aircraft, their missions, and the methodology of conducting combat in all its forms along this fourth domain, the electromagnetic spectrum.
 
When navies began to make use of the airwaves, they soon discovered those waves could also be exploited as a source of information about the opposing force. This would later be termed Electronic Intelligence (ELINT). Navies learned the value of interrupting or corrupting the enemy’s communication signals that were transmitted in the “ether,” thus began a method of fighting termed Electronic Warfare (EW). Wildenberg cuts through the secrecy about this understandably mysterious domain of combat. He offers details on aircraft and methods and provides a layman’s set of definitions of terms. Wildenberg shares lessons learned from World War II skirmishes a as well as clashes in the Korean and Vietnam wars, while providing a Fighting in the Electromagnetic Spectrum offers the reader a foundational understanding of this complex form of combat in all its forms. This volume discloses rarely covered concepts and methods which will shape future great power future conflict.
 

• Language: English
• Publisher: Naval Institute Press
• Release date: Aug 15, 2023
• ISBN: 9781682478509

Book preview

Cover: Fighting in the Electromagnetic Spectrum, U.S. Navy and Marine Corps Electronic Warfare Aircraft, Operations, and Equipment by Thomas Wildenberg

FIGHTING IN THE

ELECTROMAGNETIC

SPECTRUM

U.S. Navy and Marine Corps Electronic

Warfare Aircraft, Operations, and Equipment

THOMAS WILDENBERG

Naval Institute Press

ANNAPOLIS, MARYLAND

Naval Institute Press

291 Wood Road

Annapolis, MD 21402

© 2023 by Thomas Wildenberg

All rights reserved. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and recording, or by any information storage and retrieval system, without permission in writing from the publisher.

Library of Congress Cataloging-in-Publication Data

Names: Wildenberg, Thomas, 1947–author.

Title: Fighting in the electromagnetic spectrum : U.S. Navy and Marine Corps electronic warfare aircraft, missions, and equipment / Thomas Wildenberg.

Other titles: US Navy and Marine Corps electronic warfare aircraft, missions, and equipment

Description: Annapolis, Maryland : Naval Institute Press, 2023. | Includes bibliographical references and index.

Identifiers: LCCN 2023006233 (print) | LCCN 2023006234 (ebook) | ISBN 9781682478493 (hardcover) | ISBN 9781682478509 (ebook)

Subjects: LCSH: Electronic warfare aircraft—United States. | Electronics in naval aviation. | United States. Navy—Aviation—History.

Classification: LCC UG1242.E43 W553 2023 (print) | LCC UG1242.E43 (ebook) | DDC 623.74/6—dc23/eng/20230616

LC record available at https://lccn.loc.gov/2023006233

LC ebook record available at https://lccn.loc.gov/2023006234

Print editions meet the requirements of ANSI/NISO z39.48-1992 (Permanence of Paper).

Printed in the United States of America.

31 30 29 28 27 26 25 24 23           9 8 7 6 5 4 3 2 1

First printing

Contents

List of Tables and Figures

Preface

List of Acronyms and Abbreviations

Electronic Warfare Defined

AN Numbers

Aircraft Type Numbering System

Author’s Note on Chapter 1

1Radio Intelligence: The Earliest Form of Electronic Warfare

2World War II ELINT: New Missions for the Patrol Squadrons

3Non-Passive ECM: Jammers and Chaff in World War II

4Cold War ELINT

5ECM during the Korean War

6Dedicated ECM Squadrons

7Beggar Shadow Missions and the Loss of Deep Sea 129

8Self-Defense

9F3D-2Q and Marine Leadership in Tactical Jamming

10 New EW Platforms: EA-6A Intruder and RA-5C Vigilante

11 Vietnam: Countering the SA-2

12 Countermeasure vs. Countermeasure

13 EA-6B: An EW Platform from the Ground Up

14 Prowlers at War

15 ARIES Aircraft

16 ES-3A Shadow

17 Birth of the EA-18G Growler and the Next-Generation Jammer

18 Looking Back: A Historical Perspective

APPENDICES

ICharacteristics of ECM Aircraft

II Carrier-Based ECM Aircraft Deployments during the Korean War

III Radar Concepts

IV ICAP-III Upgrades

VDefense Acquisition Management Framework

Notes

Selected Bibliography

Index

Tables and Figures

TABLES

4-1. Incidents Involving Anti-aircraft Fire and Fighter Attacks on U.S. Navy Patrol Planes, 1950–59

8-1. DECM on the Navy’s Heavy Attack Aircraft, May 1962

FIGURES

6-1. EA-3B Operator Stations

6-2. EC-121M Internal Layout

14-1. EA-6B Evolution

15-1. EP-3E Operator Positions

15-2. EP-3E Aries II General Arrangement

17-1. Concept Drawing of Next-Generation Jammer

17-2. NGJ-LB Protest

18-1. EA-18G ECM Equipment

Preface

At the beginning of the twentieth century, naval warfare, which for centuries had been limited to the surface of the water, moved quickly into the domain below the surface and the air above it. The influence of undersea and aerial warfare in naval history is well known. The fourth domain involving the electromagnetic spectrum, which also appeared at this time, had an impact on naval warfare as well, although much less has been written about this important aspect of military conflict on the high seas.

When navies began to make use of the fourth domain, they soon discovered that it could provide a unique source of information about the opposing force, instituting a form of intelligence that would later be termed electronic intelligence (ELINT). Also discovered was the value of interrupting or corrupting the enemy’s communication signals that were transmitted in the ether, thus beginning a method of fighting we now term electronic warfare (EW).

Although EW has grown in importance over the years, few naval historians, with the exception of those interested in cryptology, have attempted to document the growth and development of the equipment, techniques, and operational use of EW. There are several reasons for this. First is the high level of secrecy surrounding EW; information about it is hard to come by.¹ Next is the fact that there is little glory attached to its use. It does not result in great battles (except for code breaking) or memorable actions. Finally, it is highly technical in nature.

The subject has not been totally ignored. There is a considerable amount of literature on cryptology, especially with regard to the work of Britain’s Room 40 in World War I and the U.S. Navy’s successful efforts to break the main code used by the Japanese Imperial Navy’s battle fleet that resulted in its defeat at the Battle of Midway. Likewise, there is a considerable field of study regarding the Enigma machine and the British code breakers of Bletchley Park. Because of its importance in the Cold War and the war in Vietnam, there is a reasonable amount of material on the U.S. Air Force’s use of EW during these two conflicts. But sources of information covering the U.S. Navy and the Marine Corps are few and far between.²

To my knowledge, there is no single source on U.S. Navy and Marine EW aircraft and equipment that provides a comprehensive picture of these services’ use of electronic warfare since its inception in 1942. It is my intention to fill this gap in the history of the U.S. Navy and Marine Corps.

Acronyms and Abbreviations

Electronic Warfare Defined

Electronic warfare has been important ever since the military forces first began using radios and radar. But the proliferation of new sensor and communication technologies in recent years has been so profound that it sometimes seems the concept of full Spectrum dominance set forth in the Department of Defense vision statements refers more to electromagnetic wavelengths and frequencies that it does to the range of potential military contingencies.³

Electronic warfare is a component of modern warfare that is particularly important in response to threats posed by technologically sophisticated potential adversaries. Electronic warfare generally refers to operations that use the electromagnetic spectrum (the airwaves) to detect, listen to, jam, and deceive (or spoof) enemy radars, radio communication systems and data links, and other electronic systems. It also refers to operations for defending against enemy attempts to do the same. The Department of Defense defines electronic warfare as military action involving the use of electromagnetic and directed energy to control the electromagnetic spectrum or to attack the enemy.

The Department of Defense divides electronic warfare into electronic warfare support, electronic protection, and electronic attack. Electronic warfare support, sometimes also referred to as electronic support measures (ESM), relies on signals intelligence (SIGINT), which is the primary means of collecting immediate threat warnings and updates on targets. SIGINT is made up of two components, electronic intelligence (ELINT) and communications intelligence (COMINT). ELINT is information on enemy threats and capabilities of systems such as radars, surface-to-air missile systems, and non-voice datalinks. It also provides accurate location information. It is, however, susceptible to deception and suffers from only being able to intercept signals on a line of sight. COMINT provides information on enemy intentions and assists in determining the enemy command and control structure.

To tactical military commanders, SIGINT operations include a dynamic update capability during the execution phase of military operations, especially in direct support to combat aircraft. Some of the shortfalls of COMINT are the requirements for linguists and for line of sight with a transmitter in the UHF/VHF band. The biggest drawback from an operational standpoint, however, is that in order to protect sources, intelligence derived from COMINT is highly classified and thus limited in distribution. A collector of signals intelligence does not want the enemy to even suspect that his communications, by whatever means he conducts them, are being monitored, for fear that other frequencies, new codes, or different forms of communications would be used. Thus, signals intelligence remains one of the most classified and protected intelligence sources. This concern, however, must be counterbalanced by military necessity—winning and achieving one’s political and military goals. Historical examples show that during military operations, information must flow to decision-makers in a timely manner in order to be useful and relevant.⁴

Electronic protection involves limiting the electromagnetic signatures of one’s own military equipment and hardening one’s own military equipment against the effects of enemy electronic warfare operations. Electronic attack (EA) involves jamming and deceiving enemy radars and radio communications and data links.

All of the above fall into the broad category of electronic countermeasures (ECM), which prevent or reduce an enemy’s effective use of the electronic spectrum. ECM can take the form of jamming—reflection of electromagnetic energy to impair enemy use of electromagnetic devices—or deception—the deliberate radiation, alteration, or reflection to mislead the enemy in the interpretation or use of the information received by his electronic systems.

Electronic countermeasures, of which electromagnetic reconnaissance is only a part, divide neatly into two parts: active measures, or jamming, and passive measures, or reconnaissance. Jamming attempts to prevent the enemy from using his electronic equipment by either saturating it with noise (barrage jamming) or deceiving it with intentionally misleading signals (beacons, repeaters, inverse amplifiers, gate stealers, and track breakers). Reconnaissance merely establishes the location and electromagnetic characteristics, or signature, of enemy transmitters.⁵

AN Numbers

Since February 1943 communications and electronics systems in the U.S. military have been designated using the Joint Army-Navy Nomenclature System, which is also known as the Joint Communications-Electronics Nomenclature System or AN System for the letters that prefaced each type name. The initial emphasis was on airborne radio and radar equipment, but the system was designed to be extendable and soon included other types of equipment. When the Air Force separated from the Army in 1947, it continued to use the system for its electronic equipment. In 1957 the system was formalized in Military Standard 196, Joint Electronics Type Designation System (JETDS).

All designations are prefixed by AN. Originally, this stood for Army-Navy, but this interpretation is no longer valid. Nowadays, AN is simply an indicator for the JETDS. In nonofficial references to electronic equipment, the AN prefix is often omitted, which will be the practice followed in this work.

In the AN system, each piece of equipment is identified by an alphanumeric designator that begins with the letters AN followed by a forward slash and three letters. The first letter indicates the installation location of the equipment (e.g., A for aircraft). The second letter indicates the type of equipment (e.g., P for radar). The third letter defines the purpose of the equipment (e.g., R for receiving or passive detection). The final element is the model number sequence. Thus, AN/APR-5 defines the fifth airborne radar receiver produced.

Aircraft Type Numbering System

Prior to September 18, 1962, when the Department of Defense’s Tri-Service Aircraft Designation System took effect, U.S. Navy aircraft designations were based on the Navy’s mission-manufacturer-number system. The dual numbering system that applied to aircraft designed prior to that date sometimes creates confusion with respect to referencing the correct version of certain aircraft described in the text. For historical accuracy, I have chosen to use the Navy system to describe all aircraft that appear in the text before September 18, 1962, and the Tri-Service system thereafter. Whenever possible I will use parentheses during transition periods to provide the previous or future name change.

Author’s Note on Chapter 1

Although the subject of this book is the use of electronic warfare by aircraft to collect electronic intelligence on the enemy’s communications, radar, or data handling systems or to provide electronic countermeasures, I believe that the reader can gain significant insights into the evolution of electronic warfare through an understanding of its inception. Thus, the first chapter covers the beginnings of this form of warfare. Readers who are knowledgeable in this area or are uninterested in the early history should skip this chapter and start on chapter 2, which covers the use of specialized aircraft and equipment in World War II for the collection of information in the electromagnetic spectrum.

1

Radio Intelligence

The Earliest Form of Electronic Warfare

Advances in technology in the late nineteenth and early twentieth centuries brought forth new forms of naval warfare that expanded the naval battle space from the surface of the oceans to the sky above and the seas below. Although much has been written about the impact of the submarine and the airplane, less has been written about the introduction of radio and the beginning of intelligence gathering by the interception of radio signals—now known as signals intelligence, the earliest form of electronic warfare.

From the earliest days of Guglielmo Marconi’s work with wireless, it became evident that the military use of radio communication had serious flaws: the transmitted signals were impossible to hide and were open to all, unless complex codes were used.¹ In any case, the source of radio communication was easy to locate, which allowed for the future determination of position. But this would come later.

The first recorded use of wireless interception occurred on January 28, 1904, when the crew of the Royal Navy protected cruiser Diana, then stationed in the Suez Canal, found that they could intercept the high-frequency radio signals generated by the Russian navy. The communications intelligence gathered by Diana’s crew indicated that the Russian fleet was mobilizing and heading to the Pacific. This information was passed to Japan, an ally of the United Kingdom, giving the Imperial Japanese Navy advance warning of Russia’s intentions. Although there is no record of either navy listening to the other’s radio communication during the ensuing Russo-Japanese War of 1904, both navies found the wireless reporting of Lionel James objectionable and took steps to curtail it. James, a newspaper correspondent working jointly for the Times of London and the New York Times, had persuaded the two papers to finance his effort to be the first to broadcast war news from a ship at sea. According to the agreement worked out by the two papers, American inventor Lee De Forest would supply, at cost, the radio equipment as well as two operators trained to send and receive Morse code.² The newspapers would pay the expenses and salaries of the two operators. In return, De Forest would gain valuable publicity for his system, leading to business for his wireless company.³

James’ idea for chartering a ship, fitting it out with wireless, and establishing a separate station on shore offered a solution to the problem of trying to get war dispatches to the newsroom in a timely manner. He had experienced great difficulties in this regard while working for the Times of London during the Second Boer War. At times he had to rely on everything from pigeons to heliographs to get his dispatches from the battlefield to the pressroom. The sheer physical challenge of getting a report from the field past military censors and to a telegraph office meant it could take up to a month before it even reached the newsroom. James had first observed the use of wireless for reporting the news during the America’s Cup races off New York in 1903 when a wireless set on board one of the press boats was used to report the race results, scooping the other papers. When the Times sent him to the Far East in December 1903 to cover the war that was brewing between Russia and Japan, he had already hatched a plan to secure the necessary wireless equipment that would be needed to outfit a ship and the two shore stations that would be needed to receive the radio dispatches.⁴

James hired the single-screw, 1,300-ton steamer Haimun to act as the team’s press boat for the sum of £1,500 per month. The 240-foot ship had a big promenade deck that ran aft from the bridge. Its main deck had a spacious saloon and twelve first-class cabins that could accommodate twenty-four passengers. Second-class cabins were located one deck below the main deck, and below that was a deck for native passengers. The crew consisted of six European officers, forty Chinese sailors, and four Malay quartermasters. The ship’s charter, crew, and expenses cost the Times £2,000 per month.⁵

James boarded Haimun for the first time in Nagasaki before the ship sailed for Weihaiwei (now Weihai) on the Shantung (now Shandong) peninsula approximately ninety miles opposite Port Arthur. Commander Tonami Kurakichi of the Imperial Japanese Navy was also on board to collect intelligence for the Japanese navy and censor James’ wireless transmissions. Commander Kurakichi’s presence on board was part of a secret agreement engineered by James to ensure Haimun’s ability to sail in contested seas without fear of interference from the Japanese navy. This arrangement, according to the authors of Journalism and the Russo-Japanese War, sprang from the British-Japanese treaty of alliance signed in 1902, which resulted in Britain sharing with its new ally the latest radio technology. The agreement to place a Japanese officer on board Haimun in return for Japan’s assistance was acknowledged by Vice Admiral Ijuin Gorô, minister of state for the Imperial Japanese Navy, when he wrote, I take this opportunity to thank you for your cordial offer to place, if required, your telegraphic apparatus and expert operator at the service of the Imperial forces and at the same time I hope you will consider that we shall be happy to give you any such assistance as you may require and which is possible for us under the present circumstances.⁶

On March 14 Haimun, with James in charge, departed Weihaiwei and sailed into the Yellow Sea heading for Chinampo (now Nampo), Korea. Eager to test the wireless for the first time, he instructed Harry Brown to send the following message when they were twenty miles from Weihaiwei: "I am at sea on board the Times steamer Haimun, enroute to Chinampo, in the hopes that it would be received by Pop Athearn, who remained behind to operate the station at Weihaiwei. Message O.K.," Brown hollered from Haimun’s radio room, loudly acknowledging that everything was working. James’ first radio dispatch to the New York Times–Times of London collaboration followed shortly thereafter. Though it contained little hard news, it was the first report from the only civilian ship in the war zone equipped with wireless.⁷

James spent the next five weeks reporting the war news obtained from Haimun’s presence in the war zone. His biggest scoop came on April 13. Acting on a tip from Commander Tonami, he sailed Haimun to the waters off Port Arthur to observe the naval engagement that was expected to take place there. At 4:30 a.m., James and the crew of Haimun observed two squadrons of Japanese warships heading to the port. A few hours later, James watched as the Japanese navy laid mines and the armored cruisers Kasuga and Nisshin shelled the port. One source claims that the Japanese were using wireless signals to correct the fall of shot. Where the spotters were located remains unknown. This same source claims that Russian operators heard the Japanese signals, realized their importance, and used a spark transmitter to jam them. If true, it was likely the first time that electronic countermeasures were used in a naval engagement.⁸

On April 15, a day after James’ long dispatch on the action around Port Arthur, Russian Admiral Yevgeni Ivanovich Alekseyev issued a proclamation warning that the Russian forces would arrest any correspondent found aboard a wireless-equipped ship in the war zone. Such correspondents would be considered spies and the vessel seized as a lawful prize. A week later, on April 21, James learned that Japan had also placed restrictions on Haimun’s movements. The Japanese, apparently tired of Haimun appearing in the wake of its fleet, prohibited the ship from going north of the line joining Chi-fu with Chemulpo. Banned from approaching the scene of action around Port Arthur and with the Times becoming increasingly disenchanted with the results, James sailed Haimun to Nagasaki and canceled the ship’s charter. No further wireless activities were involved in a naval conflict until World War I began in August 1914.⁹

At the outset of the war, all of the main navies had relatively good wireless services and equipment. As the war progressed, intercepted radio signals began to be used extensively for the first time to track an enemy’s movements, and intercepted communications were decoded to provide information about the enemy’s intentions. Two days before the hostilities initiating World War I began, Maurice Wright, a Marconi radio engineer, was experimenting with a new circuit that made the interception of long-range communications possible for the first time. This allowed Wright to pick up wireless traffic generated by the German navy. He forwarded the text of these messages to the Admiralty’s intelligence division, where they landed on the desk of its director, Rear Admiral Henry Oliver.¹⁰

As the messages began to pile up on Oliver’s desk, he gave them to Sir Alfred Ewing, an old friend with a keen interest in cryptography who was also head of the naval education branch. Starting with a couple of German language teachers from the naval colleges at Osborne and Dartmouth, who were available due to the summer holiday break, Ewing assembled a group of would-be code breakers. They, along with others teachers from other schools, worked temporarily in the corner of Ewing’s office until the start of the new term at the end of September. Whenever Ewing had visitors unrelated to his code-breaking activities, they had to hide in his secretary’s office due to the very secret nature of their work.¹¹

On November 6, 1914, Ewing’s growing staff of code breakers was moved to Room 40 in the Old Admiralty Building. Room 40 became the unofficial name of the code-breaking section even after the growing size of the staff forced it to relocate to other parts of the building. The number of personnel assigned to the section peaked at eight hundred wireless operators, ninety cryptographers, and other specialists. They were located in a maze of interconnecting ‘cubby-holes, dens, and barrack-like typing pools’ of various shapes and sizes. The code breakers in Ewing’s cryptanalysis section benefited early on from a number of German navy code books that fell into British hands and made their way to Room 40. Alfred Ewing continued to supervise Room 40 until May 1917, when it was taken over by the director of naval intelligence, Rear Admiral William Reginald Blinker Hall.¹²

Room 40 became the epicenter for British code-breaking efforts that enabled the Royal Navy to keep track of Germany’s Grand Fleet throughout the war. The code breakers who worked in Room 40 relied on a number of radio installations called Y stations established along the coast of England, many of which were set up by radio enthusiasts who went to work for naval intelligence as voluntary interceptors. Intercepts were also being reported from other radio stations operated by Marconi, British post office, and Admiralty stations, so that copies of almost every German wireless message was being forwarded to Room 40.

Radio direction-finding (RDF) was another form of signals intelligence embraced by the Admiralty’s intelligence division under Captain Hall’s leadership in the early months of 1916 (Hall was promoted to rear admiral a year later). The first British direction-finding system was developed by radio pioneer Henry J. Round, an expert in the development and application of radio tubes (valves in British parlance) working for the Marconi Company. Round, using soft C valves and a modified Bellini-Tosi directional, established a directionfinding system at