Night Fighters: A Development and Combat History E-Book

Bill Gunston

• Herausgeber: The History Press
• Kategorie: Lebensstil
• Sprache: Englisch

Veröffentlichungsjahr: 2004

Beschreibung

From its beginnings during World War I, the role of the dedicated night fighter aircraft and its pilots in the 21st century has evolved greatly. This work reflects the massive changes in technology and in tactics. It also covers the problems of tracking aerial targets by radar.

Leseprobe

First published in 1976 by Patrick Stephens Ltd.

The History Press

The Mill, Brimscombe Port

Stroud, Gloucestershire, GL5 2QG

www.thehistorypress.co.uk

This ebook edition first published in 2013

All rights reserved

© Bill Gunston, 1976, 2003, 2013

The right of Bill Gunston to be identified as the Author of this work has been asserted in accordance with the Copyrights, Designs and Patents Act 1988.

This ebook is copyright material and must not be copied, reproduced, transferred, distributed, leased, licensed or publicly performed or used in any way except as specifically permitted in writing by the publishers, as allowed under the terms and conditions under which it was purchased or as strictly permitted by applicable copyright law. Any unauthorised distribution or use of this text may be a direct infringement of the author’s and publisher’s rights, and those responsible may be liable in law accordingly.

EPUB ISBN 978 0 7524 9512 5

Original typesetting by The History Press

CONTENTS

Foreword by Group Captain John Cunningham

Author’s Introduction

Riddles of the Night Sky

1. STICK AND STRING

2. PIERCING THE DARKNESS

3. YEARS OF CRISIS

4. THE BLITZ

5. CENTIMETRIC AI

6. BATTLE FOR GERMANY

7. OTHER THEATRES

8. THE POST-WAR ERA

9. THE MODERN ERA

Glossary

Appendix

Bibliography

Acknowledgements

FOREWORD

GROUP CAPTAIN JOHN CUNNINGHAM CBE, DSO**, DFC*, DL, FRAeS

Bill Gunston, who has a well deserved reputation as an aviation historian, has an exciting story to tell of the development of night fighting from its earliest gropings in the dark to the highly sophisticated electronic art that it now is. His account of First World War pilots searching the night sky for Zeppelins in stick and string aeroplanes of frightening lack of performance, and totally unequipped for venturing aloft in the darkness, fills one with admiration for those bold spirits, while the contrast he draws with the modern Mach 3 all-weather fighter with its armoury of guided weapons and automated systems of unimaginable sophistication makes one realise how far the ‘trade’ has developed in sixty intervening years.

There could be few better guides to this painstaking evolution than Bill Gunston, who combines the personal experience of a pilot of wartime night fighters with the detailed background knowledge of a one-time technical editor of Flight magazine.

I commend this well documented and outstanding piece of research which, for me and others who may have been involved in the business, recaptures the spirit of the times and reawakens vivid memories of exciting days.

John Cunningham wrote the above for the original, 1976 edition of this book. Sadly, he died in 2002.

.

** And two Bars. * And Bar.

AUTHOR’S INTRODUCTION

to the First Edition

I am grateful to the publisher for asking me to write this book. My immediate reaction was the neutral one that, if a publisher believes he can see a successful book, who am I to argue? But as I got down to the task I increasingly recognized what a splendid story they had chosen for me to tell.

All flying is uplifting and exciting, even when you have book-ends for your log-books. Flying to fight other fliers is more exciting still. But flying to fight by night reaches pinnacles of human experience that are touched but rarely.

Do not be deceived into thinking that I am one to glorify war, or revel in armaments; I doubt if any one alive would do this. There are many who are even antipathetic towards technology, but they would probably accept that, out of aerial night fighting, man has hastened his ascendancy over cloud and darkness.

The whole subject is shot through with contrasting threads. Night fighting was not all excitement. Much of it was little more than danger, discomfort and frustration. From 1915 until about 1942 night fighters killed far more of their own pilots than they did of the enemy. And the fact that the ratio thereafter gradually changed had little to do with increasing skill or courage but a great deal to do with a new species of airborne equipment called AI radar.

I have added a glossary, because most readers will consider one is necessary. One of the problems in writing a book of this kind is that – unlike a book about the Crimea or Jutland – it is impossible to tell the story without delving into a lot of fairly modern technology. It is simply not possible to produce a book about a technical subject that will be all things to all readers. I would be less than human if I did not occasionally try to take the reader aloft, sometimes in aircraft I flew myself, and sometimes by borrowing the words of others who flew and fought by night. The publisher would certainly take it amiss if I omitted to discuss sub-types of night fighters, their colour schemes and even the occasional serial number. But to produce a history of any value one has to explain what the problems were and how they were solved.

This was simple when the technology did not go beyond a Lewis gun, a searchlight and a flare made of petrol-soaked asbestos. But how many readers are conversant with multiple-time-around echoes, or even such basic things as the difference between clutter and glint? I heartily concur with the publisher’s belief that the bulk of the book should deal with the two World Wars. The story here still needed a lot of tying together, whereas the development of combat aircraft during the past fifty years is very fully documented and can be consulted in a thousand places. That does not mean I have not covered the modern scene, but I have skimmed much faster over the surface of a subject that has become awesome in scope and complexity.

Indeed, perhaps the very notion of a ‘night fighter’ is no longer a valid one. Until the 1950s it had a very clear meaning, but today all fighters are quite big, all are exceedingly costly, and all are designed to do their job equally well by day or night. Even in those fortunate countries where the weather is always clear, I doubt if any defence staff would be rash enough to buy a fighter which was not also a night and all-weather fighter. Indeed, today the pressures of inflation have speeded the increasing versatility of combat aircraft, so that a ‘platform’ that is a night fighter by night may take off next morning as a long-range reconnaissance aircraft with multiple sensors, and then fly again in the afternoon as a bomber with a load as heavy as that of three B-17 Fortresses. So the main part of this book is concerned with aircraft that were night fighters and night intruders and did nothing else.

To give an idea of shapes, sizes and the operational equipment fitted, line drawings of 32 night fighters have been included in the text. I am grateful to my former colleague Arthur Bowbeer for preparing most of these drawings. My thanks are also due to the following: British Aircraft Corporation Ltd; Air Commodore Roderick Chisholm CBE, DSO, DFC (and Messrs Chatto & Windus, publishers of Cover of Darkness); Group Captain John Cunningham DSO**, DFC*; Ferranti Ltd (in particular Tim Notley, former night-fighter pilot); Hawker Siddeley Aviation (Hatfield); Edward H. Heinemann, of Rancho Santa Fe (who designed more successful night fighters than anyone else); Squadron Leader Jeremy Howard-Williams DFC (author of Night Intruder); Hughes Aircraft (Culver City and Tucson); Imperial War Museum (J.S. Lucas, Deputy Head of Department of Photographs); Luftwaffenamt, Porz-Wahn, Federal Republic of Germany; McDonnell Douglas Corporation (Harry Gann, Douglas Aircraft, and Herman Barkey, former MCAIR chief engineer of the Phantom); Marconi (Mrs Hance, company historian) and engineers of today’s GEC Marconi Electronics Ltd; MIT Research Laboratory for Electronics (John H. Hewitt, librarian); Ministry of Defence RAF (Group Captain E.B. Haslam, Air Historical Branch); Alfred Price, who has now left the RAF and devotes himself to the books for which he is famous; Royal Radar Establishment, Malvern; AEG-Telefunken; US Air Force (Lieutenant-Colonel King, Pictorial/Broadcast Branch); and Westinghouse Electronic Corporation.

Throughout, I have used the British word ‘aerial’ instead of the US ‘antenna’. The fact that the opinions expressed are my own is self-evident. I would welcome critical comment, especially if it throws new light on a dark subject.

Introduction to the New Edition

In the 27 years since the original edition the trend outlined above has proceeded to the point where the very term ‘night fighter’ has become meaningless: all today’s fighters have to be night-capable. Indeed, some of today’s battlefield helicopters merited a careful look before I decided not to include any. Another fairly obvious point is that, whereas in 1976 we knew little about many aircraft of the Soviet Union apart from an invented NATO reporting name, today we know all about them, and may even be pressed to buy one, to help out with the bank balance.

Another change is that this time my thanks are due to Sutton Publishing, who have taken over the PSL aviation list. Thanks are again due to Philip Jarrett, whose unrivalled photographic library has produced most of the many new images required for this considerably upgraded new edition. Another source, completely unrivalled for aircraft of the USSR and its successor republics, is Nigel Eastaway’s Russian Aviation Research Trust, to whom further thanks are due.

Haslemere, 2003

Bill Gunston OBE, FRAeS

RIDDLES OF THE NIGHT SKY

The history of aerial night fighting contains a curious number of unsolved puzzles. Referred to in greater detail in the text, they are summarized below.

1 During the First World War the RFC and RNAS (from April 1918 the RAF) were forced by the enemy’s attacks to try to construct a scheme for defending south-east England against night bombing by airships and aeroplanes. By 1918 this had become quite effective, but it was then allowed to fall into disuse, and by the 1930s Britain had no operative night defence system and no plans to build one.

2 RAF bomber squadrons enjoyed an unbroken history from the First World War to the Second World War. Many were explicitly night bomber units, yet, once the First World War was over, little attempt was made even to discover the problems of navigating and finding targets by night, far less solve them.

3 Despite the fact that the Air Ministry, Air Council and RAF bore the collective responsibility for the defence of Britain against enemy air attack, no attempt was made in the inter-war period to discover how this should best be done. When in 1934 a civil servant decided to focus attention on the problem he did so purely by chance (because he had decided to see how many files there were on how to stop enemy bombers, and was horrified to find so few).

4 When, as the result of this chance attention being paid to the problem, an expert on radio was called in, the latter proposed in great detail the system we now know as radar. But this again was purely by chance; nobody had asked him for such a suggestion, and his advice had been sought purely to pronounce on the feasibility of a ‘death ray’. He had no reason to do more than state his opinion that such a ray was not at that time practical, and leave it at that.

5 By 1936 the concept of a radar carried by a fighter, to allow it to find its prey at night or in bad weather, was fully understood by the British Air Staff. In 1937 the first such equipment began flight trials, in a converted bomber. Yet in the remaining years of peace no attempt was made to plan for a radar-equipped night fighter of any kind. Throughout the Second World War Britain’s night fighters equipped with radar comprised an inadequate converted light bomber, a large and capable fighter developed purely by chance (because top designers at Bristol thought it would be useful), an even better aircraft converted from a fast unarmed bomber developed in the teeth of official lack of interest (indeed outright opposition) and a converted American attack bomber. The first aircraft for the RAF planned as a night fighter did not enter service until 1956.

6 Radar enabled British fighters to defeat the Luftwaffe (German air force) in the daylight Battle of Britain. This was known to the Germans, and on two occasions bombers attacked the CH station at Ventnor, Isle of Wight. But the Luftwaffe never attempted in any concerted way to knock out the whole CH system, which would have been entirely within its capability, nor to approach the British Isles at low level, where the system was useless and the defending fighters would get no advance warning. On many occasions strong Luftwaffe forces approached at above 15,000 feet, where they were visible on radar over their own airfields in Europe, and then dived to bomb and strafe at low level.

7 In November 1939 British Intelligence was given a large hand-written report (by a ‘well-wishing German scientist’) which described in some detail a wealth of unknown German defence systems. So impressive was the list that it was dismissed as a hoax. Many of the systems described were of an electronic nature, emitting signals that could be detected by any suitable receiver. The British could have tested the validity of the report by detecting the German radars and blind-bombing beams with receivers over Britain or in the hundreds of Bomber Command aircraft sent on leaflet raids over Germany. No attempt was made to do this, even though this would have yielded vital information in the first weeks of the war. As it was, the existence of such enemy achievements was not acknowledged until more than a year later, when they had done great damage to both British cities and British bombers.

8 The first mass-produced German radar for point defence on land was Würzburg, designed for gunlaying. Pressed into service as a night-fighter control radar, its information output remained totally unsuitable. The ideal kind of presentation, the pictorial PPI (plan-position indicator) had been invented in Germany, but rejected by Goering as unnecessary. When a completely new Gigant Würzburg was developed, the output was kept in the same useless form of bearings and ranges, which had to be converted by cumbersome plotting devices into a form of crude synthetic PPI.

9 British scientists developed several electronic navigation aids specifically for bombers during the Second World War. One, Oboe, proved unacceptable to non-technical but powerful members of the government and air staff, because it claimed to allow people in Britain to know the position of an RAF bomber far over Germany more accurately than its own crew; many high-level calls were made for ‘this preposterous scheme’ to be stopped. Yet Oboe was the bedrock on which the entire attack method of the RAF against difficult Ruhr targets and elsewhere in Germany rested. It was the sole primary means for accurate target marking by the Pathfinder Force.

10 In contrast, another aid, H2S, immediately gained the massive support of the technically unqualified VIPs, who urged its large-scale introduction no matter how this disrupted Bomber Command. It helped the navigator by giving him a crude picture of the terrain beneath, though its accuracy was poor and it could be hoodwinked by the enemy. Worse, its emissions gave away the presence and exact position of the bomber using it. Yet the RAF crews were never told how lethal this device was, and in consequence it was switched on throughout the mission. German night-fighter crews and ground controllers could watch the H2S emissions from bombers that were still over Yorkshire. And the development of accurate route marking and target marking removed any need for it.

11 The greatest weakness of the German night fighters was their need to rely on AI (airborne interception) radar, emitting powerful signals betraying the fighter’s presence and position. RAF bombers needed a passive detector to give warning of such signals, without giving away the bomber’s own position. Yet the bombers were actually fitted with Monica, an active radar that itself emitted signals. At one stroke this rendered the device both useless and dangerous. Useless because nearly all its ‘warnings’ were caused by the presence of other bombers in the dense stream proceeding to the target. Dangerous because the German night fighters were soon equipped with their own passive detector, Flensburg, which could home on to a working Monica set from up to 130 miles away. This supposed guardian of the bombers was probably responsible for more bomber losses than any other single device, Allied or enemy, until in August 1944 (nearly two years later) crews were told not to use it.

12 The obvious way for a night fighter to attack a bomber in the Second World War was from below and slightly behind, giving the best view of the biggest target. RAF bombers were designed with three gun turrets giving perfect coverage of the whole area around the bomber except below. This vital area was not only completely undefended but also totally blind to every member of the crew. Even after it was obvious that Luftwaffe night fighters were closing with their quarry from below, no attempt was made to give any of the crew a downward view.

13 The Luftwaffe night fighters were large and powerful aircraft, and they closed to within 100 or even within 50 feet before opening fire. Almost any detection system looking obliquely downards – visual, radar, infra-red or sound – could not have failed to give warning, but no attempt was made to do anything.

14 Nearly all the Luftwaffe night fighters were old designs that were overloaded with extra equipment, fuel and weapons. Their performance margin over the bombers was usually small, and if the RAF heavies had had their useless front and mid-upper gun turrets removed, and they had been instructed to cruise at maximum weak-mixture power when over enemy territory, losses would probably have been dramatically reduced. There was no attempt to do so (except for removal of the front turret from Halifaxes, the fastest of the British heavies).

15 Likewise, the Luftwaffe night fighters were cramped and overloaded, yet nearly all carried a rear gunner with a hand-aimed machine-gun. Such armament served no useful purpose, and was no deterrent to Mosquito night fighters, yet it added significantly to weight and drag.

16 From mid-1943 Luftwaffe night fighters used oblique upward-firing cannon. This extremely effective armament had been the subject of prolonged experiments by the RAF and other air forces since 1916, yet in 1943–4 its use by the Luftwaffe caused disbelief, shock, and morale-sapping tales of ‘secret weapons’ among the surviving crews of Bomber Command. Still nothing was done to give bomber crews downward vision or armament.

17 Despite its proved superiority, the upward-firing gun was ignored by the post-war Allied air forces. When the RAF at last got round to buying jet night fighters, it not only stuck to forward-firing guns but put them in the outer wings!

18 Night after night the RAF’s heavies over Germany behaved as powerful flying radar beacons continuously advertising their exact position. With a total of 94 lb of Naxos-Z and Flensburg passive homing receivers, all the German single-seat fighters could unerringly have tracked down the RAF bombers at night, but only a few were ever fitted with Naxos-Z and none with Flensburg.

19 The RAF never had a proper single-seat night fighter until the Lightning entered service in 1960. But from 1940 it had used Hurricanes (with and without radar), the Luftwaffe had used Bf 109s and Fw 190s (without radar), and the US Navy, Marine Corps and Air Force, and the Fleet Air Arm, had used 29 different types of radar-equipped single-seat fighter with complete success. No explanation of the British policy has ever been given.

20 From 1917 onwards it has been obvious that, given a choice, bombers would prefer to penetrate defended airspace by night rather than by day. Yet, until the advent of the Lightning, the RAF equipped most of its defensive squadrons with ‘fighters’ which were incapable of intercepting at night or in bad weather; the ‘night and all-weather fighter’ was regarded as a specialized type and bought only in much smaller numbers.

ONE

STICK AND STRING

History has not recorded the name of the first pilot to fly at night. He was probably a Frenchman, and the year was almost certainly 1909. Several aeroplane flights had been made more or less in the dark by the time both competitors in the race from London to Manchester, Claude Grahame-White and the winner Louis Paulhan, kept going into the night of 27/28 April 1910. Grahame-White boldly made a take-off in the pitch blackness at 2.50 a.m., but this race took place along the main line of the London & North Western Railway, with its succession of red or green signals. The event was well publicized and had attracted thousands of lighted houses, lighted cars and even bonfires. It did not by any means signify that pilots could henceforth fly from one place to another in darkness.

Probably the most fundamental of all the things a pilot needs to know is which way is up. It is dangerous, and potentially lethal, to rely on ‘seat of the pants’ sensations. An aeroplane can move in any direction, and in doing so can impart every conceivable kind of push, pull or rotary motion to the strapped-in pilot. This is no problem in what is called VMC (visual meteorological conditions), because the pilot can see the ground. But the modern VMC pilot is forbidden to fly near clouds or at night. Put him in the centre of a large cloud, or in the sky on a cloudy, moonless night, and he may soon cease to know which way is up. He can fatally easily enter a gentle diving turn, which can become ever tighter and steeper, while feeling through his ‘seat of the pants’ as if he was maintaining straight and level flight. Of course, if he was in a modern aircraft and had been trained in instrument flying he would know better. But in the earliest days of flying there were no instruments. Everything had to be learned the hard way.

Several of the pioneer aviators did learn, and the fact that the way was often not hard masked the true peril of the learning. Even more lethal than a clear night to the early pilot was dense fog. Sensible aviators stayed on the ground in a thin mist, but young Geoffrey de Havilland once made a complete flight in quite thick fog – saying long afterwards, ‘In those days we didn’t realise how dangerous it was’. Several of the early aviators at Brooklands and Hendon often flew by night when the weather was fine, and the same was true at Issy, Pau and other fields in France. It was recognized, however, that the landing was made more difficult, because there was no airfield lighting, and little to give the approaching pilot accurate information on his position and height above the field. Some pioneers remarked on the fact that the clear horizon, visible all round on a fine night, tended to vanish as altitude was lost. Only very few killed themselves; far more died because of loss of control in broad daylight.

In parallel with the select band of sporting pilots there grew up a new species of pilot who served his country in military uniform. Some flew for fun at their own expense, but from the mid-nineteenth century there had been officially appointed military balloonists, and from 1908 military aeroplane pilots. In 1910 the first aeroplanes appeared with guns. A French Voisin biplane – the sort of flying machine immediately pictured by the expressive phrase ‘stick and string’ – was burdened by a monstrous 37 mm (1.46 in) cannon; fortunately nobody dared to fire it. In August 1910 a Springfield rifle was fired, many times, from an American Curtiss pusher; but when young Major Robert Brooke-Popham, of the Air Battalion, Royal Engineers, fitted a Lee-Enfield to his Blériot in 1911 he was promptly ordered to remove it. In 1912 Colonel Isaac N. Lewis fitted one of his promising new air-cooled, drum-fed machine-guns to a Wright biplane of the US Army; his demonstrations were received with such complete lack of interest that he packed up and went to Belgium, there to set up a gun factory at Liège that not only kept the Allies supplied with Lewis guns in the coming war but also established Belgium as a leader in the international arms business. In British service the Lewis was standard rifle calibre, of 0.303 in (7.7 mm).

British pilots were discouraged from showing any interest in either aerial armament or flying after dark. Indeed, night flying as such was expressly forbidden in the Standing Orders of the Royal Flying Corps when it was formed in April 1912. The whole purpose of the flying machine – if it had any purpose at all – was obviously that it could provide a useful elevated position for battlefield reconnaissance, as had already been proved with balloons and kites. The first RFC pilots spent their first year, mostly on Salisbury Plain, learning not only how to reconnoitre, and to ‘spot’ for artillery, but also how to communicate with ground forces. A few, including Brooke-Popham, flouted authority and practised firing rifles in the air, a task which for several seconds at a time meant that the pilot had no free hand to hold the control column. Others daringly persisted in flying at night. This was especially the case with the bold spirits of No. 3 Squadron, which Brooke-Popham now commanded.

In April 1913 Lieutenant Cholmondeley of 3 Squadron flew on a moonlit night from Larkhill to Upavon and back, making a good landing. He and other pilots later flew ‘circuits and bumps’ by the light from the open hangar doors, until in June 1913 Lieutenant Carmichael asked Brooke-Popham whether he might experiment with a row of petrol flares laid across the landing ground. Carmichael thereupon supervised the first airfield lighting, pioneering the flare-path that was to serve military flyers until after the Second World War. He also got his B.E.2 fitted with a battery-fed lamp that shone upon his cockpit instruments. Though rudimentary, and accomplished without any considered discussion or design process, these advances were real enough. With proper direction they could have resulted in the RFC becoming the nucleus of a trained fighting force, able to give battle by day or night, by the time the First World War began on 4 August 1914. Unfortunately the direction from above was totally negative. The very notion of aerial combat was regarded as a pipedream. No combat aircraft were ordered or even considered in Britain, and when war came the RFC was still a puny force equipped with a few entirely unsuitable aircraft. Its sole mission was day reconnaissance for the land armies, and until many tragic mistakes had been made no RFC pilot’s report was even believed if it conflicted with what the Army had expected.

Hardly anybody in any of the warring nations gave much thought to war in the air, except for the growing airship services of the Imperial German Army and Navy. The Army airships were a mixture of Zeppelins, designated LZ, and wood-framed Schütte-Lanz ships, designated SL. Unfortunately for their crews the Army was obsessed with the belief that its airships would prove formidable tactical bombers over the land battlefields. The Navy, which concentrated entirely upon light-alloy-framed Zeppelins, designated L, thought in more strategic terms and intended to use its airships for ocean scouting and for bombing attacks on Britain. The British government did not have its head totally buried in the sand; it recognized that German airships might be sent to bomb Britain, and wondered what it could do about it. Only the Royal Naval Air Service had any immediate answer. On 8 October 1914 an RNAS Farman flew from Antwerp to Düsseldorf to bomb and destroy LZ 25 in its hangar (on 25 August 1914 this same ship had caused great alarm and 26 civilian casualties in Antwerp). On 21 November 1914 came an even more daring raid when three RNAS Avros flew 250 miles from Belfort to bomb the Zeppelin works at Friedrichshafen. Then the advancing German armies put the Zeppelin bases out of reach of Allied aircraft.

On the other hand, the German advance made it easier to raid Britain. Such raids seemed to begin very quickly. On 21 December 1914 a lone German seaplane droned over Dover soon after midday and dropped two bombs, which both fell in the sea. Three days later, on Christmas Eve, it came again and dropped a single bomb which fell on British soil, breaking windows near Dover Castle. On Christmas Day another seaplane slowly made its way high over the Thames estuary. A Vickers FB. 5 Gunbus tried desperately to reach it, and despite suffering a spluttering engine and jammed Lewis gun, succeeded in making the intruder drop his two bombs at Cliffe, Kent, rather than London. Perhaps the Germans were foolish thus to alert Britain to its state of complete nakedness to aerial attack. With unbelievable slowness the sluggish and reactionary politicians and staff officers set about thinking of a wholly new subject: air defence.

To be fair, the problem had been at least thought about in British government circles since 1912, but nothing tangible was done until the end of 1914. Then the first rudimentary steps were taken to defend London against possible aerial attack by setting up a system of lookout posts, three small guns (not, of course, designed for use in the previously unheard-of anti-aircraft role) and twelve searchlights. The idea of a blackout, by extinguishing or screening the lights of London, was discussed but considered to be too drastic. There seemed to be a lack of people who combined authority, leadership and the ability to think clearly. The possibility of aerial attack by both airships and aeroplanes had been self-evident for years. The fact that such attack did not begin at the very outset of the First World War should, perhaps, have been regarded as a blessing, giving the nation time in which to set up defences. The weeks stretched into months, but still nothing was done. Then came the unexpected seaplane visitations at Christmas, and the talking acquired a note of urgency. And then, on the night of 19 January 1915, northern East Anglia echoed to a distant throbbing of engines.

It was a dirty winter’s night, with snow squalls and rain. Those on the ground soon knew that above them were two Zeppelins, and there was absolutely nothing anyone could do to interfere with them. Inside the Zeppelins – L3 and L4 of the Imperial German Navy – it had been a long and tiring flight from their base at Fühlsbuttel. They had set out twelve hours earlier, in company with L6 from Nordholz. L6 had set course for London but been forced to turn back with engine trouble. In fact, all three ships, plus L5, had set out for England six days earlier, and all had been driven back by severe weather. On this occasion, however, L3 and L4 did succeed in reaching the British coast, and saw the occasional lights of towns and villages. Their target was Humberside, the great city of Kingston upon Hull; but neither airship could identify the ground beneath. Eventually each let go its bomb load on the best collection of lights it could see. Bomb aiming was still in its infancy, though the crews of naval Zeppelins had trained for several years and from 10,000 feet the best crews could usually get most bombs within about 650 feet (200 metres) of the aiming point. But on this occasion they could only see the ground at intervals and did not know for sure which country it was! L3’s nine bombs went down on Yarmouth, killing two people, injuring three and damaging sixty houses. L4’s load went down on King’s Lynn, though one bomb nearly hit the wireless station at Hunstanton, the casualties being two killed and thirteen injured. Bombing ordinary towns was then something totally new, and the Germans mollified their lingering feeling of guilt by claiming that King’s Lynn’s anti-aircraft (AA) guns had ‘opened hostilities’. In fact, no such guns existed.

As virtually the entire RFC was in France, the only aircraft available to defend Britain in January 1915 were those assigned to the task by the RNAS. Three such naval ‘fighters’ were in a condition of readiness at Great Yarmouth on 19 January, but it would have been futile to take off. There was no hope of reaching 10,000 feet within three-quarters of an hour, by which time the airships might be impossible to catch. And they would have been extremely lucky to get back on the ground again in one piece.

While the British public angrily argued over what those in authority ought to be doing, the Zeppelins came two or three times a week. Today it seems almost beyond belief that this could have happened. Early Zeppelins were 490 feet long, and they grew bigger as the months went by. They had a ceiling with full load of about 10,000 feet, though this also increased and eventually reached higher than 20,000 feet late in the war. At full throttle they could make about 50 mph, a speed that was later slightly improved upon; but in a stiff gale the speed over the ground might be barely walking pace. Each ship was a spidery network filled with inflammable hydrogen gas. One might be forgiven for thinking that, with a combination of such existing technology as the telephone, the searchlight and the gun, it might be possible to destroy every airship that dared poke its nose over the British coast. What actually happened was that nothing worried the raiding airships in the slightest, apart from the weather. (Admittedly it was a different story with the Army ships over the Western Front, which generally had very short lives indeed.)

With the RFC quite unable even to build up the required forces for the land battle, the entire burden of trying to shoot down Zeppelins fell on the RNAS. Urgent experiments were made with Lewis guns firing different kinds of ammunition, with darts, grenades and, in particular, with a crude but promising anti-Zeppelin bomb. This comprised a tube filled with petrol and fitted with a series of hooks and a fuse. The aeroplane pilot carried several clipped to the sides of the cockpit, and released them through a hole in the floor. As each fell, a lanyard triggered a mechanism in the fuse which both lit the petrol and released the spring-loaded hooks. The bomb was intended to hook on to the fabric of an airship, burn through and set fire to the gasbag inside.

During the spring of 1915 the bigger and more powerful P-class Zeppelins made their presence felt from Kent to Scotland. One of these, LZ38, was held in searchlight beams as she came in over Essex on the night of 17/18 May. RNAS Flight Sub-Lieutenant Mulock saw her – the first pilot of a night fighter ever to experience the sudden thrill of seeing his enemy – and urged his Avro 504 towards the illuminated monster, its willing Gnome engine at full throttle. He would have had no chance if he had had to take out much difference in altitude, but he was already at about the same height. Unbelievably, he realised he was going to get within firing range. Closing to about 2,000 feet distance he opened up with his Lewis. He could hardly miss. Then the gun jammed! LZ38 got away, and so did her sister LZ39, despite the latter being intercepted by no fewer than three RNAS pilots as she crossed the Belgian coast on her way back to her shed at Evère, Brussels.

One of the three unsuccessful fighters over Belgium was a Morane-Saulnier Type L, flown by Flight Sub-Lieutenant R.A.J. Warneford, which had simply been unable to climb fast enough. Warneford had been hoping, against all odds, to be able to encounter an airship when he was already at its altitude and carrying the flaming anti-Zepp bombs. On the night of 7/8 June 1915 he was detailed to bomb the sheds at Evère, and his Morane was carrying instead six 20 lb Hales-type high-explosive bombs. At about 3 a.m. on the 8th, as he was setting course for Brussels, he suddenly saw LZ37 homeward bound over Ostend. Climbing as hard as he could he managed to get above the monster and, taking careful aim, began to release his bombs. The last bomb caused the whole airship to explode. As the Zeppelin vanished inside a vast fireball, Warneford’s Morane was tossed upside down and went into a spin with the engine stopped. As the red-hot skeleton of LZ37 fell into the grounds of a convent near Ghent, Warneford was forced to land with a broken petrol pipe. He was able to effect a temporary repair before the arrival of German troops, and he took off again in the dark and reached his base. The first wholly successful night interception in history won Warneford the VC. Ten days later he crashed on take-off and was killed.

This victory, though over Belgium, did much to improve public morale in Britain, and improve the image of the frustrated night-fighter pilots. But literally hundreds of subsequent sorties resulted merely in extreme fatigue, sometimes in a distant sighting of a Zeppelin and, approximately as often, a crash either at the home airfield or in a totally unsuitable place for landing as a result of engine failure. Dozens of new airfields were hastily set up – not difficult, because all that was needed was a windsock, Besonneau canvas hangar and a few tents – and freshly trained pilots arrived to fly newly built aircraft. The trouble was, the sky seemed to be a very big place, and for a pilot of a defending fighter to intercept even as huge an enemy as an airship was pure luck. There was absolutely no system of interception whatever. Pilots took off with only the vaguest idea whether airships were about at all. There was no means of communicating with them once they were airborne, and they had to rely on what they could glean from searchlights or gunfire. Unlike the airship captains, they could not safely shut down their engines and listen for enemies.

On the other hand, the Kaiser’s Imperial Navy did enlist the new sceince of wireless communication, and went one vital step further. On 15 June 1915 L10 made the long trip from Nordholz to the Tyne. She bombed very accurately on an ideal target: blast furnaces and coke ovens all going flat out and visible for more than twenty miles, with surrounding factories and houses also brightly lit. The Zeppelin hardly needed the new radio navigation system that was used that night for the first time. Special receiver aerials and instruments in the airship picked up coded signals from Nordholz and from Borkum, the most westerly of the German offshore islands, so that when each signal strength was at a maximum the crew could work out their position by a rudimentary triangulation. Certainly one of the first, if not the first, airborne radio navaids in history, this simple form of the later DF (direction-finding) loop system at least ensured that never again would an airship intending to bomb Hull cruise aimlessly and finally bomb Yarmouth, 120 miles away.

At the same time, the German radio DF system was nothing like accurate enough for blind bombing. It could ensure that an airship arrived over a particular large city, but its accuracy was measured in kilometres rather than metres. On several subsequent raids, especially that on 9 August 1915, clouds and rain so interfered with visibility that the Zeppelins just let go their bombs at random. No airship dared penetrate hostile airspace by day, and in the short summer nights the timing had to be right if the lumbering ships were to retain cover of darkness throughout the dangerous part of the mission. It was at this time that the Naval Zeppelins introduced a bold observation technique. An observer was lowered in a streamlined car on a 2,700-ft cable carrying a telephone line. The intention was that the height difference should allow the observation car to dangle below the cloud base while the airship remained hidden; the isolated officer could also listen for the sound of night-fighter aircraft. He relied totally upon the cable; he had no parachute.

In the second half of 1915 the RFC gradually began making a positive contribution to British aerial defence. When it took over from the RNAS officially in December it had ten permanent night-fighter airfields, each with two aircraft at readiness, with many more being prepared. Virtually all the RFC combat aircraft were by now of the B.E.2c type, the mass-produced general-purpose machine designed as standard RFC equipment by the Royal Aircraft Factory at Farnborough. Its dominant feature was strong inherent stability, and while this was an often fatal handicap on the Western Front in daylight, in one-sided combat against the agile Fokker monoplane, it was a major advantage in night missions against airships. On the other hand, the B.E. had only a slight performance advantage over the 1915 Zeppelins. The quoted maximum speed on the level was 72 mph and the ceiling 10,000 feet, but a B.E. significantly lower than an airship was unable to make an interception; it could overhaul the airship or climb to the same level, but could not do both simultaneously. Indeed on the night of 13 October 1915 Lieutenant J.C. Slessor – who much later was to become Chief of the Air Staff – found the greatest difficulty in maintaining control of his B.E. as it staggered along at full throttle at its ceiling in a vain attempt to reach L15, clearly visible high over a brightly lit London. Eventually he had to give up the chase, and with tanks almost dry, he glided back to Sutton’s Farm, near Hornchurch, easily found because of its distinctive coloured petrol flares. As he neared it, the airfield was swiftly becoming covered in a thin layer of dense white mist. Left alone he might have pulled off a good landing, but as he descended into the mist the searchlight crew at the side of the airfield decided to help. Aiming their beam at him he was blinded, and the mist suddenly became brilliantly white. Slessor was lucky to finish with a B.E. that was, after some discussion, judged repairable.

As the first night fighter in history, the B.E.2c might deserve careful study, but in fact it was merely a lash-up – as were most combat aircraft of the early part of the First World War. The B.E. had been designed when the War Office was adamant that the only possible use for aeroplanes was reconnaissance. Later many hundreds of all kinds of B.E. were used as bombers, being flown solo from the rear cockpit. They were hacked down in droves by the deadly Fokkers, being low, slow, incapable of rapid manoeuvre and, usually, unarmed (because they could not carry bombs and also a gun). As a night fighter, however, they were at least less likely to be shot down. In this role they were again flown solo, and a drum-fed Lewis was mounted on the centre of the upper wing, firing at an angle that cleared the propeller disc. Instruments were marked in luminous paint, and some had an internal lamp. Their stability made them steady gun platforms, and probably safer than any other aircraft in the still extremely chancy business of night flying; but their performance was marginal in the extreme.

One wonders why nothing was done to build up a strong force of faster, higher-climbing night fighters. One of the best aircraft would have been the little Bristol Scout, which as early as February 1914 reached the then excellent speed of 95 mph. Even when carrying a machine-gun the Scout C of 1915 could comfortably exceed 90 mph, and climb to 15,500 feet. Though used by many RFC and RNAS units, the Scout was issued in ones and twos, and total production was trivial (for example, 87 C models for the RFC and 74 for the RNAS). Very easy to fly, highly manoeuvrable, and capable of climbing to 10,000 feet in twenty minutes to intercept a Zeppelin, the little Scout seemed in 1915 to be the ideal night fighter, but the number in use at any time could be counted on the fingers. Indeed, it seemed to be a perverse law of the British procurement machine that, while the excellent Bristol Scout and M.1C monoplane were almost ignored, along with several other potentially outstanding fighters, the almost unmanoeuvrable B.E.2 family were built in ever-greater quantities by more and more factories.

One of the weapons carried by the Bristol Scout was the Ranken dart, a development of the hooked petrol bomb. Devised by RN Engineer Lieutenant Francis Ranken, it comprised a slim dart with an explosive head and four sprung vanes at the rear. Carried in metal boxes of 24, the darts were released three at a time. The idea was that the head would pierce the fabric of the airship, the fuse would be detonated and the charge would explode before the tail vanes had torn through. Even if no fire was caused, the rent was thought certain to cause gross loss of gas. The little Scout often carried two boxes of 24. Another weapon was the Le Prieur rocket, originally designed for destroying observation balloons. This was the simplest possible rocket, with a hard pointed nose, launched from a tube carried on the interplane struts, giving an upward inclination at launch. Many fighters carried up to eight or even twelve rockets, which were usually salvoed all at once. Incendiary ammunition, and later explosive Pomeroy bullets, were predominant in the 97-round drums made up for the Lewis guns of fighters on night Zeppelin patrol. In the experimental shops of Royal Ordnance Factories, Vickers, and other works were to be found several purpose-designed guns for destroying the raiding monsters. Certainly the few pilots who did succeed in reaching a Zeppelin were greatly disheartened to pump drum after drum of 0.303in ammunition (incendiary included) right through the vast silvery envelope and see no evident effect. In two cases there was an effect, the airship later making a forced landing; but this was not known to the fighter pilot.

During 1915 a spate of more or less bizarre aircraft were designed expressly to beat the Zeppelin raiders. One of the first was the A.D. Scout, designed by Haris Booth at the Admiralty Air Department. This lofty but quite unsuitable aeroplane had a nacelle about ten feet off the ground attached to the upper pair of wings, and carrying the Davis recoilless gun. The Davis came in several versions, the most common firing a ½ or 2-pounder shell, and had its development been carried to completion it would probably have been a formidable weapon. The Davis was also specified for the Blackburn Triplane, which resembled a slightly less grotesque form of the A.D. Scout, and also for the P.V.2 designed at the RNAS Experimental Depot at Port Victoria, on the Isle of Grain, in the Thames estuary. The P.V.2 was a fine-looking seaplane which actually flew (in June 1916). So did the Robey-Peters three-seat gun carrier, a pugnacious biplane carrying Davis gunners in streamlined nacelles on both the left and right upper wings.

Two of the aircraft featured in the author’s small sketches (overleaf) are the Royal Aircraft Factory N.E.1 and Vickers F.B.25. These undistinguished aircraft were both fitted with a powerful searchlight in the nose. There seems to be no evidence that either aircraft was used for any serious experiments to see whether or not a searchlight might be of value in finding hostile aircraft at night, but it is at once obvious that switching on an airborne searchlight instantly betrays the presence and location of one’s own aircraft. Like so many weapons and counter-weapons, an airborne searchlight might increase a night fighter’s vunerability, rather than its lethality. At the same time, when one considers that visible light is merely electromagnetic radiation, just like the emissions from radar, one is left wondering why all the later effort was put into radar, and almost none into airborne searchlights. The only serious trials with later airborne searchlights were, in the author’s opinion, ridiculous; for some reason the device was called a Turbinlite, as described later.

Returning to the First World War, all these supposed anti-Zeppelin night fighters pale into insignificance beside the weird creations of Noel Pemberton-Billing. ‘PB’ was a colourful character, to put it mildly. When the First World War broke out he asked the Admiralty what sort of aircraft it wanted, went back to his factory, drew outlines on the walls, and did not let anybody go home until the prototype was completed seven days later. (It was a surprisingly good machine.) By 1916 PB had gained a commission in the RNAS, resigned to become MP for East Hertfordshire, and designed several further combat machines. The latest, completed in the first four weeks of 1916, was the P.B. 29E, a vast but fragile-looking quadruplane. In PB’s book Air War: how to wage it appeared an explanation: ‘A fleet of defending aeroplanes is necessary. Each must be so armed as to be capable of destroying an airship at a range equal to the range of its own searchlight, which must be not less than one mile. It must have at least a speed of 80 mph in order to overtake airships. It must be able to fly as slowly as 35 mph to economise fuel and to render accurate gunfire and night landing possible . . .’ Other requirements were 12 hours’ endurance, silenced engines, dual pilots (because of the long missions) and ability to reach 10,000 feet in 20 minutes. Fast climb was not expected to be needed, because, to quote PB, the idea was ‘to stand still in the air in a 28 mph breeze and lie in wait for Zeppelins’. Commander Seddon flew the 29E at Chingford in February 1916 but it later crashed. This did not discourage PB from later building the even more extraordinary P.B.31E. Planned in mid-March 1916, this was again built for the Admiralty, and was a veritable sky battleship. The main armament was a 1½-pdr Davis on the upper floor of the crew compartment, level with the uppermost of the four wings. In the bow cockpit was a pair of Lewis guns, and on the extreme nose was mounted a powerful searchlight carried on gimbals and trained by the bow gunner. The generating plant ‘sounded like a T-T race’. Clifford Prodger got the contraption into the air in February 1917, but it was doomed by the feeble 100 hp of its Salmson engines. By this time PB had sold the works to his co-directors and it was renamed Supermarine Aviation; so the 31E was an early ancestor of the Spitfire!

Another specialized anti-Zeppelin weapon was the Crayford rocket gun, developed by the Vickers works at that Kentish town. This fearsome weapon was tested on the range but may never have flown. The first designated carrier was the Zeppelin Scout built by Parnall Aircraft in 1916. A large single-seat biplane, the ZS had the monster gun fixed on the right side at an elevation of 45°. In contrast, Vickers’ own F.B. 25, flown in the first weeks of 1917, entrusted the rocket gun to a gunner in a separate cockpit just ahead of the pilot and on the right side, with a manually aimed mounting. The corresponding machine from the Royal Aircraft Factory was the N.E.1 (Night Experimental), a slender biplane with a central pusher nacelle. In the bow was the pilot, with his own Lewis and a searchlight. Behind was the gunner, with the Vickers rocket gun and a second searchlight.

While these and other strange anti-Zeppelin night fighters swiftly took shape in British factories, established machines were used in new ways. RNAS fighters, in particular, were used in experiments aimed at increasing the proportion of each Zeppelin’s mission in which it could be attacked. Sopwith 1½-Strutters and Pups, and later Camels, with wheel or skid landing gear, were towed far out across the North Sea on lighters, some of them to alight again after their patrol on rubber-fabric inflatable bags. A few Sopwith Babies, Camel 2F.1s and Pups were equipped as night fighters operating from the world’s first aircraft carriers, HMS Furious and seaplane carriers Engadine and Vindex, with the usual fixed Vickers gun replaced by a tripod-mounted Lewis and with floats or flotation bags. Perhaps most remarkable of all, one of Vindex’s Bristol Scouts was successfully borne aloft and released from above the upper wing of a Porte Baby flying boat, on 17 May 1916. The aim was to carry the little fighter to about 6,000 feet altitude some one hundred miles beyond the furthest point it could reach in unaided anti-Zeppelin patrol; but, like all schemes which relied on a chance meeting with an airship, it was of little practical use.

Moreover, whereas the earliest German military and naval airships had had no defensive armament, their larger and more powerful successors bristled with many guns. On 30 May 1916 the first of the so-called ‘Super Zeppelin’ R-class, ship L30, entered service with the Naval Airship Division. Powered by six 360hp Maybach engines, she had a displacement of no less than 1,949,600 ft3, and was fractionally under 650 feet long. Her lifting power was such that, while the 1914 ships could barely climb above 10,000 feet with a tonne (2,205 lb) of bombs, the R-class could load five tonnes of bombs (over 11,000 lb), plus all-round defensive armament, and still climb to 20,000 feet. L30 entered service, commanded by Oberleutnant Baron von Buttlar, with a total of ten Parabellum machine-guns; soon at least one of these was replaced by a Becker 20 mm cannon. As an interesting aside, whereas the boundary layer of sluggish air at the bows of an airship might be only an inch thick, 500 feet further aft it would have grown to at least three feet. A man could crouch on top of the ship and not be swept overboard; only his hair would be ruffled by the slipstream. For this reason, defensive gunners were usually placed near the stern, where they could man their gun(s) partly outside the envelope in a gentle breeze and with a clear field of fire.

Thus, in the middle war years the advantage tended to swing in favour of the attacking airships. It was increasingly evident that the only answer to these attacks lay in improved early warning, improved tracking of the raiders, improved communications, and more and better fighters. By the end of 1916 there were thirty night-fighter airfields at instant readiness from Kent to Scotland, housing 2,000 RFC or RNAS Home Defence personnel, backed up by a further 15,000 manning searchlights or anti-aircraft gun posts. Though the airships seemed to lead a charmed life, almost every one of them encountered close AA fire over Britain and, on an increasing number of occasions, a successful interception by a night fighter. On one occasion, in April 1916, a veteran Zeppelin and crew – L15, the one that got away from Slessor – was hit by AA fire at Purfleet and finally succumbed to darts dropped by a B.E.2c; but she went down gently, and finally broke up more than two hours later off the Essex coast. What the British public wished to see was a raider going down in flames.