Fighter defenses.. the radar or the radio?

[Warship NWS]

This is an open ended discussion of covering the topic of naval CAP and land based fighter defenses. What component of the defense proved more critical in your opinion, the radio communications with the fighters or the radar detection of impending ability if available?

What are your thoughts? Note, this is not intended to be a "black and white" or "right or wrong" type of discussion but instead a discussion in theory and evolving tactical doctrines covering WW2 and how the lack of, or availability, of such systems effected, or could have effected, the outcomes of various aerial battles and campaigns.

Thanks.

[old_pop2000]

This is an open ended discussion of covering the topic of naval CAP and land based fighter defenses. What component of the defense proved more critical in your opinion, the radio communications with the fighters or the radar detection of impending ability if available?

What are your thoughts? Note, this is not intended to be a "black and white" or "right or wrong" type of discussion but instead a discussion in theory and evolving tactical doctrines covering WW2 and how the lack of, or availability, of such systems effected, or could have effected, the outcomes of various aerial battles and campaigns.

Thanks.

Examining fighter direction in the early months of carrier operations in the Pacific shows that even the manually rotated, air search CXAM radar was effective out to 100 miles or more, depending on atmospherics, in detecting unknown aircraft. However, I stress my use of the term "unknown aircraft". Keep in mind that, at any one time, there might be as many as 8 F4F's on combat air patrol over the carriers. There might also be SBD's around 2000 ft on inner patrols looking for submarines or on anti-torpedo plane station. This might mean that in the air, not counting any transiting strike group aircraft, there might be sixteen friendly aircraft in the area of the CXAM. The FDO's on the carrier would be under tight radio security. No incoming or outgoing transmissions would be allowed except under extraordinary circumstances.

In this typical scenario, one that occurred during the Wake island raid, Marshall Island raid, the raid on New Guinea, Coral Sea, Midway and Operation Watchtower, a strike may be launched, with some stragglers, eight to sixteen combat air patrol and inner patrol aircraft maybe aloft, with four or eight more available with warm engines on the deck. This means that there maybe as many as 60 aircraft aloft within a 150 to 200 mile radius of the carrier and the CXAM can see almost all of them. The fly in the ointment is that none of these had IFF. So, the FDO has no idea if the aircraft on the scope are friend or foe. They might be land based Mavis search aircraft looking for the TF, they might be an enemy strike force coming in, or they might be CAP or strike aircraft. The only solution until IFF was available to all aircraft was to radio the CAP and vector or arrow them to the unknown bogie.

That sounds easy, except, the F4F had a short range and a slow climb rate. This is especially true of the F4F-4. Sometimes, even if the FDO could contact the CAP F4F's and vector them, the bogie was too high or the F4F's were at the limit of their fuel. This happened on more than one occasion. This is especially true of incoming torpedo bombers. When they came into visual contact with the target, usually the carriers, they would climb to 13,500 ft, then begin a long decent with each chutai of four, coming in via separate routes, usually between the screen ships. This now gives the FDO four separate bogies descending, with only four to six CAP aircaft available to visually id the planes and then attack them.

So, the question at hand, which is more important? The radio is important, but can't solve all the problems and communications security and blackout was important to the safety of the whole task force. The Japanese navy, just one typical example, had radio intercept equipment in the nearby islands and on the ships, they could and did intercept our radio communcations and did attempt to spoof our pilots with english speaking Japanese.

Radar, on the other hand, could detect enemy aircraft and protect the fleet, but the radio had to be used to vector or arrow the CAP's toward the target. So, in essence both were important but instructions to both ships and aircraft could only be made through use of the radio. Radar was passive, it could only, at this stage, tell an object was in a particular location, but the radio could managed the battle area.

[old_pop2000]

I neglected to mention this. At the beginning of the Pacific War, the fighter squadrons on the carriers were equipped with F4F-3,-3A's and Brewster Buffaloes. The Buffaloes were on board the lexington, but she relinquished them to the Marines for F4F-4's in February. The F4F-4's had IFF on board, which made FDO and CAP procedures easier at Guadalcanal.

The typical air wing composition was:

18 F4F's

18 SBD's - VB squadron

18 SBD's - VS squadron

12-16 TBD's- VT squadron

However, due to operational and non-operational losses, the squadron's might arrive in the operations area, with at least two to four planes lost in flighting accidents and fuel issues. Many times the fighter squadrons had only 14 aircraft.

This was eventually remedied by the introduction of the folding wing F4f-4 and the increase in fighter strength to 27 aircraft and eventually after Midway, to 36 aircraft.

[paladin5]

I neglected to mention this. At the beginning of the Pacific War, the fighter squadrons on the carriers were equipped with F4F-3,-3A's and Brewster Buffaloes. The Buffaloes were on board the lexington, but she relinquished them to the Marines for F4F-4's in February. The F4F-4's had IFF on board, which made FDO and CAP procedures easier at Guadalcanal.

The typical air wing composition was:

18 F4F's

18 SBD's - VB squadron

18 SBD's - VS squadron

12-16 TBD's- VT squadron

However, due to operational and non-operational losses, the squadron's might arrive in the operations area, with at least two to four planes lost in flighting accidents and fuel issues. Many times the fighter squadrons had only 14 aircraft.

This was eventually remedied by the introduction of the folding wing F4f-4 and the increase in fighter strength to 27 aircraft and eventually after Midway, to 36 aircraft.


Wait they had IFF back then. I guess i learn something new every day.

[old_pop2000]

There were two basic components; the aircraft transponder and question device or receiver-transmitter on board the ship. There were two systems; The Mark II and III. The Mark III became standard since it operated with a search set in microwave band. The aircraft set was the APX-1 and APX-2, depending the ground set.

Hope that helps.

[Kyle Holgate]

You could have fairly effective cap without radio - giving course, speed and altitude information to your fighter pilots prior to their take off. The down side is that you can't change orders once they're in the air, and you can't war a standing cap when, where an enemy group may be approaching. Cap would greatly loose effectiveness, but would not be totally useless.
Without radar you loose time to get your planes to altitude and are less able to get them in the right place at the right time. Here too, cap looses effectiveness but is not totally useless. Mark one eyeball can make up for a lack of radar sometimes.

[old_pop2000]

You could have fairly effective cap without radio - giving course, speed and altitude information to your fighter pilots prior to their take off. The down side is that you can't change orders once they're in the air, and you can't war a standing cap when, where an enemy group may be approaching. Cap would greatly loose effectiveness, but would not be totally useless.
Without radar you loose time to get your planes to altitude and are less able to get them in the right place at the right time. Here too, cap looses effectiveness but is not totally useless. Mark one eyeball can make up for a lack of radar sometimes.
Mark one eyeball was no good in cloudy or partially cloudy conditions. Incoming enemy aircraft can elude CAP aircraft by staying under or in the clouds. During the Fletcher's move to Guadalcanal, the Mavis flying boats came very close to the CAP aircraft but they never saw them. Luckily both flying boats turn to port and continue on their cross wind legs and failed to find the TF, which would have given the Japanese at Rabaul four to six hours advanced notice.

[Ed Rotondaro]

You could have fairly effective cap without radio - giving course, speed and altitude information to your fighter pilots prior to their take off. The down side is that you can't change orders once they're in the air, and you can't war a standing cap when, where an enemy group may be approaching. Cap would greatly loose effectiveness, but would not be totally useless.
Without radar you loose time to get your planes to altitude and are less able to get them in the right place at the right time. Here too, cap looses effectiveness but is not totally useless. Mark one eyeball can make up for a lack of radar sometimes.

Kyle:

I have to disagree here and agree with Dennis. Even with both radar and radio communications, intercepts were very tough. Now take away the radio and they become a crap shoot. Indeed until reliable altitude detecting radar was available (sometime in 1943 I believe), radar guided intercepts still had problems. Radio nets easily got overwhelmed in the heat of combat. Radio reports often never were received, especially if a land based plane was doing the reporting. Mark One eyeball reported more mistakes than you believe during WWII.

Dennis, when did IFF become operational on US planes?

[old_pop2000]

Kyle:

I have to disagree here and agree with Dennis. Even with both radar and radio communications, intercepts were very tough. Now take away the radio and they become a crap shoot. Indeed until reliable altitude detecting radar was available (sometime in 1943 I believe), radar guided intercepts still had problems. Radio nets easily got overwhelmed in the heat of combat. Radio reports often never were received, especially if a land based plane was doing the reporting. Mark One eyeball reported more mistakes than you believe during WWII.

Dennis, when did IFF become operational on US planes?
The first real installations were in the F4F's and other carrier based aircraft. These would have been the 45 pound, SCR-535. The system mechanically swept two frequency bands looking for a signal from the interrogating radar, every six seconds. There were some sets installed in aircraft in the Battle of the Coral Sea, more in the Battle of Midway, but not nearly enough. So, the first real date of introduction for the Mark II system was in 1941.

[Warship NWS]

You could have fairly effective cap without radio - giving course, speed and altitude information to your fighter pilots prior to their take off. The down side is that you can't change orders once they're in the air, and you can't war a standing cap when, where an enemy group may be approaching. Cap would greatly loose effectiveness, but would not be totally useless.
Without radar you loose time to get your planes to altitude and are less able to get them in the right place at the right time. Here too, cap looses effectiveness but is not totally useless. Mark one eyeball can make up for a lack of radar sometimes.

Actually, the eyeball played a VERY critical role during the BoB1940 via the ROC (Royal Observer Corps) as once the raids passed over the radar chain they could not be tracked any other way. The ROC also provided identification, target raid numbers and height, and continuous updates that were sent to RAF command that in turn were updated approximately every 5 minutes. The radar chain COULD have been effectively been destroyed by the Luftwaffe if they had attacked, instead of the radars themselves, the support substations and communication links which were very vulnerable to bombing. The radio sets that the RAF fighters carried also included "Huff/Duff" which kept the RAF informed about where the RAF squadrons were located in the air. Without it, and the ROC, it would have been near impossible for the RAF Fighter Command to coordinate and organize their air defenses via air traffic control as they would not have been able to know freind from enemy. The radars were a tool that allowed for earlier warning of impending raids, however, they were not the only tool used. RDF/Signet was also used to alert of incoming raids by listening for Luftwaffe transmissions. Granted, the ROC might be limited by visual only methods that were effected by weather conditions but the ROC had thousands of locations throughout England and they could not be effectively hindered by Luftwaffe attacks. The weather was also a double edged effect because if the ROC could not see the bombers then the bombers could not see their targets, or they might not even find their targets at all, so in turn the raid may take losses during their transit while not returning with any positive results from their sorties.

So the question remains.. what was more important.. radios or the radars? For the BoB I think this is an interesting question, and one that is not out of the question to contemplate as the radars COULD have been effectively suppressed or destroyed had the Luftwaffe a) persisted in their attacks on the radars and b) had known that there were vulnerabilities in the network of radar chains.

Thanks.

[old_pop2000]

One of the new buzz words in military technology is C³ or Command, Control and Communications. The name implies battle management and tools necessary to facilitate this.

The first battle management tool in this arsenal, was the four channel, transmitter-receiver in aircraft and surface ships. It allowed for communications between ship and aircraft, aircraft to aircraft and aircraft to shore. Each using a separate channel, hopefully. They were tube based and were unreliable due to static and vibration. But it was a step forward, it allowed FDO's to contact the flight leader, directing him to the target aircraft, it allowed flight leaders and others to contact friendly aircraft to direct their operations and after combat, to regroup the divisions and squadrons for further operations or for the return to base.

It must be realized that it is lonely in a single seat aircraft. Your only contact with friends is via radio and hand signals, if close enough. This is especially true over the open waters of the Pacific Ocean. With the limited number of aircraft on board carriers, maintaining contact with those limited numbers is vital, or attrition will quickly erode your offensive and defensive capability. Despite radio security, radio's would be used if it was deemed necessary to retrieve a lost pilot. However, there were many times when the FDO's could not get permission from the Captain or the TF commander to provide a homing signal or contact a lost pilot for fear of providing valuable intelligence information to RDF sets on opponent ships. This is how the Lexington Air group Commander, William Ault, was lost at Coral Sea.

So, while RADAR was a valuable detection device and a battle management tool of its own, with IFF, there was no substitute for direct radio contact with your combat assets.

Addendum: Good article on Japanese radios in Zero's - http://www.j-aircraft.com/research/gregspringer/radios/radio_systems.htm

[Warship NWS]

One aspect of the radio in planes that I think is forgotten is intel gathering. If the radar was knocked out then without radios in planes the option of having aircraft performing recon flights watching for intruders would have been out of the question for example. Fighter squadrons keeping the RAF fighter command updated as to whether or not they were spotting enemy planes, reforming, under attack, attacking, positioning, etc.. would have also been impossible.

Thanks.

[old_pop2000]

The primary command radio found in naval aircraft starting in 1940 was the ARA/ATA. This stood for assembly receiver airborne/assembly transmitter airborne. A command radio is designed for aircraft to aircraft use. The liaison radio is used to commicate with the base or carrier. Often, this dicotomy got a little blurred. A fighter would have one transmitter and one receiver, the control box and tuning dial, with gain control mounted on the right side of the cockpit. They were painted in black wrinkle paint. Most radios use a band switch to change rf bands, this radio used a different receiver and a different transmitter. The receivers went from 520 kilocycles up to 3 megacycles.

Specific sets- F4F-3 GF-4/5/8 transmitter/RU-7/5A/13 Four Channels
SBD-3 GP-4A/5/6 transmitter/ RU-10/11

The primary radio used from 1943 onward was the An/ARC-5. Same frequency range, later version in the war were VHF sets.

Note: Scary thing happened. I found the manuals and schematics. I could read the schematics and determine the gain in some areas. Boy am I old!

[old_pop2000]

In researching the types of radio equipment on board the navy aircraft at the beginning of the war, I've found that besides the initial outfitting of the ARA/ATA system, SBD-3's and TBF-1's were equipped with the DU-1 direction finder. It consisted of a loop antenna mounted on the receiver box with a tuning dial. I've seen mountings on an OS2U Kingfisher of this unit between the pilot and radioman. It was wired to the antenna posts of the ZB-1 homing device.

The F4F's had no such capability. The ARA/ATA was replaced early in the war.

[Kyle Holgate]

Radar and radio are force multipliers. The lack of either does not prevent any effective cap, it just makes it much harder. The human eye worked well in SOME circumstances and situations, and before the advent or radar and radio that had to be as good as it got (short of messages dropped from the planes).
Let's go back and address the core question: If you were going to pick one of the two things - radar or radio comms (air to air, air to ground) as being more important toward imcreasing the ability of CAP - which would it be?
Also - let's not focus on the pacific carrier ops - war had been going on for some time prior to that (Sept. 1939 - or if you want to count the China war - much earlier). Personally I think carrier CAP should be treated seporately from general fighter defense of a country or factory, etc.

[old_pop2000]

Radar and radio are force multipliers. The lack of either does not prevent any effective cap, it just makes it much harder. The human eye worked well in SOME circumstances and situations, and before the advent or radar and radio that had to be as good as it got (short of messages dropped from the planes).
Let's go back and address the core question: If you were going to pick one of the two things - radar or radio comms (air to air, air to ground) as being more important toward imcreasing the ability of CAP - which would it be?
Also - let's not focus on the pacific carrier ops - war had been going on for some time prior to that (Sept. 1939 - or if you want to count the China war - much earlier). Personally I think carrier CAP should be treated seporately from general fighter defense of a country or factory, etc.
If RADAR and RADIOS are force multipliers, then the lack of either means that I will have to provide more fighters for defense, correct? The idea of a force multiplier is the add value to the numbers of aircraft that I have in service. If I have 600 and we consider that RADAR and the radio can multiply that by three, then I can do the work of 1800 fighters with 600. Now, where does England get 1800 or 1200 or even 900 fighters without one or the other in place. That is the essential question.

As for alternatives, I can see none for the radio. For RADAR, I can see the Royal Observer Corps, sound detectors, submarine pickets in the channel along with standing fighter patrols. So, how many standing fighter patrols will I need? I have to cover, conservatively, 1000 miles plus, of English coast line from 0 altitude up to and including 30,000 ft. Depth wise, it might be conservatively, 10 miles. So, we have an irregularly shaped box, 1000 miles across, 15 miles high and 10 miles across to watch and cover with standing patrols or 750,000 square miles? Let's figure four aircraft in a patrol, which was entirely accurate. If they flew in a race track configuration in the air, they could cover 50 miles at best, 100 miles if it is stretched. At best, the British would need, in the air at any one moment, 80 to 100 aircraft. This does not take into account that at 20,000 ft, you can't see down to sea level, so the pickets and Royal Observer Corp would have to take care of anything below 10,000 ft.

Now, besides the 80 to100 aircraft in the air, you will have to have replacements to take their place. Average loiter time, even at max. lean mixture for a Spit 1 probably less than 2 hours. It depends on time to climb, and cruising speed. I am certain they would run lean mixtures and feather back to minimize fuel consumption. But even if it were two hours, you are going to need a minimum of 80 times 3 possibly 4 to maintain standing patrols that are effective. That probably means 250 to 300 aircraft, just to maintain standing patrols which the British admitted they would have had to use, to replace RADAR. They only had, in July 1940, 640 aircraft.

If a standing patrol is at the end of their fuel loads, and the German bombers appear, then they either have to head home or attack, and hope for help from alert squadrons. Combat eats up fuel quickly, so any standing patrol that attacks, must return to base after that to refuel and rearm. The British estimated that it would have take 1200 or more fighters to accomplish without RADAR. How do the British build and maintain but most of all, pilot 1200 fighters, let alone the cost in fuel and maintenance keeping the aircraft flying. This will require numerous spare parts, and spare aircraft. At the start, there were only 269 reserve aircraft. From the RAF prior to the battle: "There is general agreement that the principle of standing patrols is impracticable due to its wastefulness. To keep sufficient strength of fighters in the air to guard our shores from attack, would be beyond the powers of the biggest air force in the world"

Just for reference, in France during the Sitzkrieg, standing patrols were used by the Allies to cover the front.

What do you think?

[Warship NWS]

I think a good overall question for this discussion is what could the British do to compensate for lack of radars vs lack of radio communications with the planes? With one you lose your most effective, but not your only, method of early warning and with the other your command and control and a major portion of your on the spot intel from the pilots is lost - both in terms of recon and from the fighter groups.

Note: The British did have patrol and civilian craft that could have been used in the Channel for as ROC pickets.

This does make for a very interesting discussion.

Thanks.

[Warship NWS]

Radar and radio are force multipliers. The lack of either does not prevent any effective cap, it just makes it much harder. The human eye worked well in SOME circumstances and situations, and before the advent or radar and radio that had to be as good as it got (short of messages dropped from the planes).
Let's go back and address the core question: If you were going to pick one of the two things - radar or radio comms (air to air, air to ground) as being more important toward imcreasing the ability of CAP - which would it be?
Also - let's not focus on the pacific carrier ops - war had been going on for some time prior to that (Sept. 1939 - or if you want to count the China war - much earlier). Personally I think carrier CAP should be treated seporately from general fighter defense of a country or factory, etc.

The arenas that would be the most interesting to compare, IMHO, would be the following,

a) CVs operating in the Pacific.
b) CVs operating in the Atlantic and Med.
c) Battle of Britain
d) Bomber raids over Europe by the USAAF.
e) Night bomber raids by the RAF.
f) The aerial campaigns over Russia.
g) The aerial campaigns over Guadalcanal.

Thanks.

[Ed Rotondaro]

The primary command radio found in naval aircraft starting in 1940 was the ARA/ATA. This stood for assembly receiver airborne/assembly transmitter airborne. A command radio is designed for aircraft to aircraft use. The liaison radio is used to commicate with the base or carrier. Often, this dicotomy got a little blurred. A fighter would have one transmitter and one receiver, the control box and tuning dial, with gain control mounted on the right side of the cockpit. They were painted in black wrinkle paint. Most radios use a band switch to change rf bands, this radio used a different receiver and a different transmitter. The receivers went from 520 kilocycles up to 3 megacycles.

Specific sets- F4F-3 GF-4/5/8 transmitter/RU-7/5A/13 Four Channels
SBD-3 GP-4A/5/6 transmitter/ RU-10/11

The primary radio used from 1943 onward was the An/ARC-5. Same frequency range, later version in the war were VHF sets.

Note: Scary thing happened. I found the manuals and schematics. I could read the schematics and determine the gain in some areas. Boy am I old!

You engineer wannabee!:D

[old_pop2000]

One of most interesting fighter defenses was the defense of Guadalcanal from August 1942 to November 1942 when the Japanese finally left the island. Let's set the stage for this aerial dual.

The Japanese aircraft took off early in the morning from the two main airfields near Rabaul, Lakunai and Vunacanau. The flight was four hours, set to arrive over Henderson and Guadalcanal somewhere between 1130 to 1430 hours. They would be spotted almost immediately by two coastwatchers, Mason or Reed, on Bougainville. Their altitude, numbers and heading was passed immediately to Guadalcanal. They would be spotted again by Coastwatcher Kennedy on New Georgia, about 45 minutes away from Henderson Field.
All this information was passed and monitored on the northwest side of Guadalcanal by RAN officer Hugh MacKensie and four Marine radio operators. The information from the coastwatchers was passed by land line to Marine headquarters.

The second layer in this was the installation of a ground based air search SCR-270 which could detect incoming raids at up to 125 miles from its location at Henderson field, closer to Lunga Point. Additionally, two more radars were later off loaded.

Once the information from these two sources had reached the Pagoda on Henderson field, a Japanese Rising Sun flag would be raised on the flag pole, signifying a raid was incoming. Pilots would then be trucked to their planes and they would scramble. They usually had over 30 minutes warning, sufficient to gain a 5000 ft altitude over the incoming raid.

One problem for the Japanese was that the Zero's they were flying were the A6M3 Model 32. These had the clipped wings to allow for more control in a dive, greater ammunition supply, but more importantly, a larger engine in the Sakae. Unfortunately, the engine change dropped the range and now, they could barely make Guadalcanal, even with external fuel tanks. Things got so bad, the unreliable radios were removed to save weight.

Ground control from Guadalcanal was spotty due to the radios in the fighters, so it wasn't possible out beyond 50 miles. So, interception farther up the slot wasn't possible. Smith and Mangrum, the Marine fighter leaders, had to wait until the bombers were within 25 miles before interception.

Hope that sets the stage for our discussions.

[Warship NWS]

Radios, why were they important?

Let us take an example.. imagine playing a wargame and instead of FOW meaning you do not always know where the enemy is.. you also do not always know where your own forces are, their status, what they see, whether or not you can give them orders, and so on. The only other real option is runners/messengers on foot or in a vehicle, for air forces that obviously won't work. That was reality. Wargames show you where you units are at all times.. in naval battles this was usually possible depending on the visibility - most major warships are pretty big and water is pretty flat, although at night or limited visibility conditions that could change. However, land and air forces.. that is a different problem all together due to terrain/clouds, much smaller visible objects, aerial units move around MUCH faster, land units are NOT always in individual contact with HQ as they had a chain of command and if it was broken, for whatever reason, the communications would often be hindered,.. and so on.

Point being.. without GPS (which is the way it feels like when you play many wargames out there) what else do you have? For practical purposes, radios.. that was it. The side with the greatest situational awareness had a decided advantage in combat but THIS REQUIRED effective communications, not just methods of detection.

These are some of the factors that I think many take for granted. FOW was not only a problem for finding and fixing enemy forces but also for managing your own forces which relied heavily on communications.

Just some thoughts to consider.

Thanks.

[Warship NWS]

To Dennis,

It is interesting to think that no effective air defense was without its "visual" backups. IOW, coast watchers, observers, pickets, patrols, etc.. I think many forget this critical consideration as radar quite often was not used entirely on its own and that backups were almost always planned on or in use.

Thanks.

[Warship NWS]

Blitzkrieg.. just a small note, we had a long discussion about the critical elements of Blitzkrieg before the forums changed over. The airplane is what made it possible to have "combined arms" operations under the concept of Blitzkrieg.. however, that MOST critical element IMHO for such warfare was the radio .. that is what made combined arms warfare on land and in the air even possible at all as it was the thread that tied the fabric of the operations together.

Thanks.

[old_pop2000]

To Dennis,

It is interesting to think that no effective air defense was without its "visual" backups. IOW, coast watchers, observers, pickets, patrols, etc.. I think many forget this critical consideration as radar quite often was not used entirely on its own and that backups were almost always planned on or in use.

Thanks.
Possibly there are factors that required visual intervention.


Lack of rotating antennas to give 360 deg. coverage
Lack of accurate altitude determination
Lack of a PPI scan display to give instant range and bearing
Opponent aircraft moving over water or unfriendly territory
Defending aircraft had low climb rates requiring more advanced notice
Lack of range of radar

Comparison of Spitfire I and Spitfire XIV aircraft climb rates

Spitfire I - 0 altitude climb rate - 2810 ft/min
20,000 ft altitude climb rate-1840 ft/min

Spitfire XIV - 0 ft altitude climb rate - 5040 ft/min
20,000 ft altitude climb rate - 3550 ft/min

First aircraft will take 10,7 minutes to reach 20,000 ft, the second will require 4 minutes. I wonder if this makes a difference. ;)
[/LIST]

[Warship NWS]

Possibly there are factors that required visual intervention.

Lack of rotating antennas to give 360 deg. coverage
Lack of accurate altitude determination
Lack of a PPI scan display to give instant range and bearing
Opponent aircraft moving over water or unfriendly territory
Defending aircraft had low climb rates requiring more advanced notice
Lack of range of radar
Identification was a critical asset for the observers, not just friend or foe either.. but aircraft by type was sometimes required to determine priority of interception.

[old_pop2000]

Identification was a critical asset for the observers, not just friend or foe either.. but aircraft by type was sometimes required to determine priority of interception.
Just a couple of notes about the observers. They were frequently overwhelmed by large aircraft formations at different altitudes. This condition prevented them from visually identifying the high altitude aircraft and also impaired their ability to provide an accurate count to Biggin Hill or their sector station. They were very susceptible to bad weather especially fog and low clouds. Most of their work was given to them by the radar units. They would receive a sighting of unknown aircraft incoming and were told to ascertain height and numbers. It was an integrated effort. How effective such a system would have been without radar is problematic.

Another point about radar. It took RAF fighters 15 minutes from the time they received the scramble order to the time they reached their patrol altitudes. The radar gave them 20 minutes at max. advanced warning. With just observers or even picket ships, that figure would have dropped to less than 10 minutes. Therefore, British fighters would never have gotten off the ground and into a height advantage to attack the incoming bomber streams. This would require standing patrols and as presented in an earlier post, there were not enough fighters to adequately support such a system.

[old_pop2000]

In Group Captain Peter Townsand's book entitled "Duel of Eagles" he brings up this about the Observer Corp.


In August 1934, the RAF's air exercises showed up the weakness of the 'early warning system'. It depended on the eyes and the ears of the Observer Corps. The earliest they could plot hostile aircraft was when they came in sight or with earshot. The warning was too short for the defending fighters -- even when the 'hostiles' were Vickers Virginia bombers cruising at seventy-five m.p.h. and at seven thousand feet.

Six years later, the German bombers would be moving at 200 m.p.h. at 20,000 ft. That is over three times the speed and 2.5 times the altitude.

[Warship NWS]

There is no doubt in my mind at all that radar bought them one very valuable asset.. *time*. As you said, it was an integrated arrangement. How they might have attempted to compensate for loss of radar is one of the interesting questions to consider since it was very possible for the Germans to have severely disrupted their radar net or at the least portions of it. Would it however, have been harder to compensate for lack of radar or radio? Another interesting question would be.. could they compensate for lack of the ROC? A note, the bombers likely would not have been flying at 200mph with moderate bombloads, likely they would have been flying at around 160-180mph depending on the aircraft and bombload, but your point is well made. The only way they could have extended the visual detection range would have been to put out naval and aerial "pickets" or possibly hidden observers on the coast of France (not sure how possible that would have been - but the British were pretty crafty.)

Thanks.

[old_pop2000]

There is no doubt in my mind at all that radar bought them one very valuable asset.. *time*. As you said, it was an integrated arrangement. How they might have attempted to compensate for loss of radar is one of the interesting questions to consider since it was very possible for the Germans to have severely disrupted their radar net or at the least portions of it. Would it however, have been harder to compensate for lack of radar or radio? Another interesting question would be.. could they compensate for lack of the ROC? A note, the bombers likely would not have been flying at 200mph with moderate bombloads, likely they would have been flying at around 160-180mph depending on the aircraft and bombload, but your point is well made. The only way they could have extended the visual detection range would have been to put out naval and aerial "pickets" or possibly hidden observers on the coast of France (not sure how possible that would have been - but the British were pretty crafty.)

Thanks.
First, A Heinkel 111A with a 15 ton bombload could do around 205 m.p.h. at 16,000 ft. A DO-17 with a 9 ton bombload, could cruise at 13,000 ft@ 186 m.p.h. The Do 17 was used mostly as a reconnaissance bomber and night bomber. Ju-88 with a full bombload could economically cruise at well over 220 m.p.h.

I have been working on the use of submarine pickets about 10 to 15 miles off of the coast of England to ID German bombers. Problems are enormous. Weather, sea state are just two of them. Even 10 to 15 miles off the coast, a bomber formation traveling at 180 M.P.H. is traveling at 264 feet per second. They make that 10 miles in a conservative time estimate of 3.2 minutes. So, the submarine observers have 3.2 minutes to spot, count and derive a speed and estimated course on the aircraft before it crosses the coast. So, it essentially does not add any real time to the problem, even if the formation consisted of over 60 bombers. Another issue is German Radio direction finders and Sig intel stations on the coast will pickup that transmission and possibly start jamming them.

[Warship NWS]

First, A Heinkel 111A with a 15 ton bombload could do around 205 m.p.h. at 16,000 ft. A DO-17 with a 9 ton bombload, could cruise at 13,000 ft@ 186 m.p.h. The Do 17 was used mostly as a reconnaissance bomber and night bomber. Ju-88 with a full bombload could economically cruise at well over 220 m.p.h.

15 and 9 ton bomb loads? You do realize that is 30,000 and 18,000 lbs.. right? ;) Also is that their fuel efficient speed or max speed with bomb loads and does that include formation maintenance flying?



I have been working on the use of submarine pickets about 10 to 15 miles off of the coast of England to ID German bombers. Problems are enormous. Weather, sea state are just two of them. Even 10 to 15 miles off the coast, a bomber formation traveling at 180 M.P.H. is traveling at 264 feet per second. They make that 10 miles in a conservative time estimate of 3.2 minutes. So, the submarine observers have 3.2 minutes to spot, count and derive a speed and estimated course on the aircraft before it crosses the coast. So, it essentially does not add any real time to the problem, even if the formation consisted of over 60 bombers. Another issue is German Radio direction finders and Sig intel stations on the coast will pickup that transmission and possibly start jamming them.


Their likely most effective pickets would have been aerial recon 2 engined birds so as to save on the more effective Spitfires and Hurricanes for the air defense. You do bring up a good point though about the channel as the weather was usually pretty poor so you would need aircraft flying above it to see higher altitude raids. The other question is still open.. the use of observers on the French coast, not sure how well that would have worked and whether or not there was time to deploy and train them.

[old_pop2000]

Just to illustrate the meteorological problems facing the mark 1 eyeball observers:

July 10 - Shower in SE England and channel. Continuous rain

July 11 -Channel overcast. Cloud base 5000ft. Thunderstorms in the midlands

July 12- Mainly cloudy with early morning fog

July 13- Early morning fog clearly by mid-afternoon

July 16-18th- Occasional rain. Straits of Dover cloudy.

July 24th- Channel and Straits of Dover cloudy. Fog and Rain.

July 25th Fine day with haze in the straits

Over the next five days, if was cloudy every day but the 29th of July.

Second phase of battle- August 8th-23th

From 8th to 12th, two days of rain, two days of fine weather

Eagle Day- 13th of August- Fair with early morning drizzle and mist, some clouds over the channel.

It goes on like that for days, weeks and months.

Source: RAF daily reports

[old_pop2000]

15 and 9 ton bomb loads? You do realize that is 30,000 and 18,000 lbs.. right? ;) Also is that their fuel efficient speed or max speed with bomb loads and does that include formation maintenance flying?



Their likely most effective pickets would have been aerial recon 2 engined birds so as to save on the more effective Spitfires and Hurricanes for the air defense. You do bring up a good point though about the channel as the weather was usually pretty poor so you would need aircraft flying above it to see higher altitude raids. The other question is still open.. the use of observers on the French coast, not sure how well that would have worked and whether or not there was time to deploy and train them.
That is the fastest speed with full bombload and fuel, but is altitude dependent. Mixed formation of He-111A, Do-17 would normally fly at a rate of 150 m.p.h. However, a homogenous formation of He-111A's would fly as fast as was possible. Nevertheless, it still made escort for the Me-109's difficult.

Airborne picket aircaft are possible but waste fuel, men and are easily eliminated. They still have the same issues with weather. In fact, if their base is overcast, they are usually grounded.

[Warship NWS]

Stating the above means that aerial pickets of 2 engined aircraft, prefered, over the channel would be absolutely critical if radar was not available. This would answer why they relied on the radar for over the channel detection and ROC over land. Either that, or backup the forward airbases so as to allow as much warning as possible.

Ok.. we have addressed the need of the radar and how it would have been difficult to compensate for.. how about the radios in the planes?

Anyone else want to jump in here?

[old_pop2000]

Stating the above means that aerial pickets of 2 engined aircraft, prefered, over the channel would be absolutely critical if radar was not available. This would answer why they relied on the radar for over the channel detection and ROC over land. Either that, or backup the forward airbases so as to allow as much warning as possible.

Ok.. we have addressed the need of the radar and how it would have been difficult to compensate for.. how about the radios in the planes?

Anyone else want to jump in here?
Those weights are the gross takeoff weights for the aircraft. Sorry, I was reading without my glasses in my books. I should never do that.

[Warship NWS]

Hey Dennis, with all the foul weather it makes you wonder how many raids were rendered ineffective on that aspect alone. I wonder how many Luftwaffe crews were lost that ended up being wasted on obscured targets. That had to have been a critical challenge for them and why a fighter defense is at an advantage. If the bombers miss they can still lose men without any tactical gains as they have to transit to the target and back in jeapordy. It is no wonder the 8th AF over Europe had a rough time of it.. fight in and fight out.. and hope you did any good at all for the losses you take.

Just a side note for consideration. Having a 3 to 1 ratio in aircraft/pilots is not as great as many make it sound when one side has double the chances of losing men and machines with limited chances of any real tactical gains.

[old_pop2000]

I would expect a lot of raids came to nothing. Operational orders usually have alternate targets, now we know why. Pathfinders were a great help to the Allied bombers, they could radio back and give accurate weather reports to the bomber streams as the proceeded across France.

I am not certain the traditional 3:1 advantage of offense over defense holds for aerial warfare.

[john964]

There is no doubt in my mind at all that radar bought them one very valuable asset.. *time*. As you said, it was an integrated arrangement. How they might have attempted to compensate for loss of radar is one of the interesting questions to consider since it was very possible for the Germans to have severely disrupted their radar net or at the least portions of it. Would it however, have been harder to compensate for lack of radar or radio? Another interesting question would be.. could they compensate for lack of the ROC? A note, the bombers likely would not have been flying at 200mph with moderate bombloads, likely they would have been flying at around 160-180mph depending on the aircraft and bombload, but your point is well made. The only way they could have extended the visual detection range would have been to put out naval and aerial "pickets" or possibly hidden observers on the coast of France (not sure how possible that would have been - but the British were pretty crafty.)

Thanks.
I see several problems with getting hidden observers in France.
1)Getting close to airfields, there maybe security patrols about.
2)RDF nuf said.
3)Gestopo may send false messages.
4)Replaceing lost obsevers is going to be difficult at best, and there will be losses
5)Obsevers are going to have to move constantly to avoid capture, so airfield may not be under constant view.

[Warship NWS]

I see several problems with getting hidden observers in France.
1)Getting close to airfields, there maybe security patrols about.
2)RDF nuf said.
3)Gestopo may send false messages.
4)Replaceing lost obsevers is going to be difficult at best, and there will be losses
5)Obsevers are going to have to move constantly to avoid capture, so airfield may not be under constant view.

Note, I am talking about observers on the French coast, not next to the airfields as they would not have had time to make such arrangements feasible.

[Warship NWS]

I would expect a lot of raids came to nothing. Operational orders usually have alternate targets, now we know why. Pathfinders were a great help to the Allied bombers, they could radio back and give accurate weather reports to the bomber streams as the proceeded across France.

I am not certain the traditional 3:1 advantage of offense over defense holds for aerial warfare.

The ~3:1 ratio was describing the greater numbers of German aircraft. Ratios may not mean much with all else considered.. one of the reasons why this particular aerial campaign is such an interesting topic.

[john964]

Note, I am talking about observers on the French coast, not next to the airfields as they would not have had time to make such arrangements feasible.
Even on the coast or a little inland they would still run into things like beach and road patrols also check points. There effectivenss would be problimatic at best they would only be able to make short transmission to avoid RDF units looking for them and move contantly. And would they use morse code or voice to send there reports. Radios transmiters back then were big and heavy. Would they use encryption for there IMC or voice tranmission if so you would have the problem of time delay of encoding and decoding. Also how long do you think it take for the germans to figure out what was going on, and they would hunt down these units and whipe them out once they figured this out making it more and more difficult for these units to operate over time.

[Warship NWS]

There is no doubt that there would be challenges if the radars were not ready in time for the BoB. The main reason for looking at this in so much detail is for two reasons,

1) If the entire British air defense would have virtually collapsed without radar assistance then was the greatest blunder of the Germans the fact that they did not prioritize the radar net as the #1 target? They had radar of their own that was as good as, if not better, then the British sets. You would think this would clue them in as to its value in the aerial battlefield.

2) Did the British plan in any way for losing their radars? If so, what did they plan to do? This is a question I do not see answered with any real detail in various references even though it could have proven a very plausible scenario with just one change of targeting priorities. The most logical possibilities, based on what we have discussed so far, would have been aerial and naval visual pickets. Granted, they might be vulnerable to some degree.. what other choice would they have? At least there WAS something that could be done.. in regards to radios in the planes, there was no replacement that would have been feasible IMHO. So if either of these systesm failed would the BoB been a failure overall?

Note, this entire discussion is not really a matter of debating the components of a system but rather to develop a better understanding of the components and how they effected the entire system and what could have happened if individual components did not exist, were nuetralized, or did not operate effectively. I am directing this discussion more at the radars and radios in the planes intentionally for a reason -- they both greatly effected battlefield management. The problem is this.. not all military forces had radios in their planes, some of the ones that did use them did not have proper communications doctrines to use them effectively, and most of all not every military force had effective, and efficiently used, radars.

To contest the air in 1940+ it was not just a matter of the planes and pilots but also how well the aerial battlefield could be managed by those controlling the aerial forces.

Thanks.

[Ed Rotondaro]

There is no doubt that there would be challenges if the radars were not ready in time for the BoB. The main reason for looking at this in so much detail is for two reasons,

1) If the entire British air defense would have virtually collapsed without radar assistance then was the greatest blunder of the Germans the fact that they did not prioritize the radar net as the #1 target? They had radar of their own that was as good as, if not better, then the British sets. You would think this would clue them in as to its value in the aerial battlefield.

2) Did the British plan in any way for losing their radars? If so, what did they plan to do? This is a question I do not see answered with any real detail in various references even though it could have proven a very plausible scenario with just one change of targeting priorities. The most logical possibilities, based on what we have discussed so far, would have been aerial and naval visual pickets. Granted, they might be vulnerable to some degree.. what other choice would they have? At least there WAS something that could be done.. in regards to radios in the planes, there was no replacement that would have been feasible IMHO. So if either of these systesm failed would the BoB been a failure overall?

Note, this entire discussion is not really a matter of debating the components of a system but rather to develop a better understanding of the components and how they effected the entire system and what could have happened if individual components did not exist, were nuetralized, or did not operate effectively. I am directing this discussion more at the radars and radios in the planes intentionally for a reason -- they both greatly effected battlefield management. The problem is this.. not all military forces had radios in their planes, some of the ones that did use them did not have proper communications doctrines to use them effectively, and most of all not every military force had effective, and efficiently used, radars.

To contest the air in 1940+ it was not just a matter of the planes and pilots but also how well the aerial battlefield could be managed by those controlling the aerial forces.

Thanks.

Chris:

This is a good concept, managing the aerial battlefield and the aerial forces. The BoB was really the first chance for this to occur, since prior to this, the Luftwaffe was pretty much dominating the air. Finally we have an example of two modern large airforces with differing agendas fighting the world first true air campaign. A great deal of what the US employed was developed from Britain's experiences in those dark days of 1940. One sees similar problems and challenges during the Guadalcanal campaign and the air war over the Solomons. You have two fairly evenly matched opponents struggling to control the airstrips and the seas lanes by day. Then add in the factor of aircraft carriers and you can see how long range detection becomes vital for survival. The entire experience of the coast watchers shows how even without radar, you could still detect the enemy and give timely warnings, but only if you had a reliable radio!

[old_pop2000]

Modern integrated air defense was born with the Tizard Committee in England, after the 1934 tests proved that a system based on visual and auditory sensors was inadequate to provide warning in a timely manner. It was during this time period that Watson-Watt was asked to determine if radio waves could be used to shoot down aircraft, the answer was no, but could be used to detect. Radio detection and Ranging was born out of this.

However, an integrated air defense system(IAD) is more than the sensors, it is data communications. The accurate and timely dissemination of data throughout the system is absolutely vital to the proper functioning of any integrated air defense network. Every IAD will have certain basic functions, I will try to illustrate and briefly explain.

My purpose is to illustrate how each piece fits together and hopefully illuminate the importance of each function.

Function 1- Detection- Every IAD will have a sensor for the search and detection of incoming aircraft or missiles. The sensor must provide bearing, altitude, range to target, possible course and if possible number of unknown targets. It must also have the ability to differentiate between friendly and hostile aircraft (IFF). Possible sensors include radio detection and ranging and forward infrared. 360 degree coverage is important, but is not mandatory. The BMEWS and dew line system's were not 360 degree systems. It must also have functionality to reduce the effects of attempts to jam or block its detection.

Function 2- Acquistion - This is an oft forgotten function of an IAD system. The IAD must have a function that acquires the target into its system. Acquisition starts by the transmission of the detected hostile aircraft parameters to central authority whose responsibility is to filter this information, compare it with other sensors and designate this hostile in the system with a unique designation. This is an important step. All sections of the IAD must work with the same data, and with the same structure of that data.

Function 3- Track- This function can be performed manually using table information or vertical plexiglass maps or automatically displayed by the tracking computer. The target is now placed in a position amongst other targets, showing its track number, estimated altitude, course and speed. This is a visual cue to the human controllers. It provides them with a 3 dimensional picture of the battle space area with all hostile and friendly targets. It facilitates prioritization of all hostile targets for interception. It is at this point, that either a human or a computer makes the decision to intercept the hostile target.

Function 4- Ground Controlled Intercept -Based on the 3 dimensional information about the target or targets, intercept by friendly forces is effected. This can be a missile or in case of the BOB, a call to a nearby ready alert fighter base. Aircraft are scrambled based on availability and priority, given the hostile track number, altitude, estimated course and speed and intercept altitude. At this time, the friendly forces are designated in the system with a track number and displayed on the manual or automatic system. This provides the controller with a 3 dimensional view of friendly forces and their movement toward the hostile target. The final act is the confirmation of the intercept and destruction of the hostile target, along witht the removal from the system of the track information.

The absolute key to all of these functions is data communciations. This can be in the form of voice signals or digital data streams between the airborne computer and ground. The communication channels must be reliable, accurate in reproduction and difficult to jam. The communcations system must have multiple channels and established, rigorous procedures developed to maintain an accurate flow of information between functions. Loss of these information channels will essentially disable the system completely.

This is a very simplified view of the basic IAD system. Some functions can be accomplished within one functional area, data communications can be multiple voice and data. Friendly intercepting forces can be aircraft or missiles. But all the functions must be present to enable the system to perform its mission.

In discussing the requirements for Radar and radios, keep these functions in mind. Sorry for the length, this is a complicated subject. Those of you with experience in IAD, it would be nice to hear your thoughts and anecdotal information.:D