Wednesday, 25 January 2017

Air combat over Vietnam

As Exercise RED FLAG kicks off once again in the US, I thought this would be a good time to finally getting around to finishing an article I started over a year ago and have sporadically returned to at times since then. A primary reason for it taking so long was the research required, the extent of which will become evident shortly.

RED FLAG was introduced as a way of training American pilots - and later allied pilots as well - in the complexities of the modern air combat environment. It calls on the principle long understood (dating back as far as the first world war, but not always acted upon) that pilot survivability increases dramatically after they have successfully completed several missions*. The oft quoted number of missions is ten, but obviously the number will vary from pilot to pilot. Thus RED FLAG endeavours to put pilots through a number of simulated combat scenarios in order to better prepare them for frontline operations.

(*Please note that chances of survival eventually fall to virtually 0% if a pilot is continuously exposed to intense combat operations over a sufficiently long enough period. There is evidence that this dynamic appears to hold true in the naval and ground spheres as well).

It is often cited that programs like RED FLAG and the US Navy's "Topgun" Fighter Weapons School came about due to the poor performance of American pilots during Vietnam. Additional training was highlighted as one area of need by various reports into the matter and since then the legend of what took place over the skies of South East Asia has grown in its own right. In such cases I always find it highly instructive to bypass common accounts and histories, and try to dig up as much first hand source material as possible*. In that regard the USAF provided a gold mine; project RED BARON.

(*For those who are interested, compare and contrast the narrative accounts of American Civil War battles with the first hand accounts of the participants on the field)

RED BARON was the USAF's equivalent of the US Navy's Ault report; an investigation into the causes of poor kill/death ratios by American pilots over Vietnam. RED BARON ended up being published in three volumes, each close to 500 pages long. This is why this article has taken a while to move from concept to finished product! On the plus side the reports share similarities with comic books and The Sun newspaper, in that many of the pages are just pictures, or in this case diagrams of the unfolding air battles.

But the report is also heavy on information, particularly the performance of the equipment and of most value, comments by the aircrews themselves. The report looked a vast array of incidents involving contact between air force and navy aircraft with those of the enemy, from F-4 Phantoms and F-8 Crusaders, to the F-105 and A-4 ground attackers, and even the odd incident involving aircraft providing electronic warfare support. These incidents range from full on air combat to simple sightings of the enemy with no engagement. Each engagement is briefly summarised, followed by a full narrative where appropriate, pieced together from interviews with the aircrews themselves.

And as I got further and further into the report, I noticed that the developing themes clashed with what I had always expected to read based on what you might call the mainstream narrative of the air war over Vietnam. As such I think the best way to proceed is to pose to you a question, then go through some of the answers in a little more detail. 

So, on that note: which of the following statements do you believe to be true based on what you have read/heard/seen on the subject of US performance in the air combats over Vietnam?

1) American pilots were not adequately trained in ACM and tactics, and thus performed poorly,
2) American pilots were poorly trained in the employment of their missiles leading to many errors,
3) The rules of engagement requiring positive visual identification of a hostile aircraft nullified the range advantage of the Sparrow missile,
4) American missiles suffered from poor reliability, 
5) The F-4 Phantom was in general a poor dogfighter,
6) The F-4 Phantom was in dire need of a gun for close in work,
7) The combat experience of the US highlighted the benefits and need for a smaller, more agile fighter, 

Prior to reading the RED BARON report I would have suggested that all seven statements above were true, as I suspect most of you reading this will. In actual fact only statements two, three and four appear to hold complete merit.

Statement two (American pilots were poorly trained in the employment of their missiles leading to many errors) seems to have been an almost universal problem. Many pilots reported going into the theatre having never fired a missile in training. Some had seen a missile fired in training, but by somebody else. Some had fired one, maybe two "Sparrow" medium range, radar guided weapons in training, and one, sometimes two "Sidewinder", short range, heat seeking weapons. A handful of crew had fired more.

As such American pilots by and large, both naval and air force, went into combat with an inadequate understanding of the capabilities and limitations of their missiles, which frequently resulted in missile shots being taken "out of envelope", or in other words at times and under conditions where the missile had little if any chance of actually hitting the target. A small caveat should be inserted here, noting that in some cases pilots deliberately fired missiles without a lock knowing full well they would miss as an improvised measure for distracting enemies on a friendly's tail and forcing evasive manoeuvres.

This problem was exacerbated by the limitations of the missiles performance. Both the Sparrow and Sidewinder had relatively long minimum engagement distances and could not be used inside of these. Though the Sparrow missile could be used in "boresight" mode to engage targets directly in front of the launch platform, it was not especially well suited to close quarters engagement. The Sidewinder missile was more practical and more useful, but also suffered from problems with the limited cone of vision of its seeker head and problems handling high-G turning targets.

This was not nearly as much of a problem however as statement four (American missiles suffered from poor reliability) which was far and away the biggest issue faced by American pilots. In some engagements pilots found that as many as five or six of their missiles were simply not operational due to various faults. The three most common problems were; a failure to track the target in flight, especially by the Sidewinder missiles, a failure to launch off the rail (common to both missiles, but more of a problem for the Sparrow) and failure of the missiles motor to ignite after release from the aircraft (almost exclusively a problem with the Sparrow). 

Numerous engagements were turned from what should have been a steam roller victory for the US into a stalemate with no kills scored due to multiple weapons failures. Now again we have to caveat this a little by remembering the lack of training in missile use that many pilots complained about, which undoubtedly contributed to many of the failures to track (particularly by Sidewinders) as the missiles were released outside of their operating parameters. But this does not exempt the weapons themselves from their role in the poor K:D numbers.

It's at this point that we have to bridge the issue of the Ault report, conducted by the US Navy. It's finding led directly to the creation of the "Topgun" Fighter Weapons school which is often credited with turning around the path of the air war and putting the US back on the road to success in air combat. The somewhat less sexy and less well noted effect of the Ault report was to identify many of the main causes of failures in the various missiles and to help the navy and air force to take corrective measures to prevent such failures in the future.

One of the biggest issues raised was simply the amount of wear and tear the missiles themselves were undergoing. Often starting at sea level, the missiles were first subjected to conditions of high heat and humidity. Once the aircraft were aloft and climbed to cruising altitude, the missiles were now subjected to freezing temperatures for several hours, only to be returned to the high heat and humidity on landing. For missiles carried by naval aircraft there was the added problem caused by the large accelerations and decelerations that occurred during the catapult assisted takeoffs and arrested landings.

These problems were not insurmountable by any means and the missiles had been designed with such issues in mind. However it was found that missiles were frequently subjected to multiple cycles due to a lack of rotation. The same missiles would often be sent out on mission after mission until they were finally expended in combat, while fresh ordnance was kept untouched until required for replacement. 

Thus one of the most important changes that occurred as a result of the Ault report was essentially an administrative one. Missiles were now taken off the aircraft after landing, inspected for damage and tested for functionality, then returned to the stock and placed at the back of the proverbial queue to be used again at a later date, while fresh ordnance was drawn out, inspected and tested, then fitted to the aircraft for its next mission. The reality is that this one simple procedural change probably had the greatest impact on improving US performance in air combat, simply by reducing the number of weapon failures that occurred.

Statement three (The rules of engagement requiring positive visual identification of a hostile aircraft nulified the range advantage of the Sparrow missile) was unquestionably true and was enacted for good reason. Many pilots found themselves being vectored to intercept enemy aircraft, only to discover on arrival and with closer inspection that the potential MiG was in fact a friendly aircraft. The pilots comments throughout RED BARON are littered with calls for an Identification Friend or Foe (IFF) system that would have permitted friendly aircraft to detect each other, and more importantly allowed aircraft such as the F-4 to engage the enemy at much greater distances with a higher degree of confidence that the aircraft they were shooting at did indeed belong to the enemy. The absurdity of this situation is highlighted by the fact that reasonable quality IFF systems were in use during the second world war. 

Statement one (American pilots were not adequately trained in ACM and tactics, and thus performed poorly) is partially true, but the extent of the problem has been GREATLY over stated. Many pilots noted that they felt they had received insufficient Air Combat Manoeuvre (ACM) training prior to deployment, which some felt had hampered their chances of scoring a kill and led some to believe they would have responded differently given a second run at a particular engagement.

That said, the American pilots appear to have performed admirably under fire. Many of those who felt under trained actually demonstrated a good knowledge and application of what we would now recognise as common staples of ACM, such as using barrel rolls and high yo-yos to prevent themselves overshooting their targets and achieving better positions for an attack. In general the US pilots made good use of the strengths of their aircraft and frequently reversed highly unfavourable opening situations into good opportunities for a kill, of which they scored many, and as we have seen earlier would have had more if it hadn't been for various technical failures.

Overall I get the impression that while pilots certainly had a legitimate gripe about the amount of training they received, history has done a very poor service to these men and their achievements. Yes, the enemy they were fighting were generally rated as not that competent and often used very rigid tactical approaches*, but the American crews did a superb job in the face of a confluence of problems and deserve a great deal of respect for their fighting prowess and the results they garnered.

(*As a side note, the North Vietnamese did develop two quite clever approaches early in the campaign, and adapted a third later on. The first was as militarily effective as it was ingeniously simple and involved demonstrating openly for an attack against a package of strike aircraft such as F-105 Thunderchiefs, forcing them to jettison their unarmed ordnance and prepare for combat. At this point the MiGs would often simply fly off having achieved their primary objective of preventing the strike aircraft from hitting their targets! 

The second was less successful and involved trying to lure American pilots into a dogfight before breaking off towards heavy SAM concentrations with the intent of luring pursuing aircraft onto the missiles. The third was a later response to the increasing effectiveness of US fighters and involved a switch to "hit and run" tactics, using a single high speed pass to engage an unsuspecting target before roaring off into the distance with no attempt made to engage in a prolonged battle).

All this leads us nicely to statement five (The F-4 Phantom was in general a poor dogfighter) which is one of the oddest conclusions to have come from the war, especially in light of the pilots comments and the results they achieved. 

Most of those F-4s that were downed in air combat were hit during the initial springing of an enemy ambush. Once the fight evolved into what is commonly accepted as a "dogfight", the Phantoms and their pilots proved more than a match for the enemy, largely due to the immense power of the Phantom's engines. While the Phantom lacked the ability to sustain a turnfight with aircraft like the MiG-17, it absolutely ruled the roost in vertical manoeuvres and straight line speed.

The latter advantage proved to be the most useful and echoed back to the traits of second world war fighters such as the P-51 Mustang and the original F-4, the Corsair, as Phantom pilots discovered that like their predecessors they could use their excess speed advantage to disengage from any fight that didn't favour them virtually at will, using the separation gained to either return safely to base or (fuel permitting) to reposition themselves and return to re-engage the enemy under more favourable circumstances. 

This ability almost cannot be over stated. It's best parallel would be that of the old naval tactic during the age of sail of "holding the weather gauge" (being upwind of the enemy), which afforded the ship or ships in possession of it virtually complete control over the terms of an engagement, deciding when, where and even if at all to give battle, with the enemies only options being either to try and run away or to accept battle when offered by the attacking party (which would almost certainly be under conditions that favoured the attacker).

Pilots had their minor gripes about the plane, desiring a future aircraft to have slightly better roll rate and better turning ability if possible in order to capitalise on their advantages, but on no account was this to be achieved to the detriment of the aircraft's speed and vertical ability. Pilots also seemed adamant that the single most important feature was the twin engines, which not only contributed to the immense power of the aircraft relative to the enemy, but also provided an added level of safety and redundancy when operating over enemy territory and at sea. The second and third most important features will be discussed later. 

All in all there seems to be absolutely no evidence whatsoever to support the notion that the F-4 was somehow out of its depth going up against the various types of MiG. Although the F-4 was not really a dogfighter per se, designed more for the rapid acceleration and climb rate necessary in an interceptor, in close combat the F-4 proved to "have it where it matters", contrary to all previous assertions I had ever heard on the matter before actually reading the reality of what transpired.

Now you're probably thinking at this point that either the second or third most important desired feature mentioned above would refer to statement six (The F-4 Phantom was in dire need of a gun for close in work). It's one of the most common statements you hear about the deficiency of the F-4 in Vietnam. And you'd be wrong.

Those pilots who brought up the subject of a gun in their comments generally fell into one of three camps. The first camp were those that felt a gun - either internal or external - would improve the capability of the aircraft. Many of them had encountered the problem of either getting on the enemies tail or else engaging the enemy in a head on pass and being unable to use the Sidewinder due to the range being too close and thus inside the minimum engagement distance of the missile. Granted I didn't think to jot down all the occurrences, but the desire for a gun seemed to be most prevalent among those pilots who had also complained about a lack of ACM training prior to deployment and who failed to score a kill during their engagement due to missile failures.

The second camp felt that a gun could be a useful option, but only if it met certain criteria such as being internally mounted, didn't use any of the space currently used for fuel and, most commonly, that it didn't interfere with the operation of the radar or the number of missiles carried. Many of these pilots suggested an equal or superior measure would be simply to develop a short range missile that was more reliable, had a wider field of view for its seeker head, better capabilities under high-G forces, and most importantly a shorter minimum engagement range. 

The third camp took quite the opposite view on having a gun, and it's worth noting that many of these pilots were more experienced fighter pilots, some former instructors, and many successfully achieved kills over Vietnam using missile systems. They felt that a gun was actually a bad idea on the premise that it would simply encourage pilots - especially inexperienced ones - to do something stupid like trying to turn fight a MiG in pursuit of a lead gun solution. They too offered up what they thought to be a better alternative of simply having a more reliable and more capable short range missile.

It's worth noting here the opinions of F-8 and F-105 pilots for comparison. Both aircraft types carried cannons internally, and the F-8 also routinely carried the AIM-9 Sidewinder as you would expect from a fighter. Neither aircraft was fitted with a proper search radar like the F-4 and as such even the F-8 was unable to use the Sparrow missile. Pilots of these aircraft were almost exclusively in favour of having a gun on a future fighter, which is surprising to some degree given the even poorer performance of guns than missiles.

It was almost guaranteed for example that the guns on the F-8 would jam after firing more than about 25 rounds. Engagements with the gun tended to be unsuccessful for the most part as the high speeds at which combat was now occurring made calculating lead a difficult task even for radar range finders, a problem that was made worse due to frequent technical problems with the F-8's sight under high-G loadings. Even when hits were scored, aircraft seemed decently resilient to the damage, often able to at least escape the fight even if they were unable to continue it. 

Overall then it seems that while many pilots agreed that a gun would be advantageous in any future fighter, there are a number of serious caveats that went with that, as well as some very experienced dissenting opinions. On balance it would seem that having an internal gun would be a step in the right direction, but the absence of one such as on the Typhoon might not be quite the critical flaw that some believe, and the first hand evidence of the fighting certainly paints a differing picture about the issue of guns on the F-4 compared to the generally accepted narrative that we always hear about.

And that leads us nicely to the final statement, statement seven (The combat experience of the US highlighted the benefits and need for a smaller, more agile fighter). This is often understood to mean the F-16 for the USAF and the F-18 for the US Navy. In particular though the F-16 is cited as being essentially the blueprint of what was desired following the combat experience in the skies over Vietnam. I know, because I used to tell people this to.

Dipping into the detail and in particular reading those pilot comments it quickly becomes obvious however that the F-16 was anything but what the pilots wanted. While it did possess a number of desirable features, it was fundamentally in opposition to a lot of the stated factors that combat experienced crews wanted in their aircraft. As we've already seen, the desire for a powerful twin engined aircraft was high on the list of requirements as it provided pilots with their most advantageous weapon by far; control of the engagement. What other factors though were considered important? Again, I didn't think at the time to record them all for scoring purposes, but here is the order that generally seemed to stand out.

The second most important factor after having two engines with an excess of power seems to have been having two crew. Time after time pilots commented on how valuable the second crew member was, especially in night operations. The second crew member not only provided a second set of eyes to watch for enemy fighters and SAMs, but could also reduce the pilots workload significantly by taking control of navigation, operating the radar and watching the aircraft's six during an engagement, or alternatively tracking friendlies and even targets while the pilot had his head briefly down in the cockpit for some reason. 

There was a small debate about the nature of the back seater. At the time of Vietnam the back seater was also a qualified pilot and some front seaters thought this was useful during an engagement, having a second set of very similar thinking eyes backing them up. Some also commented that this was a good place for a pilot to start and gain experience over time without being leaned on too hard under the pressure of combat (in a sense similar to the second world war practice of German tank crew starting as loaders).

The consensus though, and it was by a country mile, was that the back seat operator should be a specialist position for a non-pilot. It was felt by most that the man in the back was often more concerned with getting himself a spot in the front than he was in learning how to use all of his systems effectively. Generally it seems to be agreed that a dedicated back seat operator would have been more use to the pilot in general and would have done a better job lowering the work load.

The third most important factor desired in a new fighter design might surprise you, but it seems to have been a fairly common desire even across a variety of platforms, and that was for improved "switchology". In other words, pilots wanted far less steps between different actions such as taking missiles from a safe to an armed state. This appears to have been a huge problem in the F-105 (admittedly a ground attacker) as the transition from air-to-ground mode to air-to-air mode required three different switch changes, all of which often had to be performed in the middle of a dogfight. Pilots generally desired a much simpler, single switch system to access various critical functions, something which is now prevalent on more modern aircraft such as the new F-35.

Fourth, and very apt given talk of the F-35, was for a move away from multi-mission aircraft. Pilots cited two reasons, generally together, for this proposal. The first was optimisation of the airframe for a given mission type. It was felt that in order to succeed at a mission the aircraft ought to be tailored in design for it. The second, which provided support for the first, was that pilots felt there was insufficient training time available to truly become an expert in more than one mission set. This was echoed to some degree by the British experience over Libya in 2011, as Typhoon crews were reported to lack the necessary training to carry out air-to-ground missions despite the aircraft being capable of such.

Fifth and six were possibly a tie, and that was for greater endurance and greater visibility. Pilots frequently complained that having disengaged themselves from a "hassle" with the enemy and acquired a more favourable position from which to re-engage, they instead were forced to recover back to base due to low fuel. Pilots also disliked the limited view to the rear of the aircraft due to the canopy arrangement and the constriction caused by the safety harness, again a remarkable complaint given that pilots had expressed the same concerns during the second world war, which was ultimately fixed then (as now) with the use of bubble canopies.

Finally, clocking in at seventh place, some pilots were concerned with the ability of the F-4 to decelerate when needed in order to avoid over shooting. Many pilots found they had to use techniques like the barrel role in combination with moving the throttle to idle to avoid closing too much on the enemy, and even then often encountered difficulty in maintaining sufficient safe distance to permit a missile shot. Although not explicitly stated, an airbrake and combat flaps could be used to some degree to help with this problem.

One major issue for aircrews that seemed to plague everyone, although one that had nothing to do with any of the specific aircraft themselves, was communications. More specifically the saturation of communications channels at critical moments, which frequently prevented pilots from communicating warnings to one another or passing instructions to help manage a fight, and is included for completeness.

So, if not the F-16, did any aircraft come close to meeting all these criteria? Well one good candidate is the F-15, originally designed and built by McDonnell Douglas, who as it happens designed and built the F-4. Though the final requirements for the F-15 were prompted by something of a panic over the emergence of the Russian MiG-25, the F-15 incorporated virtually all the issues raised by pilots with combat experience over Vietnam. 

Twin engined, with an exceptional amount of power, speed and quite stunning vertical performance, a powerful radar for medium range missile engagements, an internal gun to supplement its short range missile armament, improved roll rate, better turning capability in the dogfight, less demanding "switchology", a design philosophy that was allegedly summed up with the phrase "not a pound for air to ground" (a phrase that was later somewhat undermined when the F-15E Strike Eagle was developed for the air-to-ground mission!), greater fuel capacity for increased endurance, a canopy designed to give the pilot virtually unrestricted vision in all directions, and of course an airbrake and combat flaps. The only criteria it failed to meet was to be a two seater.

And how has it fared? To date the F-15 holds a record in air-to-air combat of 104 kills with zero losses. Not bad I would say.

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