Tag Archives: aircraft

Choosing a Jet Trainer

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While not glamorous, jet trainers are an important part of an air force’s inventory. And with the US Air Force looking for a replacement for its venerable T-38s, I thought I might do likewise. As always, we’re looking for something off the shelf, which is doubly important for a trainer. A trainer’s most important evaluation criterion is cost; it should be cheap to buy and cheap to operate. It should, however, have a reasonably sophisticated cockpit so students can start learning on the sorts of instruments they’ll see on your front line fighters, as this will reduce training time there.

Cost is always a hard thing for the armchair strategist to analyze, however recently Poland sought a new trainer. Looking at their tender, we can get an excellent idea of relative costs, since Poland makes none of the three leading contenders. They compared the current model of BAE’s Hawk trainer, Alenia’s M-346, and Korean Aerospace’s T-50. All three are new-build aircraft, complete with modern comforts like glass cockpits. Costs for the bid (for a fixed initial number of aircraft) broke down as follows: M-346: 1.168 billion złoty, Hawk: 1.754 billion złoty, and T-50: 1.803 billion złoty. The M-346 won in Poland. It has also won a similar comparison in Singapore, but I don’t have their competitive bids to examine.

We might next ask if we ask anything more of our trainer. Some smaller air forces have trainers that are tasked to also be light attack aircraft. Were this the case, like any other tender we’d start discussing payload and compatible weapons fit. However, since we do not have such a role in mind for our trainer, we do not need to make such comparisons.

Since the M-346 is our lowest-cost option that meets our capability requirements, the M-346 is our choice.

Retro Air Force Procurement II: Lightweight Fighter Edition

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It’s time for another classic showdown. Let’s look at two competing lightweight fighters. Specifically, the F-16 Viper and the F/A-18 Hornet. We’re going to keep this fair, so we’re generally looking at older Vipers, from back when both were in production. For a mid 90s procurement challenge, we’re going to have the F/A-18C/D Hornets go up against the F-16C/D Block 50/52 Vipers.

The F-16 was the fighter that (re)popularized the light fighter concept. It’s relatively small, has one engine, and a reasonable amount of capability. For a western fighter, it’s pretty cheap too. One engine means that the maintenance and support costs are going to be lower. Plus, it’s engine is common with that of the F-15, which is awesome if you operate the bigger type. It has possibly the most cockpit visibility ever. It can do any mission you please. It’s great.

The F/A-18 Hornet brings something a little different to the table. It’s got two engines, a navy-grade undercarriage, and some really fancy avionics for the time. The Hornet was small and advanced, but it cost more both to buy and to maintain. It’s also multirole, and was the first aircraft to shoot down enemy aircraft with missiles and complete a bombing mission on the same sortie in the Persian Gulf War. It’s also got great cockpit visibility.

So let’s break this down:

  • Cost: Viper. Duh. Viper is cheaper to buy, cheaper to fly. Has just the one engine. And it’s the same engine used in the F-15, which is a big bonus if you also operate Eagles, because then you don’t need to add another engine’s parts to the support list. And we do operate Eagles.

Looking at FY98 prices for both (using total program cost for each, because that’s what I happened to find), Vipers will run $26.9M and Hornets will run $39.5M.

  • Cockpit Systems: Hornet. The Hornet has three displays compared to the Viper’s two, and they’re bigger displays at that. The Hornet can run a moving map display too, which is really cool.

  • Engine Power: Viper. Even though it only has one engine compared to the Hornet’s two, the Viper has a lot more thrust, and a pilot can use this thrust to get out of trouble. Or take off quickly.

  • Low-Speed Handling: Hornet. The Hornet is a fantastically high-alpha jet. It performs well at low speeds and high angles of attack, so it’s a great turning dogfighter.

These two previous points mean that while the two aircraft fight very differently, they’re both very capable machines. Practical dogfight capability is a draw.

  • Targeting Pods: Viper. Both aircraft have access to the full range of NATO FLIR targeting pods like LITENING, which use infrared-spectrum cameras and lasers to identify targets. However, the Viper can also mount the ASQ-213 HARM Targeting System pod, which allows for identification of type, bearing, and most importantly range of enemy radars. Accurate range data allows the AGM-88 HARM to be used more effectively.

  • Weapons Fit: Tie. Both aircraft can operate a wide variety of ordinance, with no significant differences between the two.

  • Jamming Systems: Tie. Mostly because both can mount modern ECM pod options, and those are a pain to compare with unclassified data. So we’ll call it a wash.

  • Towed Decoys: Viper. The Viper can be equipped with the ALE-50 towed decoy system. While the bigger Super Hornet can also be so equipped, the standard Hornet cannot.

  • Naval Capability: Hornet. If you want to operate your fighters off of carriers, the Hornet is CATOBAR capable and the Viper isn’t.

  • Twin Engines: Hornet. Lots of Hornet export customers like the twin-engine reliability, since they have big, foreboding, sparsely-populated regions. Like with Naval capability, if this is important to you, the Hornet gains points.

  • Radar Range, Track Fighters: Viper. Based on totally shady open-source materials, I’ve found the maximum radar range to track a small fighter to be 80 km for the Block 50/52 Viper (with the APG-68(V)7 radar) and 72 km for the F/A-18C Hornet.

  • Radar Range, Track Bombers: Hornet. The same source gives the F/A-18C Hornet a maximum radar range to track bombers to be 150 km and the Block 50/52 Viper with APG-68(V)7 radar a maximum tracking range of 140 km.

  • Recon: Hornet. The Viper requires a camera pod for reconnaissance missions. The Hornet can replace the gun and ammo package with a reconnaissance camera package,

  • Pending Upgrades: Viper. In the above, I’ve compared what was flying in 1998 for both aircraft. However, both Greece and Israel were looking to buy some Vipers, and a number of improvements were offered. Specifically, the Apg-68(V)9 radar and removable conformal fuel tanks were available for F-16s ordered in 1998, and both of these features were purchased by the Israelis.

Okay, so where do we come down for Borgundy? We’re going to go with the Viper. The Viper provides excellent multirole capability while also being relatively low cost to purchase and operate. As a bonus, it can have common engines with our Eagle/Strike Eagle fleet. In the late 90s, the Viper is not only super popular in the export market, but it also continued to see development. It does a good enough job at everything we’d like it to do, while also being cheaper than the competition. It’s superior SEAD functionality is a bonus, as we take that mission seriously.

Note that while I picked 1998 as the year for this, mostly because I had price data for that year, the conclusion is similar for other Hornet/Viper matchups of similar vintage. The key differentiators that would push for a Hornet buy are naval aviation (or a naval/land common fighter project) or large remote spaces that would lead to a favoring of a twin-engine design. Neither of which applies for Borgundy, unless the United States wanted to sell one of their (likely conventional powered) carriers to us as well.

Harrier II short takeoff roll reference table

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I was looking for this information as part of my still-forthcoming Harrier blog post, and couldn’t find it anywhere. So, here it is: a quick table of Harrier II short takeoff rolls by gross weight and headwind, assuming the Pegasus -408/11-61 engine, standard temperature and pressure (15 degrees Celsius, 29.92″Hg), and 0% datum hover performance.

Gross WeightTakeoff Roll (no wind)Takeoff Roll (20kt headwind)
20000 lb400 ft.275 ft.
22000 lb450 ft.325 ft.
24000 lb550 ft.375 ft.
26000 lb725 ft.500 ft.
28000 lb1025 ft.750 ft.
30000 lb1350 ft.1000 ft.

Sources and Charts

These numbers come from the Harrier II NFM-400 manual. Please don’t share the download link off-site; it’s a fairly large PDF, and we’re pretty shoe-string budget-wise.

The relevant charts are reproduced below.

hover chart

To use the hover capability chart, enter from the bottom, beneath the JPT half of the chart, from the appropriate ambient air temperature. Move up to the 0-degree datum line. Then, enter the chart from the bottom, beneath the RPM half of the chart, from the ambient air temperature. Move up to the RPM limit line. From the lower of the two intersections, move right to the hover performance 0% datum line without following the adjustment guidelines.

The JPTL adjustment values are maintenance-provided and outside the scope of my table. To use them, move up to them rather than to the 0-degree datum line. The hover adjustment guidelines are also out of scope. To use them, after moving right to the 0% datum, follow the guidelines up or down.

For 15C, neither JPT or RPM limits performance. Move across the chart to the 0% hover performance datum and read from there: 21,000 lb.

rotation chart

To use the nozzle rotation airspeed chart, enter from the left using the corrected hover value from the hover chart. Move straight across to the 29.92″Hg datum. Move parallel to the guidelines to the ambient pressure.

From there, move straight across to the takeoff gross weight. Stop at the intersection, move directly downward, and read the nozzle rotation airspeed off the bottom of the chart.

For a 22,000lb gross weight, start at 21,000lb, the corrected hover weight, and move across to the 29.92″Hg datum. Since the pressure is 29.92″Hg, continue moving directly across to the 22,000lb gross weight line. At the intersection, move down the chart to find the nozzle rotation airspeed of about 63 knots.

takeoff chart

To use the takeoff chart, enter from the top left using the nozzle rotation airspeed calculated before. Move horizontally to the 29.92″Hg datum, then move parallel to the pressure guidelines to the ambient pressure. Move horizontally to the start of the temperature guidelines, then parallel the temperature guidelines to the ambient temperature. From there, move horizontally to the curved line to the right. At the intersection, move down to the zero-wind line at the top of the ground roll chart to find the 0-knot takeoff roll. Follow the solid line down the chart to the appropriate line to find the headwind takeoff roll.

To continue the example, enter the chart at 63 knots and move to the pressure baseline at 29.92″Hg. Move horizontally left to the start of the temperature guidelines, and parallel them to the 15C baseline, at about 66 or 67 knots. Move horizontally to the reflector line, then move vertically to find the takeoff roll of roughly 450 feet. Parallel the solid headwind guidelines down to a 20-knot wind to find the headwind takeoff roll of about 325 feet.

Brief Comments

Experience with DCS Harrier suggests that these numbers include a good deal of margin. I have no trouble getting off the Tarawa deck with at least 200 feet to spare, even at loads north of 30,000 pounds. These are, however, the by-the-book numbers.

CAS Aircraft Revisited

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I’ve spoken before about CAS-specialist aircraft. I’ve spent a lot of time with the virtual A-10 in DCS, and I’m a big fan of the aircraft. In my heart, I love that gun. But the heart can make us do stupid things. We can’t always trust it. Similarly, the A-10 has saved the bacon of a great many American soldiers in combat. They adore the Warthog, and rightfully so. But they would adore any aircraft that saved them.

We want to know whether or not the Dedicated CAS aircraft is a good buy. Keeping it simple, we’ll compare it to buying more multirole aircraft instead. In USAF terms, A-10s or F-16s. Given that this is 2017, and we have combat data on both, is it worth it to put money towards maintaining the A-10 fleet, or should that money be switched over to the F-16s and F-35s?

The close air support mission is a peculiar one, and one full of contradictory requirements. The A-10 seems tailor-made for the mission, with plenty of armor and a massively powerful gun. It’s optimized for flying low and slow, and this kind of flight profile maximizes the utility of the gun and the ability of the pilot to see things.

That sort of flight profile make a number of assumptions:

  1. Local air superiority has been achieved and can be assumed
  2. Enemy air defense is extremely limited in number
  3. Enemy air defense is gun based or nonexistent

In a conventional shooting war, or even a low-intensity conflict with a sophisticated adversary, we don’t get to assume these are true.1 In a COIN conflict, we get (1) and (2) but we may not have (3). The enemy may have access to MANPADS like Stinger or Igla. As seen in the Soviet experience in Afghanistan, this forces aircraft to medium altitudes, i.e. out of the gun envelope.

Let’s look at the combat record. The A-10 has seen combat in Gulf War I as well as providing close air support as part of US military operations in Iraq and Afghanistan. The first Gulf War is as close as we get to seeing the A-10 in a conventional war. The A-10 was not sent in against the Iraqi SAM systems. But it did see plenty of use against troops of both the Iraqi Army as well as against those of the Republican Guard. The Republican Guard was better equipped and better disciplined than the conscript regular army. The Republican Guard did not have much in the way of MANPADS or other short-range SAM systems, but they fought back with guns. Many A-10s sustained combat damage, and two were lost on February 15, which caused A-10s to be tasked to other targets. While the A-10’s armor usually allowed it to make it back to base, the A-10’s lack of speed was identified as a deficiency that made it more vulnerable to gun hits.

The primary tank-killer for the A-10 in the Persian Gulf was the IR-guided Maverick, not the GAU-8/A. Of course, other aircraft can also carry these Mavericks, and these other aircraft also racked up a respectable tally of destroyed tanks with the AGM-65s. The A-10A had very little provision for precision-guided ordnance2, and so did not use laser guided bombs to “plink” tanks, unlike the F-111. Again it doesn’t take a purpose-built aircraft to carry precision ordnance, and these can be delivered from medium altitude, away from AAA and MANPADS.

Lots of aircraft have done CAS duty in Afghanistan, including of course, the A-10. Again, the big star weapon hasn’t been the gun. It’s the JDAM, which are GPS guided. Also using the JDAM to excellent close air support effect are the B-1B and the B-52H. And many others too, but I’m highlighting heavy bombers because they’re big, high-altitude behemoths that aren’t really “designed” with CAS in mind. But they can do it with modern weapons. As can F-16s, F-15Es, F/A-18C/Ds, F/A-18E/Fs, and just about every other multirole tactical aircraft you care to name. Tactical aircraft give up the giant gun and the armor plate. But there’s a net gain in survivability from more speed because they can evade missiles better, and they can perform the vast majority of modern CAS missions just as well as a purpose built type.

For COIN, one might be tempted to look for savings in aircraft types. These can be provided from UCAVs like the MQ-9 Reaper or from something like a Super Tucano. Both of these will provide more sorties per dollar than the sort of big armored CAS-optimized plane. And if there’s negligible threat, they’ll drop precision guided munitions just as well.

Against a hypothetical, sophisticated opponent with modern integrated air defense systems, all of the above will all require large strike packages to approach any kind of reasonable survivability level, and those aren’t feasible for CAS. Maximum survivability is provided by aircraft with low-observability characteristics, such as the F-35 or F-22. In Desert Storm, coalition air commanders had faith only in the stealthy F-117 to penetrate the formidable air defenses around Baghdad. The alternative to stealth is a big, Rolling Thunder-style strike package with ECM and SEAD escorts, plus fighter escorts. Which isn’t going to be generated for an aircraft to loiter in support of ground forces.

Let’s look at a more modern example: recent events in the Ukraine. Here’s a radar map of the Ukraine.
ukraine air search radar map
That’s a map of all of the air search radars in the region. Have fun with that. And remember, lots of these SAM systems are going to be reasonably modern units that can move. Everyone saw the success the Serbians had by shutting off their radars and moving their air defense systems around to frustrate NATO SEAD strikes. And you can’t sortie your A-10s until you get air superiority and deeply reduce that SAM umbrella.

The gun on the A-10 is a fantastic weapon, but it’s a trifle outmoded these days. If a gun and armor were the sine qua non of CAS, we’d sortie Hs 129 B-3s. With modern precision munitions, the role can be filled by multirole or low-observable-multirole types with no loss of effectiveness. And in hostile airspace where the opponent has some actual air defenses, the A-10 and its ilk are the least survivable types. A mess like the Donbass is begging for low-observability if you want to actually survive to deliver ordnance and live to strike again tomorrow.

  1. Cf. MH 17. ↩
  2. Rectified on the A-10C. ↩

Fishbreath Flies: DCS AV-8B NA Harrier Review

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Let’s talk weird, floaty planes.

Floatiness (more technically, and henceforth, V/STOL, vertical/short takeoff and landing) has long been a desired trait in warplanes. As far back as the Convair XFY Pogo, a helicopter in airplane’s clothing, designers have seen the advantages in a plane that can land nearly anywhere. The Pogo, however, served to demonstrate some flaws with the plan: namely, that a hovering plane is hard to fly1.

The idea languished for a bit. Like all useful ideas, it didn’t stay down for long. The Harrier was born from this second wave of V/STOL aircraft; it was made possible by a stonking great engine.

The stonking great engine, the Bristol-Siddeley (and later Rolls-Royce) Pegasus, is a fascinating piece of equipment but probably a topic for another day. For now, suffice it to say that the thrust vectoring is built in, the compressor stages rotate in opposite directions to reduce gyroscopic effects, and the limiting factor for power—turbine blade temperature—can be temporarily exceeded by means of a water injection system2. Some sources will tell you the Harrier’s engine is mounted in the fuselage. This is misleading. In a very real sense, the engine is the fuselage, with a little bit of plating to cover it up. Look at a Harrier from the front. You’ll see half of the fan on either side.

Over the years, variants accumulated, as they do for successful airframes. The Americans bought in, and the AV-8 and Harrier GR. number lines separated slightly, in terms of avionics and equipment. As an American and, less importantly but more pertinently, a DCS-based flight simmer, I’m most concerned with the AV-8B, and most specifically, the DCS AV-8B Night Attack variant by Razbam.

The AV-8B entered service with the US Marine Corps in 1985, and was followed quickly by the Night Attack model in 1989. Both versions feature modern glass cockpits, but the Night Attack (N/A going forward) has a few intriguing extra features. Color MFDs, for one3; a color moving map page, too. The HUD is wider, and there’s a FLIR system in the nose. That about covers the built-in night attack capability. Later, it was properly wired for the LITENING pod; the IR-capable LITENING can cue the attack systems for more range than the Mk. I Eyeball (NVGs and FLIR out the HUD) permits.

Weapons-wise, the N/A Harrier4 carries nearly every ground-attack munition in the modern American inventory; dumb bombs, rockets, Mavericks, and guided bombs of every shape, size, and guidance technique make an appearance. So also does the AGM-122 Sidearm, a sadly-out-of-production weapon which mates an anti-radar seeker to a Sidewinder body. It’s a useful self-defense system for aircraft which can’t carry the HARM (like the Harrier), or aircraft whose primary mission is not SEAD.

How is it to fly? Well, it ranges from extremely peppy (loaded light) to rather piggish (with lots of stores hanging off of the wings). One of the obvious-in-hindsight traits of a VTOL aircraft is that it must, in at least some configurations, have an engine thrust greater than their weight5. I never thought of the Harrier as a particularly good performer, but my familiarization flights have certainly changed my mind. It reaches its top speed with surprising and gratifying alacrity with the throttles forward, and maneuvers like you’d expect from what is, when you get right down to it, a very small plane. Carrying a full load—31,000 pounds—the Harrier is much less exciting. Rolls become sluggish, as do all maneuvers; then again, it isn’t hard to understand why. The Harrier’s maximum rolling takeoff weight is about two and a half times its empty weight. No small, fun aircraft can survive that kind of load.

And now for the moment of truth: is it worth buying? Razbam have done an excellent job with the flight modeling, as far as I can tell. The Harrier performs believably, and landing vertically is as much a challenge as you might expect, especially if you’re trying to hit a point on the ground. Helicopter sim experience, like I have, is helpful but not a panacea. To some extent, the Harrier takes unique skills.

As seems to be the case for DCS planes in 2017 and 2018, the Harrier is currently unfinished. The basic flight modeling is there, as are dumb weapons, Mavericks, the built-in targeting systems, and a limited targeting pod implementation, but much remains to be done. Early access aircraft are here, I’m sad to say. If that doesn’t bother you terribly much (knowing that this is DCS, legendarily buggy, whose best-working releases tend to be the most recent releases), I’d say you can’t go wrong buying it. The Harrier is one of the best planes to date.

If, on the other hand, you want a full manual and a fully implemented plane, you should wait. The price goes up at release, but not by very much. If you want a dynamic campaign, well, you’re probably just going to have to wait. Bafflingly, a campaign engine is still not on the DCS radar, despite being an obvious killer app for the platform. The DCS world is growing faster and faster nowadays; the third parties can keep up the aircraft release pace, but eventually the number of planes available is going to exceed the capacity of mission designers to make interesting things to do with them. A campaign is, going forward, a must.

But I digress. The Harrier is a good module, and well worth the purchase if you’re interested in the plane even a little. Thumbs up from me.

  1. Especially one which lands on its tail. Flying into a vertical climb, then looking over your shoulder to locate your landing spot, is not a great design. ↩
  2. As all engine nerds will tell you, any engine is instantly made much cooler6 when water injection is added. ↩
  3. For night-vision compatibility, the color is primarily green. ↩
  4. And its sibling, the AV-8B Plus. The Plus ditches the late-70s Dual-Mode Tracker (read: 6x TV camera and laser spot tracker) in the nose, and replaces it with an old-time F/A-18C-era radar. It can sling AMRAAMs. ↩
  5. The F-35B is a curious counterexample. For a direct comparison, let’s look at aircraft sans payload plus 4,000 pounds of internal fuel. We’ll use maximum rated dry thrust, with some caveats7. Late-model AV-8B Harrier IIs have an empty weight of just under 14,000 pounds, for about 18,000 pounds with our fuel requirements. (4,000 pounds is somewhat over half of the Harrier’s fuel capacity.) The empty F-35B weighs in at more than twice as much, nearly 32,500lb empty and 36,500lb with fuel. The Harrier’s engine generates 23,500 pounds of thrust, but can only do so for a very short time. Knocking ten percent off for sustained power still leaves it north of 21,000 pounds; the remaining three thousand pounds between thrust and weight easily fits a pair each of Sidewinders and AMRAAMs, or a full fuel load. The F-35B engine, on the other hand, makes only 25,000 pounds dry. The lift fan makes up the difference in vertical flight modes. ↩
  6. I swear I didn’t notice this pun until after I wrote it. ↩
  7. The Harrier can’t sustain its maximum thrust rating for very long. There are lift thrust ratings at up to 120% nominal RPM, which the engine control unit won’t allow outside of VTOL configuration. Combat power is 111% nominal RPM. ↩

Parvusimperator Reviews the F-22 Raptor

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No fighter discussion would be complete without mentioning this one, even if it’s technically not available for the procurement games.

To understand the F-22, we should first look at the ATF, or the state of military aviation in the ’80s. The core of the USAF was the F-15 and the F-16. These were great fighters, but the Soviets had counters, namely the Su-27 and the MiG-29, which were at least the equals of the American fighters. In the maneuverability area, they might even be considered a bit ahead.

American doctrine was heavily invested in air superiority, and the USAF was always looking for the next big thing, so they put out a design concept for the ATF. It was to fly faster and higher than other fighters. Or, more precisely, to cruise higher. Speed is good, since speed is energy that can be converted into maneuvers. Energy is life. But supersonic speed meant afterburners, which burned fuel rapidly. So most fighters couldn’t sustain supersonic speeds for very long. The USAF’s idea was to use new engine technology to push the envelope of cruise speed, not maximum speed. The resulting fighter would not be faster than the Eagle, but it would be able to maintain supersonic speeds without lighting its afterburners (to “supercruise”). These engines would be designed to work at higher altitudes, because altitude can be converted into energy. Energy is life. Energy is winning.

Of course, there were secret projects in the works too, and so the USAF added stealth requirements. Stealth demanded careful shaping, special skin, and internal carriage of weapons. This helped the supercruise, since it reduced drag. A protracted development period due to the end of the cold war, and a competition between the Lockheed and Northrop Grumman entries eventually resulted in the F-22 we know today.

The F-22 is the king of the skies. Full stop. There is no better aircraft at aerial combat. None. Fighting with a Raptor really, really sucks. The Raptor has a massive, powerful, highly advanced, low-probability of intercept radar, and the obvious stealth features. So it’s going to see you first. And because it cruises at mach 1.2-1.4 at a higher altitude than you, the Raptor has the energy to decline any engagement it pleases, or dictate the range as it pleases.

If the Raptor chooses to engage BVR, as we’ve mentioned it’s going to get the first shot. It sees you first. It gets to position favorably. Plus, if you’ll recall, it’s flying higher and faster than you. So its missiles get that much more energy, because they start from a supersonic platform, and get a gravity assist as they dive down. Which is a great recipe for an intensely frustrating exercise. And by ‘exercise’, I mean ‘simulation of being smote by an angry god’.

But that’s BVR. The Raptor owns BVR. What if we force the merge and go to WVR? Probably by stipulating in the exercise rules that it’s a WVR fight, but still. Well, here go some of the advantages, though it’s still a massive pain to acquire a lock on the Raptor. At least you can see it. And you can engage with IR seekers, but not super well. Everybody dies in WVR. The Raptor is no exception. But it has the best aerodynamics of any fighter around, with a very high thrust/weight ratio and very low wing loading. It also has thrust vectoring. So even in WVR engagements, the Raptor is a winner more often than everybody else. It’s kill to death ratio at Red Flag is hilariously lopsided, and that’s against pilots who dogfight for a living.

If you’re thinking this is quite gushy, and excessively positive, you’d be right. I love this thing. But it’s not tops at everything. The internal weapons bays are somewhat limiting. The Raptor was designed around a warload of six AMRAAMs and two Sidewinders internally. This isn’t a bad loadout, though it could be bigger. However, those bays are not very deep. So the F-22 can’t carry much in the way of bombs. And it can’t carry any bombs that are all that big. The F-35 can’t carry many bombs, but it can carry two of just about any air to ground weapon you please. The F-22 is limited to bombs of 1,000 lbs or less, and that size class also rules out most standoff weapons. Plus, it only recently got ground-oriented radar modes. Ground attack is not its thing. Though the USAF is trying, and has made special small GPS-guided glide bombs so the Raptor can bomb more stuff.

Oh, and it’s out of production. Even when it was in production, it was super expensive. You could theoretically restart the production line, but that would cost a whole bunch of money. And the USAF only bought 187, which isn’t a lot. And there are have been issues with the onboard oxygen generating system, which have restricted that flight envelope. Those should be fixed by now.

So it’s an expensive, gold-plated, air-superiority fighter with gimped ground attack in a world of strike operations. Would we buy it?

Well, we can’t. Production lines were closed in 2011. Sorry. Blame Rumsfeld, not me.

Feels like a cop-out, doesn’t it? Okay, fine. Suppose they got their act together and started making them again. Raptors rolling off the production lines. Would we buy them?

Well, we still can’t. Even if the production lines were reopened, there’s a pesky act of Congress in the way. Really. There’s a law in the United States that says Thou Shalt Not Export the F-22. Even to one of America’s favorite and closest allies, like Japan or Australia or Israel. No Raptors for you.

Sigh.

Okay, that’s another cop-out, right? I’m still avoiding the question. Fine, fine. Remove both pesky intrusions of reality. Would. We. Buy. One?

We’d need a price, right? Well, let’s be awful and take the figure from an offhand quote of an Israeli Air Force general of $200 million, rather than the much more favorable wiki flyaway cost of $150 million. So. 200 million dollars a copy. Would we buy?

Hell fucking yeah, we’d buy.

Did you really think I’d say no to the greatest aerial combatant of all time? Are you mad?
We’d be all over this, if the above conditions were met. Even at $200 million. It’s got Wunderwaffe-class awesomeness. It’s also an absolutely beautiful fighter. It looks right. It is right.

Since this is a game, you might be thinking I should try to trade Fishbreath something so we can both skirt our self-imposed rules a little. He’d never go for it though. He doesn’t like spendy wunderwaffe.

Author’s Notes: This review was not sponsored or paid for in any way by Lockheed Martin, the Fighter Mafia, or members of the United States Air Force.

Fishbreath Flies: DCS AJS 37 Viggen Review

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Leatherneck Simulations is at it again: a 1970s aircraft modeled in loving detail. Once more, we get a plane which has virtues beyond accuracy. Leatherneck’s DCS Viggen has heart.

I’ve written about the Viggen’s history already, so if your first thought is, “Why should I care?”, there’s your answer. With that out of the way, we can move onto the plane itself.

Graphics
Digital Combat Simulator made huge strides on this front with the release of its new rendering engine in 2015; Leatherneck has proven itself well above average at the graphical side of DCS module development. The MiG-21 was a work of art, and the Viggen is perhaps even more so. The external model is well done, and seems perfectly realistic to me1. The real artistry comes inside the cockpit, though. Flip on the battery and the low pressure fuel pump, and the master warning lights (labeled HUVUDSVARNING, because Swedish) come on, bathing the cockpit in a luminous flashing red. Turn them off and get through the rest of the startup checklist, then turn the radar on. The CRT casts its eerie green CRT glow over everything, and seems to glow with the inner light all displays of its type do.

Beyond the superb lighting effects, the cockpit also has the weathered feel you would expect from twenty-year-old airframes. (Remember, the AJ 37 Viggen is a 1970 plane; the AJS 37 Viggen is the 1990s update). It isn’t dingy, but it does look and feel as though it’s been used, and that adds tremendously to the plane’s character.

Sound
We come now to perhaps the best part of the Viggen: its sound design. Although the DCS engine may not do very well at exterior sounds for any plane, Leatherneck has still managed to make the flyby sound meaty, especially in afterburner. In-cockpit, the state of things is much better. Turn on the AC power, and the computer’s fans spin up with a sound that reminds me of my childhood machines. The master warning alarm has the same warmth to it as the light does. Later, the insistent chirp of the radar warning receiver gives way to the thunder of the afterburner, growing deeper by stages as the throttle clicks past its detents through the three afterburner power bands.

Sound is an important and underrated component to immersion in sims. The Viggen gets it spot-on. It’s good as any sim I’ve played to date.

Systems and weapons
The Viggen flies a mission profile rather out of favor in today’s world: interdiction. That is, it’s designed to fly at ludicrously high speeds and ludicrously low altitudes, carrying a wingload of bombs, rockets, or rudimentary guided weapons. It gets to its target, pops up at the last minute to aim its weapons, makes one pass, and heads home.

This is reflected in its design: the canarded double delta makes quite a bit of low-speed lift, but it does so inefficiently. The Viggen is happiest in its native habitat: Mach numbers greater than 0.6, altitudes lower than 500 meters above the ground. It does not fit into the low-intensity COIN world of DCS nearly so well as (say) the A-10C, the Ka-50, or even the Su-25. The weapons fit requires you to know where your target is, and even the air pressure at the target’s location. All of this (except for the air pressure) must be programmed into the computer ahead of time, or using the wee six-digit input display while flying.

So, don’t expect to do much loitering, waiting for JTAC, and dropping bombs precisely. Even if it was more straightforward, the Viggen has very little facility for dropping quantities of its weapons smaller than ‘all’. Only guided missiles fire one at a time.

Having introduced this section with an extended ramble, let me get back on point for a paragraph. The systems modeling feels right to me. I’m not an expert on Swedish systems of the 1970s and 1990s, but everything feels plausible enough, modulo some early-access issues Leatherneck is working through in weekly patches. Notable fun items include the overwhelmingly programmable RB-15 anti-ship missile, the BK-90 totally-not-a-low-altitude-cluster-JDAM, and the RB-05A manually-guided missile (easier to use than it sounds). The air-to-ground mapping radar works as expected; that is to say, it’s very cool, albeit with the confusing wrinkle that green means no radar return and black means return.

There are some ongoing issues with rearming, as well as some others involving weapons and multiplayer, but I’m confident Leatherneck will be able to get those squared away.

Gameplay
On to the most subjective point! Is it fun?

Yes. Yes it is.

The design of the HUD, with few numbers and lots of indicator lines, makes you feel like you’re flying a Swedish X-Wing, and the rest of the cockpit supports that impression. As the treetops zip by at four hundred knots, and the waypoint distance line on the HUD shrinks to indicate you’re closing in on your target, you can just picture yourself hurtling down the Death Star trench.

Maybe that’s an exaggeration, but the Viggen’s mission profile makes for a certain sense of rising anticipation as you speed toward your target. Do you know that stereotypical scene from adventure movies, the one where the sun inches toward a bejeweled staff placed just so, or the one where some narrator is speaking while an orrery clicks toward planetary alignment? Everything is building toward a single moment, and then, bam—the payoff. The sun sparkles off the jewel and lights up the model of the city below, the orrery’s planets align. That’s the feel of a Viggen mission done correctly. Your range-to-target dial—and it is a dial; the Viggen may be computerized, but it isn’t that computerized—ticks down toward zero. You pull up, catching a glimpse of your target as you do. You roll onto it, lining up the sighting mark in the HUD, and then, bam. You pull the trigger and your weapons strike home. There’s the payoff.

It’s tremendously exciting.

Verdict
I recommend the Viggen wholeheartedly, based on its production values and on the sheer thrill I get out of flying it. I offer the following two caveats, though. First, it’s an early access product; more importantly, it’s an early access DCS product. There are still plenty of gremlins. Second, if you’re a multiplayer-primary player, be warned that there are several bugs and several usability issues to contend with. Even with those caveats, though, it’s an excellent aircraft, and I very much doubt you’ll be disappointed with your purchase.

  1. I don’t count rivets, though. ↩

Resurrected Weapons: Douglas F6D Missileer

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We looked at the long-range, high performance Eagle missile on Tuesday. Now, let’s look at the plane to carry it.

As ever, the US Navy was concerned about saturation attacks on its carrier battle groups. To counter the new threat of bombers armed with large, long-range antiship missiles, the Navy had two projects under development in the late fifties. One was the Typhon long range SAM, with a projected range of 200 nautical miles. The other was the Eagle/Missileer project.

Missileer was, unusually for the jet age, a subsonic fighter. Given that it had to stay on station more than 200 nautical miles away from the fleet, and that more loiter time was significantly better, the decision was made to keep the design subsonic. Long loiter also conveniently sidestepped delays in interception from launching alert fighters, since the fighters could be orbiting and ready. Subsonic design made mounting a large, advanced radar and large, advanced missiles easy. We’ve already talked about the massive, 1,284 pound Eagle missiles. The Missileer was designed to carry six of them. It was also designed around the large APQ-81 radar.

APQ-81 was an early pulse doppler radar. In an era when a fighter radar with a 24 inch diameter dish was considered large, APQ-81 had a dish 60 inches across. It could detect a standard radar target1 at 120 nautical miles, and track sixteen of them simultaneously at 80 nautical miles. It had a track-while-scan mode. It was designed with innovative anti-jam features from the beginning, including a narrow, 3° beam with a 24 kHz bandwidth, both chosen to avoid most available jamming systems.

Unsurprisingly given that it had to carry such a large load, the F6D was fat and ugly. It was 53 feet long and had a wingspan of 70 feet. It was powered by a pair of Pratt & Whitney TF-30s, engines that would go on to power the F-111 and the F-14A.

Like the AAM-N-10, he Missileer was cancelled by McNamarra to free up budget space for other things. The aircraft itself would be easy to develop but the radar and systems integration (and the AAM-N-10) would be risky and expensive. Plus, they’re overspecialized for a single mission. The F6D had to be bought in conjunction with another, more conventional fighter, since it could not provide strike escort capability or establish air superiority. It was a project that was somewhat ahead of its time, like Typhon. The US Navy would later get a much more reasonable set of systems with similar capabilities in the 1980s with Aegis and Tomcat/Phoenix.

Verdict: Funding request denied by the Borgundy Aircraft Procurement Board

  1. In the late 1950s, the standard radar target was assumed to have a radar cross section of 5 square meters. This corresponds to the radar cross section of a B-47 bomber. ↩

F-35 First Red Flag Performance

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The F-35A is at its first Red Flag! And we’ve gotten some reports of how it’s doing.

First, a little review. Red Flag is the most advanced aerial combat exercise in the world. In a given year, there are several Red Flags, operated out of Nellis Air Force Base in Nevada and Eielson Air Force Base in Alaska. There, the US Air Force and US Navy squadrons join with squadrons from other NATO and Non-NATO allies to engage in a series of realistic training exercises. They have the full suite of AWACS support, and air combat is staged against the Aggressors, instructor pilots who fly F-15s and F-16s and are trained in a wide variety of foreign flight tactics.

The Aggressor pilots are the best dogfight pilots in the world. That is literally all that they do. Their job is to be the nastiest guys in the sky, to catch pilots making mistakes in training where there’s a nice debrief so they can learn from their errors. Beats the Hanoi Hilton.

And the F-35 is, of course, the next fighter of the US Air Force, the US Navy, the US Marine Corps, the Royal Navy, the Israeli Defense Forces, South Korea, Australia, and a whole lot of others. It’s a huge, complicated, advanced program. And it’s had its share of problems as well as its share of detractors. And it was my pick for Borgundy’s Fighter in the Procurement Games. Despite the problems, I stand by that decision.

So with all that in mind, let’s see how it did. Keep in mind, this is only one Red Flag exercise. Small sample sizes can lead to problems. But it’s the data we have, and given the questions, it’s worth commenting on now.

As befits USAF doctrine, the F-35 has been primarily tasked with strike and SEAD missions. The USAF has F-22s for air combat. And the F-35 has done great. They didn’t lose any fighters on day one of the exercise when they engaged enemy air defenses, which is not something that usually happens. The Aggressor Team had to revise their exercises to be more complex and difficult in order to make life more difficult for the ‘Blue’ team (the good guys with the stealthy fighters). These tests are only interesting when they are hard.

But let’s talk about dogfighting. Nobody else has Raptors, so the rest of the world will need the Lightning II to be ready to mix it up, and the F-35 got some dogfights in. We do not know any of the specifics of the engagement–range, circumstances, rules of engagement, simulated loadouts, etc. But we do have a final score. 15-1 in favor of the Lightning. Questions abound, of course. What were the rules of engagement? What were the circumstances? Were these all WVR? BVR? We do know that the Aggressor pilots have had a lot of experience dogfighting (and mostly losing) to the F-22, so they may have been a little more ready for the F-35 than one might otherwise expect.

Pilot impressions of the Lightning II continue to be positive. The situational awareness is better than anything else in the sky, and unsurprisingly, pilots love being able to see and know more. No complaints about the aircraft have emerged. Also, it’s done great on the flightline. No F-35s have missed a sortie for maintenance problems, and the planes report a 92% mission readiness rate. Most legacy aircraft have a 70-85% mission readiness rate.

So despite the problems, many of which do not affect the -A variant, we can see that the Lightning is doing well in unscripted exercises. It’s a very good sign for the program.

And no, we do not expect the program to be cancelled as part of President Trump’s review.

Sunday Puzzle: Air-to-Air Refueling Edition

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Need something to wash the taste of Patriots victory out of your mouth? Try the Sunday puzzle.

Much ink has been spilled about the limited range of modern American carrier fighters. It’s one of parvusimperator’s biggest bugaboos. Sometimes though, it’s difficult to get a good sense for the penalties imposed by limited range. Let’s formulate it as a riddle.

You, Colonel Reader, command a fighter wing in Friendly Mideastistan. You have orders to strike a target in Enemy Mideastistan. Your target is six hours away from your airbase. Your fighters only fly for three hours on one tank of fuel.

Some additional parameters: your fighters fly at a constant speed without respect to payload or altitude, and their fuel consumption is also constant. You have exactly one airfield to work with, placed six hours from the target. Planes may not take off from or land anywhere else, nor may a plane run out of fuel in midair. (It looks bad.) Planes may refuel each other; there is no limit on how much fuel a plane may transfer. Takeoffs, landings, and refueling are assumed to be instantaneous.

Question 1: for each plane which drops a payload on the target, how many planes are required for refueling?

Question 2: describe the pattern of refueling which is required to get one plane to the target.

Answers and analysis:

Spoiler for

I first saw this as a question about circumnavigating the globe, so I’m going to talk about 180 and 360 minutes instead of 6 hours.

Two refueling planes are required per strike plane. All three take off at T+0. When they reach T+45, all three have 135 minutes of endurance remaining. The first refueling plane fully refuels the other two, at the cost of 90 minutes of endurance. It has 45 minutes of endurance remaining, and returns home. The other two have 180 minutes of endurance left.

At T+90, the first refueling plane has landed. In the air, the two remaining planes each have 135 minutes of endurance remaining. The second refueling plane fully refuels the strike plane. The refueling plane is left with 90 minutes of endurance, and the strike plane now has a full 180. The refueling plane turns for home.

At T+180, the strike plane drops its payload on the target, with 90 minutes of endurance remaining. The second refueling plane has landed. The first refueling plane, now refueled, takes off.

At T+270, the strike plane and the first refueling plane meet. The strike plane is running on fumes, with 0 minutes of endurance left, and the refueling plane has 90 minutes. It transfers half its fuel to the strike plane, leaving both with 45 minutes of endurance. The second refueling plane takes off.

At T+315, the strike plane and the first refueling plane meet the second refueling plane. The first two are running on fumes. The latter has 135 minutes of endurance remaining. It transfers 45 minutes of fuel to each of the first two planes, leaving all three with 45 minutes of endurance: just enough to get back to home plate.

And this, of course, is the best-case scenario. Our model is simplistic in the extreme; it doesn’t account for the time taken to refuel, the time taken to find the tanker, the difference between fuel consumption based on payload, the ordinary requirement that strikes be flown at a speed and altitude different from those used for best cruise performance, and a myriad of other factors.

Let us consider a real-world example which closely matches our riddle in its setup: the Black Buck raids, flown by the RAF during the Falklands War. The distance between the closest British airfield, Wideawake on Ascension Island, and Port Stanley Airport, in the Falkland Islands, is 6,300 kilometers. Different sources list the Vulcan’s cruising range at between 4,100 and 7,000 kilometers. Even if you choose the worst possible figure, the Vulcan’s endurance is nearly two-thirds the required range, much better than the half in our riddle. Of course, I haven’t been able to find actual range figures; this column does not merit that much investigation.

What it does merit, however, is the answer to our riddle for the real-world case. For each Vulcan strike (they were flown as single-aircraft raids), eleven tankers were required, refueling each other, then refueling the Vulcan six times on the outbound leg and once on the return trip.

Refueling is hard. Not only is it difficult mechanically, not only does it require specialized aircraft (or limited refueling performance, for buddy stores), it also gets you into a vicious cycle in the same vein as rocket design. When you have to carry your fuel, you need more fuel to carry your fuel to where it’s needed, and so on and so forth. The United States has an enormous advantage in that it already operates refueling assets worldwide; much of its fuel is already where it needs to be. This may not always be the case, hence our advocacy for aircraft designs with legs built in.

I hope you enjoyed the inaugural Sunday puzzle. There may be others.