Chair Force Engineer

Wednesday, May 31, 2006

Hurricane Hugo's "Hot Air" Force

Venezuelan President Hugo Chavez has major plans for his nation's air force. Those plans appear to be motivated more by his overall goal of irritating the United States instead of sound military planning. Venezuela is already ordering MiG-29's from Russia. It is currently investigating the purchase of Russian Su-35's and the sale of its current F-16's to Iran or Cuba.

The Su-35 is an excellent fighter, perhaps the most maneuverable production fighter in the world. Still, Venezuela can't back up its claim that the Su-35 is the best fighter in the world. That honor belongs to the F-22 Raptor. Because of the F-22's stealth, it can fire off a salvo of radar-guided missiles long before it can be spotted on an enemy fighter's radar. In mock combat between the F-22 and F-15, the results haven't been pretty for the Eagle drivers (even in times when they have enjoyed overwhelming numerical superiority.) For an Su-35 pilot facing an F-22, all of the "Cobra maneuvers" and "J-Turns" in the world won't be protection against a missile fired from a fighter that can't be seen until it's too late.

MiG-29's from Russia don't offer significant advantages over the F-16, but Venezuela sees two benefits here. First, the Russians will be happy to sell "Hurricane Hugo" the parts he needs to keep the MiGs flying, while the US will no longer give Venezuela the F-16 parts needed to sustain a reasonable mission-capable rate. Second, replacing American planes with Russian ones is an expensive way of hammering home Chavez's anti-American agenda.

The prospect of Iranian F-16's is somewhat frightening, but not for the reasons that immediately come to mind. The Venezuelan F-16's that may be sold are the older "A" models with virtually no ability to fire radar-guided missiles. While the planes weren't originally built to drop precision weapons, these capabilities have allegedly been added to the Venezuelan planes by our perfidous Israeli "allies." Still, the planes are day fighters that could be shot down easily by modern F-16's like the Block 50 F-16C. Rather, the danger is that Iran could reverse-engineer technologies from the F-16 and develop Iran's domestic manufacturing capabilities.

Over the years, Iran has strengthened its domestic aviation industry. Some sources will contend that Iran has no means of maintaining the Venezuelan F-16's and will resort to cannibalism. While many authoritative sources claim that Iran's Tomcat fleet is essentially grounded and most of its Phantoms were cannibalized, a new view is emerging that Iran has a domestic capability to maintain these planes with spare parts and home-built munitions. Additionally, Iran is working on new fighters that resemble an unholy hybrid of the F-4 Phantom II and F-5E Tiger II (here, here, and here.) It would be a major boon to Iran's aviation industry if they got their hands on the F-16's fly-by-wire control system or F100 turbofan engine.

Monday, May 29, 2006

An Airman's Prayer on Memorial Day

Today we gather to celebrate this day with our comrades
In full knowledge of those comrades who will never be able to join us at this table

Until that day when all are one, we will keep them alive in our hearts
We ask that the sacrifices that have been made, and that the sacrifices yet to come,
Will enable us to bring Your peace into Your kingdom

Let all those who do evil in your name know that You are love
And that we will use the gifts You have given us to spread Your love for us throughout Your kingdom

In Your name we ask these things, Amen

Friday, May 26, 2006

Everyday I Write the Book

Congratulations to Mark Wade on the tenth anniversary of Encyclopedia Astronautica, the internet's most authoritative and wide-ranging reference on all things space.

Still, it appears there are some gaps in his latest updates. No mentions of the New Horizons launch (Atlas V,) the FalconSat2 + Falcon I failure, GOES-N (Delta IV,) or COSMIC (Minotaur I.) Perhaps, in time, Encyclopedia Astronautica will become like Wikipedia, and rocket nerds across the internet will be able to update it.

Mr. Wade has been quite prolific in updating his blog, though. A few of his points are worth commenting on.

--His point about designing the CEV before selecting a mode is very good. As I've said before, I prefer an L1 rendezvous over the current plan to perform one rendezvous in earth orbit and a second one in lunar orbit. (Yes, it's occurred to me that you'll have to rendezvous twice at L1 if you want to bring the crew back home. I still like it better than the current ESAS plan.)

--His insistence that hit-to-kill interceptors can't work consistently isn't a fair assessment. The Air-Launched Miniature Vehicle, dropped from an F-15 in 1985, successfully destroyed the Solwind target satellite. It was politics, not technical challenges, that killed ALMV. Of course, it's much easier to hit a satellite in a predictable orbit than it is to kill a reentry vehicle from a ballistic missile. Still, not much can be said about the PAC-3 based on its performance in Operation Iraqi Freedom, aside from the fact that it's very good at killing Tornado GR.4's and F/A-18's.

--Another excellent point is made about the CLV upper stage. Why can't NASA order a stretched version of Delta IV's upper stage (or Atlas V's dual-engine Centaur, for that matter?) I think it has everything to do with crew comfort during aborts (see below.) Insufficient thrust might also be a problem.

--I totally agree that NASA's "crew comfort" requirements for aborting a launch are totally bunk. Aborting a manned spaceflight might hurt like a bitch, but that's okay as long as the crew survives. The same holds true for ejection seats in military jets. Crews often break arms and legs during ejections, but 100% of these people will tell you that they'd rather survive with broken limbs than perish inside the cockpit.

--Mr. Wade asks the question, "Why a thumpdown?" In reference to the lack of steerable parafoils on the CEV, it's because steerable parafoils are really heavy--far more so than standard parachutes. In the end, I'd like to see a comparison between the weight of the CEV's parachute+rocket landing system versus a parasail and skids, but I'm confident that parachute+rocket will come in at a lighter weight.

I should probably add that the rumored weight problems which dictated the "Walmart" lunar lander are being addressed with the increased girth of the CaLV (which enhances the amount of cargo it can put in LEO.) Still, if the weight problems persist, NASA should seriousuly look into a nuclear-thermal rocket for the Earth Departure Stage.

Thursday, May 25, 2006

The Heinlein Award

The much-anticipated Heinlein Award has been awarded to Peter Diamandis, father of the X-Prize, X-Prize Cup, Zero-G Corporation, and Rocket Racing League. Overall, I think it was a good choice.

My three candidates for the Heinlein Award were Burt Rutan, Max Hunter, and Buzz Aldrin.
--Rutan's inclusion on that list is obvious, for his work on SpaceShipOne.
--Max Hunter (the least-known of my candidates) deserves recognition for his work on the Starclipper and X-Rocket, which agitated the pot for more reusable launch vehicles. The X-Rocket inspired the DC-X, while Starclipper would have been a better option for NASA's space shuttle than the design that emerged.
--Buzz Aldrin's accomplishments after his moonwalk have inspired our future plans for solar system exploration. Before there was the Columbia Disaster and ESAS, Aldrin had written Encounter With Tiber, which talked about the Endeavour disaster, shuttle-derived rockets, Burt Rutan winning the X-Prize, flyback boosters, Apollo II flying to the moon, cyclers, and landings on Mars.

Rutan would have been an easy choice, but Diamandis, in hindsight, was the correct choice. While Rutan succeeded in building one spaceship, Diamandis is trying to create an entire industry based around the idea of private spaceflight. Besides, Rutan pissed off a lot of people by bashing ESAS as "archaeology" and brushing off the Rocket Racing League.


Phillip Kaufman, director of 1983's The Right Stuff, is poised to make another space-themed film, entitled Challenger.

I vaguely remember the 1990 made-for-TV movie Challenger; in hindsight, it seems hard to make a movie about disaster if there isn't a strong bright spot to conclude with. For instance, United 93 relies on the heroism of the passengers in thwarting the attack against our capitol. Oliver Stone's upcoming World Trade Center is supposed to focus on two firefighters who survived inside the rubble of the towers against all odds.

Kaufman finds a happy ending, of sorts, by making his movie about the accident investigation instead of the accident itself. The main protagonist looks to be the iconoclastic Richard Feynman. It sounds like it will be worth watching, although it will be hard to top The Right Stuff.

I've felt that if Hollywood wanted to make a movie about a space disaster, it should come up with a screen version of Rick Husband's biography High Calling. The book was so good that I cried when I read it. Although Rick Husband's life came to an abrupt and premature end, it's clear that in his 46 years on earth (and space,) he accomplished more than many people would dream of doing in several lifetimes. While the book's overtly-Christian themes might make it more suited for the PAX network instead of theatres, the success of The Passion of the Christ could pave the way for High Calling to get a worthy screen treatment.

Tuesday, May 23, 2006

George Washington's Hatchet

Historians have a joke about a museum claiming to display the hatchet that young George Washington used to chop down his father's cherry tree. The only problem is that the handle rotted and had to be replaced, then the head rusted and had to be replaced.

The joke cuts to the heart of the question, how much can you replace on something and still call it original? NASA is having a hard time with this stumper. After promising "shuttle derived" rockets for returning to the moon, the CLV and CaLV are looking more and more like the old Saturn series. The only shuttle-derived component is the 5-segment SRB (which still uses a different fuel grain and nozzle than the original SRB.)

With aerospace vehicles, designs are often optimized for a certain performance. When off-the-shelf parts and designs are reused, they often require significant re-engineering. Some programs will try to reuse aircraft avionics inside spacecraft, but this often requires significant re-engineering to make the parts radiation-tolerant. Similarly, the A-7 Corsair II light bomber started as a redesign of the F-8 Crusader, a supersonic fighter. By the time the subsonic A-7 took to the skies, it had almost no commonality with the F-8.

The CaLV is looking more and more like a resurrected Saturn V with SRB's, and CLV now uses an Apollo-derived engine on stage 2. We can't call it "shuttle derived" anymore, but I never had much hope that reusing shuttle hardware would lead to appreciable cost-savings. Inevitably, it would require re-engineering to meet the needs of Project Constellation. If it wasn't the CaLV being enlarged to 10 meters, it would have been a significant re-engineering of the SSME into the "expendible SSME," or another significant change to the SSME to make the "air start" SSME for the CLV.

On the plus side, NASA's recent decisions actually reduce the amount of money that would have to be spent on engine development. RS-68 would be minimally modified, while J-2X requires a new thrust chamber and nozzle (but reuses the old J-2S turbopumps.) By contrast, the air-start and expendible SSME's would have both been significant new developments, on top of the J-2X work that is necessary for the CaLV's second stage.

Similarly, the tankage issue is not a big change over what was in last fall's ESAS study. A stretched Shuttle ET with thrust structure on the aft end would be no trivial modification from the old ET. The 10m tankage isn't much worse off. In fact, it will probably reuse the external plumbing found on the Shuttle ET. The tank will probably be built with modified jigs from the Shuttle ET, unless there are Saturn V jigs and other pieces of tooling still stored at Michoud.

For people who were sorely disappointed by the lack of commonality with the shuttle, I think that they were sailing on a sea of false hopes. The new rockets are significantly different from the shuttle system and will inevitably evolve away from their shuttle roots.

The new CaLV is like South Park's "Manbearpig." It's part Delta IV (engines,) part Saturn V (tankage and upper stage turbopumps,) and part shuttle (SRB's.) Space cadets shouldn't be disappointed; it will be more capable and cheaper than the original CaLV design.

Monday, May 22, 2006

Acquisition Officer: An Oxymoron

Many pundits have accused the Air Force's space acquisitions programs of being broken. Some have suggested various fixes. While I haven't seen enough of the space acquisition environment to observe what is broken and what effect any potential fixes might have, I can offer my thoughts on what I feel is a very broad problem: the oxymoron of the "acquisition officer."

The Air Force trains its officers to be leaders. The difference between "leaders" and "managers" is illustrated, and "management" is frowned upon. "Leaders" are supposed to motivate their subordinates, take care of their troops, and basically be like John Wayne or Optimus Prime.

In spite of this, the acquisition career field lends itself to a manager, not a leader. Acquisition officers manage resources, whether they be people or money or materiel. Everything I have seen up to this point has reflected management instead of leadership. Managers remind me of Office Space's Bill Lumbergh: "Yeah Peter, I'm gonna have to ask you to come in on Saturday, and I'm gonna have to ask you to come in Sunday as well..."

I'm not saying that acquisition managers need to change their management styles. What I do suggest is that the Air Force stop treating its acquisition officer candidates in the same way that it treats the potential jet jockeys. Acquisition officer candidates should be identified at an early stage in their training and be trained in the ways of acquisition management. This way, the Air Force avoids the post-commissioning letdown that hits these officers like a wall of bricks upon their first acquisition assignment. A person can go from being a squadron commander in his or her ROTC detachment to being the commander of the copy machine and shredder. It's a situation that leads to false expectations and disillusionment. The Air Force should let these officers know what they are getting into before they commission, and this will help them find the people best suited for acquisition.

Saturday, May 20, 2006

The Name Game

What will the Joint Strike Fighter's name be? The question will supposedly be answered this July. I personally like the name "Condor," going with the "Birds of Prey" theme established for the F-15, F-16 and F-22. In fact, "Condor" almost became the F-16's name.

As a second choice, I could go for "Ghost Hawk." This name was used in Lockheed's promotional materials for the Joint Advanced Strike Technologies program (forerunner to the JSF) in the 1994 time period. It compliments "Nighthawk," the official name for the F-117. It's very appropriate, in light of the JSF's role in replacing the F-117.

Friday, May 19, 2006

Penance and Forgiveness

My regular readers will remember an unpleasant encounter I had at a Firestone service center back in January. Well, I just returned from a > 900 mile trip to Denver and back, and I was in dire need of another oil change.

I wasn't going to let Firestone off the hook so easily, even though the lady who did the customer satisfaction survey never got back to me. I called up Firestone's centralized call center, and they transferred me to the manager of the Central Avenue Firestone that was the scene of January's crime.

I explained my grievance in an objective way, without losing my temper. When the manager asked for my suggested remedy, I asked for coupons towards a future service. He suggested that I needed an oil change soon (judging by the time elapsed since January) and offered to do the job free of charge. I couldn't refuse the offer.

After work got out, I pressed on to the Firestone (doing my best to be punctual, as to not be a hypocrite) and got the oil change (with self-tapping plug installed.) I was in and out within 45 minutes. All-in-all, I was satisfied.

The moral of the story is that not every person who works for a major retailer is out to dick you over. The majority of the people want the customer to be satisfied and to come back. For customers, they can go quite far if they rattle the right cages, and if they can calmly talk about their feelings of dissatisfaction instead of making angry accusations.

Wednesday, May 10, 2006

X = 17

The Air Force badly wants new aerial refueling planes. So badly, in fact, that it's ending its C-17 buy after just 180 planes (instead of the 220 needed) just to pay for the new tankers.

The KC-X competition will determine who builds the next tanker (or tankers, if the buy is split between Boeing & Airbus.) The specifications have been written broadly, and the contractors are scratching their heads. Does the AF want a large plane like the KC-10 to carry a lot of fuel? Does it want several smaller planes like the 767 and A330 to generate a lot of sorties? Does it want a small plane like the KC-130 or 737 to fly from austere runways?

In this environment, the best solution is the overlooked C-17. Specifically, a KC-17 variant with a refueling boom (mounted on an interchangeable cargo door, or above the door.) The KC-17 would be nearly as big as the KC-10, but can still take off from austere airstrips (while the KC-130 can also do this, I think it's absurd to think that a 737 would even be considered for this requirement.)

The best part is that the KC-17 can also fill the shortfall in cargo aircraft numbers if necessary. If the boom is mounted out of the way of the cargo door, loading cargo will be easy. If it has to be mounted on the door, the door could easily be removed. In either case, the KC-17 kills two birds with one stone.

The KC-135E was a penny-wise and pound-foolish upgrade, using old TF33 engines from retired 707's to provide a quick fix for the KC-135A "water wagons." The F108 engine that came around shortly thereafter and made its way into the KC-135R has proven to be a good investment. The F108 allows the KC-135R to fly much faster and more reliably than the KC-135E. It's time for the KC-135E to fly into the sunset. And the KC-17 represents the best replacement.

Tuesday, May 09, 2006

Call me a rocket archaeologist

Burt Rutan has earned the disappointment and even anger of the space cadet community for calling the ESAS plan "rocket archaeology." Frankly, I'm a bit surprised by Burt's comments myself, as they don't reflect the record of safety that Burt is known for.

The secret to success in the lunar return is to rely on technologies that are mature and well-understood. If the lunar return plan looks a lot like Apollo, it's because we haven't developed the new technologies to a sufficient level of technical readiness. The aerodynamics of the capsule haven't changed, even though the materials and the avionics are all new. The physics behind the rocket haven't changed, either.

One area where I think we have been let down is nuclear propulsion technology. A major letdown of the early 70's was the cancellation of Project NERVA by the Nixon administration. If we had a mature nuclear-thermal rocket, astronauts could get to the moon and back in 1/3 the time it currently takes with chemical rockets (check out the LANTR proposal for details.)

ESAS must start with well-understood technologies. At the same time, there must be a balance between utilizing old technologies and developing new ones. If the correct balance is struck, new technologies can be matured and incrementally added to the human lunar program.

For instance, we currently face the dilemma of storing cryogenic hydrogen and oxygen in the Earth Departure Stage while it waits for the CEV to dock with it. Now imagine that after a few moon missions, the chemical EDS is replaced by a nuclear-thermal EDS. The propellant boil-off problem isn't as severe, because the specific impulse is twice the value for a LOX-Hydrogen rocket.

Reusability is another good example. If propellant depots can be built on the moon, the landers can be refueled and reused, acting as shuttles between the lunar surface and lunar orbit (or L1.) Nothing in the current ESAS plan precludes this. It requires a new development of a single-stage lander, but that lander can be subbed in for the old, two-stage expendable lander.

There's nothing wrong with being a rocket archaeologist, as long as you learn to evolve. In the battle of budget politics, the principle of "survival of the fittest" still applies. We will initially use what we know to return to the moon, but we will learn along the way and learn how to do things better. If we fail on this count, we will stagnate, and ESAS will die Apollo's death.

Sunday, May 07, 2006

Paint the ISS red

The idea of a US-Chinese cooperation in manned spaceflight is actually in discussion; this is quite revolutionary when considering that China was a Cold War enemy (at least until Nixon's visit,) and when considering many American misconceptions about China's manned space program.

I, for one, would like to see China join the ISS alliance. From an American perspective, there are many benefits to consider. Competition between the Chinese Shenzhou and Russian Soyuz will control the price on flights to the ISS. It will also make China more transparent about any military applications of Shenzhou, such as remote surveilance. For the Americans who are afraid of China landing on the moon (something that I feel is very far off, not for another 20 years or more,) involving them in ISS ensures that the US can keep tabs on China's manned space activities. Cynically, the ISS can be viewed as a quagmire from which China's space program will never be able to escape, and never go to the moon.

I don't want to immediately welcome China into the ISS alliance with open arms. I want China to demonstrate its capabilities on its own, and make them earn a spot in the ISS alliance. Let them put Shenzhou through its paces, shake it down, and demonstrate its capabilities before docking it to the ISS.

At the same time, there are some opportunities for improving space cooperation with China before Shenzhou is fully proven. US technical advice (within the ITAR boundaries) might prove useful. An agreement to rescue stranded Shenzhou crews with the shuttle might be a welcome paper gesture. In light of China's slow pace in launching Shenzhou missions, a small number of Taikonauts could fly on Shuttle and Soyuz missions.

The shifting American attitudes represent a good chance for opening China's secretive space program up and fostering beneficial cooperatin between the US and China. At the same time, China should be put on notice that any cooperation should be on an equal playing field, instead of the US playing a parental role in advancing China's spaceflight program.

Saturday, May 06, 2006

Vandy's not so handy

The status of SpaceX at Vandenberg Air Force Base is questionable, thanks in large part to the construction of an Atlas 5 pad at SLC-3 East. SpaceX had originally planned on near-polar flights of Falcon I from the neighboring SLC-3 West, and had built a pad there for that purpose.

If SpaceX can successfully launch a Falcon I from Kwajelein Atoll, it would seem like Vandenberg would become redundant. Vandenberg's prime advantage is the ability to launch into polar and retrograde orbits. Kwajalein can probably handle most of the trajectories that could be flown from either Vandenberg or from Cape Canaveral, due to its remote location. Vandenberg also has its fair share of baggage, like the environmental impact fees changed by the People's Republic of California because of damage to aquatic mammals caused by rocket launches.

It doesn't seem like there is any benefit for SpaceX to build up facilities at Vandenberg. Similarly, SpaceX really doesn't need Cape Canaveral, as long as it can build up its facilities at Kwajalein to handle the bigger Falcon IX and the Dragon manned capsule. As Elon once said, Omelek Island is "The Island of Dr. Yes."

If Omelek is too size-constrained for the Falcon IX and Dragon programs, the Cape is back on the table. And SpaceX would be wise to make this determination soon. If they want to reuse the old Titan IV launch pad for the Falcon IX, they will have to snatch it up before NASA tries converting it to a launch pad for The Stick (one of many options currently being considered.)

Thursday, May 04, 2006

Falcon Plucker

The F-16 Fighting Falcon, nearly 30 years after first entering production, is still the backbone of America's tactical fighter force. In over 70 dogfights, the F-16 has emerged the victor every time. When grunts on the ground need firepower, the F-16 is there with a reasonable dose of fire and steel.

Yet there are many myths that still persist about the F-16 which don't go challenged. They are certainly part of the plane's myhtos, and something the fighter jock community wants to preserve. But they also create false beliefs in the plane's strengths and capabilities that can prove fatal.

1. The F-16 is a model of a well-run aircraft acquisition program, employing the spiral development model. FALSE. If anything, the F-16 is a textbook example of what people in the acquisition community call "requirements creep."

The idea for the F-16 was sired from the fact that the new air superiority fighter, the F-15 Eagle, was too expensive for 1:1 replacement of the F-4 Phantom. The Fighter Mafia, a group of influential tacticians led by John Boyd, pushed for a lightweight fighter with a lot of thrust, which could out-maneuver any airplane in a dogfight.

The requirements for a Lightweight Fighter (LWF) were issued, and two competing aircraft were flown against each other in 1974: the YF-16 and YF-17. The contest went to the YF-16, due to its superior range and maneuverability.

But the Air Force had second thoughts about the very narrow mission of the LWF, which was to defeat enemy aircraft in dogfights. The F-16 soon gained the role of tactical bombing. Northrop's YF-17 was actually the better platform for the air-to-ground mission. Unlike the F-16, it wasn't naturally unstable, and it was a steadier platform for air-to-ground missions. This certainly played a factor when the US Navy chose the YF-17 (reborn as the F/A-18) over the F-16.

Since its conception, the F-16 has seen more capabilities crammed into its airframe. More air-to-ground munitions like the Maverick were integrated. Block 30 saw the introduction of AMRAAM compatibility (eliminating the case for a highly-maneuverable fighter,) Block 40 added all-weather, precision-strike capabilities, and Block 50 allowed the plane to suppress enemy radars. These are all capabilities that had existed in different variants of the F-4 Phantom; the lightweight F-16 was quickly growing into a smaller version of an airplane that was nicknamed "Rhino."

All of these changes came at the expense of performance. Pilots noted a dramatic decrease in performance when the Block 15 aircraft came out with bigger tailplanes. Block 40 had beefier wheels to accomodate heavier weapons loads. With Block 50, the structure of the plane has gotten heavier to better withstand heavier loads.

What started out as a lightweight fighter is now an affordable replacement for the F-4 Phantom. While the F-16 has served admirably in this role (in the same vein as the Shooting Star and Thunderjet from the Korean War, and the Thunderchief and Phantom from Vietnam,) it's a far cry from what Harry Hillaker originally had in mind when he dreamed up the F-16.

2. The F-16 is a Mach 2 fighter. TECHNICALLY TRUE, BUT DECEPTIVE. A wise rocket sage once put the question to me, "The F-16 has one engine. The F-15 has two of the F-16's engines, weighs twice as much, but goes faster. Why is that?" I pondered the question for a moment before he explained to me that the F-16 has a normal shock inlet (instead of the F-15's oblique shock inlet) which limits its top speed. He also pointed out the aluminum leading edges of the F-16, which are not built to withstand Mach 2 flight for any given period of time.

I didn't believe him at first when he told me that the F-16 wasn't capable of Mach 2. All of the Air Force fact sheets said so. I decided to go to the source, a former F-16 pilot who had flown the Block 10, 15 and 25 aircraft. He told me that while Mach 2 was capable above certain altitudes, the fastest he had ever gone was Mach 1.2. I also suspect that in order to see Mach 2 in an F-16, you'd have to burn so much fuel in afterburner that your Mach 2 dash would have no military utility.

To the F-16's credit, the F-15 probably uses a lot of fuel in afterburner too; I really don't see any situation where the F-15's top speed (around Mach 2.5) would be militarily useful. It's more effective when you can cruise at speeds above Mach 1 without the aid of a gas-guzzling afterburner, like the F-22 does. I've heard that F-16's with the GE F110 engine can also cruise supersonically, but the F-22 is truly optimized for it.

3. The F-16XL was the greatest thing since sliced bread. FALSE. This is a whopper I would love to believe, because the "XL" variant of the F-16 was a beautiful airplane, with its cranked arrow wing. The XL had increased capacity for internal fuel and could carry a heavier weapons load, which is just what the F-16 needed for the strike mission it was eventually tasked with. However, it had to compete against the F-15E Strike Eagle, and it tried to replace the much bigger F-111 Aardvark. The Strike Eagle was an even better strike platform, and its twin engines pushed it at speeds faster than the poor little XL could dream of.

I remember reading an old issue of Air Force Magazine from 1982, stating that the XL had double the range/payload of the standard F-16, and could take off with just 2/3 the runway length that the F-16 required. The first claim about range and payload is probably true; the bit about shorter takeoffs is extremely disingenuous. It may be true if the XL is carrying a minimal fuel load, so that it has a takeoff weight equal to the standard F-16 (and a lower wing loading, due to the XL's greater wing area.) Once the F-16XL was loaded up with a useful fuel and weapons load, its takeoff performance was actually worse than the standard F-16. Not only was it a heavier airplane, but it lacked any leading-edge devices like slats to help reduce the takeoff distance. At least the standard F-16 has leading-edge flaps.

A retired flight-test engineer from the F-16XL program put it to me this way: F=ma (yes, Newton's classic second law.) But it's a simple way of explaining the F-16XL's sluggish performance. It had the same amount of thrust from the same engine as the standard F-16, but it weighed almost twice as much. The drag profile on the XL was probably better than the standard F-16, but not by enough to offset the mass penalty.

In short, the F-16XL would have probably been an excellent mud-mover if tasked with the current strike missions that F-16's perform. But it was misplaced in the medium bomber role, where it couldn't hold a candle to the Strike Eagle or the Aardvark. The excellent dogfighting capabilities of the F-16 would have also been lost had the XL gone into production.