The Aerospace Agenda

Terrafugia Roadable Aircraft Gets Weight Break from FAA, But Still Far From Production

2010-07-05T20:00:31Z

The Terrafugia Transition roadable aircraft that I have blogged about before is in the news again. A recent press release from the company states that the FAA has upped the maximum gross weight (plane, fuel, passengers, baggage) limit of the Transition by 110 pounds, for a total of 1430 pounds at takeoff. The Terrafugia team is attempting to certify the Transition in the Light Sport Aircraft category to reduce certification costs and complexity. The FAA made the exception for the Transition due to the fact that it is designed to be driven on roads like a car after landing at an airport. The additional weight will allow the Transition to include typical car safety features such as airbags.

While this is encouraging news for the Transition, I believe the company still has a ways to go before they can deliver a production aircraft. After talking with a Terrafugia rep at Oshkosh last summer (see picture below of the Terrafugia display at Oshkosh), I am a little less optimistic than I originally was that the company can deliver an aircraft in the time frame they are currently quoting (4th quarter 2011), if at all. Although the prototype did fly successfully, from what I read, and saw in company videos, it never flew a complete circuit around the airport during the flight test program. That would require a series of 90 degree turns, of which I have never seen any video. It appears that the test pilot only took off and flew straight ahead, landing further down the very long runway. To me this indicated they encountered stability and control issues with the prototype that would not be acceptable in a production aircraft. The rep at Oshkosh said they had to go back to redesign parts of the aircraft to address stability issues, but nothing that couldn't be solved in the second design iteration. In the press release announcing the gross weight increase, Terrafugia says they will unveil "...computer graphics of the production prototype design.." at the big Airventure airshow in Oshkosh, WI later this month. But I'm thinking If they only have computer graphics to show at this time, the first flight of their second version must not be scheduled for any time soon. Add on the extensive flight test program that will be required to certify the production-ready Transition after first flight, and it looks like the end of 2011 to begin delivering production aircraft is very optimistic. I think the real problem is not as much technical as it is financial. I got the feeling from the Terrafugia rep that they need more money to get them through the certification process successfully. Having to build a whole new pre-production aircraft and test it certainly doesn't help with the cost situation. With the estimated cost of a production aircraft near $200K, they probably don't have enough deposits to keep them going until production.They claim to have 70 deposits of $10K each, for a total of $700K - in my opinion not nearly enough to get to production. I'm sure they are seeking other investors to help them out, but in these tough financial times, investors in high risk ventures are much harder to find. I'm still pulling for Terrafugia to be successful, but sometimes having the best, most innovative aircraft design does not always mean you will be successful. Luck and timing has a lot to do with it, and ufortunately Terrafugia is trying to make all this happen in one of the most difficult economies the world has seen in the past 50 years.

F-35 Joint Strike Fighter Formation Photos

2010-05-17T20:19:00Z

A friend sent me these pictures last week of two Lockheed F-35s in formation flight:

Taken recently, as far as I know these are some of the first official photos of several F-35s in formation flight. These two aircraft are AF-1 and AF-2, the Air Force version of the F-35. AF-1 is the first to fly, and it looks like it has had the vertical stabilizers repainted with lightning bolts, obviously a reference to its nickname "Lightning II". The other version flying is the U.S. Marines F-35B VSTOL version currently undergoing flight test at Patuxent River, Maryland. The Navy version, F-35C, which will have a larger wing, stronger landing gear and tailhook for carrier operations, has not flown yet.

The F-35 has been receiving a fair amount of attention recently because it is one of the most expensive DOD programs, and has been flagged for schedule delays and cost increases. So far there have not been any big technical issues.

Lots of Bull With Record Skydive Attempt

2010-03-16T23:58:00Z

I've noticed more and more coverage in recent months of another attempt to break the 50 year-old altitude "record" for skydiving, including this article in the New York Times science section. Sponsored by the energy-drink maker Red Bull, the Stratos project appears to be well-funded venture, with a team consisting of veterans from the aerospace industry including Joe Kittinger, who made the highest free-fall skydive of 102,800 feet back in 1960. (Though when Kittinger made his jump, he wasn't trying to break any records. He was doing it as part of pioneering aerospace research in the early days of the space program.) Like this other attempt to "out-jump" Kittinger that I previously blogged about, Red Bull is claiming that the Stratos project will provide valuable scientific data on bailout for future astronauts. After reading about this project, my BS meter was again fully pegged. I remain just as skeptical about the Red Bull science as justification for this project as I did for French sky diver Michael Fournier. The only difference is the Red Bull team is much better funded than Fournier. As I wrote previously, there really isn't much to be gained from these type of high altitude parachute jumps. In my experience working on high-performance escape systems, including participating in studies on escape systems for the hypersonic X-30 National Aerospace Plane and the Space Shuttle, manual bailout is not a viable option for escape from high performance aircraft and/or spacecraft. Emergencies happen so fast that you would never have time to manually bailout, especially if there were multiple crew onboard. You really need some type of automated, encapsulated escape system to protect crewmembers at extreme speeds and altitudes. The military and NASA already realize this, and that is why you don't see them doing anything remotely like this anymore. Even if you could justify this project on scientific grounds, risking a person's life would not be the way to do it. The latest scientific manikins (crash dummies) built today are so sophisticated that they can provide much more physiological data than anything available when Kittinger made his jump. That's why you never see human testing of aircraft escape systems, or even less risky car crash testing, any more. I'm sure Stratos sky diver Felix Baumgartner is a very competent and courageous person, but let's not be fooled that he and his sponsors are doing it for the sake of science. Red Bull's marketing is all about adventure sports and breaking records, and to me, this looks like the ultimate marketing ploy to sell a whole sh--load of energy drink.

The Aerodynamic (Winter) Olympics

2010-02-27T15:35:00Z

I was talking with a friend of mine the other day who is also an aerospace engineer, and he made a very true statement. He said that much more than the Summer Olympics, the Winter Olympics is all about aerodynamics. Even though I have blogged about the use of aerospace technology in the Summer Olympics, the use of aerospace technology, and especially aerodynamics, is even more important during the Winter games. In many of the sports, the difference between gold and bronze is usually hundredths of a second. At this level, the athletic prowess of the top athletes are so comparable that it is usually the one with the best technology, including aerodynamics, that winds up standing on the podium. Wind tunnel testing has lead to refinements in bobsleds, luge and skeleton equipment, along with the slick race suits all the skiers (cross-country and alpine) and speed skaters wear. Wind tunnel testing has also been used to "fine tune" the body position of alpine skiers as they rocket down the slopes. Generally the higher the speed of the Winter Olympic sport, the more important is the aerodynamics. This is especially true of the downhill alpine event and the bobsled, both events where speeds in excess of 80 mph are common. But the winter sport that has seen the biggest advancements due to aerodynamics is ski jumping. Ski jumpers use to jump with their skis parallel. But back in the 80's, wind tunnel testing revealed that a V-shaped position of the skis produced greater aero lift, longer flight times, and thus greater jump distances. Also, watch closely during the slow motion video of the jumpers and you can see how they make small movements of their hands to adjust their flight path. They are using their hands just like a rudder or ailerons on an aircraft to control the yaw and roll of their body. I'm sure these techniques were also refined in the wind tunnel to give ski jumpers the best chance of taking home a medal.

Aerospace Engineering Ranked High in CareerCast Job List

2010-01-30T15:39:00Z

Here is some good news if you are an aerospace engineering college student currently struggling with fluid dynamics or stability and control courses: a recent list of 200 jobs ranked by CareerCast.com shows Aerospace Engineering coming in at number 18. The web site rankings, from best to worst jobs, were based on a score compiled using five major categories: work environment, stress, physical demands, income and hiring outlook. After compiling the scores, CareerCast listed Aerospace Engineering as the second highest engineering field, only two notches behind Industrial Engineering. The good news is that even though the hiring outlook for industrial engineering was higher than Aerospace (very good vs. moderate), the average salary for aerospace engineers was almost $20,000 more per year than industrial. Even though the airline industry (and thus orders for new aircraft) has taken a big hit with the recent economic downturn, I would surmise that the job market for aero engineers is still relatively good due to the strong defense budgets in the U.S. This is a big turn around from when I went to college in the late 70s, with friends trying to talk me out of aerospace engineering due to the dismal job market. (The aerospace industry was still reeling from the end of the Viet Nam war, the Apollo space program and the cancellation of the Boeing SST. Thousands of aero engineers lost their jobs, especially in the Seattle area, leading to this infamous billboard near Seattle's airport.) They suggested I switch to a more broad major such as mechanical engineering, but my interest in aviation and space was so strong I didn't want to compromise my dreams so early in my career. I stuck it out with aerospace engineering, managed to get a co-op job with the DOD while still at Purdue University, and then a full-time offer at graduation. Since then I have been working steadily in aerospace for over 28 years, and haven't regretted my career choice. It's been challenging, interesting, and most of all, rewarding. So for you aerospace engineering students still slogging your way through one of the toughest undergraduate programs you can take, hang in there. The hard work will be worth it, just as the CareerCast list indicates.

One-Man Electric VTOL Concept Proposed By NASA

2010-01-21T02:31:00Z

The web was awash with stories today on an intriguing concept for a personal Vertical Take Off and Landing (VTOL) aircraft being studied by NASA. Called the Puffin, the one-person VTOL would have twin rotors/propellers and be powered by small electric motors. Several web sites, including Scientific American, had stories providing details on the Puffin. Conceptual pictures show the Puffin taking off and landing on it's tail, similar to the experimental Convair XFY Pogo that flew successfully way back in the 1950s. A NASA video shows how the Puffin would take off, transition to horizontal flight, and then back to vertical flight for landing. It appears that unlike tilt-wing or tilt-rotor aircraft such as the Bell-Boeing V-22, the Puffin rotors are fixed, and transitional flight is accomplished by deflection of aerodynamic tail surfaces under the influence of the rotor down-wash. Also unique is the fact that the pilot would be in the standing position for take off and landing, but in the prone position during horizontal flight. Not explained in any of the info I read about the Puffin is what would happen if you had a failure of one of the electric motors driving each rotor, resulting in a very dangerous asymmetrical thrust situation. In the twin-engine V-22, both rotors are can be powered by a single engine driving an interconnected shaft if one engine fails.

While the Puffin concept is intriguing, it is currently just some pretty computer-generated pictures and video. Though it has a healthy pedigree with engineers from NASA, MIT and Georgia Tech behind it, I'm always somewhat skeptical of these ideas for radical flying machines, especially VTOL types. While I applaud any new aerospace concept based on sound engineering principles, the Puffin researchers will have to get a prototype or scale model flying to begin to win me over.

Successful Solar-Powered Aircraft Flight Over the Alps

2009-06-16T01:37:00Z

Though it didn't receive much coverage in the mainstream press, the recent flight of the Sunseeker II solar-powered aircraft across the Alps in April showed that the technology for such flight is advancing rapidly. The motor-glider sporting solar cells on the wings and horizontal stabilizer was piloted by one of the pioneers of solar-powered flight, Eric Raymond. I wrote a blog entry last year about electric aircraft, including the work of Raymond and his early solar flight achievements with Sunseeker I way back in 1991. It was good to see Raymond finally receive some mainstream media (MSM) coverage in a recent New York Times article. As impressive as the aerospace/solar technology integration engineering that Raymond is doing, his web site about the European flights of Sunseeker II is equally impressive. The site features some spectacular photos and video of Raymond piloting Sunseeker II over the Alps. With the automotive industry spending millions to develop electric cars, I think you are going to see the development of lighter, more powerful and less costly battery technology, some of which can be applied to light aircraft. Thanks to pioneers like Raymond, electric flight may become practical sooner than later.

Terrafugia Roadable Aircraft "Transitions" to Flight

2009-03-19T00:59:00Z

The Terrafugia roadable aircraft ("flying car" is so yesterday) flew for the first time on March 5, 2009, according to a statement and videos on the company web site. Called the "Transition", the light aircraft/car hybrid was designed, developed and built by aerospace engineering graduates from MIT. As I wrote about in one of my blog entries a little over a year ago, of all the "flying car" concepts I'd seen throughout my career as an aerospace engineer, I felt this one had the best chance of not only flying, but being successfully marketed and sold. Looking at the video posted on their site, it looks like they were very conservative on the first flight, basically flying straight and level only about 50-100 feet off the runway. It appears that the test pilot then landed straight ahead on the long runway at Plattsburg, NY, although you can't really see it touching down. (I'm still curious to see how it lands, especially with its four-wheel landing gear.) The runway at Plattsburg is over 11,000 feet long, which was probably why it was chosen for the first flight. The long runway, built to accommodate B-47 and B-52 bombers during its military days, is also 200 feet wide, making it an ideal place to fly an untested aircraft. As was predicted by the Transition team, the takeoff angle was relatively flat compared to the high pitch angle seen on many light aircraft takeoffs. The low wing, short coupled fuselage configuration pretty much drives a flat takeoff angle, leading to a longer takeoff roll, so the Transition will not be the ideal aircraft to fly off of short runways. Even though the video only shows the airplane flying straight ahead, there is a still photo that shows a Cessna flying chase next to the Transition that seems to indicate that it flew higher than shown in the video. It's possible that the aircraft flew a complete circuit around the airport on a subsequent flight, but that the company is waiting to show that more exciting video at a later time.

So, we've seen the Transition driving on the road, and now in flight. It appears that the major technical obstacles of a roadable aircraft have been overcome. For aerospace engineers, that may actually be the easy part. Since I wrote my blog entry about the Transition in February 2008, the projected price has ballooned from $140K to almost $200K. In these very difficult economic times, will Terrafugia have not only the money to finish development and certification, but also enough orders to begin and maintain production? As an aerospace engineer, I'm definitely pulling for them to succeed. If they do, it could inspire more young people to pursue an aerospace engineering degree, knowing that one day they may not only be able to start a successful aerospace company, but have a heck of a lot of fun doing it.

Supersonic Transport History From an Old LIFE Magazine

2009-02-24T19:59:00Z

I was cleaning out some old magazines recently when I discovered an interesting article about the first flight of Concorde, the British-French Supersonic Transport (usually shortened to SST when first referred to in the 1960s). It was in an old LIFE magazine article from March 14, 1969. The cover story for that issue was about the Grumman Lunar Excursion Module (LEM) which was used to deliver astronauts to and from the lunar surface during the Apollo space program. That's probably why I had that issue laying around. However, as I was paging through the magazine, I stumbled upon the article "The Race for the SST" (pictures below of the title page, and also of a side box article titled "Meanwhile, back in Seattle, Wash..." ). The article talked about the race for the first commercially viable supersonic transport, and mentioned how the Anglo-French Concorde and the Russian TU-144 had already flown, while all the U.S. had to show was a fiberglass mockup. The article went on to mention that the U.S. design by Boeing was at least three years behind the other two SSTs. But it would offer superior speed (more than 300 mph faster) and passenger capacity (229 versus just over a hundred for the other two designs) when it did fly. I remember seeing pictures of the Boeing mockup when I was a kid, but I always thought it was about the same size as Concorde or the TU-144. Having seen the Concorde and TU-144 in person, I can tell you they are not very big aircraft - similar in size to a DC-9. Discovering this article I learned that the U.S. SST, if it would ever have been built, would have been a much larger aircraft. Even more surprising to me was to read that Boeing already had orders for 122 aircraft from 26 different airlines, even though they had only built a partial mockup. Alas, the U.S. SST never took off, grounded by budget and sonic boom issues. Russia only flew their SST commercially for a few years, and then relegated them to hangar queens. However, I happened to see one of them parked at Zhukovsky airfield outside Moscow during a trip to Russia in 1993. Grounded at the time of my visit, it eventually flew again as a supersonic test bed partially funded by Boeing and Rockwell. Of course the famous Concorde was flown successfully by British Airways and Air France for almost 3 decades before finally being removed from service in 2003. Seems they were so costly to operate, though, that they were more status symbols than money makers for the two carriers.

Factors That Helped Flight 1549 Avoid Disaster

2009-01-17T16:12:00Z

The successful ditching of US Airways flight 1549 in the Hudson River has made headlines all over the world since the mishap occurred on Thursday, and rightly so. At a time when the whole world, and especially the U.S., is in a deep funk, a feel-good story of quick-acting professionalism and heroism by every-day citizens can't help but lift people's spirits in the dead of winter. There is already a lot of info on the web and in the main stream media about the crash, so I won't rehash much of that. I will give my opinion, as an aerospace engineer and private pilot, on the factors I feel helped make the ditching of US Airways Flight 1549 so successful.

When I first heard about the mishap as I left work on Thursday, a co-worker said a flight departing LaGuardia airport in New York city had ditched, and that survivors were seen leaving the plane. My first thought was that the plane, an Airbus A320, had run off the end of a runway and into Flushing Bay by LaGuardia, similar to a USAIR 737 accident in 1989. In that mishap, all but two of the passengers and crew survived, mostly because the plane was in shallow water just off the end of the runway. As more details of flight 1549 emerged, I heard that it had ditched in the Hudson River. Hmmm, the Hudson is on the other side of Manhattan Island from LaGuardia airport, I thought, so this must have been a real, but very rare, ditching of a commercial aircraft on water. As soon as I got to a TV, I saw that in fact the A320 had glided to a controlled ditching in the Hudson River after both engines "flamed out", most likely (at the time of this blog entry) to bird strikes. Early pictures showed the plane floating intact, with the nose, wings and the forward two-thirds of the fuselage out of, or on top of, the water, with a bunch of passengers standing on the wings waiting to be rescued. It turned out all 155 passengers and crew survived with minor or no injuries, another rare feat in an even rarer occurrence.

So what went right to make flight 1549 100% survivable? Here is a list of factors I think helped:

1. First, a very experienced flight crew, including pilot Chesley Sullenberger and co-pilot Jeff Skiles. Sullenberger had almost 20000 hours of military and civilian flying, is an adviser on aviation safety issues, and also a glider pilot. Sullenberger's experience as a glider pilot would have given him knowledge of how an aircraft without power handles inflight, and also provided a rough idea how far the A320 could glide without engine power. Obviously not far enough to get to the closest airport in Teterboro, N.J., so he made the wise decision to ditch on the Hudson river.

2. The A320 had reached a sufficient altitude (about 3000 feet above ground) to allow the flight crew some time to make critical decisions about where they could land. If the bird strike had happened right after lift-off from LaGuardia, their options would have been very limited. This altitude also allowed them to have control of the aircraft all the way down to the water. It looks like they had full control of the A320, and the altitude allowed them to set up a landing on the river just as if it had been a runway. It's always better to have a controlled crash than an uncontrolled one.

3. The mishap occurred during the day. This is very important. If it had happened at night, it would have been much tougher for Sullenberger to judge how far he was above the water during the ditching. It can be tough even during daylight to judge your height above water due to depth perception issues, but at night, with no visual cues, the aircraft could have hit the water at a higher velocity or sink rate, possible damaging the aircraft further. Also, night time makes it more difficult for rescuers to find victims, and it would be easy for a passenger to slip under the water and drown without rescuers noticing.

4. The A320 did not break up on impact. If the fuselage had broken apart, or a wing broken off, the plane would probably have sunk much quicker, leading to a higher probability of fatalities. It appears that at least one of the engines, which are mounted under the wings, tore off, but without significantly damaging the wings. This is critical too, since the engines probably acted like big scoops when they hit the water.

5. The planes wings were full of fuel, which helped keep the plane afloat. Since the plane had just taken off for its flight to Charlotte, the wing fuel tanks were probably full. Since aviation fuel is lighter than water, the fuel tanks acted like big flotation bags. You can see this in the numerous pictures that show many passengers standing on the wings waiting to be rescued, yet the plane is floating perfectly stable in the Hudson River.

6. The plane ditched on one of the busiest waterways, right next to the largest city, in the U.S., allowing quick response by rescuers. That section of the Hudson has many passenger ferries plying the river from New Jersey to Manhattan throughout the day, and the first ferry reached the downed plane within minutes. On a cold, January day when the water temperature was near freezing, survivors would not have lasted long in the frigid Hudson river. Also, NYC has numerous Coast Guard and police rescue units that were quickly on the scene with boats, helicopters and rescue swimmers to aid in the recovery.

7. Finally, aircraft safety features required by the FAA and developed through years of aviation accident lessons-learned helped everyone survive. These features include 16-G seats that don't break away from the floor during a hard impact. When seats break from the floor, it makes evacuating a full plane much more difficult. The emergency slides inflated from the exits are also designed to be used as life rafts, and you can see the passengers sitting on the slides/rafts waiting to be rescued, just as designed. Also, you can see many passengers wearing those yellow life vests that flight attendants demonstrate (but many passengers ignore) before most commercial flights.

Because of the successful outcome of this rare ditching mishap, I'm sure this accident will be studied for years to come by aviation safety experts. When studying aviation accidents, it has been shown that it usually takes a certain chain of events to occur in a particular order for a normal flight to turn tragic. Break any one of those links in the chain, and the accident would not have happened. The same can be said about the survival factors for flight 1549. If any of the factors that I mentioned above had not been present, there is a good chance that some of the passengers or crew on the A320 would not have survived. This time all the factors lined up to their benefit, and for once we can all applaud some very good news.