September 2010 Archives

A spate of flat tyres has beset the operators of Embraer's new light jet, the Phenom 100. The latest incident occurred on 25 September at the Williams-Gateway airport in Mesa, Arizona, involving the aircraft pictured at the bottom of the page (N644RM).

According to the FAA, the pilot reported brake problems during his approach to the airport at 9am that morning. "The plane subsequently blew both main tires while landing," the FAA says. "There was no other damage to the aircraft and nobody was injured. The Scottsdale FSDO is investigating."

In a similar-sounding incident two weeks and one day before, a Phenom 100 landing in Texas also blew both main tires. In that case, the pilot had received a brake failure message during the flight. When he landed, the Phenom 100's brake-by-wire system had indeed failed, so he resorted to use the approved backup method - the emergency brake. The emergency brake however is quite sensitive -- if you pull too hard, you blow the tires. Here's an article I wrote about the incident, with an eyewitness account. 

The NTSB is investigating the Texas incident, but Embraer has been looking into the problem for some time, and is retrofitting new brake controllers and other equipment into the fleet to fix the issue.

Eurocopter has unveiled its long awaited "X3" technology demonstrator helicopter, a new design first hinted at (by mistake) at the 2009 Heli Expo show. Rolls-Royce made the blunder, saying they had provided an RTM 322 turboshaft engine to Eurocopter for the X3 program, after which all high ranking officials associated with the program turned white and lost their ability to speak!

Based on some patent applications, we had sort of thought the X3 would look like this...

Instead, Or like this other patent app:

Eurocopter today unveiled the actual demonstrator design, which the company says will be used for long-distance search and rescue, coast guard duties, border patrol, transport missions and inter-city shuttle services.

The company says in today's press release: "The X3 demonstrator's first flight occurred September 6 in southern France at the Istres Center of "DGA Flight Testing", which is operated by the French DGA government agency and ensures a secure and controlled environment. Initial testing will continue through December with reduced power, progressively opening the flight envelope to speeds of approximately 180 kts. After a three-month upgrade, X3 flights will resume in March 2011 with the goal of reaching sustained cruise speeds in excess of 220 kts.

The unveiling comes just on the heels of Sikorsky announcing that it's very cool looking tech demonstrator, the X2, has exceeded 250kt and has a lot more ummph left in its speed envelop.

Based on what Eurocopter has built, I think Sikorsky won the first round of who's got the coolest new helicopter.

Here it is (below). What do you think? Personally, I don't see how Eurcopter will keep passengers and crew from getting sliced and diced by those props!

An observant (read: Eyes outside the cockpit) Delta Airlines Boeing 757 pilot prevented what could have been a disaster late Sunday night at the JFK Airport in New York.

The attached audio file, prepared by a contributor to the LiveATC.net website, reveals that the tower had given Delta flight 122 ("Delta 122") the Ok to move into "position and hold" on Runway 13R for a departure to Ireland. The pilot calls back, however, and says someone else -- a Galapagos Aerogal Boeing 767 ("Aerogal 700 heavy") arriving at the airport from South America -- looks to be aiming for his same piece of real estate.

The emotion in the controller's voice shows how close this call may have been. Click on the file below to launch your MP3 player, then grab something and hold on...

JFK_wrong_way.mp3

Here are some additional facts and figures that Sikorsky has provided regarding its 15 September high speed flight of the X2 technology demonstrator in Florida.

• To date, Sikorsky has flown the twin contra-rotating main rotor pusher for 17 flights and 16.2 flight hours.
• Sikorsky expects to fly four more flights before the vehicle is retired, after which it will likely travel to a variety of airshows as a static display item. Two of of the four remaining flights will be for noise measurements; the other two for speed.
• Test pilot Kevin Bredenbeck reached the 250kt target speed for the program about halfway through the 1.1h flight at 5,500ft altitude. Aircraft weight was approximately 6,500lb
• Bredenbeck says there was approximately 300hp of power reserve in T800 engine at 250kt
• The main rotor was slowed by 5% compared to hover speed for the high speed cruise testing
• Bredenbeck says vibation levels with the active vibration cancellation system on were "consistent with Blackhawk at 140kt cruise speed". He says the vibration levels plateua at about 200kt and remain the same thereafter  
• Bredenbeck accelerated to 260kt by putting the X2 in a shallow dive of "1-2 degrees" nose down
• Control feel: Bredenbeck says it flies like a fixed wing aircraft "as soon as you utilize the prop and go into X2 modes". Sikorsky exercised the X2 through 30 deg of bank and up to 1.5G, though pilots have flown some "higher aggressive profiles" in simulator, says Bredenbeck, adding, "Yet to be discovered is the potential of this aircraft"
• Test flights have provided a "test verified" digital model of the X2 which is being used for future designs  
• Fuel burn - Sikorsky says that the X2 at 210-220kt speed has the samne fuel flow as a conventional helo at 120-130kt due to its improved lift-to-drag ratio
• Sikorsky is currently installing a "sail fairing" between the two main rotors for the upcoming two high speed flights, which could see cruise speeds beyond 265kt. The picture below shows how the stationary fairing is mounted

I like trying to figure out what a manufacturer might be up to based on subtle and not-so-subtle clues. In the case of Sikorsky's very fast X2, which hit its programme target speed of 250kt earlier this week and will go faster soon, I thought I had deducted the perfect reason for a N-number change a few months ago.

In May of this year, N41AX morphed into N525SA. Why I wondered? Hmmm. Must have something to do with speed. Let's see, if 525 were a speed, it would likely be km per hour which converts to 284kt. Bingo! Well, sort of..,.

Sikorsky X2 chief engineer Steve Weiner told me that the X2 will likely go faster than 165kt in the coming months as the company puts the finishing touches on rotor fairing (here's an associated Flight International story), but almost another 20kt faster?

Wow. I was on to something BIG. 

Next I asked Sikorsky media relations exec Marianne Heffernan what the N525SA stands for, expecting that she'd deflect the question and quickly discuss the weather or the Washington Redskins woes. She'd know I was on to their secret plan.

Alas, no. 

Marianne says Sikorsky changed the registration to N525SA (Sikorsky Aircraft) in May for a very honourable reason - to mark the 25 May birthday of its founder, Igor Sikorsky.

I'm not giving up yet though as there may be a double entendre at play. What better way to honour Mr. S than to hit 525 km/h with a new aircraft with top speed written on the side? 

University of Maryland aerospace engineering doctoral candidate, Evan Ulrich, has developed a new micro air vehicle that, like the bumble bee, should technically not be able to be flown and controlled, yet here it is.

Ulrich has started a new company, RoboSeed, to market the fruits of his masters and doctoral labour.

Here's a video of Ulrich talking about and flying the latest version of the RoboSeed at the University of Maryland Robotics Center open house on 10 September 2010.  

Here are more details on the program for a story I wrote for the 21 September issue of Flight International:

RoboSeed perfects single-wing rotorcraft
John Croft / College Park, MD

A biologically inspired graduate school project taken on by a University of Maryland student could become a money-making commercial venture for the doctoral aerospace engineering candidate later this year.

Evan Ulrich's thesis topic - controlling the flight of a maple seed, or samara - has led to an unusual but surprisingly viable unmanned air vehicle that he is not only using as a dissertation topic but as the launch platform for his new company, RoboSeed.

Since beginning the project in 2005, Ulrich has built more than 100 versions of the patented device, which he says is the world's smallest single-wing rotorcraft. Wing spans have ranged from that of a maple seed, about 3.5cm (1.4in), to 50cm. The most recent version, which

Ulrich is marketing to military and government agencies, features carbon fibre construction and an 18cm wingspan. With a 480mAH lithium polymer (LiPo) battery, the $500 device weighs 72g, can fly for 15 minutes at an altitude of 150ft (45m) under the control of an operator with a two-channel radio control unit. Alternate designs have flown for as long as 30 minutes at up to 400m altitude, says Ulrich.

During the research phase of the project, Ulrich studied the effect that changes in wing geometry have on the different flight dynamics of a samara through drop testing in the laboratory. "We found that the seed will travel in one of two flight paths - either straight down or a helical flight path, the difference between the two being the wing angle," says Ulrich.

It turns out that a high wing angle with respect to the ground plane, causes the samara to go in a straight line down while a low angle causes it to fly in a circle, the size of which depends on the angle. This led to a control scheme which uses an electric motor and propeller to provide the rotational energy that gravity offers in nature, and a wing pitch mechanism to control the radius of the circular path. After the motor is running, the operator controls the flight path through the pitch control only, with higher wing angles resulting in a tighter circle. If power fails, the device autorotates to the ground, seed-like, and the tough construction prevents damage to any components.

Tradeoffs between weight and payload will be key going forward. Ulrich says about 30% of the RoboSeed's weight, or about 20g, comes as a result of protective features of the design, which have made it a rugged test platform.

The first job of the new company, which Ulrich hopes to devote his full attention to once he receives his doctorate degree later this year, is to develop sensor packages and a closed loop autonomous control system for the RoboSeed. Ulrich plans to install a video camera payload, that in combination with a miniature on board magnetometer for attitude control and software for image processing in an iPad or other PDA device held by the operator, will allow for low-cost surveillance in combat zones or border areas. "At a height of 150ft, the RoboSeed would give an extended line of sight up to 10 miles in every direction," says Ulrich. Estimated cost for such a system would be about $50,000 per unit, which would include the 40g sensor package and extra battery.

"With this particular application, we're able to compete with the Predator drone for border patrol," says Ulrich. "For $5 million, you could have 100 of these covering 20 mile diameter circle each along the entire border."  Given the simplicity of the device and its manual control, Ulrich says no US Federal Aviation Administration approval would be required.

Another potential military application will be to use the device for 3d mapping of tight areas, such as caves. For this work, Ulrich says the RoboSeed would have to be fully autonomous and carry a laser range finder for obstacle detection and avoidance, magnetometers for control and accelerometers for directional sensing. Ulrich is hoping to work with Lockheed Martin on such a program, with Lockheed supplying the sensor suite. Lockheed is also researching the maple seed concept internally with its Samurai nano air vehicle program.

On the civilian side, Ulrich is trying to get the National Atmospheric and Oceanic Administration to consider the RoboSeed as a low-cost method of obtaining pressure, temperature and other data inside of tornadoes and hurricanes. -ends-

On the market later this month will be a truly unique, but otherwise baffling flying machine, the AirBouyant VertiPod 2 (VP2).

AirBouyant bought design from Virginia-based Performance Aviation Manufacturing as the PAM 100B individual lifting vehicle in 2008, with plans to "aggressively" build and market the personal air vehicle (PAV).

On its website, Indiana-based AirBouyant at the time had said the VertiPod 2 would carry two people and fly at 60mph, though the company admitted the design "will require a lot of refinement to make it a viable, supportable, and safe product for the general flying public". The intent was to begin selling the twin-engine, contro-rotating propeller driven PAV in kit form for $60,000 some time in 2009. "We intend to take our time to do it right, but we will not string the market out indefinitely in R&D delays," the company stated.

Here's some video of a PM2 test flight that didn't go so well...

Improvements over time have included a protective pilot's "cage", "simplified" controls, new rotor blades, and a new, improved main frame. Operators control the PAV by using the throttle for altitude and weight-shifting for forward and aft motion control. It also has two propellers, one on either side, for yaw control.

In its announcement, AirBouyant says the VP2 can "skim over flat or rutted ground, grass, sand, or water, at speeds of 20mph or more; and its useful load allows full fuel plus 400 pounds, making it possible to add instrumentation or equipment in further development".

There's one requirement on the prospective new owner however. AirBouyant president Pete Bitar says he's looking to sell the prototype to "someone or some museum that will appreciate it".

A new paper by a Sikorsky technical fellow involved in the X2 technology demonstrator program reveals that an attempt to reach 250kt (the target speed for the advancing blade concept, coaxial rotor vehicle) in August ended with significantly less.

Published by the IEEE this month, the paper, written by Thomas Lawrence (the technical fellow) and David Jenney reports that engineers had planned to reach the 250kt (463km/h)speed goal during a flight in August, but the LHTEC 800-powered pusher quit accelerating at 235kt (435km/h). In July, Sikorsky announced that the aircraft had reached 225kt (417km/h).

..Most recently, we set our sights on 463 km/h.

On the day of that flight, in August of this year, the test team got started at the crack of dawn. To ensure that the pilots would be flying in smooth air, the crew had to be on site by 5:00 a.m., before the sun had a chance to heat the air enough for the wind to pick up. The crew rolled the aircraft out onto the runway, where a dozen safety officers in bright orange jumpsuits and noise-canceling headsets were on patrol. Two chase vehicles were there to observe the test flight--another helicopter and a fixed-wing turboprop. The latter would be needed to keep up with the X2 as it accelerated to higher speeds. The test team was on high alert as it orchestrated flight activities to keep the three vehicles a safe distance apart.

With everyone's nerves on edge, the X2 started up its engine at 6:30 a.m., and the helicopter took off. Within a few minutes the X2 had reached a speed of 350 km/h. A dozen people watched from the ground as the airspeed crept up, first to 400, then 410, and finally topping out at 435 km/h--not quite the goal we'd set, but good enough for this round. Cheers and applause broke out on the ground. The pilot slowed the X2, turned it around, and flew back to land on the runway....

Even so, Sikorsky broke the long standing official speed record for a helicopter set by Westland Lynx in 1984 at 216kt (400km/h). The company's own XH-59A coaxial demonstrator in the early 1970s however recorded an unofficial speed of 263kt (487km/h), though technology at the time couldn't handle the types of vibrations required to go that fast.

The company has said it will continue pushing the X2 until the end of September, with  simulations putting the ultimate top speed between 251kt and 264kt, just a tad faster than the XH-59A.  

Roadable aircraft maker Terrafugia says it is "setting up for low-volume production" of its Transition car/light sport aircraft (LSA) as early as late 2011 in a new 19,000ft2 facility in Woburn, Massachusetts.

The company unveiled its latest design at the EAA AirVenture show in Oshkosh, Wisconsin in July.

Compared to the test aircraft, which flew 28 short-duration test flights at low altitudes over the runway, the new design will feature a single stabilator at the back of the aircraft, with an open rather than closed fuselage bottom that allowed for a larger, three-blade pusher propeller between the twin tail booms. For ground transport, the Transition's 100hp Rotax 912S engine will power the rear wheels rather than the front wheels on the proof-of-concept vehicle. Wings continue to fold in toward the cabin accordian-style

Two prototypes are now under construction in the facility, says Terrafugia, one of which will undergo drive testing while the other will be used for LSA flight testing to earn ASTM validation.

"Experience from the construction of these prototypes will also be used to finalize the initial price point of the vehicle, which is expected to be between $200,000 and $250,000, says the company.

Here are some pictures just in of the diminutive Cri-Cri on the ground and in the air during its first flight in France today... Original story below.

EADS says its all-electric, four-propeller Cri-Cri composite single has achieved first flight at Le Bourget airport near Paris on today.

Built by EADS Innovation Works, Aero Composites Saintonge and the Green Cri-Cri Association, the low-wing technology testbed was unveiled as the Green Aviation Show at Le Bourget in June.

"Take-off and climb were smooth, no vibrations could be felt and manoeuvrability was excellent," says EADS in a press release. "All systems performed well and the plane returned safely after 7 minutes."

The electric aircraft is designed for 30 minutes of autonomous cruise flight at 68mph, 15 minutes of autonomous aerobatics at speeds reaching up to 155mph and a climb rate of approximately 1,000fpm.

"We are allowed to start aerobatic manoeuvres only after five hours of flight and 15 landings, says test pilot Didier Esteyne. "But we are still at the beginning and have a lot to learn.

EADS says it hopes to "get a lot of useful information out of this project" for powered larger aircraft with batteries in the future. The Cri-Cri is based on a French home built design.

"The aerobatic plane incorporates numerous innovative technologies such as lightweight composite structures that reduce the weight of the airframe and compensate for the additional weight of the batteries, four brushless electric motors with counter-rotating propellers which deliver propulsion without CO2 emissions and significantly lower noise compared to thermal propulsion, and high energy-density Lithium batteries," says the company.

Judging from this year's EAA AirVenture, all-electric is hot all around, with Sikorsky even prepping to fly an all-electric helicopter, the Firefly.

Jepp has issued a one-time approach chart title "Hudson Miracle" to a very special group of aviators - Pilots Sully Sullenberger, Jeffrey Skiles and flight attendants Sheila Dail, Donna Dent and Doreen Welsh. Sully (right) and Skiles (centre) are pictured with Jeppesen president Mark Van Tine.

If you don't recall, Sullenberger and Skiles piloted the goose-whacked US Airways A320 that ditched in the Hudson river just west of New York city on a very chilly January day in 2009.

Jepp presented the comical chart (below) to Sully and Skiles at this year's AirVenture show at Oshkosh.