July 2009 Archives

Images from the public unveiling of Piper's new single-engine PiperJet at the AirVenture 2009 show in Oshkosh, Wisconsin, this week reveal a new tailpipe design for the Williams International FJ44-3AP turbofan engine.

Compared to the prototype I saw in Florida at Piper's home base one year ago (left)...... 

 

....the Oshkosh version (right) appears to be shorter, with less up-tilt, but with a top-hat extension on the top side.

Could this be a Coanda effect modification that Piper had revealed it was working on with Williams last year?

If so, the top hat would likely tilt upward at during high-power situations, causing the engine's thrust to bend upward, thereby reducing the downward turning pitch moment caused by high-thrust line of the tail-mounted engine. Piper had been spending much time and energy trying to minimize such pitch changes to make the aircraft pilot-friendly, particularly in high-thrust situations like go-arounds. 

Below is the video of the PiperJet taken by my colleagues at FlightGlobal at the Oshkosh show this week, showing the tail pipe and other details of the PiperJet in much more fidelity.  

The fatal connection between a flock of American white Pelicans and a Cessna Citation 500 business jet at 3,100ft over a lake in Oklahoma in March 2008 is the fuel behind some new safety recommendations issued by the US National Transportation Safety Board yesterday.

The collision with one or more of birds, which tend to weigh on average about 20lb according to the Smithsonian's Natural Museum of History, took out the right engine but more crucially, damaged the aircraft's wings to the point that it was uncontrollable.

The resulting spiral, simulated by the NTSB below, sent the two pilots and three passengers to their deaths.

 

After some rehashing of radar data, investigators determined which clutter was most likely the flock of pelicans in the vicinity at the time. Blue dots indicate pelicans while the aircraft's track after it departed the Wiley Post Airport in Oklahoma is in yellow.

Here's the ultimate result of the collision...

First, an image from a surveillance video camera in the vicinity.

Then the final outcome...  

What can be done?

The NTSB made 10 new recommendations, some dealing with how the aircraft was operated, but others focused on mitigating the increasing frequency with which birds and aircraft are meeting.

The simplest strategy, other than see-and-avoid, is to give pilots an understanding of the bird strike energy for which their aircraft are certified. Under Part 25 certification rules, a Cessna Citation 500 must be able to sustain a hit to the wing of a 4lb bird at cruise speed and be able to continue flying. and perform a safe landing.

The image below shows the damage caused by a 4lb bird at a cruise speed of 287kt...

The empennage must be able to handle an 8lb bird at cruise speeds.

The trick is to figure out how fast the airplane can then hit a 20lb pelican, assuming the pilot obtains information that such birds are in the area. 

Based in the laws of physics (kinetic energy = 1/2 * mass * velocity-squared), the equivalent energy of the 4lb at 287kt is 14,586 ft-lb, according to the NTSB. 

To stay below that energy, the aircraft would have to be traveling at 128kt or slower when it hits a 20lb pelican, according to my calculations. It's a large decrease in speed, but one that might be worth considering an aircraft's brief duration at such low altitudes, given the consequences..

What's the old saying - "An ounce of prevention is worth a lb of cure"? 

 

Cessna Citation jets in close formation at the Sapporo Air Show in Japan give this TV reporter something to shout home about. Translations anyone?

Q: How do you pollinate thounsands of acres of hybrid rice plants in Texas?

A: With a Robinson R22 helicopter.

This YouTube video posted by Mike shows almost 10 minutes of how it's done. Apparently helicopter-driven wind is a good way to move pollen from one plant to another, ensuring a good harvest of seeds, in this case, rice.

It's certainly low work (skids about 1ft above the plants), but it's not slow, and an occasional yaw maneuver, to get some air into the cockpit, shows just how maneuverable a rotorcraft can be.

The advanced avionics offerings of Cirrus are out to spoil pilots of all stripes. On an 8 July night flight in a Cirrus SR22 turbo, the company's top-of-the-line single, I sampled the aircraft's new enhanced vision system working in tandem with its synthetic vision system as Cirrus mid-Atlantic regional sales director Boni Caldeira worked the controls.

Side-by-side, the two make for a powerful situational awareness and safety tool. If you don't believe me, check out this video I made of a low approach to a very dark and deserted airport. Note the highway-in-the-sky boxes that are part of the Cirrus' flight guidance display on arrival to the airport and later showing the missed approach course.

Even with the runway lights off, the airport environment is laid out with the synethic vision, and unmasked with the Max-VIz EVS-600 enhanced vision system (EVS).

A US Coast Guard crew was witness to the agony of defeat for French kayaker Jean-Gabriel Chalala, who's monumental 20,000mi quest to circumnavigate the globe via human power -- kayaking and cycling -- came to an untimely end in the Bering Sea, 40mi off the coast of Alaska's St. Lawrence Island on Saturday.

Chalala had already kayaked across the Atlantic Ocean to Florida, then cycled to Alaska, only to succumb to fatigue and rough waters during a relatively miniscule 250mi kayaking leg to St. Lawrence Island..

A Coast Guard Jayhawk rushed to the scene, plucking Chalala from the waters and taking him for medical help for his mild hypothermia.

Fast forward to the 1:55 point to see Chalala floating away from his specially built kayak, which was not rescued.

 

Even from its Chapter 7 grave, Eclipse Aviation, maker of the now infamous Eclipse 500, continues its grim legacy, as Cirrus chairman Alan Klapmeier recently found out....

Klapmeier over the past few months has been out shopping for private equity to create a new company to finish development of the Cirrus Vision SF50 personal jet. What's on investors minds?

"Fairly quickly in conversations with investors, the statement, 'Hasn't Eclipse proven this can't be done?' comes up. It's always an obstacle that must be explained," says Klapmeier.

 "I would have much preferred that Eclipse was successful and people ask how we would compete."