Saturday, May 04, 2013

Aviation Update

The horrible crash of the Boeing 747-4 series cargo aircraft departing Bagram AFB was caught on tape and has now made the rounds of even mainstream news outlets, along with expert and non-expert commentary.   My commentary, aside from sincere condolences to the surviving family members, would be that the expert opinion about shifting cargo makes a lot of sense when combined with the video showing a high angle of attack followed by a stall.  But an investigation may reveal other things. 

Assuming a load shift occurred the question is how.  How did the vehicles get loose?   Was it a design problem?  Negligence?  Pilot error in climbing out?  Or perhaps sabotage, ie, were there any local Afghans helping service the aircraft?  The black boxes may shed some light on those questions--there was a report the crew mentioned a load shift over air traffic radio--but if that was causative it wouldn't necessarily shine any light on why the load moved if the cause was something that occurred during pre-flight.

Weather should not be completely ruled out either as there were thunderstorms in the area and some blowing dust, which could indicate downbursts in the area.  Most modern aircraft now have windshear detection equipment and it's likely the crew might have commented on weather before the incident, which would be picked up on the CVR.   There's also the possibility of malfunctioning flight controls or some other onboard system failure.  It may be awhile before something conclusive is learned.   

One thing the video does show clearly is that a shift in the center of gravity on a huge airplane like that while in flight causes a fairly immediate stall.  The government tried to say TWA800, a smaller 747-100, rose several thousand feet after it lost its forward section in a fuel tank explosion, which explained the streaks of light witnesses saw off the coast of Long Island during the evening of July 17, 1996.  Although the flight profiles were different this video seems to show the laws of aerodynamics better than the initial explanation given the American people about flight 800.


Keep in mind the flight was coming from Camp Bastion to Bagram for refueling before heading to Dubai.  It had taken off from there and landed safely at Bagram and did not add any additional cargo.  Meanwhile there was an explosion at Camp Bastian Thursday night and three Brit troops were recently lost in an IED explosion on a highway in Helmand riding in a vehicle thought to be resistant to such things, suggesting the Taliban have new detonation technology.  Add the five Americans lost this morning and it's obvious there is still a war going on over there whether the media or public wants to acknowledge it or not.  And the people attacking us are the people who sheltered those who attacked us on 9/11.  

While it seems (feels) like the National Airlines cargo crash at Bagram was just an accident the loss of a KC-135 stratotanker refueler in Kyrgyzstan on Friday seems a little more suspicious. While the NTSB tends to dismiss eyewitness testimony as being unreliable (it often is), here's what the locals are saying:
One resident of the agricultural and sheep-grazing area said the plane exploded in flight. “I was working with my father in the field, and I heard an explosion. When I looked up at the sky I saw the fire. When it was falling, the plane split into three pieces," Sherikbek Turusbekov told an AP reporter at the site.
Supporting that are pictures of the crash site: ...and the fact they haven't found the front section of the aircraft yet:
The front section of the aircraft has not yet been found, Kyrgyz Emergencies Minister Kubatbek Boronov told the Associated Press. He said searchers also have not found the flight recorders from the plane, which was badly burned in the crash.
..which suggests an in-flight breakup, unless the forward section was buried in the impact crater. An aircraft intact all the way down tends to leave a deep smoldering hole similar to United 93 on 9/11. An in-flight breakup would leave a larger debris field with shallower impact craters along with some pieces of the plane relatively intact and displaced, such as the vertical stabilizer or pieces of the wings. 

Before blaming this one on retaliation for Boston keep in mind the kids arrested on Wednesday were from Kazakhstan, not Kyrgyzstan (thank heaven for Firefox spellcheck). But as the Air Force Times relates, this does amount to the third aircraft loss in the AfPak theater in the last week, which is troubling considering the Taliban are on the warpath again and just killed five US soldiers with a roadside bomb in southern Afghan this morning.


The Daily Mail can be a great source on many stories, providing up to the minute content and pictures not available on most US mainstream news sites.  But they do tend to get a little loose with the facts at times, witness this report: "Terror in the sky":
Travellers were left fearing for their lives after an airplane engine burst into flames thousands of feet above ground. Minutes after the flight took off from a Helsinki airport with 168 people on board, the engine exploded and caught fire. The German-bound Airbus suffered a number of technical problems before streaks of flames emitted from the left engine, 15 minutes after leaving ground.
They include a picture of the jet at the link with a shoot of flame out the back.  Apparently it made a loud noise.

While the loss of an engine on takeoff is certainly problematical for pilots keep in mind that major two-engined commercial aircraft are designed to fly safely on one engine if necessary, certainly long enough to get to a nearby airport (this is how they are certified to cross the ocean). Based on the story this appears to be a 'compressor stall' or an engine failure, probably of the 'contained' variety.  Pilots train for engine outages all the time so while this might have been terrifying for the passengers it wasn't necessarily a near catastrophe, based on the facts contained in the story. 

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