NEPALESE ATR-500 CRASH APPEARS TO BE LEFT ENGINE FAILURE

The tragic loss of life in this crash is appalling and appears to be due to a loss of power on the left engine.

The airplane was approaching the airport slowly and as it slowed further it appears that it rolled into the left engine and went down knife edge into a ravine.

The video is a typical engine failure scenario where if one engine fails and power is applied with the remaining engine the aircraft will want to roll into the dead engine.

For that to happen the aircraft has to be slower than VMCA, the minimum control airspeed with engine failure and the good engine at takeoff (not landing) power.

What happens is that when surprised by engine failure or loss of power the crew may swimming in glue in the cockpit unable to address the airplane’s abnormal flying characteristics quickly enough to prevent it from going out of control.

Other potential causes are propeller failure which adds drag on the left side or just a stall (aerodynamic not engine) from getting too slow on the approach. One would hope with all the built in safeguards an inadvertent stall is the lowest likelihood on the list.

Lastly, every airliner today takes off overloaded. The weights of the typical passenger are much higher than the weights that are computed when the airplane is certified for both men and women (just look around you)and baggage is much heavier as well. This makes an engine failure even worse and stall speeds even higher than published.

The cockpit voice recorder and flight data recorders will be important as well as the experience and training of the crew. It would be important to see what speed the airplane was flying on this approach as it appears slow and that may well be a factor as control was lost.

May the memories of all aboard be a blessing to their families.

Arthur Alan Wolk

January 15, 2023

Contact The Wolk Law Firm
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c: (610) 733-4220
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Arthur Wolk presented with the Wilbur and Orville Wright Master Pilot Award

The Federal Aviation Administration presented the founder of The Wolk Law Firm, Arthur Alan Wolk, with the coveted Master Pilot Award.

It is reserved for those pilots who have dedicated themselves to aviation safety for fifty years.

The Wolk Law Firm is unique in that its founder holds multiple Type Ratings in jet aircraft, is airshow qualified for aerobatics down to 400 feet AGL and is airshow formation qualified.

He is also an Airline Transport Pilot for both single-engine and multi-engine land and sea airplanes.

The Wolk Law Firm is proud to acknowledge this achievement, demonstrating compelling reasons for it to be considered the standard against which all other aviation law firms are measured.

 

November 16, 2022

Contact The Wolk Law Firm
p: (215) 545-4220
c: (610) 733-4220
f: (215) 545-5252

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The FAA’s misinformation about airframe icing is like getting a gift of ice in the wintertime. For years we pilots have been taught that airframe icing can be expected when the outside air temperature is within 10 degrees F. of freezing and we are flying in visible moisture.

The same information is made applicable to jets but in most instances airliners have no anti-ice or deice over their tail surfaces, just heated leading edges of their wings and engine inlets.

Now there is a dearth of information out there of just what a manufacturer has to show the FAA to get Known Icing Certification and for good reason. If you knew, you would ground your airplane in icing conditions.

I was flying my Eclipse Jet out of Pueblo Co. yesterday and into the clouds that I had just vacated on my arrival. Even though the layers on approach were one layer at FL 200 (twenty thousand feet) and another at 12,000 feet there was no ice accumulated.

As I climbed toward the front range of the Rockies on my departure Westbound and looked at those nasty looking clouds over the mountains I remembered the words Orographic Cooling from my distant past and several cases I handled where jets were quickly overcome with ice in the mountains.

Orographic Cooling occurs when the winds are thrust up the windward side of the mountains and as they travel ever faster into the higher elevations the droplets of water that are clouds become supercooled.

If you have the misfortune to fly through some of it, even though there is no warm front overriding a cool surface, and no SLD (supercooled liquid droplets associated with warm rain dropping into cold air below and forming water that forms ice on contact) , you will accumulate ice, usually rime ice, at temperatures and at flight levels you never dreamed of.

So, as a precaution I turned on the engine inlet heat and waited. Well it didn’t take long for the airframe ice to start accumulating. Milky white rime ice on the leading edges of the wings began as the outside air temperature exceeded minus 12 degrees C! The ice continued to accumulate, though the deicing boots shed it quickly and effectively, through FL 240 and OAT of minus 20 degrees C. For those who speak only F, the ice started at 10 degrees F. and ended at about minus ten degrees F., well below any temperature the FAA has told us to expect airframe icing.

Lessons learned?

  1. Everything we have been told about airframe icing is useless when flying in, over or near mountains.
  2. Airframe icing can occur at temperatures well below the “within ten degrees of 32 degrees F”.
  3. Airframe icing can continue all the way up into the flight levels.

Now many will read this and say that all it means is that flying in the mountains is different than non-mountain flying. That might be true but only two of the jet icing  accidents I have handled occurred in the mountains and all of the turboprop icing accidents I have handled were in the flatlands.

Arthur Alan Wolk

January 22, 2020

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The Last of a Breed ,a decade of piloting the last flying Grumman Panther.  As the founding partner of the Wolk Law Firm, which specializes in aviation law and in improving air safety, his two great passions are woven together.  He was recently profiled in The Warbird Watcher, a website dedicated to sharing Warbird news and veterans stories.

Mr. Wolk’s involvement in the Warbird community began in 1984 with the purchase of a Korean War era Grumman F9F-2 Panther jet fighter.  He says, “I had been a pilot for many years and was interested in flying a Warbird…the Panther became available for sale due to the death of its owner and so I acquired (it)”.  At the time this was the only airworthy F9F Panther flying in the world. The aircraft was pieced together using airworthy parts from other F9F airframes in order to piece together one airworthy jet.

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