ANALYSIS: AirAsia 8501, Extreme Weather, and the Crash of Pulkovo 612

2014 is behind us now. Thank goodness, because it was a lousy year for public confidence in aviation. Our confidence was undermined substantially, not by engineering, but by aviation marketing spin.

Our engineering progress has been great. We are developing new technologies and learning how to fasten hundreds of people inside ‘flying jetfuel tanks’. These new aircraft are technical marvels: reliable, while also increasingly lighter, more powerful and more fuel-efficient.

But, our aviation marketing is a flop. Not the marketing that makes people feel they need to buy a ticket and fly off on a vacation or for business. No, I mean the marketing that protects people from what the airlines and the aviation regulators feel might diminish demand. 2014 was a flop in this area because of the miserable mishandling of information about three major air crashes. First Malaysia 370; then Malaysia 17; and closing out the year with Indonesia AirAsia 8501.

To be fair, there was some improvement, in that Indonesian authorities did release some detailed information much more quickly than had happened nine months earlier. But, it has now been eleven days since the crash of a radar-tracked Airbus 320 into relatively shallow seas, and we still have not located the ‘black box’. Plus, we are seeing over and over again: the airlines – and the regulators who serve us them – want to keep us in the dark. Classic spin control: he who controls the information controls the show. On top of that, we are saddled with an obsolete regulatory framework that perpetuates this informational inequity. Relatively primitive black box technologies that minimize transparency, maximize airline/regulator control of critical flight data, and frankly ensure that the revealed facts are kept as fuzzy as possible.

There are Always ‘Design Limits’

No matter how good our engineering is, and no matter how robust a system is designed and built, we cannot avoid the fact that there are limits. Design a roof to hold the huge weight of a two-foot snowfall in an area where nobody has ever seen that much snow, and the roof should work just fine. But, what if the weather suddenly produces three feet of snow? We design to expected extremes, but what if our expectations are wrong, or what if the measured extremes are intensifying over time?

It is entirely conceivable that the design for today’s airliners does not offer real protection from the most hazardous phenomena associated with today’s most intense thunderstorms, the ones that tower to 50,000 feet. The windshear and turbulence, or the rate of icing, may be too much. Then, too, our pilots may be becoming complacent, losing the fear of weather that, in the past, would have caused all pilots to simply stay on the ground until the thunderstorm was done.

If the aircraft seems invincible and the pressure from airline management to keep the whole day’s schedule ‘on time’ is more intense than the fear of a weather forecast, a commercial pilot will fly on, even into danger, unaware until it is too late that he has more than met his match. And, this appears to be exactly what happened eight years ago, with Pulkovo Flight 612.

The Crash of Pulkovo Flight 612

20060822.. Tu-154 picThe accident happened on August 22, 2006. All 170 onboard were killed. The aircraft was a Tupolev Tu-154 with three engines at the tail, a design quite similar to the Boeing 727. The flight data showed convincingly: the flight was cruising at FL380 (38,000 feet) near a strong storm cell, was suddenly lifted to near FL420, and then entered a flat spin, descending all the way to a terrain impact (near 1,000 feet MSL) in less than three minutes.

20141228pic initial_radar_QZ8501

Photo showing the QZ8501 datablock, just prior to disappearing.

The Pulkovo Flight 612 accident scenario is consistent with the reports that QZ8501 made a sudden extreme climb while losing airspeed, just prior to disappearing. This was covered in a few articles, including the BusinessInsider piece by Paul Colgan on January 2nd. A tweet posted hours after the QZ8501 disappearance included a photo of the radar display, showing (red ellipses, added) an altitude of FL363 and climbing, with an airspeed of 353 knots. The article includes a second photo with a leaked printout, indicating that seconds after the climb and dangerously slowed airspeed, QZ8501 was showing a descent rate of nearly 12,000 feet per minute – far in excess of even the steepest controlled descent. And, the printout showed the speed had decayed to just 61 knots – indicating the A320 was no longer flying, but was simply falling like a rock.

Below is a paragraph from the Pulkovo Flight-612 accident summary, as posted in the Aviation-Safety.net database.

Pulkovo flight 612 departed Anapa (AAQ) for St. Petersburg (LED) at 15:05. The Tu-154M climbed to the cruise altitude of 35,100 feet (10.700 m). Because of storm cells ahead, the pilot decided to change course laterally by 20 km and attempted to climb over the storm cells. However, the thunderstorm front was unusually high, extending up to 15 km (49,000 feet). The Tu-154 entered an area of severe turbulence, pushing up the airplane from 11.961 m to 12.794 m within just 10 seconds. The angle of attack increased to 46 degrees and the airspeed dropped to zero. It entered a deep stall from which the crew could not recover. The plane crashed and burned in a field.

A more thorough analysis has been compiled at this aiREFORM webpage: aiR-Link

What Might We Conclude?

Obviously, to be absolutely certain, we have to wait for the real flight data, once the black box is recovered. But, even without that, it is clear that the existing data shows the QZ8501 accident had many similarities to the Pulkovo 612 crash. While many people are looking closely at the Air France 447 accident in 2009, they should be paying as much – and perhaps even more – attention to what we know about the Pulkovo crash in 2006. And, both airlines and regulators need to take another look at what they are doing to keep pilots from getting too close to mega thunderstorms.

See also…

12/28/2014
Indonesia AirAsia Flight 8501 Missing, with 162 On Board
aiREFORM Post
12/30/2014
QZ8501: Debris Field and First Bodies Reportedly Found
aiREFORM Post
1/2/2015
The Truth is the First Casualty of any Air Crash
aiREFORM Post