Thursday, December 22, 2005

CESSNA 208 CARAVAN NEEDS CRITICAL "KNOWN ICING" IMPROVEMENTS FOR SAFETY

The Cessna 208 is a marvelous airplane for carrying lots of people and heavy cargo, but only in good weather. Flown in icing conditions the airplane is dangerous and has crashed thirty times, and nearly crashed many more. The NTSB has designated curing its dangerous history of accidents Public Enemy Number One. Nine people have been killed this icing season so far, and it's only half over.

We have represented several families whose lives have forever been changed because of the Caravan's poor performance in even light icing conditions, conditions for which Cessna Aircraft Company (the plane’s maker), and BF Goodrich (the designer and maker of the deicing boots) have said the airplane is suitable. In fact, it is not. The Caravan should not be flown in any icing conditions, and some of the operators refuse to dispatch it into any known icing weather.

The problems with the Caravan are simple. It is underpowered and, in fact, it appears to have the lowest power to weight of any turboprop single. That means it cannot climb above the ice and thus avoid it before its aerodynamics are so compromised it suffers a drastic loss of performance and control.

It has too much parasite drag, meaning there are so many unprotected surfaces that when ice collects, it seriously and quickly degrades performance to dangerously inadequate levels.

It has deicing boots that are simply inadequate to protect the wings and tail so dangerous ice accumulations even when the boots are used properly, quickly and dangerously compromise control and thus safe flight. Often there is insufficient margins to exit icing conditions safely and climbing may be impossible due to low power.

The Caravan uses engine bleed air to operate the cabin heat and the boots. It has no separate pump to operate boots like some other turboprop airplanes and has no water separator to keep moisture that collects in the boot inflation tubes from freezing and compromising the boot inflation. The bleed air extraction, together with the loss of power from deployment of the inertial separator designed to keep ice from damaging the engine compressor, drastically reduces the already underpowered airplane's ability to exit icing conditions.

The aerodynamics of the Caravan also play a role in its inability to safely handle ice. Its horizontal stabilizer does not have ice protection to the tip and the elevator balance horn is entirely unprotected. The tail provides an up force, unlike most others that provide a down force. Thus, the top surface of the horizontal stabilizer is critical. Ice on this surface causes a pitch up, loss of airspeed, wing stall, tail stall, and drives the center of lift on the wing so far aft that regaining control at any airspeed is questionable.

The failure of the FAA to understand the aerodynamics of this airplane is unforgivable given the repeated concerns expressed by the NTSB and its own knowledge of the problems reported by pilots in Caravan winter operations.

Recent Safety Recommendations by the NTSB about the Caravan bring credit on that agency's understanding that "something is wrong here" and that previous blame on pilots for accidents beyond their control is unfounded.

The Caravan is fundamentally a good design for fair weather flying. It should have had anti-icing equipment, not deicing boots that by design allow dangerous amounts of ice to collect before shedding and leave lots of ice as a residual of their operation. The Caravan should have had a cantilevered wing, instead of drag producing struts and, if cargo pod equipped it desperately needed, pod anti-ice protection. The powerplant is in need of twice the horsepower for this mission, and elevator balance horn anti-ice protection is vital.
The Caravan can be fixed and, if it had been fixed when the FAA first started to investigate icing incidents and accidents shortly after the aircraft was introduced, the airplane might have been well suited today for the all weather operations it is touted by Cessna to be capable. It is not, and the Randolph, Fry and Silvey families have suffered horribly, as have then ten little girls who have been left fatherless.

The FAA and the NTSB must do better. Twenty years have gone by since the first investigations and still no positive and effective efforts to fix the airplane. It is clear that at least the FAA lacks the technical expertise or will to understand the aerodynamics of the Caravan. At this late date, after three separate safety investigations, the FAA still thinks the bottom surface of the horizontal stabilizer is the critical lifting surface. It isn't!

It is also unfortunate for Cessna, who has had ample opportunity to fix the airplane, yet still denies it has a problem. This is litigation driven no doubt so, instead of fixing it and avoiding other accidents, other tragedies for the victims' families and other lawsuits for wrongful death, it denies the problem that everyone, including the federal authorities, knows about, and allows more accidents and more claims. Aside from the moral bankruptcy of such a position, from a purely economic standpoint, it is inexplicable.

There is hope, however. Others recognizing the problem have started addressing it themselves. Weeping wing TKS retrofits are now available to provide anti-ice protection. Larger and more capable powerplants are being STC'd by others for the aircraft and even a hot wing anti-ice system is being tested. Hopefully these non-Cessna designed and built modifications will save lives, but must be purchased at substantial cost by operators of these aircraft.

The icing accidents and incidents involving the Caravan have reached intolerable levels. Something must be done and done quickly if others are to be saved. After nearly forty years litigating airplane crashes, it never ceases to amaze me that aircraft manufacturers won't listen. Airplanes always telegraph their intention to fail long before they suffer a fatal accident. Fixing the airplane before the first accident is the least expensive means to reduce the cost of air crash litigation liability, and fixing it after the first accident will guarantee that there will never be a claim for the same defect after the payment of the first one.

Icing Season 2005/2006

Wednesday, June 8, 2005

American 1420: A Federal Jury v. the NTSB

"NTSB" is a familiar abbreviation for the National Transportation Safety Board, the governmental entity tasked with investigation of all major aviation accidents in this Country. But, given the manner in which it investigates accidents (inviting participation from manufacturers and other litigation interested parties), it frequently fails to get all the facts and interpret them accurately.

The investigation by the NTSB after the June 1, 1999 crash of American Airlines Flight 1420 at Little Rock, Arkansas is the best recent example. As usual, the NTSB blamed the pilot, this time for landing in a level 6 thunderstorm and failing to arm or deploy the spoilers (devices on the wing that pop up after landing to spoil the lift to assist in stopping) while citing a multitude of crew errors, including failure to recite the approach briefing and pre-landing checklist to name just a few.

As it turns out, the NTSB was wrong about nearly everything. The crew completed every item of the required approach briefing and pre-landing check list, the spoilers were, in fact, armed but did not deploy, and the sole cause of the deaths and injuries were towering steel approach light structures illegally placed by the Little Rock National Airport in what should have been the Runway Safety Area - a supposedly safe place 1000’ long by 500’ wide and reserved for aircraft that leave the runway for any reason.

No less than six times in the preceding six months, and as late as 10 days before the accident, the aircraft’s spoilers were squawked by flight crews as showing warning signs of imminent failure, yet no corrective action was ever taken. Despite these unresolved and uncorrected maintenance deficiencies, the NTSB criticized the flight crew for not arming the spoilers, even though electrical anomalies were found after the crash and the spoiler handle was discovered in the deployed position. At least six times before the crash, crews experienced asymmetric spool up times in the aircraft’s engines, sometimes by as much as 15 seconds, with no correction, and yet the NTSB accused the crew of improperly using asymmetric reverse thrust on the night of the accident. Frequent reports of binding of the reverse thrust actuators were likewise ignored by maintenance crews, yet the NTSB accused the flight crew of exceeding EPR (engine pressure ratio) limits when applying reverse thrust. With several reported instances of unresolved brake anomalies, the flight crew was even faulted for improper application of the brakes.

The crew was further vilified for flying into adverse weather, a level 6 thunderstorm, yet the Flight Data Recorder revealed virtually no turbulence, proving there was no such encounter. The crew was faulted for exceeding crosswind landing limits and ignoring lowering visibility when the good in-flight visibility confirmed that the crew had been given Runway Visual Range information from the wrong runway and the actual crosswinds were light.

Who came out unscathed from the NTSB investigation? The Little Rock National Airport and the FAA.
The FAA originally wanted no part of a non-standard Runway Safety Area and refused Little Rock National Airport’s repeated requests for a Medium Intensity Approach Light System. The FAA’s rationale made perfect sense. First, the lights would not reduce precision landing minimums for the runway and, therefore, provided no operational benefit. Second, siting problems meant that the Runway Safety Area dimensions would have to be dangerously reduced and non-frangible support structures would no doubt be required.
The Airport, with the application of "political pressure," forced the FAA to reverse itself, reduced the Runway Safety Area from 1000’ to a mere 453’, and then, just beyond this non-standard Runway Safety Area, erected a three-story steel catwalk with 16" diameter steel poles that would, and did, shred the MD-82 that was American 1420, killing Captain Richard Buschmann and ten of his passengers.

After the accident, wanting to head for the hills, the airport management backdated transfer documents so it would appear that the FAA owned the approach light system and catwalk at the time of the accident, instead of the Airport.

An Arkansas federal jury made short shrift of excuses by the Little Rock National Airport and found in favor of the Buschmann family in a recent trial, the only liability trial following this crash. Their multi-million dollar verdict found the Airport liable for the death of Captain Buschmann, effectively exonerating him of any responsibility for the accident but, more importantly, exposing the NTSB’s shockingly inept investigation.

The trial team consisted of Arthur Alan Wolk, Alan D. Mattioni, and Cheryl DeLisle of the Wolk Law Firm, and Mitch Llewellyn of Fort Smith, Arkansas.

June 8th, 2005