Archive for April, 2012

Spiral into the Gulf

Wednesday, April 25th, 2012

There was an unfortunate reminder last week that the high skies, despite a former United Airlines advertising slogan, are not always that friendly.  A Cessna 421C on an IFR flight from Louisiana to Florida failed to respond to a Center frequency change and began to circle, inexplicably, as shown in the image. All comments here are purely speculative until the accident report is completed, although my hunch is it will read something like, “Pilot incapacitated, probable cause undetermined.” Recovery of the Golden Eagle is unlikely since it is reportedly in deep water in the Gulf of Mexico.

It is exceedingly rare for pilots to become incapacitated due to an unnoticed pressurization fault. We are trained to go on oxygen immediately before doing anything else and then to start an immediate descent. There are only two GA accidents that I can recall that fit this profile: Golfer Payne Stewart in a Lear 35 (1999) and Bo Rein, the Louisiana State football coach who was lost when a Cessna 441 went off course on autopilot, climbed to more than 41,000 and flew for several hours before spiraling into the Atlantic (1980). Both the Stewart and Rein flight profiles looked similar—aircraft flew in a relatively straight line until fuel exhaustion brought them down. Altitudes were fairly stable.

The flight path in this accident, involving a 65-year-old pilot, looks different with circling and multiple altitude excursions. In all these cases, military aircraft intercepted the target aircraft and noticed there was no response.  The cabin windows were fogged over indicating a possible pressurization fault. I asked David Kenny, the Air Safety Institute’s database manager, to do a little research and to speculate with some other AOPA staff pilots on why the flight path looked as it did. You can add your own thoughts:

  • The pilot recognized the loss of pressurization in time to disconnect the autopilot, but not in time to actually manage the descent. If he was holding the yoke when he lost consciousness, that might explain the initial right turn which would be consistent with a turn back toward Louisiana. Any deflection of the yoke or asymmetric thrust after he lost consciousness would have been enough to produce circling flight.  As long as the airplane was trimmed level or nose up, it would have more or less maintained altitude or gradually climbed until it stalled.
  • The autopilot was set to wing-leveller mode without altitude hold.
  • The autopilot was tracking away from a VOR and reverted to wing-leveller mode once VOR reception was lost.  This is consistent with the track, which was following a radial from the Leesville (LEV) VOR when the wandering began.  The flight plan had been filed as “/G,” but we don’t know whether he was navigating by VOR or GPS at the time.  Again, we’d have to assume that it wasn’t set for altitude hold.

Another mystery involves the reportedly “gentle” splashdown after the aircraft ran out of fuel.

The FAA sums up the best practices in the advisory circular AC 61-107A  OPERATIONS OF AIRCRAFT AT ALTITUDES ABOVE 25,000 FEET MSL AND/OR MACH NUMBERS (MMO) GREATER THAN .75. It’s a good review.

Here are a few reminders:

The time of useful consciousness at FL270, the flight’s filed altitude, is about three minutes if the cabin suffers a slow decompression and about half that with a rapid decompression.  There is an annunciator light to warn the pilot, and there are some physiological signs such as euphoria, sweating, headache, fatigue, tunnel vision, hot flashes, etc. The lack of oxygen affects all of us a bit differently.

When in doubt, quickly don the mask (cannulas are OK below 18,000; you did remember to check mask/cannula before takeoff and that there is adequate supply?) and then figure out what happened. Those of us who don’t fly the flight levels still need O2 for prolonged flight above 10,000 (5,000 at night), although using it at lower altitudes couldn’t hurt, and may in fact be necessary if lack of sleep, age, smoking, and other habits are causing a hypoxic condition before ever leaving the ground. It’s better for your brain and your alertness level. There are a number of mishaps where a perfectly capable pilot does something unexplainable where oxygen deprivation seems as likely as many other answers, and it’s easy to remedy!

Our condolences to the family and friends of this C421 pilot—unexplained accidents are always unsettling.

Hope is Not a Strategy

Wednesday, April 18th, 2012

Last week I had the privilege to address the International AOPA as well as a group of South African pilots in a separate safety presentation. The meeting was held near Capetown, South Africa. IAOPA, as you may have read elsewhere on the AOPA website, was formed in 1962  and now represents 70 countries.  Here is their website: http://www.iaopa.org.

After listening for several days to presentations from various countries, several themes emerged:

1) The U.S. has the best freedom to fly of any place in the world.

2) Our FAA is a model of efficiency and reason compared to many other regulating authorities (!)

3) We must all hang together, or assuredly we shall all hang separately (with apologies to Ben Franklin).

4) We need to be engaged with the regulatory and local authorities on a regular basis lest politics begin to influence airport and aviation operational decisions – as if that could ever happen!

The President of AOPA South Africa, Koos Marais, very graciously offered me the left seat in his Cessna P210 and we flew around Capetown and the Cape of Good Hope one afternoon. I haven’t flown a P for some 30 years after leaving Cessna but it all came back—the aircraft has a “classic panel” with the original Cessna avionics and they still work.

A quick comment on airspace will illustrate my points above. We departed from a small GA airport near Capetown, but their TMA or traffic management airspace (think of it as Class B), began at about 600′ agl. We immediately contacted ATC, but because we were so low they couldn’t see us until we popped over a hill between us and the radar site.  This required flying close to the ground over houses etc., and we weren’t near any airspace that would have conflicted with any airline or international airport traffic—not well designed at all IMO.

Upon clearing the hill, they picked up the transponder and immediately cleared us to the coast where the flight altitude was 1,000. It was a spectacular view and the place where the Indian and Atlantic oceans meet is also the graveyard of over 650 ships! One wants to proceed cautiously in such an environment.

A lasting impression is that flying is pretty much flying in every part of the world, but humans can make it far more complex than it needs to be for bureaucratic and economic gain. Preserving our freedom to fly sure makes sense—for many of our fellow aviators, much of their freedom has been irrevocably lost.

Hope is not a strategy—commitment and action will carry the day and it’s my hope that it remains the American way!

It Seemed Like A Good Idea

Wednesday, April 11th, 2012

In the “It’s never too early to speculate” file, but relying upon what reliable witnesses observed, the only fatal accident near Oshkosh (OSH) during AirVenture 2011 appears to have been the result of some really bad decision making.

According to the NTSB’s preliminary report—with all the caveats and edited here for length, “A Piper J-3 Cub crashed into Lake Winnebago following a loss of control while performing an aerobatic maneuver. The ATP and the passenger onboard were both fatally injured.

The Cub departed OSH along with another Cub for a local sightseeing flight over Lake Winnebago. The pilot and the pilot-rated passenger in the other airplane stated both airplanes flew down the coastline at altitudes varying between 1,000 feet and 1,400 feet…the accident pilot performed a maneuver described as a Hammerhead. The airplane pitched up, climbed, and yawed to the left, entering a descent. During the course of the maneuver, the airplane became inverted and impacted the lake.”

Here’s a not-so-minor detail: Lake Winnebago’s elevation is reported as 741 msl, so the height above ground, or water level, is somewhat less than 300-700 agl. Not exactly a recipe for success in aerobatics unless you’re a pro with a waiver. However, the preliminary report doesn’t specify msl or agl although most pilots set their altimeters to msl.

This will likely be logged as stall/spin and the root cause in my preliminary review is extremely poor risk management/decision-making. “Preliminary” is italicized because it is plausible, not likely, but plausible that there was a control malfunction. The factual report will make that clear and we’ll revisit if anything is different.

If these assumptions are correct, does anyone wonder about the pilot’s thought process and whether the passenger had any understanding of the risk involved?  The next question is if a 47-year-old ATP doesn’t understand that low-level aerobatics is more than just a bad idea, is this a systemic fault where we, as an industry, failed to advise and educate?  Or, is it an individual fault where all the right information was provided but the pilot elected to show off? Either way, GA gets another black eye. Should this show up in the annual “accident” tally or should it be characterized as something else? How should we address this? The same question could be asked of any accident where low-level aerobatics turn out poorly. In a similar vein, how should we look at VFR into IMC where the clouds were clearly present?