Archive for February, 2010

Living off the end of Runways

Wednesday, February 24th, 2010

FogLast week’s Cessna 310 crash in Palo Alto follows a rare but unfortunately high visibility path. The aircraft went down shortly after takeoff in heavy fog. At this point no one has any idea what happened, yet there are already concerns about what an airport was doing in the middle of a housing development.

The airport likely preceded residential development by a considerable margin but to the public and politicians that is often of small concern. As usual, when dealing with low probability, high consequence events facts and emotion often get mashed in together.

In the vast majority of cases, the occupants of the aircraft fare far worse than the people on the ground, but that doesn’t change the facts that every so often non-participants suffer in accidents. This is why there are runway safety zones and, hopefully, local zoning ordinances that avoid putting residential and other high value targets in areas where it is unlikely, but not unforeseen either, that an aircraft might drop in.  Disclaimer: At this writing I don’t have enough detail to know exactly where the Cessna hit relative to the runway so there may be mitigating circumstances.

Here are some facts over the past several years relative to off airport injuries and fatalities:

In the last ten years for which we have complete data (1999-2008), there were a total of 25 GA accidents that killed or seriously injured off-airport bystanders, an average of about one every six months.  A total of 21 people were killed and 43 more were seriously hurt.  2008 was the worst year, with five accidents that caused eight deaths and five serious injuries; 2001 had four, killing one and seriously injuring nine.  No other year in the period had more than three.

ASF maintains this information and provides it to media,  AOPA Airports division and government officials provide more light than heat for the discussion.

As pilots, we should be well armed with factual data on these incidents and get involved in helping local official make the right choices regarding development or re-location for the right reasons.

I am much happier when flying into airports in more sparsely populated areas than where buildings crowd up to the airport fence. It improves the odds, small as they may be, that there will be an unhappy outcome.

High Alpha?

Wednesday, February 17th, 2010

AOAThere’s been much consternation over the Colgan Airways Q-400(Dash8) accident in Buffalo last year that was basically the result of a stall. There are many circumstances leading up to that and we’ll have more to say in an upcoming issue of AOPA Pilot. Most CFIs who’ve  taught for any extended period get to understand the aerodynamics but a question is whether all of that knowledge gets passed along in a usable format. It is a mantra for students to regurgitate that an aircraft can stall at any airspeed but when angle of attack and distraction are high, that’s when things get really interesting.Too many are confused and unfortunately school is out by then. Gravity wins.

AOA or “Alpha” as the engineers call it, is one of the most important concepts for any pilot to really get. Too many of them don’t.  Perhaps the language used is also problematic. We say that the airspeed is slow instead of saying that the Alpha is high. In many cases the airspeed IS slow but might the language be creating a subconscious connection that it is airspeed and not angle that’s critical?

In the Colgan accident one of the revelations was a high level of distraction (there are many other revelations as well). Had the captain had a better concept of Alpha and a better appreciation for distraction, 50 people would be alive today. The real world of training and the real world are two different things. In training we strive to recreate reality but it is often contrived and the student catches us setting things up. Some CFIs also may not explain things thoroughly.

Essential AerodynamicsHere’s a shameless plug to ASF’s award winning online course on Essential Aerodynamics.  There’s video of a really accelerated stall,  a terrible density altitude accident and you’ll even get to do some surfing as we simplify Alpha to clarify it beyond any doubt. Even if you don’t need the review, perhaps there’s a new pilot or CFI who could benefit. It also qualifies for the FAA Wings program and the AOPA Accident Forgiveness and Deductible Waiver Enhancement program.

Let us know what you think.

Terrain Awareness

Thursday, February 11th, 2010

Despite last week’s collision between a tow plane and a Cirrus in Colorado, they are a small part of the GA safety picture. I’d like to draw your attention to a much bigger problem: VFR into IMC. When comparing the two in terms of media play, collisions get much more attention but are far less common.

Midairs average between 7-10 annually. To be fair, you need to double the number of hull losses because it takes two to tangle but here’s the interesting part. Typically, the fatal accident ratio on midairs is about 50% because many occur just over the touchdown zone. It results in a really hard landing but nobody falls very far and there are often no injuries. That is NOT to minimize the severity of any particular accident, as we saw last week – just relating the stats.

In the 30 or so annual VFR into IMC accidents, usually 90% result in fatalities. Too often the pilot chooses not to get a weather brief or download, or gets it, and ignores the warnings. It doesn’t help that “VFR Not Recommended” is occasionally in error. The flight launches and before too long the pilot is getting squeezed between cloud and terra firma. Doesn’t take much imagination to figure out what happens next. The widow makers are terrain ( mountains), towers and, of course, spatial disorientation  – Flying in low visibility over mountainous terrain is just not smart and towers will show up anywhere.

ASF created an Accident Case Study based on this all-too-common scenario and a Pilot Safety Announcement with a fairly pithy message. But how would a VFR pilot know what his or her minimum altitude should be and how low could the clouds descend before deciding to throw in the towel? First question is, What part of cloud don’t you understand?

There are several ways of determining this but we came up with something called a Terrain Awareness Plan ( TAP). It starts with a sectional chart and the maximum elevation figure.

If  you’d like to go more high tech go to the Aviation weather Center’s HEMS Tool and download (It’s still experimental) as an option.

If you’ve got another way, we’d like to hear it. We don’t want more posthumous Darwin Award trophies  this year so spread the word to those who push VFR limits. It can be said with absolute certainty that not one of the pilots who crashed in weather last year thought an accident would happen to them.