A Safety Journal for General Aviation
by Max Trescott, Master CFI & FAA Aviation Safety Counselor
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To paraphrase the old adage, "April showers bring May Flyers." Flying season is finally upon us, so enjoy it! I've listed lots of events at the bottom of newsletter so pick whichever one is most attractive to you and go flying! April also brought it's share of fatal and non-fatal accidents, and you'll find more details below. Rather than report on every "fender bender," I want to focus on those that are either educational or interesting in some way.
It's also the time of year when there's a rather dramatic shift in the accident risk profile in the S.F. Bay area. One aspect is obvious. With the longer days, we have far fewer night accidents--not that we want to in any way minimize the additional risk of flying at night, particularly near S.F, where the night fatal accident rate is more than double the rate in the rest of the country. If you look back over the last 10 years, there were 30 fatal night accidents in S.F. Bay area; 23 of them occurred during the months of October through March, while only 7 of them occurred during the months of April through September, so indeed night is less of a concern now.
However, there is a risk that does increase in the summer months that's probably not obvious. Interestingly, the risk of having a VFR into IMC fatal accident during the daytime is greater in the summer months than the winter months. And while you might not think that's a big deal, consider this. Half of all VFR into IMC fatal accidents occur in the daytime! Here's a summary of fatal VFR into IMC accidents in the S.F. Bay Area over the last 10 years.
|Total VFR into IMC
|Day VFR into IMC
|Night IFR into IMC
|April - September
|October - March
Since night and VFR into IMC fatal accidents are several more times likely than in the rest of the country I continue to focus on these dangers. This month, please look at the article on Night Takeoffs, which highlights a unique danger about which many pilots are not aware.
Those of you who read the April issue know that I've been very impressed by the glass cockpits and believe that they make flying in IMC easier and more comfortable, due to the very large displays. A glass cockpit intro class is being held at the Palo Alto airport on May 7. Afterwards, there will be a Cirrus SR22 and a G1000 equipped C182 and DA40 on display. If you're interested in attending, just send me an email.
On April 22, I was hosted by the Silicon Valley 99's at the PAO airport, where I talked about accidents in the Bay area, and focused in particular on the twin dangers of night and VFR into IMC. The 99's are an incredibly accomplished group of women and future women pilots, and I enjoyed meeting more of them. You can learn more about this fun, active group at 99's.
One of the 99's asked me how having an Instrument rating affected one's chances of having a Night or VFR into IMC accident in the S.F. Bay area. The question has come up several times in the past, so I reviewed the 102 fatal accident reports, dating back to 1991, for the Bay area and found the answer. Look below for the article below on Advanced Training Matters.
If you've ever wondered if attending the FAA Wings seminars really make you a safer pilot, the answer is unequivocally Yes! I just saw some data that compared two adjacent areas within California, one which holds many seminars and has many pilot volunteers helping the FAA, and another which has relatively few volunteers and seminars. The one with all of the attention (which I live in) has seen the accident rate drop 50% in just the last five years, while the other area has had no change in the accident rate. So keep going to seminars and earning your Wings!
Feel free to forward this newsletter to your flying friends and encourage them to subscribe. If you're on the distribution list, you'll receive an email each month highlighting the information contained in the online version of the newsletter. Submissions and feedback are always welcome!
Also, you'll find it on a new website I created at www.pilotsafetynews.com. Besides having the past newsletters on the site, I've added a page on Night Flying Safety, and will add other information over time.
Enjoy the longer days, and
have fun flying safely!
Max Trescott, Master CFI
Night Flying Dangers
Somatogravic Illusion - Watch out for it on Night Takeoffs
Have you ever read an accident report where an airplane crashed immediately after taking off at night, usually within a mile of the end of the runway? Like me, you probably wondered, how could that happen to a pilot?
Unfortunately, the answer is VERY EASILY, particularly if you're not familiar with Somatogravic illusion. Don't feel badly if you don't recognize the name. Although it's covered along with a long list of illusions in most Instrument Flying texts, it doesn't appear in many private pilot texts--which may be one reason pilots continue to crash because of it.
According to the FAA Instrument Flying Handbook, "Flying in instrument meteorological conditions (IMC) can result in sensations that are misleading to the body's sensory system...A rapid acceleration, such as experienced during takeoff, stimulates the otolith organs in the same way as tilting the head backwards. This action creates the somatogravic illusion of being in a nose-up attitude, especially in situations without good visual references. The disoriented pilot may push the aircraft into a nose-low or dive attitude."
We don't notice this illusion in the daytime, since we have enough visual cues that we overpower this instinct and make the airplane climb (nothing like seeing trees ahead to get one to climb!). At night, particularly when departing over dark, poorly lit terrain, we lack the visual clues and can descend into terrain if we rely on our body's senses.
the Instruments when departing at Night!
The best solution is to cross check your instruments during night takeoffs. Check the VSI to see that you have a positive rate of climb. Check the airspeed indicator to see that you're at the Vy climb speed for your aircraft. Check the Attitude indicator to assure that the wings are level and that the miniature is above the horizon line.
There's one other time that I often see the effects of Somatogravic illusion, and that's when I with pilots flying Instrument approaches--and it happens nearly as often with instrument rated pilots as with non-rated pilots. It occurs at the very end of an instrument approach, when pilots reach the missed approach point just before the runway. This is where you look up from the instruments and, if you see the runway, you land and if you don't you add full power and climb.
Often, I see people add full power at the missed approach point and continue to fly level for a very long period of time. That's when I know they're experiencing Somatogravic illusion and they're not cross-checking their instruments. Flying level at 200 feet over the ground at full power in the clouds is not a healthy recipe for longevity! So instrument pilots, when you go missed, make sure you pitch up, and have a positive rate of climb!
Here's an example of a night take-off accident from the NTSB where somatogravic illusion was probably involved.
A witness observed the airplane's lights, and heard the engine at full power after the airplane departed the runway. He saw the airplane turned left, at an angle of about 45 degrees, and then descend into the waters of the Gulf of Mexico about 1/4 mile from the airport. Witnesses described the weather as a dark night, with no stars visible, patches of fog, and light haze existed over the water. Recovery personnel reported seeing fog at the crash site about 1 hour after the accident. Examination of the wreckage did not reveal any discrepancies with either the airframe, engine, engine components, or propeller.
The National Transportation Safety Board determines the probable cause(s) of this accident as follows: the failure of the pilot to maintain control of the airplane due to spatial disorientation resulting in the airplane descending and colliding with water. A factor in the accident was a dark night.
Thought Patterns that lead to Accidents
We are What we Eat so Do we Crash What we Think?
In my FAA Wings seminar on "Bay Area Accidents," I have a slide that talks about dangerous thoughts including
We can probably get through the mountains here
I think I see the lights of the Bay ahead
This might be the right way
I've always made it through before
It sure is dark. I hope the controller has me above the minimum vectoring altitude (and doesn't forget me!)
Visibility is probably still at least 3 miles
The point I try to make is that in flying we should always be thinking about plans and solutions with guaranteed outcomes. That is we should pick course of action that we know will work out, not ones that we hope or think might work out. When you're flying and you catch yourself thinking about a plan for which the outcome is uncertain--watch out! Anytime you have these kind of dangerous thoughts, formulate another plane with a known, safe outcome.
Nothing illustrates this better than a fuel exhaustion accident that happened this past month on April 15. Looks at the words the pilot used as reported by the Idaho State Journal. Photo from Idaho State Journal.
small, twin-seat airplane on its way from California to Bozeman, Mont., crash
landed in a farm field near McCammon Friday afternoon after it ran out of fuel.
"The pilot, Thomas Moody of Kalispell, Mont., has reportedly had his license for a year. He told Nielsen he thought the plane had about an hour's worth of gas left and he was trying to make it to Pocatello before refueling."
See the dangerous words? Not much of a plan was it? Hopefully all of our readers know to measure their gas by using a watch to time how long the engine has been running. You cannot rely on the fuel gauges. FAR Part 25 requires that they only be accurate at one position, and that's when the tanks are empty--which doesn't make them very useful.
But then again, maybe there's more going on here and perhaps the pilot is just a little too laid back as one local witness commented: "They were pretty lucky," Larsen said. "It didn't seem to bother them much. When I walked over, they were just outside walking around."
Here's my favorite comment from the witness: "They didn't even know where McCammon was." Of course I'm guessing most people don't know were McCammon is but, if anyone should know where it is, the pilot should. I hope most instructors still teach pilots to keep track of where they're located while flying on a cross-country. Though with the advent of GPS, people may not be doing as good a job of this anymore.
Was this accident avoidable? Of course. Were these people lucky? Probably. According to the witness "if the plane had gone another 150 feet it would have run into some large trees."
Fortunately, most fuel management accidents are not fatal. However, in the 8 year period from 1993 to 2000, we had six pilots flying to and from S.F. Bay area airports had fuel exhaustion accidents that were fatal. Obviously they were not so lucky. Make sure dangerous thoughts do not creep into your thought patterns so that you don't have to rely upon luck!
Recent Fatal crash Northern California
In-flight breakup of Cessna T210
From the Santa Rosa Press Democrat
.....The single-engine plane, laden with luggage, wine and fuel, began to break apart, perhaps because its heavy cargo shifted, throwing the plane off-balance. Walt Smith, regional director of the Federal Aviation Administration, said the plane probably lost its tail section first and fell into a steep dive that ripped off a wing. An explosion apparently came next, raining debris over a mile-and-a-half swath of farmland in an area about 25 miles west of Fresno.
"That area is very well known for surface turbulence," Smith said. "It rolls down the mountain ranges into the valley. Within seconds, the machine just disintegrated."
The tail was found a distance away, he said, indicating the "aircraft exceeded its design performance based on weight and balance." But, Smith added, "the investigation is very preliminary at this point." It could be several months or even longer before a report is issued.
The FAA requested meteorological data to see if weather played a role.
Jerry McDonald of Tranquillity, a crop duster, said rain and 15- to 30-mph winds kept him grounded Thursday.
Maneuvering Speed and High Performance Aircraft
Most of us know that when we hit turbulence, we need to slow the aircraft down to Va, known as maneuvering speed, immediately, so as to not over-stress the aircraft. This is easy in a simple fixed prop trainer--pull the power and it will quickly slow to maneuvering speed--but is more difficult in faster, complex aircraft.
In many high performance airplanes, you want to reduce the power more slowly, perhaps 1" of manifold pressure per minute, to minimize potential damage to the engine. Even if you do decide to pull the power off rapidly, it still takes a long time for these slicker airplanes to slow down.
I used to own a T210 similar to the one in this crash, and it was apparent to me that if you hit turbulent weather, pulling the power would not be sufficient. If you really want to slow up quickly, you should immediately initiate a climb, and drop the landing gear when you reach landing gear extension speed. Don't worry about busting an assigned altitude. Severe turbulence is an emergency which requires that you take whatever action is required to slow to maneuvering speed.
But Maneuvering Speed won't always save the
But occasionally, getting to maneuvering speed won't save the plane. I can hear some readers now saying what? Isn't the definition of maneuvering speed that full control inputs cannot break the airplane below maneuvering speed? Here's what Flying Magazine had to say about it in a recent article.
The crash of the American Airlines Airbus in New York in November of 2001, has revealed that what nearly every pilot of all experience levels believed about maneuvering speed, Va, is incorrect. It turns out that a pilot can break the airframe by moving the flight controls even when flying at an airspeed below Va. The significance of Va has usually been taught to pilots as a negative. “Do not make full or abrupt control inputs when flying faster than Va,” is the standard description of the meaning of maneuvering airspeed. The implication of this teaching is that full or abrupt control inputs at airspeeds below Va can’t break the airframe.
The truth of this belief is hammered home with explanations of how the wing will reach the stalling angle of attack just as the G loading on the airplane reaches the design limit. Thus the wing stalls and unloads itself before exceeding the structural limit. This is true if the sudden change in angle of attack is caused by a wind gust—turbulence—that doesn’t exceed the certification standard.
We have all been taught that an airplane won’t break when flying at airspeed below Va because it will stall first even if the sudden change in angle of attack was caused by the pilot moving the flight controls.
"Va is a calculated airspeed based on the actual gross weight of the airplane and the wing’s response to a 50-foot per second wind gust, or movement of the elevator. There are certification limits for the loadings caused by the gusts of turbulence, for maneuvering with the flight controls, and the combination of gusts and maneuvering. Va is at the corner of the combined gust and maneuvering limit. What we were taught, and believed, about not being able to break the airplane with the controls when flying at or below Va is mostly true when it comes to the elevator, but the elevator may break.
The loads on an airplane are complicated because gusts are not symmetrical, and because the flight controls exert their own bending and twisting loads when they are deflected. That’s why each element of the airframe and its flight controls have their own design limit loads. When controls are moved in combination, and there is turbulence, the calculation of the loads on the airframe become very complex and Va doesn’t offer structural immunity in every situation.
So there you have it. When you first start to hit turbulence, you need to slow to Va. And if it's severe turbulence, you may need to get even slower than Va.
Recent accidents in Northern California
Bonanza without shoulder straps causes serious injuries
On April 19, a Bonanza crashed while enroute to Reid-Hillview airport from Southern California, resulting in serious injuries to both pilots. Interestingly, the crash received very little local media coverage, unlike a Hayward crash that occurred earlier in the month where the pilot walked away from the crash after the engine on his homebuilt apparently quit after takeoff. Of course one crash happened in a metro area where news helicopters could easily shoot video, and the Bonanza crashed half a mile short of Paso Robles airport.
The entire NTSB report says in part:
On April 19, 2005, at 1823 Pacific daylight time, a Beech 35-C33A, N299X, collided with terrain during a forced landing at Paso Robles, California. The airplane was operated at Reid-Hillview of Santa Clara County Airport, San Jose, California, as a rental airplane under the provisions of 14 CFR Part 91. The commercial pilot and passenger were seriously injured, and the airplane was substantially damaged. Visual meteorological conditions prevailed, and an instrument flight plan had been filed. The flight originated at Van Nuys, California.
The pilot told the sheriff's deputy at the accident scene that the airplane had lost engine power and smoke had filled the cockpit. The pilot turned towards the Paso Robles Airport in an attempt to make an emergency landing. He determined that he was not going to make it to the airport and landed in a vineyard about 1/2 mile east of the airport.
According to an FAA source I talked with, a piston went up through the #4 cylinder head and through the side of the airplane. Apparently this is not unheard of in older engines, even if they are well maintained. Separately, I heard that both pilots hit their heads on the dashboard, leading to serious injuries. The aircraft had no shoulder straps, but did not require any since it was an older plane. At least one Bonanza owner told me that he's now considering adding shoulder straps through an STC available for his airplane. It's also made me think twice about teaching in older aircraft that have only lap belts.
Also in April, a Cessna 172 crashed at Palo Alto airport and fortunately both instructor and pilot walked away from the crash. The information on the FAA website regarding the crash says: "Aircraft on departure roll, veered off the left side of the runway, spun around and ended up on the taxiway." What's interesting to me about this crash is not the facts of the crash (which I don't know beyond what's been published), but rather where the aircraft is now stored. It's currently situated on the edge of the airport property where it can be clearly seen by anyone driving by!
I probably wouldn't have thought further about it, except that the plane that crashed at RHV on April 1 is stored in a similar fashion--in a place where any casual observer passing the airport can see it. What kind of message do you think this sends to the hundreds of potential pilots passing these wrecks each day? I'm sure in both cases these were the most convenient places to the store the aircraft, but am I the only one who thinks this is crazy?
As an industry, we often talk about how the safety of small airplanes is so badly misunderstood by the media and the public. While there are lots of reasons for it, it seems to me that we aren't helping the cause of advancing flying and flight training if we leave our occasional failures on such public display. What other industry puts its mistakes on display for potential customers to see?
But the rating alone won't keep you safe!
One of the 99's asked me how having an Instrument rating affected one's chances of having a Night or VFR into IMC accident in the S.F. Bay area. The question has come up several times in the past, so I reviewed the 102 fatal accident reports, dating back to 1991, for the Bay area and just got the answer. The numbers don't quite sum up, since some of the reports may mention that someone is, for example, a private pilot, but neglect to mention if he or she was instrument rated.
Here's the data for fatal VFR into IMC accidents
|Total # VFR-IMC
As you can see, the majority of these accident are by Private pilots. I don't know the overall split of Instrument vs. non-instrument pilot in the population, but I research it for next month. Looking at the data, you can see that a lot of local instrument rated pilots are still having VFR into IMC accidents.
Here's the data for fatal Night accidents
|Total # Night
If you remove the four Part 135 accidents (primarily flying freight), the data shifts a little:
|Total # Night
Night seems to be an equal opportunity killer. Clearly, having an advanced certificate or instrument rating does not protect you from an accident. Staying proficient and taking a thoughtful approach about the risks for each individual flight you take is probably your best protection. And of course attending safety seminars.
for Night Flying
I had a message from a pilot sometime during the past month (and I'd mention his name, but I can't find the email as I'm writing this) that he has found a headlamp that he likes for night flying and pre-flight that's available from Wal-Mart for $13.
Callback newsletter from NASA ASRS
I'm sure most of you are aware of the Aviation Safety Reporting System that's run by NASA. Pilots are encouraged to report incidents to the service, and NASA culls them for common patterns and produces summary reports of the incidents. The benefit to you as a pilot is that if you inadvertently break a rule and file a timely report, the FAA won't proceed with enforcement action, though you may still be required to take remedial training.
You can learn more at the NASA ASRS web site at http://asrs.arc.nasa.gov/main_nf.htm. You can also read issues of CALLBACK, NASA's monthly publication that summarizes the incidents, online. For really easy reading, I recommend that you subscribe to the monthly mailing of CALLBACK by sending an email to email@example.com and include your name and mailing address. Each month you'll receive a single, folded blue sheet in the mail which provides lots of interesting reading.
So now you know.
May 7, 2005 10AM Glass Cockpit Intro Class Palo Alto Airport Call 650-224-7124
B-17 Rides To Reserve a ride go to www.b17.org/tour
$355 for EAA members; $395 non-members
May 6-8 Watsonville, CA
May 13-15 Hayward, CA
May 17-18 Napa, CA
May 14, 2005 8AM Truckee Tahoe EAA Pancake Breakfast Call 530-587-4811
May 19, 2005 All Day Wings of History Open House South County Airport
May 19-21 All Day Hayward Proficiency Air Race 925-784-7128
May 27-29 All Day Watsonville Fly-In & Air Show 831-763-5600
June 12, 2005 All Day Truckee Tahoe Airport Open House & Pancake Breakfast 530-587-4811
June 19 All Day Father's Day Fly-in Columbia Airport 209-533-5685
Pilot Safety News
© 2005 by Max Trescott
Master CFI & FAA Aviation Safety Counselor
Please contact me with your feedback or if I can be of service to you.
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