Aviation Safety has stated that there are basically two smoking guns with the Tomahawks history: the stall/spin and yoke [Aircraft Analysis, February]. As a private pilot with nearly 400 hours in a privately owned Tomahawk, I can only comment on what Ive witnessed.
The yoke problem, as mentioned in the article, was addressed by a couple of SBs. Prior to flight, I commence several box checks with the yoke and have never had the aircraft give a hint of yoke lockup. Regardless, if the yoke bushing is found to be faulty, it can be remedied with an engineering fix followed by another, more thought out, SB, AD or STC. Happily, a replacement bushing or bracket should be a relatively painless remedy.
The stall/spin characteristics are much harder to remedy if indeed a problem does exist. Certainly there are many factors to consider. More than a year ago I, too researched many of the Tomahawk accidents. Not all were the fault of the aircraft. I seem to remember one spin involving a new pilot buzzing a canoe in a lake. Another, which I believe is the 1994 accident referenced in the article, involved a student and instructor doing MCA at 750 feet. Not a smart decision in any aircraft.
As a passenger, I allowed a few spins in my plane about a year or so ago. The Tomahawk seems to stall abruptly, gathers speed and is fairly quick spinning. It did recover as the POH stated. What is never mentioned in past accidents, or can never be fully confirmed, is the condition of the Tomahawk. Poor maintenance and incorrectly repaired damage could certainly be a problem.
These are trainers and some do get beat on. Since every Tomahawk has probably been spun at least once in its lifetime, there should be many more crashes than the 22 reported.
The Tomahawk requires positive action on behalf of the pilot. It is not a C-150. You must fly this airplane. You also have the incipient phase to react with rudder and appropriate elevator before you have a fully developed spin. In most crashes, two pilots were on board, yet the aircraft were allowed to develop into a spin. Panic, surprise or incorrect responses could certainly account for other accidents.
The article stated that no Tomahawks have spun in from the pattern. This trend may be due to the fact that the plane demands the pilot to fly it constantly. As a result, inattentiveness is far from our minds.
Although I have never seen photos of the preproduction Tomahawk, it is stated that entire wing ribs were eliminated from production models, along with a wing root fairing and vertical stabilizer offset. If this was a negligent act, then as an owner I would like the company to modify the fleet of existing airplanes. If there is no neglect or danger, then it boils down to engineering some docile qualities back into the airplane to suit the owner.
An aftermarket company could produce a dorsal fin and wing root fairing along with more efficient wing tips (droop tips are currently available). Strengthening the wing is certainly more difficult, but maybe a rigid tube through the forward wing ribs would work, or perhaps a rigid stall fence along the entire leading edge. By computer designing these parts, you can leave the question up to the individual owner, thus eliminating a war with the FAA, and allowing us to go about our business and pleasure of flying Tomahawks.
The characteristics of the Tomahawk seem to defy explanation. Some seem to be squirrelly and threatening, others seem to be capable. The unpredictablility is whats troubling.
If the whole idea behind certification, annual inspections and approved maintenance procedures is to ensure that they’re all similar and safe, then something doesn’t smell right to us.
The Check Stops Here
Your editorial at first was interesting, and after some thought quite disturbing [Editors Log, February].
Yes, fatigue was the problem, but was it really the reason for failure? You didnt have a checkride, you had two complete and separate checkrides with no chance to rest or recover in between.
We learned in professional aviation many years ago that any pilot can be pushed until the point he breaks. We also learned many years ago that the ability to learn begins to decline as fatigue begins to take effect.
I dont fault your performance. You had already flown several hours to complete a difficult instrument check. And as far as calling it quits prior to the last landing, in most checkride scenarios calling a halt prior to completion of the landing is considered a failure of the checkride.
I do directly fault your instructor/check pilot. Checkride scenarios should be scripted and agreed to prior to the start of the checkride. Your instructor is directly responsible for knowing the difference between reasonable workloads and overwhelming task saturation.
Checkrides lasting several hours in different airplanes should never be agreed to without adequate rest between rides Otherwise it just becomes a contest between pilot and instructor. Somewhere along the way the real purpose for the check becomes lost.
Just remember that anything and everything will eventually break if subjected to enough stress.
We agree with your conclusions, but were willing to cut the instructor some slack. The second (taildragger) flight could in no way be construed as a checkride, so the question of failure was moot. The instructor was not driving the decision to make the two flights back to back. What it boils down to is that the PIC made a poor judgment call based on a tight schedule.
Taking the CO Out of Copilot
Only a few weeks ago I purchased an electronic carbon monoxide detector, the AIM SAS-696D. Ive long been afraid of CO and have used the little dark spot detectors both in airplanes I fly and in my VW bug for years.
When it came time to replace the latest ones this winter, I decided to upgrade to an electronic one now on the market. As far as Im concerned, it paid for itself already.
I went out flying yesterday with a student in Squadron 2s mellow old C-170B. The student hadnt flown the airplane in a number of months so we began by going down southwest of South County for some airwork. We did a number of steep turns, some slow flight, and just one or two stalls when the student said he was starting to feel slightly nauseous and would like to do something a little more sedate. I suggested that we just head on over to South County for some pattern work and he agreed, wiping a little sweat from his brow.
Nausea, hmm. I looked down at the CO gadget for the first time in quite a while. Id been very actively scanning for traffic during our steep turns and such. Yikes! It showed 80 ppm. Not enough to be immediately lethal, but not good either.
I would have turned off the heater at that point but we had already discovered it was on full-blast and could not be turned off with the panel control. To compensate, we already had the overhead air vents open almost all the way.
We opened the windows and I told my student to do a full stop so I could put on my jacket. (OAT was around 50F.) With the windows open, the CO concentration went back to zero within a few minutes. We flew around the patch several times with the windows open before heading back to SJC. On the way back, as an experiment, we closed the windows and air vents and watched the CO meter. It only took two or three minutes before it started to show increasing readings. When it got up to 100 ppm, the vents and windows got re-opened and stayed open until the airplane was secured after our flight.
San Jose, Calif.
Where Theres Smoke …
I read with interest and admiration about the pilot who listened to his wife at a time of crisis (that alone gets my admiration!) and opened the cockpit door after getting smoke in the cockpit [Learning Experiences, February]. That was a very clever move that worked beautifully for them but should there be concerns about doing this?
Seems I recall fire authorities recommending not introducing more fresh air to a fire, even a smoldering one. Could one of your fire/smoke in-flight experts comment on this?
Its impossible to make a hard-and-fast rule that opening the door is either a smart or dumb thing to do.
On the one hand, the wind coming in through the door could fan smoldering insulation into a blaze. On the other hand, fumes and toxic gases are generally more dangerous in a cockpit fire than the flames, unless the flames are being fed by fuel leaking into the cockpit.
If the smoke is light and seems to generally be contained, as in burning electrical insulation, wed recommend keeping the door closed so you dont whip it into an inferno.
If the smoke is heavy, however, eliminating it may be essential to survival. In addition, if the smoke is so thick you cant see, you wouldnt be able to land safely anyway, so you have nothing to lose. Use the door as a final option to clear the air, but be prepared for the inferno the breeze may generate.
Making the Impossible Turn
An article in another flying magazine motivated me to develop impossible turn criteria specific to my own aircraft, a Mooney M20J. Your article [Airmanship, November] and the letters that followed have motivated me to share the techniques Ive learned with other general aviation pilots.
The impossible turn is possible but probably not on the first attempt. Like any complex maneuver it needs to be practiced occasionally. The military axiom of train like youll fight is applicable here. The following series of steps should take you to the point where you feel confident in your abilities, which gives you options when the engine quits.
By the time I reach an altitude that would enable me to even begin contemplating the impossible turn my aircraft is configured for cruise climb, gear and flaps up. So that is the configuration I use in practice.
First, youll need to practice engine outs in the regular landing pattern. Start by just pulling the throttle to idle when abeam the intended point of landing, then pitch to best glide and point the nose toward the runway. If you cant make the runway then your normal landing pattern needs adjustment. When the runway is assured the flaps can be gradually lowered to bleed off airspeed and adjust the intended point of landing.
After youre comfortable with the landing pattern practice its time to enter the regime of the impossible turn. Start by a careful reading of the performance section of your POH. The parameters I chose were max gross weight with gear and flaps up. This gives a book stall of 99 mph at 60 degrees angle of bank and 82 mph at 40 degrees for my Mooney. The best glide speed at max gross weight is 105 mph. If I maintain best glide speed, then I have a 6 mph margin at 60 degrees and a 23 mph margin at 40 degrees. I found the actual angle of bank needed to be somewhere in between and am therefore comfortable with the stall margin provided.
Make a normal takeoff and when configured for cruise pull the power at an initial altitude that is comfortable for you. I initially used 700 feet but was eventually able to feel comfortable making successful returns at 450 feet. Turn into the wind using about 50 degree bank while executing a 1g turn back to the runway. This can best be described as a nose-low slice with one hand on the gear handle and your attention focused on airspeed and point of landing.
After a while youre not only comfortable but having fun. The final parameter to enter into the impossible turn equation is situational awareness. I mentally plan and brief every takeoff choosing a return, no return msl altitude based on the following: runway length, weather, terrain, obstacles, wind direction, intended departure route and climb profile. If an engine failure occurs I already know whether Im landing straight ahead or returning to the airport. Its nice to have that option available and to have trained yourself to successfully use it.
Thats exactly the kind of approach every pilot should take toward learning how to make the most of the altitude they have. Every plane is different; practice is crucial.