Piper Tomahawk thoughts

Discussion in 'Hangar Talk' started by bigred177, Jul 12, 2011.

  1. kyleb

    kyleb En-Route

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    Please find some of those structural failure accident reports and put an end to this debate. As an ex-Tomahawk owner, I'm pretty familiar with the type. To the best of my knowledge those accidents or reports didn't happen and don't exist.

    Also, can explain how the control yoke bushing AD you listed is a stall or weak structure issue?
     
  2. Tom-D

    Tom-D Ejection Handle Pulled

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  3. Cap'n Jack

    Cap'n Jack Final Approach

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  4. kyleb

    kyleb En-Route

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    I'd say that is a pretty fair article. The Tomahawk does have aggressive spin characteristics, and you don't want to stall one on the base to final turn. You can say the same thing for a Cub or my RV-6, but the Tomahawk does bite fairly hard for a "modern" trainer.

    Funny, though, I didn't see any mention of structural failures. Wasn't that your original premise?
     
  5. Tom-D

    Tom-D Ejection Handle Pulled

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    In the articles I quoted there is mention of them, If you look hard enough you'll find them. the cracks didn't develop from being over built, no matter the stall characteristics.
     
  6. kyleb

    kyleb En-Route

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    Tom, your premise was that there were accidents due to structural failures. You haven't supported that with a single example.

    And why can't you find even one to support your argument? Because, to the best of my knowledge as someone who was in that community for years and has kept up with the type, there haven't been any.

    Unless you come back with an accident caused by a structural failure, I consider this a closed issue.
     
  7. Tom-D

    Tom-D Ejection Handle Pulled

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    It was a few posts back as far as I'm concerned.
     
  8. kyleb

    kyleb En-Route

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  9. Henning

    Henning Ejection Handle Pulled

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    There hasn't been a structural failure accident. That does not mean there hasn't been a structural failure, just that it became evident before it went catastrophic. The production models had fewer ribs than as were tested, and some planes that had abused spin recovery oil canned some wings. The planes were safely landed, but make no mistake, that is a structural failure. Luckily it was built well enough to not explode from abuse. Not to derail the subject, but this is where aluminum has advantage over carbon. Aluminum has a progressive failure mode whereas carbon has an explosive one.
     
  10. bigred177

    bigred177 Cleared for Takeoff

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    Going back to the PIO on takeoff. I have flown a DA-20 for a number of hours and have never noticed a difference in handling at all from the T-tail. Is it different in other T-tail planes?
     
  11. Henning

    Henning Ejection Handle Pulled

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    No, and there's nobody else that can really tell the difference either. With a low tail in the prop wash you'll get it to rotate the nose up a bit quicker on the runway, but it'll still fly off at the same point.
     
  12. Tom-D

    Tom-D Ejection Handle Pulled

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  13. kyleb

    kyleb En-Route

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    The issue with the Tomahawk is that if you hold full "up" elevator on takeoff, the elevator is stalled until some point. When it unstalls, you get an immediate, HARD, rotation. Smart pilots only experience that once and learn from their experience.

    It may not matter in short field takeoffs, but it is a negative on soft fields - you can't hold the nosewheel off at the speeds you can with a conventional tail. Not that it really matters - not a lot of Tomahawks are flown off of soft fields, but it *could* be an issue under the right circumstances.
     
  14. brcase

    brcase Cleared for Takeoff

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    I must be getting old. I seemed to recall that most of the accidents that lead to the reputation and AD's the Tomahawk recieved were due to the tail failures when performing spins. I just reviewed the NTSB site again, it has probably been 15 years since I previously did that for the Tomahawk.

    The site has change and I am not convinced I am getting the same results I got 15 years ago. Especially when comparing it to the 150/152 accidents I don't think I am getting all the data.

    While I didn't review all of them, I will have to admit I didn't find any confirmed structure failures.

    I was surprised at how many low altitude stall spin accidents the NTSB reported for the Tomahawk, but this did remind me of the AD to install the Stall strips on the Tomahawk, which probably really helped with this. I never flew one without the stall strips installed.

    I never thought a Tomahawk was any more prone to dropping a wing than a 150/152 was. In fact I have flow 152's what did it much worse than the Tomahawk did.

    Still I think the Tomahawk with the current AD's complied with is a great airplane.

    I do seem to recall the clutch problem on the Trim being fairly common. I don't know what the fix or cost was for it though.

    Brian
    CFIIG/ASEL
     
  15. nick2024

    nick2024 Filing Flight Plan

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    Bigred177>>>>>>where in Austin you at? I fly out of Georgetown and have been looking at buying a tomahawk as well. I am a A&P Mech.
     
  16. bigred177

    bigred177 Cleared for Takeoff

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    Went to the flight school and flew one yesterday. The small instructor I was scheduled with ended up not being able to make it so I had to go with the next guy who was 180 lbs. We figured it up and found we'd be okay if we had ~10gallons of fuel. The plane was topped off from the previous flight so we found a bucket and opened the sumps. About an hour later we were finally down to 10 gallons.

    Climbed in it and got all strapped in. It is a pretty comfortable cabin for a small two seater, even with two good size guys in it. I actually had to move the seat up one notch to be comfortable on the rudder. We finally got ready to go and I initially had a hard time taxiing. It seems like the toe brakes are really straight up so my feet kept hitting them when I'd mash a pedal. Takeoff and climb were SLOW since we were so heavy on a tired engine. Had to watch the oil temp since it was pretty hot by now. Once we got up to altitude I started playing a little bit. Steep turns were easy since it is so sensitive in pitch. I also found that the plane is much more responsive in roll if you lead with some rudder. Stalls were a non-event. There was a definite buffet and break, but as long as you stayed on it with the rudder she came down straight. We skipped slow flight since the engine was still pretty hot and came back in to land. Once I got the feel for it landing the plane is pretty easy and I had a decent one.

    The plane seems perfect for my mission since 90% of the time I'm solo and 5% I'm with one person less than 150lbs. The other 5% i can rent a Cherokee. It really was a pleasure to fly and it was comfortable. Now if the seller would just be a little more pleasurable to work with maybe I'll be posting pics of my new plane sometime soon. :)
     
  17. write-stuff

    write-stuff En-Route

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    I think the Tomahawk has gotten a bumb rap over the years. I did primary with a student in one a few years ago and found it to be a nice flying airplane with excellent visibility and a comfortable cabin. It can sometimes set up a little yaw oscillation, but tap the rudder a couple of times and it stops. Stalls were benign, predictable, and easy to recover from.

    I flew it off a short grass field numerous times. Climbs were poor on hot days, but otherwise, short/soft performance seemed fine to me.
     
    Last edited: Jul 19, 2011
  18. cessna182b

    cessna182b Pre-takeoff checklist

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    I've never flown one - or even sat in one. However, I'd consider it as a good choice for a two-seater. The interior room would be a big draw (though I'm not overly large at 5-11 and 205 or so). 150s are rather tight - especially the older ones.

    On the climb issue, I note that some have an engine upgrade to 125 HP - probably worth the extra money if it will give you a reasonable climb rate at gross.

    I had a look at the listings and was surprised to find that few are for sale. Could be that they are keepers.

    Dave
     
  19. kyleb

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    Your current review of the NTSB website agrees with the ones I did when I was a Tomahawk owner (and before the NTSB revised their site).

    Accidents caused by structural failures in the PA-38 fleet are a fig newton of the imagination. There haven't been any.

    The type does have a big number of stall spin accidents, but (IIRC) there was exactly one instance of someone (a student, not trained in spin recovery) who went in from what should have been a safe altitude. The others were a bizzarre collection of accidents caused by people accidentally stalling the airplane at low altitude because of all the usual reasons (over-gross, base to final turn, low altitude aerobatics, etc.).

    Coincidentally, my old airplane N2463K went down in a fatal stall/spin following an apparent engine failure. After I sold it, the airplane was damaged in a hailstorm and was an insurance write-off. Someone bought it from the insurance company and continued flying it:

    http://dms.ntsb.gov/aviation/AccidentReports/dds4l2fvqe0e5e45f52i2uus1/E07192011120000.pdf
     
  20. flyersfan31

    flyersfan31 Touchdown! Greaser!

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    Stall/spin in the pattern and you're in trouble, I don't care what you're flying.

    Perhaps, and there is evidence to support this, the Tomahawk spins more readily than your average trainer.

    Recall that, to enter a spin, one must first enter a stall. If you do stall, and don't recover from the stall (or better yet, the incipient stall -- the buffett) by unloading, then, well, have fun.

    Lesson? Don't stall on base/final. Don't hold a deep stall unless you have altitude.

    I'd rather have a Tomahawk than a Skipper. Why? Price, and value.
     
    Last edited: Jul 20, 2011
  21. Tom-D

    Tom-D Ejection Handle Pulled

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    Does it really matter that the structure failures were caught before it killed any one?

    The cracks found and the ADs prove there was a design flaw, and it has never been really corrected, proven by the repetitive inspection requirements of the AD.
     
  22. kyleb

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    Virtually any aircraft you can name has AD's against it. Cessna seat rails. Cessna gear saddles. Cherokee spar corrosion. Grumman prop inspections. Bonanza tails. The Tomahawk's are for repetitive inspections and component changes in the tail. What's the big difference?

    And, yes, it matters very much that there haven't been any accidents related to structural failures. A problem that manifests itself in a scheduled replacement before failure or a <presumably> slow propagating crack is a different animal than one that results in immediate catastrophic failure. Don't you agree?
     
  23. Henning

    Henning Ejection Handle Pulled

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    Right there you have exemplified the primary difference between aluminum airplanes and modern "composite", especially CF.
     
  24. Tom-D

    Tom-D Ejection Handle Pulled

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    To me there is a big difference between a primary structure failure, and an AD that was generated by lawyers such as the cessna seat track AD. All manufacturers have had bad designs, it is what they do about the problem that counts. Cessna changed the design in the later models, Piper quit building the Tomahawk, for good reason.

    OBTW just because Beechcraft is bad doesn't make the Piper any better.
     
  25. bigred177

    bigred177 Cleared for Takeoff

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    Does the 125hp STC limit the fuel to 100LL only or could I still use mogas? They bump up the hp by putting higher compression pistons in.
     
  26. Ken Ibold

    Ken Ibold Final Approach

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    OK, I'll bite.

    The issue with the Tomahawk's structure stemmed from the fact that the number of wing ribs in the non-conforming prototypes was reduced for the production models, but the spin testing was done on the earlier wings. The result is that sometimes, under some loading conditions, on some airplanes, when the airplane spins the wings apparently will oilcan enough to throw off the recovery dynamics and cause the spin to flatten. The problem is that these reported incidents generally cannot be replicated reliably, and they happen unpredictably.

    Yes, there is video around of the tail shaking like hell in a spin, but to my knowledge no accidents have been blamed on that.

    I will mention two data points on the question of the wing structure. The first is that Bill Kelly, Piper's chief engineering test pilot a few years after production began, had a scare in one when it would not recover from a normal upright intentional spin. As a result, he refused to fly another one and recommended to Piper brass that they buy back all the T-hawks and destroy them. Obviously they did not take that advice.

    The second instance involved a DPE who was an accomplished aerobatic pilot and, as I recall, a student on a checkride. They got into a spin and the aircraft would not recover until both of them unbuckled their seatbelts and leaned forward on the instrument panel to get the nose to drop. I'm going off memory on this, but as I recall the aircraft recovered with a hard pull a couple of hundred feet agl and was structurally damaged in the pullout.

    As a result of these kinds of incidents, there was concern that certification standards had not properly been followed because of the use of both conforming and non-conforming prototypes. The FAA did a paperwork review and concluded there was no reason to dig further.
     
  27. steingar

    steingar Touchdown! Greaser!

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    I've heard both those stories as well, but couldn't verify their authenticity for anything.
     
  28. Jim Logajan

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  29. Ken Ibold

    Ken Ibold Final Approach

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    Bill Kelly told me his story personally.
     
  30. Ken Ibold

    Ken Ibold Final Approach

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