looking to purchase turbo arrow, some questions


I'm looking to purchase a 1977 Turbo Arrow and thought I would check the forum wisdom here.

Yes I fully plan on having a pre-purchase evaluation done by a reputable shop.

The plane has lived on both coasts and in Utah.

The particular AC I'm looking at has about 8000 TTAF and TTSO of 1700

How successful have folks been going past the 1800 TBO time ?

What shop would you recommend for an engine overhaul ? or would you recommend new engine ?

Eddy current inspection was done last year and was good, according to the logs

Should I be worried about the 8000+ TTAF

In looking at ADSB data, it seems the AC gets around 160 mph at 10,500. (I averaged several round trips to factor in head/tail winds). Would this be a safe planning speed ?

What things to worry about in the merlin turbo system?

What "pay attention" things for this type of AC should I look for in the logs.

I'll note that the logs are pretty clean and tick-tock with history, including some damage history and documented repairs. So I have some confidence that the logs are pretty accurate...

Thank you mucho


  • Hi, corrosion is the great airplane killer, so pay attention to that. Regarding TBO and engine hours: TSIO-360's (I've owned 9 of them), won't make it to 1,800 or past without cylinder replacements and/or top overhauls. The high manifold pressures bring heat and extra pressure to the cylinders. I've just recently had one cylinder in my turbo Arrow III go from 70 lbs to 40 lbs in four months time, but the engine still ran well. Also, any 100 hour inspections in the log? Probably not in a turbo airplane but you should look anyway. Also, regarding overhaul shops, I've used many: Poplar Grove among others. Good luck and keep asking questions!

    Scott Sherer
    Wright Brothers Master Pilot, FAA Commercial Pilot
    Aviation Director, Piper Owner Society Forum Moderator and Pipers Author.

    Need help? Let me know!

  • Hi

    I am going thought an overall right now on a TSIO360 for a TAIII and here are a few things to add to what Scott mentioned. I have been in OH since Feb, its not the shops fault, everything is way behind. The turbo OH took almost 5 months, the case took 6 months to get back we ordered a 3 blade prop in Jan and only got it delivered a month ago. My cylinders were fairly new with a few hours so I just OH them but if you need new ones I hear they are a nightmare to find and cost a small village.

    So needless to say, everything is behind so you need patience more today than ever. We just got my case back this week. Good luck.


  • Oh my, good luck on that!

    Scott Sherer
    Wright Brothers Master Pilot, FAA Commercial Pilot
    Aviation Director, Piper Owner Society Forum Moderator and Pipers Author.

    Need help? Let me know!

  • To everyone that has responded. THANK YOU. Here are some replies to questionss and a few more questions

    @Scott Sherer There ar 100hr inspections early in its life. With the current owner there seem to only be annual inspections.

    Should I worry about the 8000+ hours of total time ?? I look at it as "the plane has been getting use, which is better than sitting and rusting ;) "

    I called 4 overhaul shops, only one responded. Got a call from the President of Poplar Grove (Steve Thomas). Was very helpful, went the extra mile in trying to figure out options. Quote me around 18 weeks for an overhauled TSIO-360 motor. I also asked him about my pair of lycoming's on my Aztec. He said Lycoming hasn't made new cyl's in more than a year and they have a backlog of 30K++ . So no good news on Lycomings until next year, maybe...

  • Hi,

    Highly recommend the Merlyn system. It will eliminate the need to ride the throttle while climbing/descending and give you at least another 10 kts at 15K and above; and their customer service is excellent should you run into any problems with the wastegate controller.

    Poplar is a great shop, but everyone is seeing turnaround times much longer than expected these days. I wouldn't be surprised if that 18 weeks turns into 36 or more. Suggest finding a way to refresh your engine that won't leave you stuck on the ground. While you're flying the last 100+ hours on the current engine you might have a new one on order, or find a core and overhaul it. Either way you can resell the existing engine as a core, because there's sure to be someone looking for one.

  • Perhaps stating the obvious, but make sure the wing spar inspection has been done. Also, if your shop knows Arrows, they are probably familiar with more expensive Piper SBs and can check for signs of trouble. E.g. there was a rib cracking SB that can be expensive to fix.. don’t ask me how I know 😀

    Many airframe hours are not necessarily a source of doom if the airplane has been well maintained and is free of corrosion. I have a 7500+ Turbo Arrow 4. Multiple 100h inspections over the years. Other than the rib issue, no problems so far (knock on wood). Passed the spar inspection no problem.

    Hipe your purchase goes well, but be mentally prepared to walk away if trouble surfaces!

    Karol Zadora
    PA28RT-201T Turbo Arrow IV
    Seattle Area

  • I have a 1977 TA III that is currently in engine overhaul with Pinnacle Engines (over 4 months now). As others have stated everything is backed up. A huge problem appears to be turbo overhaul. Apparently Hartzel Engine Technologies was subbing out the manufacture of the center housing, and the vendor went out of business suddenly. Hartzell is spooling up to do the manufacture in house, but it is a slow process. I was told there is a backlog of hundreds of turbos awaiting parts. The last I spoke to Pinnacle a week or so ago, they have no idea when they will get the turbo back. Strongly recommend look into repairs to keep flying as long as safely possible. Given what I know now, I would not have gone for overhaul at this time. I don't know what happened to all of the parts manufacturers. I guess everything is coming on a slow boat from China.

    When I started looking at overhaul shops, I narrowed it down to Poplar and Pinnacle. It really was a coin toss. Tipping point for me was Pinnacle included the turbo in the overhaul, Poplar did not. Firewalls Forward would not even provide a quote, they were so backed up. Penn Yan has a good reputation, but they were crazy expensive.

    My experience is that 160 mph (133 kt) at 10,500 is reasonable, although this is based on very limited data.

    Merlin upper deck controller seems to be very solid. As others commented, really helps with manifold pressure management.

    Good luck.


  • Good to know, Ben. Thanks for the update and I'm wishing you a quick completion to the overhaul.

    Scott Sherer
    Wright Brothers Master Pilot, FAA Commercial Pilot
    Aviation Director, Piper Owner Society Forum Moderator and Pipers Author.

    Need help? Let me know!

  • I'm creating another post that has overhaul pricing I have received.

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