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  • #83742

    I spoke to Charles White at Micro Aero today to follow up on information he gave Trevor Steel a few years ago on Micro VGs for the T303. Citing slow progress thorough the FAA he thinks it will be at least a year before we can get VGs.
    If you are interested I would suggest you contact Charles and add your name to his list of Crusaders.
    Charles White, Micro Aero, 800.677.2370
    http://www.microaero.com, micro@microaero.com
    John Hodgson N1385V KMEV

    #95784
    bthomason
    Participant
      quote JHODGSON:

      … Micro VGs for the T303.

      John, I’m new to the 303 but I’m amazed at the slow speed characteristics of the airplane as is. What are the projected benefits of VG’s for the 303?

      #95787
      rtowe
      Participant

        I responded to Charles and this is the response I received:

        I would be overjoyed, delighted and thrilled to develop a Micro VG Kit for the beautiful Cessna 303 Crusader. BUT — even with 50 lbs above gross the 303 will not meet single engine rate-of-climb. Not enough horsepower. And all the 303 owners want a Gross Weight Increase.

        The good news though is that you get 20% discount on the models listed on our web site <micro@microaero.com> When you get an order just phone us with the N=number, Serial Number, Shipping Address and any credit card. (painting charge is $200.)

        Charles at Micro Aero

        Not really sure what to think about the potential opportunity for VG’s…

        #95789
        rtowe
        Participant

          Ok, just got an email from Charles regarding the VG’s…Here is what he wrote:

          Robert: Yes, we could do the FAA STC work for approval of VGs on the 303. But here is the deal —–It costs us around $60,000 to do the certification. If I had about 6 owners ready to make a deposit, YES, we could go ahead. …….Charles

          That being said, are there any takers? I’m in…

          #95793

          Bob, what I would like is any gross weight increase. Slow speed improvement would be nice of course but that is not a great interest, John

          #96088

          There will never be VG’s for the 303 because there is no improvement to be gained. This aircraft already has VG’s in selected appropriate areas and one of the best features of the VG kit on twin Cessna’s – the nacelle strakes, originated from the Cessna 303 anyway. This is a case of the egg before the chicken etc. they were first developed by Cessna and used on the 303, then the technology was later “borrowed” for STC kits on other older types.

          VG’s are only worthwhile on an airfame with room for improvement. In terms of low speed control, handling and stall the 303 is as optimum as it can realistically be.

          #96089

          By the way; nor will there ever be potential for a gross weight increase. Vg’s don’t give you more lift, they can only reduce the stall speed. This in turn allows a paperwork game with the FAA on the minimum allowable SE climb rates so that provided the structure is OK there is then potential for some legal “over loading”. The weight increase is always just a certification game and always comes with a corresponding reduction in climb due to the higher weights.

          In most cases the weight is limited by a FAA minumum SE climb requirement which is directly proportional to the stall speed. So; decrease the stall speed (with VG’s) and suddenly the minimum SE climb requirement goes down. Next you increase the weight until the the performance has dropped to the new (lower) climb requirement. Thats it. Of course there are structural issues to be checked too but the Cessna twins usually have plenty of reserve here so it is the min. SE climb that sets the weight in nearly every case.

          The 303 already has a very low stall speed which cannot realistically be improved upon. It also has a very anemic SE climb performance (allowed due to the low stall speed) which is right on the minimum required so sure as heck we arent going to see an increase in gross weight STC.

          #96091
          rwelsh
          Participant

            Didn’t somebody get an STC for the 303 to increase the takeoff horsepower by increasing the RPM and or MP much like RAM does on the other twin Cessnas? I heard they also got a gross weight increase with the increase in power.

            #96092
            rtowe
            Participant
              quote RWELSH:

              Didn’t somebody get an STC for the 303 to increase the takeoff horsepower by increasing the RPM and or MP much like RAM does on the other twin Cessnas? I heard they also got a gross weight increase with the increase in power.

              The only STC that I am familiar with is the 24″MP to 27″MP increase for cruise power settings(I have it on mine)…It is basically a remarked MP gauge and new cruise power settings inserted in the P.O.H. .I have done lot’s of research on the T303 and I’ve never seen any STC like the one mentioned but, if you find one, let me know…. 😆

              #96167

              I really wish there was a gross weight increase, but nope there never will be sadly… again the structure is fine (cessna had the same thing in mind) but the 303 is power limited (not strength limited) as related to the certification FARs. Unfortunately the engines will never be upgradeable as they are a unique variant. Unlike others with common core engines (the RAM mods for example) whereby it is no big deal to convert a TCM TSIO520 to a different dash number etc, as TCM did all the work for you already. In the case of the 303 the engine is unique and has no spin off or onward family tree so unless someone certifies a CHANGE of engine its not going to happen.

              AND the change of engine STC will never happen; there arent enough 303’s in existence to justify the cost which would be far higher than for another light twin. First the 303 engines are lighter than any other equivelent TCM engine so the FAA would want big answers on structural analysis, fatigue etc because anything else you can think of to drop in would weigh considerably more. Second, anything else that would fit would not be counter-rotating so now you open a big can of worms with the certification on flight characteristics, VMC issues, single engine controllability, blue line speeds, etc, etc. the cost would be prohibitive even if there were a thousand potential airframes to modify (not just a couple of hundred built like the 303) not to mention the time it would take to put that through.

              Take it from me; there will never be a VG kit (it doesn’t need it), a power increase, or a gross weight increase. Sad but true. I love the 303 and think it is one of the best piston twins ever built. I wish Cessna had continued with yearly incremental improvements, just imagine what it would have become! But no, what we have been left with is how it is going to stay.

              #96199

              I have a question and some thoughts re the VG’s. I understand the concept where our low stall speed really can’t me improved upon but regarding SE performance: in our light twins I was not aware of any requirement for SE climb for part 91. If you’ve ever flown an Apache at gross and I think the Bamboo Bomber you would discover that they will not climb on one. My manual claims 396 feet/min on one at gross and sea level. That’s pretty good for many light twins.

              thanks for your comments

              #96217

              The requirement is a design certification one, not an operating one (such as part 91 or 135) and it applies to twin engined aircraft with a gross weight over 5000lbs or a max weight stall speed above 61 knots. the Apache is below both these figures and hence has no requirement to demonstrate any single engine performance at all.

              #96218

              And by the way the min SE climb requirement I have been referring to is at 5000ft, not sea level.

              #96278
              jmiller
              Participant

                Robert Wyatt at Outlaw Field whom has the 190 kt cruise STC (24 to 27 mp) claims to have the STC for 300lb GTW increase if coupled with the cruise STC. He states the liability insurance is cost prohibitive to market and sell.
                Maybe he could be approached by group of buyers (LLC) to sell STC for their own use.

                N2275C

                #96313

                Heck that would be great! If he would, or could, I reckon nearly every 303 owner would buy it. I would be interested to know more, and also how, as I am sure everyone reading this forum would too. If it is an actual STC (and not just a 337 field mod) then it must be listed in some database somewhere. Do you have the STC number?

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