Question:

I was wondering if any info is available as to what size pilot the Flitzer will accept. I know small biplanes tend to be somewhat critical in weight and balance envelope and was wondering if the envelope on the Fitzer would allow my 6' 212 lb frame. And can anyone tell me about cockpit comfort for someone my size. I have no trouble getting into and flying a Rose Parakeet.

Also has anyone considered using one of HCI's (www.hciaviation.com) 5 cyl. radials that produce 75 hp? It would seem a natural to me for the Flitzer.

Brent Taylor

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Answer:

Hi Brent,

The last Flitzer I flew was the 'wide bodied' Z-21A 'proof-of-plans concept' demonstrator built by the old Bell Aeromarine Co. This variant is fully detailed on my basic Z-21 plan set, which allows the fabrication of two different fuselage widths. Two Z-21As have been completed and flown in the UK, along with the prototype Z-1 (the forerunner of the Z-series) which to all extents is similar to the Z-21, except that it retains the smaller prototype tailplane. This Z-21A prototype, G-FLIZ, had been rigged for its then owner, with the rudder pedals in the fully forward position. The owner was 6'6" in height, and had no difficulty whatsoever in getting into and operating the controls of the Z-21A. I measure 5' 7.5", and could not reach the pedals, needing a substantial cushion behind me to acheive adequate rudder control. Happily this did not restrict full aft stick travel to any extent.

The prototype Flitzer (Z-1) has been flown by pilots of almost every size and weight, the heaviest weighing about 215 lbs., so you'd be alright on both counts. The criterion would be to build it light (ie. don't add extraneous items and watch out for overweight materials) and concentrate the weight where the strength is required - all of which is shown on the plans. The current CG travel is limited to 3", but I calculated a safe 4" travel on the original. This is represented by approx. 0.25" forward and 0.75" aft of the present range.

The HCI radial, and newer European 4-stroke engine/gearbox combinations, such as the lightweight Belgian 110 hp. Masquito (helicopter) motor, and the 75 hp. BMW-Rotax engine/g'box combination, promise excellent power/weight ratios and a substantial weight saving overall, compared with the VWs.

I tend to sit low in the aeroplane, which I prefer, and there is no slipstream effect in the cockpit worth mentioning, so I can fly without goggles if I wish. Cockpit ergonomics suit me well, and I can fly comfortably for hours - certainly to the fuel endurance of the aeroplane. A 5'10" pilot, who used to fly it regularly, never wore a helmet or goggles. The only time you will notice the slipstream, is side-slipping to the right (assuming a LHT propeller), when the upwards-helical slipstream will tear your goggles off! Slipstream effect in a left hand slideslip is negligable. There is no need therefore to increase the size of the period windscreen, unless you sit very tall.

Tony Morris has the standard windscreen on his Z-21A, and he finds it perfectly adequate. He is about 6'1" tall, and weighs over 200 lbs. He is averaging more than 750 fpm. climb, despite his tare weight being high - over 500 lbs., [compared to 479 lbs. tare on the Z-1, and 483 lbs. tare on the Z-21A prot.,] but his cruising speed is lowish, about 82 mph., due to the small propeller he's fitted. He has recently fitted streamlined leg fairings and (against my earlier recommendation) wheel disc covers. I thought that the latter might de-stabilise the a/c in yaw, and cause 'snaking' at high speed, (which it does with the Boredom Fighter, at least one of which has been fitted with an oversize fin/rudder to compensate) but so far this is not the case. He reckons to be getting about 5 mph improvement in level performance with these additions, but I reckon he'd achieve even better with a 61" x 33" propeller. At higher speeds, or at Vmo (100 mph) the wheel discs might have more effect on stability.

Tony Morris' Flitzer Z-21A in original form, without leg fairings & wheel discs
The later Z-1 Type S Stummelflitzer, although a smaller aeroplane all-round, should have the same drag characteristics and weigh approximately the same, but is optimised for aerobatics. Care has been taken to minimise drag around the cockpit and outboard of the interplane struts on the otherwise thicker, lower aspect ratio wings, which are equipped with four ailerons. This machine retains the narrower (22") cockpit of the first Z-1/Z-21, but could, with care, be personalised for the wider cockpit to suit individual requirements.

I always thought the Rose Parakeet a very attractive little aeroplane, with its lineage, I believe, originating with the Lincoln Sport. What's it like to fly, Brent?

Best wishes,

Lynn

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