October 2005 - American Bonanza Society

INTERIORSTHE INSIDE STORYPART IVBY DENNIS WOLTERAIR MOD. CINCINNATI. OHIOIf you were with me last month, youknow the design is fi nalized, thepunch list is completed and thematerials are selected. The next stepmay not be as visually exciting, butis definitely one of the most importantdesign steps we take to develop an optimuminterior.ErgonomicsSince you physically relate to yourairplane through the seat you sit in,making the flight station as ergonomicallycomfortable and functional as possibleis extremely important. It's timenow to take the numerous ergonomicmeasurements to ensure the best fit possiblebetween the airplane and its users.Fortunately for me, my first jobafter college was working in the medicaltraining film department at theUniversity of Cincinnati MedicalCollege. One project we did thereinvolved making cinemascope X-rays(X-ray movies) of people walking, sittingand standing, allowing us to seehow the body structure articulates indifferent positions and doing varioustasks. One of the many things I noticedabout a person sitting in a straight-backchair with no lumbar support was thattheir vertebrae became misaligned intheir attempts to get comfortable.Some of this orthopedic informationI picked up has really paid off inmy aviation career. When you becomeuncomfortable and begin to squirm inyour airplane seat, you are subconsciouslychanging from one musclegroup to the next until all of your musclesare tired.In a nutshell, if your skeletal tructureis held in its proper position by theseat you are sitting in, your muscleswon't have to work to hold you in thatposition. Obviously then, the design ofa seat and foam shape is critical to comfort.And pi lot comfort is a major factorin fatigue control and flight safety.Remember, the hard part of flying usuallycomes last. You want to avoid beingtired or in pain when you're shoolingthat tedious approach.Fitting a seat to a person can be donein one of two ways. If the person is ofnonnal stature (5' 2" to 6' I ") and has nophysical anomalies such as fused vertebraeor scoliosis, we can use the standardmeasure-of-manseat that is in the Beechcabin mock-up we keep in our office, andwhich many of you have probably seen inmy booth at conventions.With the customer sitting in thatseat, we add (if necessary) additionalfoam shape in various places, makingslight adjustments until the customer iscomfortable. Multip le dimensions andmeasurements are taken to completethis full ergonomic study of the personin the airplane. The seat, armrest andglareshield are all factors.It sounds like a daunting and complextask, but it is actually quite intuitiveand simple. The process really justinvolves cutting to fit and adjusting forcomfort. The goal is for the customer tobe comfortable with the shape of theseat and the position of the armrest, andbe able to see without difficulty over theglare hield as well as see and reach allinstrumentation and controls.A word about the "standard measureof man." Periodically, an ergonomicstudy of the US popu lation is taken andthe re ulting data analyzed to establishthe physical dimensions of the averageAmerican. This standard measureallows manufacturers of automobiles,furniture and other commodities tobuild production items that fit 90 percentof the people who are likely to buythem. At my shop, we most often custom-buildthe pilot seat for the ownerpilot,and fabricate the remaining cabinseat to the standard measure of man.If a person is taller than 6' I "or hasFitting a customer to his partiallv foomed seat.a special medical condition, we askthem to allow additional time for us tore-sling their seat and build the foambefore they leave. While the customer issitting in his airplane, we then cut ourfoam and install lumbar, thorax andthigh supports as the customer gives usprogress ive feedback. We continue unti lwe are assured by the customer of correctgeometry and approval.What a benefit that all of this takesplace before we actually cut or sew anyupholstery. For those customers withback issues, we've even made use of alateral X-ray as an aid in coming upwith a correct and comfortable seatbuild.Due to the fact that most Beechseats are mounted directly to the sparand for all practical purposes don 't havea height adjustment, a very tall personmay require a quite radical approach tothe seat build. We're not miracle workers,but a surprising amount of adjustmentandlor modification can be done tothe seat bases, seat backs, foam build,armrests and even headl iners to squeezeevery inch out of these cabins. We'llcover this in more detail later.Taking InventoryWith that behind us, it's time tofocus on the airplane itself. The firstthing we do is taxi it to the avionicsPage 9270www. bonanza.orgABS October 2005