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Pipers twin engine placement

gray eagle

gray eagle

SOH-CM-2025
It seems to me that one of the trademarks I've noticed is that Piper seems to place their twin engines well forward on the wings thereby blocking some of the view from the cockpit.
Not as bad as from say Cessna or the others. Wonder what the rationale was for engine placement on the wings so far forward?
 
It's usually driven by the need to get the longitudinal center of gravity located properly. Sometimes it can be due to wanting to locate the props forward and away from cockpit. For the Aztec and Apache it might have simply been that the Apache was designed to use four cylinder Lycoming engines. The Aztec and 235 Apaches went to six cylinder Lycomings.
 
As normb says, it`s mostly a CofG issue as well as aerodynamic balance. Location of thrust lines,wing spars and the load package affect where you have to put the 'other bits'. Remember that most of the smaller twins are forced into the same package issues... short fuselage length, human sizes, etc. The drawings below show the similarity between an Apache, C340 and KingAir. Seat height has an effect as well and many of the Piper twins are pretty small aircraft (the Aztec was certainly better than the Seneca and Seminole as you sat quite 'high in the saddle'). Common design theory also aimed at placing the pax as near the CofG as possible to minimize the sensations related to pitching/yawing motions so baggage went aft and engines sat forward.

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A few, such as the Aero Commander (and related Aerostar) took advantage of other design options which shifted the parameters somewhat.
Remember that for most of these types, downward visibility is not a major criterium although pax often fare better than the pilots (who probably should be looking ahead more than sightseeing).
Aircraft that fit a need for low-floor access, ground clearance etc often have a side-benefit of good vis because they are often high-wing designs with other trade-offs.
 
Side views and Quartering side views are usually poor in a twin, however the view straight forward is excellent. When I landed a Duchess or Seminole, I could see the runway all the way through the flare.....unlike a Comanche or 182, which might as well be taildraggers during the flare phase lol.

Cheers
TJ
 
The turbine Duke is a good example of the weight difference between a recip and a turboprop. You have to really extend the engine mounts to keep the bird in CG range. Open the cowls on the Duke or any King Air and see how long the engine mounts are. Same with the turbine conversions of the single engine Cessnas.

Norm
 
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