Stall Speeds

C

crumast

New member
In comparing the stall speeds listed in my 1419's flight manual to the speeds listed in the 1419-2's, I find a marked difference. The 1419 speed is 54 mph, TIAS, with gear & flaps, 0 bank, power off. The -2 number for the same setup is 48 mph,TIAS. Clean speeds have an even higher disparity(about 10 to 14 mph, depending on bank angle.)

The 1419 has a lighter gross wt. by 100 lb. C.G. ranges for both are comparable.

How can this be? Different pitot/static installations? Different airspeed indicators? I noticed in an April 1950 ad, the stall speed is stated as "43 mph." Hardly an official number.

Any ideas? Tom Robinson
 
Tom, based on my experience you can basically tear the performance pages out of the flight manual and throw them in the trash. The design of our beloved planes are inspired and amazing, however that is in stark contrast to any and all of the documentation produced by the factory back in the '40s, '50s & '60s. The data is largely inaccurate and the presentation is disgraceful. In some cases you can find two different pieces of documentation pertaining to the same model that states different facts. Worse yet, the POH got worse as the years went by. The 14-19-2 manual is more professional that the 14-19-3 manual, the latter containing many spelling errors and most of the diagrams look like they were sketched out on a napkin. When I compare the quality of the Bellanca manuals to the Piper, Cessna & Beechcraft manuals it's really a sad story.

All my complaints aside, the location of the pitot tube can impact indicated airspeeds, especially at low speed. The -3 manual says the stalling speed is 49 MPH - I think all of the 14-19 triple-tails drop at about 50 MPH, but this cannot be accurately measured on the airspeed indicator. My approach to establishing various performance details is to run time/speed studies flying back and forth along roads using my GPS measurements. I think you will find considerable variations from aircraft to aircraft, even within the same model.

My comments probably aren't of too much help - these are just my observations. I would be interested in other feedback as well. --Rob
 
Thanks Rob. I pretty much agree. The "data" is mostly a starting point for these old beaters, and not the final word. I've found that if I try to apply 1.3 times the stall speed-it's a bit of a floater.

The 1419 wasn't equipped with a stall warning system(apart from planet earth getting larger in the w/s.) Perhaps Bellanca felt they could drop the speeds, with the installation of the system in the -2.

It is a puzzlement. Tom
 
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