Originally Posted by
Chris Scott
Your final statement is broadly correct, and probably includes the accident type.
But your first two paragraphs regarding the DC-3/C-47 are sweeping statements, Eric. Goes without saying the performance varies enormously with the conditions, as well as the all-up weight. In a sea-level, UK-based public-transport operation in the late 1960s, we had to demonstrate - following an engine-failure soon after take-off - a climb to circuit height, followed by a circuit, approach and landing. The CofA-renewal air test recorded the rate-of-climb figures on each engine separately. Admittedly these were done at fairly low weights, but the expectation was that the aeroplane was flyable on one engine up to our MTOW of 28,000 lb in temperate conditions. Not that we would have wanted to put that to the test, because we preferred to nurture our old Twin Wasps...
In the same airline group at the same time, to put the above in context, the twin-jet BAC One-Elevens were operating under Performance "A" rules which - as fox niner states above - demanded a single-engine, second-segment climb-gradient of at least 2.4%.
Chris
Of course Performance will vary enormously with weight and density altitude. I'm not disputing that.
I'm not disputing that the DC-3 will fly on one engine - it was designed to. At lower weights it may even climb on one engine - however to the best of my knowledge this wasn't part of the original certification. That is why I used the word 'maintain' - which I believe was also used in the Douglas advertising for the type.
I have had an engine failure in the DC-3. It was cold and the density altitude was very low. With climb power on the good engine I was able to maintain altitude with a speed of 95 knots. The aircraft was well below maximum weight.
The important point is that operating these older aircraft needs to be done with the realisation that they may be certified to different standards. They may not have the Performance margins that more modern aircraft have.