Hmm, they are not all "over there"!Quote:
Originally Posted by Hugh Jars
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Hmm, they are not all "over there"!Quote:
Originally Posted by Hugh Jars
From this it seems that N04 was shut down and feathered, but for some non-obvious reason, the plane was not performing as well as it should have on three engines, resulting in undershooting the runway. Not suggested in this account, but I wonder if the propeller damage to No3 was the result of impact on the approach lighting.
With only 1 and 2 providing thrust and trying to drag it onto the runway, a right swing is not surprising, but the question remains - why low and slow?
Quote:
Originally Posted by JDNSW
That was my take, based only on this report, which seems to say that the tip of No3 was found 700 metres back.
Quote:
Originally Posted by JDNSW
Low and slow, no flaps ( sure, I get the drag thing, but lift is important too ). Tipping we won't know for more than a year.
You have to think about the one or more engines inoperative performance certification for the type. Transport category aeroplanes MUST perform to a certain standard. In Australia, CAO 20.7.1B is the governing document. I don’t know what the equivalent FAR is.
There’s a chance that the B17, being a military aircraft, was not (and didn’t need to be) certified to perform following an engine failure. I don’t know.
Back in the 80’s a Super Kingair crashed into the sea wall at the end of RWY34 Sydney during an air-return on one engine. It was found that the company (Advance Airlines) was doing unauthorised and incorrectly executed reduced-power takeoffs. When conducted correctly, you will get the required climb performance should an engine fail at V1.
This mob was using an unapproved technique, and when the engine quit, the aircraft failed to perform (not unexpected, in hindsight). The long-short of it is that maximum continuous power was not set on the good engine, the aircraft did not perform as required, and it hit the sea wall, killing all on board. The irony is that they crashed only a few feet below the top of the wall. Had the correct procedure been followed, over 10 people would be still around today.
So what does this have to do with the B17, you ask? It didn’t seem to perform too well on 3 engines, and crashed short of the runway on return, just like the Kingair, so is there a parallel?
The aircraft had 3 zero hour (rebuilt) engines. I have 3 questions:
1. Was normal takeoff power used, or did the crew ‘baby’ the engines (less power) because they were freshly rebuilt?
2. If the crew did use less than takeoff power, did they set max continuous power on the 3 new engines following the failure of #4?
3. Were the 3 rebuilt engines defective in some way, and not capable of delivering the required power?
Just a few factors that *might* have contributed to the prang...
Yes, that would be the sort of thing I would be thinking of.
Worth noting though that the B17 is a 1930s design (1935 first flight), and I would be very surprised if engine out performance was even considered in its specifications. It had four of the most powerful available engines, simply to provide enough power to meet the speed, range and payload specified, although Boeing claimed it was the first combat aircraft that could continue its mission after one engine failed. This would have been a result of the total power needed to meet the specifications, rather than a design issue.
Not really relevant, but the prototype was destroyed when it crashed on its second evaluation flight - taking off with control locks in place will do that!
As more powerful engines became available, these were fitted - but MTOW went up along with the increased power, and also defensive armament and hence parasitic drag was also increased. By modern standards these are very 'dirty' aircraft.
Well this is a video of the aircraft a month before the crash. I sincerely none in the video were involved in the crash.
YouTube