Thread: Lost propeller

I note in the paper this morning the pilot reported an "uncalled for engine reaction" or something similar prior to losing the prop.

This led me to remember the doco on Beaufighters recently where the pilots would put the engine on full power if they saw oil pressure dropping and when it seized the prop would fly off and not create drag.

Leads me to wonder if the motor seized .

Regards Philip A

just a noob question,,
would losing a prop cause the engine to over rev?

I am only guessing, but perhaps the engine seized, then the prop sheared off!
My uncle who is 93 and still living, flew on Beaufighters (30 Squadron RAAF) during world war two and says if during combat they sustained damage to an engine, they would then try to flee the combat zone and head for the open sea, with the damaged engine running at full revs, so that once it seized the prop would shear off. They would then put the plain down in the open sea and be rescued by one of the Catalina's, that were normally skirting the battle zones for these situations. This happened to my uncle three times in his WW2 service.
I assume they didn't perform very well on one engine, they were known to be very "twitchy" on take off with two engines, due to the fact that the engines were very powerful, so maybe landing on a strip with only one corkscrew going was extremely difficult.


Cheers, Mick.

If the engine didn't seize, there should be separate overspeed protections built in for the propeller and engine itself.

The engine is a gas turbine so at the revs they spin they do not seize - they disintegrate with turbine blades going every where and fire and flame outs - that did not happen so more like a failure in the output end of the gearbox - as mentioned fatigue in the shaft is a likely option.

The other option is that it did loose one one blade and the immediate imbalance ripped the who lot out. I guess we have to wait and see.

Garry

Originally Posted by kogvos

That's just a backronym. The original comes from the French word panne. Similar to mayday (venez m'aider) and most of the others such as securite, seelonce, etc.).

As the RN would say, back in the day, all disasters came from the French.

Looks like the actual whole shaft has sheared inside the reduction box/ planetary assembly... very very lucky it didn't slice through the fuselage. They are a big bladed prop...😮

Sheared or just detached? - I don't know what holds the shaft in, but seeing it is normally 'pulling' it will have some sort of thrust bearing, possibly a tapered roller bearing, and if this fails, could it leave the thrust (pull) unsupported, or just supported by an alloy case - which would very rapidly wear away. This scenario could result from loss of oil in the reduction box.