Propeller danger zone on the inside of aircraft fuselage?

#23
there red and white danger stripes and tags all over mil a/c, the best I heard was the one about the HE bombs loaded for transport on a c130 the bombs had remove before flight pins and tags on the nose fuse so someone did!
 
#24
OffTopic:
In 1976 we took ownership of Scorpions from 1RTR. Cabbying across The Plain and Larkhill Impact Area all summer, converting from Chieftain. Ours died with a ghastly knocking. Jock, the driver, was a Chieftain Driver Mech, so after the last but one J60 in UKLF turned up, he watched with interest while Bluebell installed it and ensured the alignment of the fan, just to the driver's right behind the firewall, was just right. Jock paid great attention. We ended up spending a whole day sunning in the 1976 summer. Fixed, Bluebell fired it up. Sweet as. We spent the evening catching up with the squadron.

Jock figured this sunbathing on The Plain was a great idea, so that evening whilst Last Parading the Scorpion, he undid the fan mounting bolts. Next morning, sure enough...

This time Tiffy himself oversaw the installation of the last J60 in UKLF and fan alignment. Tiffy had been technical adviser to THAT recruiting advert in case the Chieftain broke. "I'm a tank gunner and I get £40 a week." As he finished he passed comment. "It's bad. I'll have to grip my lot. You're all very lucky. Had that fan come adrift under load, line of least resistance is through the firewall. Would've killed the driver. Next line of least resistance would be the commander's legs."

Our crew didn't lose any more J60s.

Return;
Googling 'J60' to confirm it was the Jaguar lump I thought it was, I found this on the Historic Military Vehicle Forum:
"One of the Foxes I purchased at the Jackson's sale had spectacular evidence of catastrophic engine failure. From the large quantity of debris (that had been saved in one of the flotation bins) and the remaining devastation, I conclude that the following series of events had occurred.

The engine had had a major seizure whilst the Fox was travelling at high speed. The momentum of the vehicle and the action of the gearbox, fluid flywheel and transmission (being effectively a direct geared system at this speed) had ripped the engine from its mountings and rotated the complete engine several times within the engine bay. The fluid flywheel had exploded into about 50 pieces, taking with it the bell-housing and rear gearbox flange, which suffered a similar fate.

There were pieces of the rear engine mounting,sump and fan gearbox in the debris, so I presume these were also involved!

On it excursion round the engine bay the engine had shredded both rear propshafts and all the oil cooler installation, meanwhile severely damaging the firewall and turret floor steelwork. Finally, having nearly ripped its way into the turret it mangled the rear of the commanders seat...which must have been quite a surprise for him!

One can only imagine the event from the crew's point of view. There would have been quite a sustained noise, followed by a large quantity of steam, oil, petrol and high speed hot debris, not to mention sparks from both mechanical abrasion and the severing of the starter feed cable!"
 
#25
Is this correct? Do the propellers really make more noise than the engines? If so, is it becasue their speed breaks the sound barrier?
Yes. That and vibration.
 
#27
there red and white danger stripes and tags all over mil a/c, the best I heard was the one about the HE bombs loaded for transport on a c130 the bombs had remove before flight pins and tags on the nose fuse so someone did!
Eh?
 
#28
A lot of prop types also have a strip of thicker metal or plastic riveted on the fuselage along the prop plane to protect against chunks of ice coming off the blades.
Ice plates are the proper term. The majority of those that are made of composites are factory produced and are screwed on and sealed with PRC rather than riveted as they need to be removed for skin corrosion checks. The aluminum type is produced through STC’s individually for the specific aircraft getting modded. They start out as just a sheet of aluminum and you need to cut, shape, edge and fit individually rather than buy off the shelf as no two fuses are identical even if they’re the exact same type. For some reason the metal versions are generally riveted with chromate paste sandwiched in between to stop corrosion. The absolute worse ones to make are for the KA series avionics doors as you can fcuk the door up and warp it. I spent a couple of miserable years making ice plates, installing de-icing boots, and initial VG kit’s on a daily basis, not the highlight of my career.....
 
#29
there red and white danger stripes and tags all over mil a/c, the best I heard was the one about the HE bombs loaded for transport on a c130 the bombs had remove before flight pins and tags on the nose fuse so someone did!
I think @MagicMushroom may know the proper story, what with him being a sky-god (bows head, touches forelock). The one I heard concerned a cargo of Sidewinders destined for the South Atlantic and the Loady removed the pins and flags. I shall refrain from commenting on the gender of the person who allegedly done that deed.
 
#30
Mind you if a prop blade is shed it doesn't matter where it goes because the imbalance is going to rip the engine from its mounts before any attempt to shut it down is successful. Then it is in the lap of the gods as to what happens.

A SAAB 340 on a regional flight in Australia lost one of its props (the whole thing sheared off) and luckily missed hitting any part of the aircraft. Having travelled on numerous turbo-prop aircraft I cannot recall seeing any warning markings on the inside of the fuselage but there again, where the prop arc is the manufacturer always ensures that there is no window. If one was sitting next to the prop arc the noise would be horrendous as the majority of prop aircraft noise is created by the propellers.
Iirc Jeff Quill was enroute to France in a miles something or other when it shed a prop blade followed by the gipsy motorin very short order.
They survived by his hauling the wife Clare and other ballast from the back seat into the front to help with the c of g followed by a fast glide and a landing that had his undivided attention.
I’ve lost the tip of a wooden two blade after a stone strike on take off and the vibration was bloody horrendous.
 
#31
ISTR Concorde test pilot Brian Trubshaw mentions losing a prop from a Vickers Viking in his autobiography, saying that it luckily spun outwards and away from the aircraft.
In general, a complete propeller will go forwards if it detaches from the engine. Just think of how all the forward pressure there is on it in order to pull the aircraft along is suddenly free to accelerate it away.
 
#32
The Q400’s run by AC Jazz doesn’t have the prop arch marked inside the aircraft as the woman who got hit in the head with a blade found out the hard way. Amazingly she only received minor head injuries as the airframe absorbed the energy before making contact with her skull.....
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#33
Ice plates are the proper term. The majority of those that are made of composites are factory produced and are screwed on and sealed with PRC rather than riveted as they need to be removed for skin corrosion checks. The aluminum type is produced through STC’s individually for the specific aircraft getting modded. They start out as just a sheet of aluminum and you need to cut, shape, edge and fit individually rather than buy off the shelf as no two fuses are identical even if they’re the exact same type. For some reason the metal versions are generally riveted with chromate paste sandwiched in between to stop corrosion. The absolute worse ones to make are for the KA series avionics doors as you can fcuk the door up and warp it. I spent a couple of miserable years making ice plates, installing de-icing boots, and initial VG kit’s on a daily basis, not the highlight of my career.....
Do Fokker also call them that? I seem to remember something different from the type rating course way back in the dim and distant.

Isn't the chromate paste slightly radioactive as well? That should get the geiger counters hopping, along with the platypus on a Herc.

Building the spar for my toy, I used chromate paste between panels and stiffeners before riveting. Horrible stuff with all kinds of warnings on the tin about protective clothing which don't work so well in a 48 deg hangar in mid summer.

In general, a complete propeller will go forwards if it detaches from the engine. Just think of how all the forward pressure there is on it in order to pull the aircraft along is suddenly free to accelerate it away.
That's the theory. Throw in lateral movement and relative inertia and the chances of it heading off straight forward in a correct and soldierly manner are not that good. Saw a C207 that shed the prop with a chunk dinged out of the wingtip as it departed. The bloke flying did comment on the excellent glide characteristics without all that drag from a windmilling prop though...
 
#34
That's the theory. Throw in lateral movement and relative inertia and the chances of it heading off straight forward in a correct and soldierly manner are not that good. Saw a C207 that shed the prop with a chunk dinged out of the wingtip as it departed. The bloke flying did comment on the excellent glide characteristics without all that drag from a windmilling prop though...
I should imagine that the period of acceleration would be quite brief - followed by the aircraft catching up with it.
 
#35
Do Fokker also call them that? I seem to remember something different from the type rating course way back in the dim and distant.

Isn't the chromate paste slightly radioactive as well? That should get the geiger counters hopping, along with the platypus on a Herc.

Building the spar for my toy, I used chromate paste between panels and stiffeners before riveting. Horrible stuff with all kinds of warnings on the tin about protective clothing which don't work so well in a 48 deg hangar in mid summer.



That's the theory. Throw in lateral movement and relative inertia and the chances of it heading off straight forward in a correct and soldierly manner are not that good. Saw a C207 that shed the prop with a chunk dinged out of the wingtip as it departed. The bloke flying did comment on the excellent glide characteristics without all that drag from a windmilling prop though...
Never did any for Fokkers so haven’t read up on their requirements. The STC’s I’ve gone by called them ice plates, so that’s how I entered them in the logbooks. Ya, the warnings and ppe required to use chromate paste can be over the top, if it’s radioactive hopefully the black heli’s aren’tcoming as I have a few pint tins I found sitting in my cellar, handy stuff.....
 
#36
If a full prop disconnects rather than a blade wouldn't the direction of the prop spin also affect which way it moves away from the aircraft. i:e, either away from the cabin or towards it ?
 
#37
Is this correct? Do the propellers really make more noise than the engines? If so, is it becasue their speed breaks the sound barrier?
Generally speaking engines and their propellers are so designed that the prop tips do not exceed the speed of sound because of the large drag penalties, therefore reducing efficiency. The noise is a minor inconvenience.
I'm a bit biased having grown up with prop engined aircraft, such aircraft are music, jets on the other hand are just noise machines.
Slight drift, many years ago when the RAF had the super all singing all dancing Javelin (Gloster Javelin - Wikipedia) the nav sat abeam of the compressor blades, and on at least one occasion the compressor shed a blade or three resulting in the nav ending up as a short Arrse. The good news was that he didn't need to bull his boots.
 
#38
I should imagine that the period of acceleration would be quite brief - followed by the aircraft catching up with it.
Hopefully the prop's acceleration downwards due to gravity would be working in the plane's favour.
Of course, much is down to the initial trajectory of the prop as it separates from the aircraft.
 
#39
Not a propellor, but a Vulcan shed an entire turbine compressor disc which cut into the fuselage like a circular saw, severing the controls. The pilot only ejected after the aircraft had rolled more than 90 degrees and survived only because his un-inflated parachute snagged a power line and fused to it, lowering him gently to the ground; the luckiest lucky sod in the universe. The turbine disc wasn't found.

Does anyone remember my Dad? 'Vulcan Bomber' - PPRuNe Forums

Modern passenger jets usually use high-bypass turbofans, the engine casing should contain all the shrapnel if the rotating parts break free.
 
#40
Googling 'J60' to confirm it was the Jaguar lump I thought it was, I found this on the Historic Military Vehicle Forum:
"One of the Foxes I purchased at the Jackson's sale had spectacular evidence of catastrophic engine failure. From the large quantity of debris (that had been saved in one of the flotation bins) and the remaining devastation, I conclude that the following series of events had occurred.

The engine had had a major seizure whilst the Fox was travelling at high speed. The momentum of the vehicle and the action of the gearbox, fluid flywheel and transmission (being effectively a direct geared system at this speed) had ripped the engine from its mountings and rotated the complete engine several times within the engine bay. The fluid flywheel had exploded into about 50 pieces, taking with it the bell-housing and rear gearbox flange, which suffered a similar fate.

There were pieces of the rear engine mounting,sump and fan gearbox in the debris, so I presume these were also involved!

On it excursion round the engine bay the engine had shredded both rear propshafts and all the oil cooler installation, meanwhile severely damaging the firewall and turret floor steelwork. Finally, having nearly ripped its way into the turret it mangled the rear of the commanders seat...which must have been quite a surprise for him!

One can only imagine the event from the crew's point of view. There would have been quite a sustained noise, followed by a large quantity of steam, oil, petrol and high speed hot debris, not to mention sparks from both mechanical abrasion and the severing of the starter feed cable!"
That must have been hilarious - do you have a VRM?

I'd just like to check for fatalities given the Fox's record.
 

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