Audio of Lancaster Under nightfighter attack

Dave Eadsforth wrote:

Hi Gord,

Thanks for all that - you have just completed my education as to how the
bomb carrier worked. I knew that there was an arming unit on the front
of the bomb carrier, but in my ignorance I thought it was a one time,
one-way operation.

Re. the arming solenoid, just so I have that correct, would I be right
to assume that the arming unit had a default of allowing the bombs to
drop safe, i.e. the arming wire was free to drop with the bomb unless
the solenoid was energised by the arming switch to trap the wire to the
carrier as you described?

Cheers,

Dave

No, it's just the opposite Dave, you need power to enable a
'safe' drop (of course, thinking about it, you need power for
'any' drop don't you). Perhaps they figured it'd be better to
have it 'fail safe' to 'armed' just in case there was a fault in
the arming circuit which would preclude an armed drop,

In other words maybe they thought this 'safe drop' wasn't a real
important feature and didn't want to endanger the mission for
it's slight added advantage, If you had to jettison them because
of an impending forced landing then you could jettison live over
the ocean or the countryside.

Perhaps Art could give us some pointers?.
--

-Gord.

"Gord Beaman" wrote

No, it's just the opposite Dave, you need power to enable a
'safe' drop (of course, thinking about it, you need power for
'any' drop don't you). Perhaps they figured it'd be better to
have it 'fail safe' to 'armed' just in case there was a fault in
the arming circuit which would preclude an armed drop,

On current aircraft, the fail mode is safe. The arming solenoids need power
to energize and retain the clip and wire.

The ejector carts run on different, multiple circuits.

Pete

"Pete" wrote:


"Gord Beaman" wrote

No, it's just the opposite Dave, you need power to enable a
'safe' drop (of course, thinking about it, you need power for
'any' drop don't you). Perhaps they figured it'd be better to
have it 'fail safe' to 'armed' just in case there was a fault in
the arming circuit which would preclude an armed drop,

On current aircraft, the fail mode is safe. The arming solenoids need power
to energize and retain the clip and wire.

The ejector carts run on different, multiple circuits.

Pete

Thanks Pete, I didn't know that, I wonder what the rationale
would be for the change?... Could it be that during WW2 they
considered it more important to avoid a failed bomb run than they
do now?. Interesting indeed.
--

-Gord.

"Gord Beaman" wrote

On current aircraft, the fail mode is safe. The arming solenoids need
power
to energize and retain the clip and wire.

The ejector carts run on different, multiple circuits.

Pete

Thanks Pete, I didn't know that, I wonder what the rationale
would be for the change?... Could it be that during WW2 they
considered it more important to avoid a failed bomb run than they
do now?. Interesting indeed.
--

That's probably the case. Peacetime vs WWII mindset. Better design and
greater reliability reduces the chance of the mechanism failing, so we can
default to the 'safe' mode, and arm only on request.

Consider a training mission, with live ordnance. Aircraft has a problem, and
the pilot has to jettison the munitions. Do we jettison safe or armed? Since
we are always over friendly territory, defaulting to safe mode would be
preferable.

Pete

"Pete" wrote:


"Gord Beaman" wrote

On current aircraft, the fail mode is safe. The arming solenoids need
power
to energize and retain the clip and wire.

The ejector carts run on different, multiple circuits.

Pete

Thanks Pete, I didn't know that, I wonder what the rationale
would be for the change?... Could it be that during WW2 they
considered it more important to avoid a failed bomb run than they
do now?. Interesting indeed.
--

That's probably the case. Peacetime vs WWII mindset. Better design and
greater reliability reduces the chance of the mechanism failing, so we can
default to the 'safe' mode, and arm only on request.

Consider a training mission, with live ordnance. Aircraft has a problem, and
the pilot has to jettison the munitions. Do we jettison safe or armed? Since
we are always over friendly territory, defaulting to safe mode would be
preferable.

Pete

Certainly sounds plausable...
--

-Gord.

In article , Gord Beaman
?@?.? writes
Dave Eadsforth wrote:

Hi Gord,

Thanks for all that - you have just completed my education as to how the
bomb carrier worked. I knew that there was an arming unit on the front
of the bomb carrier, but in my ignorance I thought it was a one time,
one-way operation.

Re. the arming solenoid, just so I have that correct, would I be right
to assume that the arming unit had a default of allowing the bombs to
drop safe, i.e. the arming wire was free to drop with the bomb unless
the solenoid was energised by the arming switch to trap the wire to the
carrier as you described?

Cheers,

Dave

No, it's just the opposite Dave, you need power to enable a
'safe' drop (of course, thinking about it, you need power for
'any' drop don't you). Perhaps they figured it'd be better to
have it 'fail safe' to 'armed' just in case there was a fault in
the arming circuit which would preclude an armed drop,

There's logic to that, even if it is a bit counter instinctive to the
modern way of thinking.

In other words maybe they thought this 'safe drop' wasn't a real
important feature and didn't want to endanger the mission for
it's slight added advantage, If you had to jettison them because
of an impending forced landing then you could jettison live over
the ocean or the countryside.

I just loved that old story about the RAF bomber that returned to base
after a leaflet raid in 1940. They reported to the IO that they had
been attacked by a fighter and had had to jettison the bales intact
rather than first cutting the wrapping wires.

'Good God,' said the IO, 'you could have killed someone!'

Perhaps Art could give us some pointers?.
--

-Gord.

Cheers,

Dave

--
Dave Eadsforth