Kiltonge
Greetings Earthling
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Some interesting snippets of could-have-beens about HOT as I slowly work my way through the COMHART volume on anti-tank weapons http://www.scribd.com/doc/38606186/COMHART-T10-Armements-antichars-missiles-guides-et-non-guides-France-2008.
1. Initially the booster motor exhausted through two pipes passing through to the tail, but these resulted in slightly wobbly acceleration and consequent guidance-wire breakages ( I assume from one wire being overstressed as the missile yawed ). Four exhausts were therefore installed in the current location, forward of the bobbin assembly, but this led to instability when leaving the tube as the centres of pressure and gravity were now reversed.
2. To address this Nord proposed dispensing with the booster and using a version of the Milan gas-generator expulsion, to eject the missile from the tube but studies showed that this would have to have generated six times the force of the Milan unit and have an expulsion noise level of 185 dB!
3. MBB instead proposed a twin-gyro active stabilisation solution which was adopted; mechanically complex and only used for the first fractions of a second during boost, but reliable.
4. Due to stretching of the guidance wires ( actually cables ) the missile only needed 3.8 km of wire for a full 4 km flight, and this was demonstrated in trials, but the customers requested the full load as they were still doubtful of the physics! Wasted weight.
5. A man-haulable pack-load launch / guidance complex was requested, with five or six components that could break down into 20 to 30 kg elements. However this would not have been particularly portable and the low height of the launcher restricted the visible horizon to little more than Milan could reach, so this was abandoned.
Edit: though a similar portable complex existed for TOW, to replace the 106mm RCL rifle. So I assume the US Army felt the compromise was acceptable and it also provided flexibility in being installed on small, non-armoured vehicles.
1. Initially the booster motor exhausted through two pipes passing through to the tail, but these resulted in slightly wobbly acceleration and consequent guidance-wire breakages ( I assume from one wire being overstressed as the missile yawed ). Four exhausts were therefore installed in the current location, forward of the bobbin assembly, but this led to instability when leaving the tube as the centres of pressure and gravity were now reversed.
2. To address this Nord proposed dispensing with the booster and using a version of the Milan gas-generator expulsion, to eject the missile from the tube but studies showed that this would have to have generated six times the force of the Milan unit and have an expulsion noise level of 185 dB!
3. MBB instead proposed a twin-gyro active stabilisation solution which was adopted; mechanically complex and only used for the first fractions of a second during boost, but reliable.
4. Due to stretching of the guidance wires ( actually cables ) the missile only needed 3.8 km of wire for a full 4 km flight, and this was demonstrated in trials, but the customers requested the full load as they were still doubtful of the physics! Wasted weight.
5. A man-haulable pack-load launch / guidance complex was requested, with five or six components that could break down into 20 to 30 kg elements. However this would not have been particularly portable and the low height of the launcher restricted the visible horizon to little more than Milan could reach, so this was abandoned.
Edit: though a similar portable complex existed for TOW, to replace the 106mm RCL rifle. So I assume the US Army felt the compromise was acceptable and it also provided flexibility in being installed on small, non-armoured vehicles.
