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Handley Page Victor
23 Feb 2020 12:58 - 23 Feb 2020 12:59 #33
by PETERTHEEATER
Replied by PETERTHEEATER on topic Handley Page Victor
Stevies Post 10 MAR 18 (above) has a rear aspect photo of a Victor where the brake parachute release doors can be seen open at the base of the fin.
In 1959 it was an Armourer's job to install the brake chute because the main attachment point to the airframe was a No 3 EMRU (Electro Magnetic Release Unit) which was actually a bomb 'slip' designed by Vickers and used on all three 'V' Bombers to carry and release the heavy store (nuclear weapon) The twin doors (see photo above) had a convoluted linkage (the product of a troubled mind at Handley Page!) which were also kept in the closed position by a smaller No 1 Mk1 EMRU as used on the 1000 pound bomb carriers.
It took two men, Man A and Man B, to load the brake parachute pack into the tight fitting compartment. If the airbrake doors were open (as in the photo) we could stand on the airbrake operating beams but, usually, a ladder was required and some balancing skills. After locking the brake chute lug into the main EMRU the two linked doors were pushed down by hand onto the top of a small pilot drogue and pressure applied to encourage the other end of the door linkage to engage the small EMRU and lock the doors closed. Ha ha! That was the theory but, due to wear and tear and maladjustment and the bulky parachute pack underneath, a lot of pressure was required in one spot. Man A stood on the tail cone with his nose pressed against the centralised rudder with the flat of his hands squeezing the rudder and forced to lean back whilst Man B , on the ladder, supported his back. Man A used his left foot to hold the spring-loaded doors closed and then stamped hard with the heel of his right foot at the point where the internal linkage was attached forcing the linkage to lock into the STREAM EMRU. The ideal spot on the righthand door was easy to identify from a permanent dent!
The EMRU consisted of a pair of forged steel hooks - satin chromed- enclosed in an alloy case. The hooks, when closed, were locked by a linkage operated by a rotary motion coil assembly. A hinge point in the linkage formed a geometric lock which positively prevented the hooks from opening until the electro magnetic coil was activated by 28 VDC triggered by the pilot operating the STREAM switch from the cockpit.
The installation as designed and built had the main EMRU mounted vertically in its housing with the jaws facing rearwards. The cockpit switch was a three position toggle switch STREAM - OFF - JETTISON. During the landing run the pilot would select STREAM, the small ERU would operate and the spring-loaded doors would fly open releasing the small drogue which caught in the slipstream and dragged the main chute out to deploy and develop, the retardation load being transferred to the airframe through the big EMRU. When the plane had slowed the pilot flicked the switch to JETTISON and the main ERU 'fired' releasing the chute onto the runway. That was normal operation. But every so often when STREAM was selected the doors would open and the entire brake chute still in its pack would be dragged out and dumped onto the runway because the main EMRU had also unlocked!
I should explain at this point that the electrical circuit was arranged so that, should the compartment doors open in flight due to not being positively locked , the main EMRU was automatically 'fired' and the chute jettisoned to prevent loss of aircraft control. Keeping this in mind Investigation of the recurring fault had the electricians baffled since everything checked out. It was then determined that the the fault occurred only on heaver than normal landings and that hard impact caused a kind of whiplash through the airframe the inertia of which caused the internal linkage of the main EMRU to 'break' its geometric lock and open its jaws.
The solution was simple but did require a formal modification and that was to turn the main JETTISON EMRU 180 degrees. In that position any 'G' load forced the geometric lock of the linkage into the locked position.
I often wonder if the brake parachute system was improved later in the life of the Victor. The RAF were obliged to introduce Health and Safety procedures and I can't imagine the antics of the early 60's being tolerated in the 90s!
In 1959 it was an Armourer's job to install the brake chute because the main attachment point to the airframe was a No 3 EMRU (Electro Magnetic Release Unit) which was actually a bomb 'slip' designed by Vickers and used on all three 'V' Bombers to carry and release the heavy store (nuclear weapon) The twin doors (see photo above) had a convoluted linkage (the product of a troubled mind at Handley Page!) which were also kept in the closed position by a smaller No 1 Mk1 EMRU as used on the 1000 pound bomb carriers.
It took two men, Man A and Man B, to load the brake parachute pack into the tight fitting compartment. If the airbrake doors were open (as in the photo) we could stand on the airbrake operating beams but, usually, a ladder was required and some balancing skills. After locking the brake chute lug into the main EMRU the two linked doors were pushed down by hand onto the top of a small pilot drogue and pressure applied to encourage the other end of the door linkage to engage the small EMRU and lock the doors closed. Ha ha! That was the theory but, due to wear and tear and maladjustment and the bulky parachute pack underneath, a lot of pressure was required in one spot. Man A stood on the tail cone with his nose pressed against the centralised rudder with the flat of his hands squeezing the rudder and forced to lean back whilst Man B , on the ladder, supported his back. Man A used his left foot to hold the spring-loaded doors closed and then stamped hard with the heel of his right foot at the point where the internal linkage was attached forcing the linkage to lock into the STREAM EMRU. The ideal spot on the righthand door was easy to identify from a permanent dent!
The EMRU consisted of a pair of forged steel hooks - satin chromed- enclosed in an alloy case. The hooks, when closed, were locked by a linkage operated by a rotary motion coil assembly. A hinge point in the linkage formed a geometric lock which positively prevented the hooks from opening until the electro magnetic coil was activated by 28 VDC triggered by the pilot operating the STREAM switch from the cockpit.
The installation as designed and built had the main EMRU mounted vertically in its housing with the jaws facing rearwards. The cockpit switch was a three position toggle switch STREAM - OFF - JETTISON. During the landing run the pilot would select STREAM, the small ERU would operate and the spring-loaded doors would fly open releasing the small drogue which caught in the slipstream and dragged the main chute out to deploy and develop, the retardation load being transferred to the airframe through the big EMRU. When the plane had slowed the pilot flicked the switch to JETTISON and the main ERU 'fired' releasing the chute onto the runway. That was normal operation. But every so often when STREAM was selected the doors would open and the entire brake chute still in its pack would be dragged out and dumped onto the runway because the main EMRU had also unlocked!
I should explain at this point that the electrical circuit was arranged so that, should the compartment doors open in flight due to not being positively locked , the main EMRU was automatically 'fired' and the chute jettisoned to prevent loss of aircraft control. Keeping this in mind Investigation of the recurring fault had the electricians baffled since everything checked out. It was then determined that the the fault occurred only on heaver than normal landings and that hard impact caused a kind of whiplash through the airframe the inertia of which caused the internal linkage of the main EMRU to 'break' its geometric lock and open its jaws.
The solution was simple but did require a formal modification and that was to turn the main JETTISON EMRU 180 degrees. In that position any 'G' load forced the geometric lock of the linkage into the locked position.
I often wonder if the brake parachute system was improved later in the life of the Victor. The RAF were obliged to introduce Health and Safety procedures and I can't imagine the antics of the early 60's being tolerated in the 90s!
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