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The forgotten war of Aden. RAF Thumier in Radfan - Restored 1965 Film.

That was excellent! If the film had been made a year earlier you probably would have seen Royal Navy Wessex helicopters from 815 Naval Air Squadron. They were based at RAF Khormaksar, operating daily from Thurmeir for only a month before returning to HMS Centaur. I wasn't on 815 until the following year but those who were said what a welcome relief it was from our usual anti-submarine role. The loss of a Wessex on 10 June 1964 was sadly a fatal one involving one of the soldiers amongst the 8 personnel on board. A paragraph accompanying the photo above:

A Royal Navy Westland 'Wessex' HAS1 anti submarine helicopter of 815 Naval Air Squadron, HMS Centaur, arrives at Thumeir airstrip with an underslung load. these aircraft flew daily into the Radfan between 22 May And 25 June 1964. the sonar equipment was removed for the duration of the operation. one aircraft was lost on 10 June

Seeing those Wessex helis load lifting made me wonder what their hot and high performance was like?

One of my Nav course went to Beverlys and his traditional navigation training had no relevance. It was more by note book and sketch map as printed charts frequently had blank areas and apologetic notes.

What a different world today, now, from my armchair at home I can 'walk' a route anywhere in the world and in many places even street views.

TheGreenGoblin wrote: ↑

Tue Nov 16, 2021 3:56 am

Seeing those Wessex helis load lifting made me wonder what their hot and high performance was like?

After all these years I can't remember specifics on Wessex 1 hot and high performance but to up your internal payload availability above hover limits it was easy to do a 'running take off' if the site allowed. Pull in power with the collective, stuff the cyclic forward and keep accelerating until the beast came off the ground. Of course you couldn't do that when load lifting! The first photo showing load lifting looks as though the pilot has the collective up around his armpit - that's quite a coning angle on the rotor blades.

I might have some relevant performance graphs in my pussers tin trunk in the loft - will look later when I'm back from town.

It was more by note book and sketch map as printed charts frequently had blank areas and apologetic notes.

The good thing about the Beverley was that he had time to write the book and draw the map as he flew along and have it finished before the aircraft arrived there...........

CharlieOneSix wrote: ↑

Tue Nov 16, 2021 9:31 am

TheGreenGoblin wrote: ↑

Tue Nov 16, 2021 3:56 am

Seeing those Wessex helis load lifting made me wonder what their hot and high performance was like?

After all these years I can't remember specifics on Wessex 1 hot and high performance but to up your internal payload availability above hover limits it was easy to do a 'running take off' if the site allowed. Pull in power with the collective, stuff the cyclic forward and keep accelerating until the beast came off the ground. Of course you couldn't do that when load lifting! The first photo showing load lifting looks as though the pilot has the collective up around his armpit - that's quite a coning angle on the rotor blades.

I might have some relevant performance graphs in my pussers tin trunk in the loft - will look later when I'm back from town.

I appreciate your answer C16 and look forward to your data and wish you an early return from town.

Okay - found some info. The MAUW of the Wessex HAS Mk1 was 12600lb with an overload weight of 13,300lb. The max height at normal weight was 10,000ft and at overload weight was 8000ft. To talk you through the example on the graph above, let's assume we want to find out at what weight a vertical landing or take-off can be made at 5000ft with an OAT of +15C. The turbulence is expected to be worse than light so Pilot's Notes limitations oblige us to reduce the answer by 1000lb.

Enter the chart at the green arrow - far left lower corner. Climb up vertically to 5000ft then diagonally up the black line until 15C red line is reached. Move horizontally to just below the 12000lb pecked line. This gives us a max weight of 12050 lbs for a vertical take-off or landing but this must be reduced by 1000lb because of the turbulence. Continue horizontally across the envelope and you will see that the max speed at 12050lbs is 85 kts IAS or 95 kts at 11050 lbs. The angle of bank at 5000ft is restricted to 15 degrees. I don't know what the altitude of Radfan operations was, nor do I know the temperature but the Wessex - and any 1950/1960's era helicopter - would have been severely limited.....that is if anybody bothered to get the books out in the front line!

All of the above assumes that you remain within a movement of 2 inches of left yaw pedal. If more than 2 inches is used then the tail rotor becomes stalled. The Mk1 Wessex needed careful handling once you got away from sea level!

This website may be of interest - 45 Commando in the Radfan. http://britains-smallwars.com/campaigns ... 45commando
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CharlieOneSix wrote: ↑

Tue Nov 16, 2021 6:43 pm

Okay - found some info. The MAUW of the Wessex HAS Mk1 was 12600lb with an overload weight of 13,300lb. The max height at normal weight was 10,000ft and at overload weight was 8000ft. To talk you through the example on the graph above, let's assume we want to find out at what weight a vertical landing or take-off can be made at 5000ft with an OAT of +15C. The turbulence is expected to be worse than light so Pilot's Notes limitations oblige us to reduce the answer by 1000lb.

Enter the chart at the green arrow - far left lower corner. Climb up vertically to 5000ft then diagonally up the black line until 15C red line is reached. Move horizontally to just below the 12000lb pecked line. This gives us a max weight of 12050 lbs for a vertical take-off or landing but this must be reduced by 1000lb because of the turbulence. Continue horizontally across the envelope and you will see that the max speed at 12050lbs is 85 kts IAS or 95 kts at 11050 lbs. The angle of bank at 5000ft is restricted to 15 degrees. I don't know what the altitude of Radfan operations was, nor do I know the temperature but the Wessex - and any 1950/1960's era helicopter - would have been severely limited.....that is if anybody bothered to get the books out in the front line!

All of the above assumes that you remain within a movement of 2 inches of left yaw pedal. If more than 2 inches is used then the tail rotor becomes stalled. The Mk1 Wessex needed careful handling once you got away from sea level!

This website may be of interest - 45 Commando in the Radfan. http://britains-smallwars.com/campaigns ... 45commando

Thanks for the fulsome and detailed answer C16. The Pressure Altitude graphs are well laid out and easy to read that's for sure. Unlike some of the more convoluted ones I have seen in my time on light, smaller aircraft. I must admit the MAUW of the Wessex (e.g. HAS Mk1 as noted by you) is higher than I might have imagined. The yaw pedal limit must have required a light but "squeazy" touch on the pedals. I also imagine that with a stalled tail rotor, the Wessex was pretty difficult, if not impossible to recover, when heavily laden (inertia) at altitude?

I will also take much pleasure in reading the 45 Commando in Radfan link.