The Argonaut, or DC-4M2, was a classic Canadair hybrid. Derived from the DC-4, but pressurised, it had square DC-6 cabin windows and had 1760 h.p. RR Merlin engines instead of the 1450 h.p. P & W R-2000s of the DC-4. Max takeoff weight was 80900 lb. In BOAC, it was configured either in 40 seat 'Majestic' or 54 seat 'Coronet'. Normal crew complement was 7: captain, first officer, navigating officer, radio officer, two stewards and a stewardess. The Argonaut, like the DC-4, didn't carry a flight engineer. It entered service with BOAC in 1949 and soldiered on until 8 April 1960. One wonders why BOAC favoured the Argonaut over the bigger, faster, sleeker Constellation. That said, the only bad thing I ever heard about it was that fitting the crossover exhaust manifold was a nightmare, especially with the hot sun beating down. (edwardh1, your 'unsheduled engine change' please note! Delhi? Calcutta? At either place and all round the other routes, BOAC had an army of people and spares.)
A fuel flight plan for BA165 G-ALHF Cairo - Khartoum is shown in the book Airline Pilot by Eric Leyland (long since out of print). 880 n.m. stage length, 4.20 flight time, at FL135/140, 8000 lb. fuel consumption, loadsheet fuel 14840 lb., planned take-off weight 80000 lb. The number of pax is 54, so 'HF was in Coronet (tourist) config. Planned time of climb to FL135 is 49 minutes (!) at an average TAS of 171 kt. Initial cruise TAS is 197 kt., increasing to 211 kt. by top of descent, at which point the TAS increases to 221 kt. for the last 20 minutes.
There was no weather radar in them thar days, of course. I can personally attest to being frightened rigid on my first ever flight, in a BOAC Argonaut, in June 1953. Somewhere over France, en route Heathrow - Tripoli, eventual destination Accra, we entered a CuNimb. For what seemed for ever, we were flung around, to the accompaniment of vivid lightning flashes and the clattering of the ice coming off the props and hitting the fuselage. Eventually, we came out the other side, calm was restored and the business of serving dinner got under way. What a welcome to flying! No soothing words from the captain on the p.a. The Argonaut didn't have one of those either. As was the custom, he did eventually pay a visit, resplendent in his four (three and a half? three?) gold bars, wings and medal ribbons.
Ah, the Hermes 4! In contrast to the Argonaut, it entered service with BOAC on 7 August 1950. All 19 were gone by 1 October 1953. As early as August 1952, BOAC were passing some on to Airwork. Apparently it was: " ... the biggest Heap that anyone ever flew, that it built up an unenviable reputation among passengers for monstrous irregularity and non-appearance, and that it did more damage in its ludicrously short operational life to BOAC's reputation than all the other aeroplanes we ever owned put together." (Horizon - The Magazine of BOAC Flight Operations September/October 1966.)
Gosh! That said, the Hermes was gratefully received by Airwork and then Britavia. They were operated on trooping flights to Africa and the Far East. 11500 feet over Zakho, eh? I suppose that's as high as the Hermes could climb with all those 68 people aboard. I'll bet there was double and treble checking of the navigation. Just north of that position, the MSA is shown as 13.1, rising to 16.0 in the Baghdad FIR and the MEA on the airway is FL195! Interesting to note that between them, Airwork and Britavia wrote off five Hermes (Calcutta, Orleans, Sicily, Blackbushe and Karachi) although with what loss of life isn't mentioned.