On Thu, 1 Apr 2004 18:52:03 -0600, "Jon Berndt" <[EMAIL PROTECTED]> wrote:
>> BTW I never said 'whole aircraft drag' - always just the drag >> due to the cooling system. In this article we have some better >> numbers: 350lb of additional thrust on an aeroplane generating >> c. 1000lb of thrust via the prop. Or 400lbs worth of drag >> reduced to 50lbs. >> >> The Spitfire MkIX wasn't a particularly inefficient aeroplane, >> there has to be a reason why the Mustang (unquoted Mk but >> assumed to be roughly equivalent) was (according to this >> article) 30mph faster. Wing, duct or both? > >I've got plenty of articles around here somewhere ... this sounds familiar. >I'll see if I can find a reference. Some comparative numbers from WWII RAF (late 1943) testing. The Mustang was a P51B. Vs Spitfire IX: '... the Mustang is a much cleaner aircarft...' Wing Loading: 43.8 vs 31 lbs per sq ft Range with full fuel: 1.5 to 1.75 that of Spitfire Fuel Load: 183 vs 101 US Gal Oil: 13.3 va 7.5 US Gal Fuel with long range tanks: 330 vs 210 US Gal 20-30 mph faster at all heights. Heights for best performance: Similar, 10,000-15,00 ft and 25,000 to 30,000 ft Full power climb inferior: Spitfire formates with 5lb less boost with Mustang at full power. (full power in 18lbs boost) Climb at 175mph similar. Pulls away from Spitfire rapidly in a dive. Spitfire requires 4-6lbs more boost to remain in formation Inferior in turn. Turning circle not noticeably improved by flaps. Inferior in roll at normal speeds. Equivalent at 400 mph Vs Spitfire XIV Speed: No practical difference. Climb: Spitfire 'very much better' Dive: Advantage less marked than with Mk IX Vs FW190 A-3 (no water-methonol boost) Speed: c 50 mph faster than FW190, 70 mph above 28,000 ft. Climb: 'little to choose' Dive: Mustang can always out-dive FW190 Turn: Slightly superior. Roll rate: FW190 markedly better. Vs Bf109G-2 (no water-methonol of nitrous oxide) Faster at all heights. Bf109 best heights 16,000ft (Mustang 30 mph faster) and above 25,000 ft (30mph increasing to 50mph at 30,000 ft) Climb: Similar, Mustang slightly better above 25,000 ft, slightly worse below 20,000 ft Dive: Better in prolonged dive. turn: Mustang greatly superior. Roll: Not much to choose. In a tight turn the Bf109s wing slots open when a rapid change of bank is attempted producing an 'embarrassing' rate of roll. Wing tanks effect on performance: 40-50 mph loss of speed. Still faster than FW190 above 25,000 ft (but still slower than BF109). Climb: Out climbed by FW90 and Bf109. Followed by FW190, 'definitely outstripped' by Bf109 Dive: With 'fairly full' tanks still out dives FW190 and Bf109 turn: As tightly aa FW190, definitely better than Bf109 Roll: Handling very little effected. Vs Tempest V Speed: Mustang 15-20 mph slower up to 15,000 ft, same to 24,000 ft, Mustang 30 mph faster at 30,000 ft. Climbs 'Compare directly with speed tests' Rate of turn: Mustang slightly better Roll: Tempest V inferior. On power, the '1000 lb' quoted by Atwood probably referred to the P51A's powerplant, I don't have figures but the P51D may well have double the power. Rick -- Help the Waterway Recovery Group to help restore the Uks canal network Make a donation to the 'Right Tool' Appeal http://www.wrg.org.uk/cgi-bin/fmaker.pl?appeal.htm _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
