MSN 152
"Lady Southern Cross"

Issue #7 Compiled by Ron Cuskelly 03JAN01

Lockheed Inter-Dept Memo


As Delivered to Australia (P.G. Taylor) Australian
CofA #443
Australian CofA #443
(Extra fuel * noted as not approved)
Centenary Air Race
(P.G. Taylor)
Pacific Flight
(Smithy and P.G. Taylor)
(Note 1)
(Note 4)
  25MAY34 17JUL34 26SEP34 26SEP34 29SEP34 21OCT34 19OCT35
EMPTY WEIGHT (Note 1) 3675

3675 3675 3675 3737 3737
CREW (2 x 170 lbs) (Note 2) 320

340 340 340 340 340

EQUIPMENT (Note 2) 48

20 20 20 20 10

RADIO (Note 2) 20

46 46 46 46 14

UNACCOUNTED (Note 1/5) nil

5 5 135 nil
OIL (U.S. GALLONS) (Note 3) [40] [24] [33] [33] [24] [24] [14]
OIL (IMP. GALLONS) (Note 3) [33] [20] [28] [28] [20] [20] [12]
OIL WEIGHT (7.5 lbs per U.S. gallon) 300 180 249 249 180 180 105

FUEL (U.S. GALLONS) (Note 3) [506] [502] [394] [510] [384] [618] [151]
FUEL (IMP. GALLONS) (Note 3) [421] [418] [328] [425] [320] [515] [126]
FUEL WEIGHT (6 lbs per U.S. gallon) 3036 3012 2365 3057 2304 3708 907


[2365] [2365]


(1 @ 24US/20 IMP)


(2 @ 91US/76IMP)



MAX ALL UP WEIGHT (Theoretical) 7399




Any study of this particular Altair will reveal that a feature of its short life was the seemingly never-ending series of modifications to the fuel system. This table attempts to bring together all available information on these modifications in a form which will allow the reader to follow the aeroplane's development. Sources and dates are quoted at the head of each column. Please bear in mind that there will be anomalies in these figures by virtue of the varied sources, together with the likelihood of errors arising out of assumptions and conversions relating to fuel and oil quantities. It should also be noted that another feature of this aeroplane's history is bureaucratic self-preservation! This is the author's best attempt at clarifying these matters. Please be guided accordingly.


1 In the absence of an empty weight on available Lockheed documents, the empty weight from the Australian CofA has been used in the first column. Empty weight (deduced from max A.U.W.) had increased by 149 lbs to 3824 lbs when the U.K. CofA was issued. Presumably this is predominantly the weight of the Wackett tanks.

A message from the Australian District Superintendent of Civil Aviation dated 10th October 1934 (which see) indicates that the weight of the additional tanks was 62 lbs, thus increasing the empty weight to 3737 lbs. The empty weight in the Pacific flight column has been adjusted accordingly. Similarly, the empty weight in the U.K. CofA column has been amended even though the U.K. CofA suggests that the empty weight had risen to 3824 lbs. The outstanding 87 lbs is probably accounted for by additional equipment not specified on the U.K. CofA.
2 Weights for Crew, Equipment and Radio, once established on the Aust. CofA, have been carried across as reasonable estimates. However, different weights were specified by Lockheed and on the U.K. CofA. Lockheed used 160 lbs for each crew member.
3 Figures shown in brackets are not to be added to the weight calculations, being either volumes or weights added elsewhere.
4 The U.K. CofA was in reality a validation of the original U.S. Export CofA which specified a max A.U.W. of 5200 lbs.
5 Although P.G. Taylor used lower fuel/oil figures for the Centenary Air Race, he still quotes the A.U.W. as 6700 lbs, as per the Aust CofA which was issued to facilitate the Altair's entry in the race.
6 All weights in the above table are in pounds.
7 Note that Wackett claims to have added four (4) wing tanks whereas P.G. Taylor and Smithy both claim he added only two (2). However, all basically agree on the total capacities of the wing tanks added by Wackett. Available evidence suggests that Sir Lawrence Wackett's recollections may have been in error after the passage of forty years. It should be noted that the two Wackett wing tanks were removed by Lockheed after the Pacific flight but the Wackett fuselage tank under the pilot's seat was retained.
See How Many Wackett Tanks?
8 To convert Imperial to U.S. gallons multiply by 1.2
To convert U.S. to Imperial gallons multiply by 0.8327


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