The following specifications relate to a standard Altair 8E. They appear in Ted Wixted's booklet "The Search for the Lady Southern Cross" and evidently originate from Lockheed.

NOTE: A study of the history of the Lady Southern Cross will reveal that even the regulators of the day found it difficult to obtain appropriate performance data for this much-modified aeroplane, so it is perhaps not surprising that we must make do with data for a different version of the Altair! The inapplicability of some of the data to the Lady Southern Cross will be obvious in some cases and not so obvious in others, therefore it is most important that the following information is used with caution, for there has been no attempt at modifying these specifications to make them relevant to the Lady Southern Cross except where noted. Although it is not normal policy to include specifications in The Lockheed File, an exception has been made in the case of the Altair as it is "Special", both in name and in character.


Pratt & Whitney Wasp S1D1 (See Note: 1)
Engine HP at Rated RPM
550 hp at 2200 rpm
Engine Rated Altitude
5000 ft
1525 m
Engine Blower Ratio
Engine Compression Ratio 6:1
Engine Fuel Octane Rating Required
28 ft 11 in (See Note: 2)
8.82 m
Span (Wing)
42 ft 9 1/4 in
13.03 m
Height (Tail on ground)
9 ft 3 in
2.82 m
Wing Root Chord
8 ft 6 in
2.59 m
Wing Tip Chord
5 ft 2 15/16 in
1.61 m
Wing Area (incl ailerons and fuselage)
294.1 sq ft
27.3 sq m
Wing Incidence
Wing Dihedral (median line)
4° 30'
Wing Airfoil Section at Root
Clark Y (18%)
Wing Airfoil Section at Tip
Clark Y (9.47%)
Wing Taper in Plan
1.62 to 1
Wing Aspect Ratio
Fin Area
11.0 sq ft
1.02 sq m
Rudder Area
12.8 sq ft
1.18 sq m
Stabilizer Area (both sides)
38.0 sq ft
3.53 sq m
Elevator Area (both sides)
21.6 sq ft
2.01 sq m
Aileron Area (both sides)
22.4 sq ft
2.08 sq m
Landing Gear Tread
11 ft 7 in
3.53 m
Span Tail Surfaces
16 ft 0 in
4.88 m
Fuselage Material
Wood (Spruce)
Wing Material
Wood (Spruce)
Empennage Material
Wood (Spruce)
Shock Absorbing Unit (landing gear)
Aerol Strut
Total Volume Cargo Compartment
100.0 cu ft
2.83 cu m
Max Width Inside Cargo Compartment
44 in
1.12 m
Max Height Inside Cargo Compartment
45 in
1.14 m
Max Length Inside Cargo Compartment
11 ft 0 in
3.36 m
Gross Weight
5800 lb
2630 kg
Empty Weight (with standard equipment)
3550 lb
1610 kg
Useful Load
2250 lb
1020 kg
Pilot (one)
170 lb
77 kg
1306 lb
593 kg
Maximum Oil Capacity (12 gal / 45 litres)
90 lb
41 kg
Maximum Fuel Capacity (175 gal / 662 litres)
1050 lb
476 kg
Normal Fuel Capacity (114 gal / 432 litres)
684 lb
309 kg
Wing Loading
19.72 lb/sq ft
9.64 kg/sq m
Power Loading
10.54 lb/hp
4.78 kg/hp
Takeoff Run at Sea Level (at max gross weight)
900 ft
274 m
Takeoff Time at Sea Level (at max gross weight)
13 sec
Max Rate of Climb at Sea Level (wheels up)
1400 ft/min
427 m/min
Landing Speed at Sea Level (flaps down)
63 mph
101 km/h
Fuel Consumption at 75% Power
33 gal/hr
125 litres/hr
Cruising Range at 75% Power (175 gal / 662 litres)
1050 mi
1690 km
Fuel Consumption at 65% Power
28.5 gal/hr
108 litres/hr
Cruising Range at 65% Power (175 gal / 662 litres)
1150 mi
1850 km
Service Ceiling
22000 ft
6720 m
Absolute Ceiling
24500 ft
7480 m
Maximum Speed at Sea Level (90% power)
200 mph
322 km/h
Max Speed at 5000 ft (1525 m) at 100% Power
220 mph
354 km/h
Cruising Speed at Sea Level at 75% Power
187 mph
302 km/h
Cruising Speed at 11000 ft (3355 m) at 75% Power
205 mph
330 km/h
Cruising Speed at Sea Level at 65% Power
176 mph
284 km/h
Cruising Speed at 5000 ft (1525 m) at 65% Power
185 mph
298 km/h
Cruising Speed at 13000 ft (3960 m) at 65% Power
197 mph
318 km/h


When Lockheed began assembling the Altair (Ship # 152) which was to become the Lady Southern Cross, a works order dated 11 May 1934 specified that the standard Pratt & Whitney Wasp S1D1 be installed. However, another works order dated 25 May 1934 specified a Pratt & Whitney Wasp SE rated at 500hp at 11,000 feet. An Application for Registration lodged in Australia on 26 July 1934 stated that the engine installed was a Pratt & Whitney Wasp SE serial number 5522 rated at 550hp at 11,000 feet.
An Application for Certificate of Airworthiness lodged in Australia on 26 July 1934 quotes a maximum length of 27 feet 10 inches.


Added a table of known variations relevant to the Lady Southern Cross.

Return to the Altair Menu
Return to the Lockheed File