Appendix F Lift Table for Helium and Hydrogen at Standard Temperatures and Pressures Helium density: 0.01056 pounds/cubic foot at STP Hydrogen density: 0.00535 pounds/cubic foot at STP Air density: 0.07651 pounds/cubic foot at STP Envelope volume: 1,000 cubic meters (35,320 cu. ft.)  Lift Table for Helium and Hydrogen at Standard Temperatures and Pressures  (1,000 cubic meter envelope) Altitude (feet MSL) Pressure (in. Hg) Air Temperature (°F) Gross Lift (Helium) Gross Lift (Hydrogen) 0  29.92  59.00  2,329.35  2,513.37 1,000  28.86  55.43  2,262.40  2,441.13 2,000  27.82  51.87  2,196.05  2,369.54 3,000  26.82  48.30  2,131.99  2,300.42 4,000  25.84  44.74  2,068.58  2,232.00 5,000  24.90  41.17  2,007.54  2,166.14 6,000  23.98  37.61  1,947.21  2,101.03 7,000  23.09  34.05  1,888.46  2,037.64 8,000  22.23  30.48  1,831.36  1,976.04 9,000  21.39  26.92  1,775.05  1,915.28 10,000 20.58  23.36  1,720.42  1,856.33 11,000 19.80  19.79  1,667.54  1,799.27 12,000 19.03  16.23  1,614.68  1,742.24 13,000 18.30  12.67  1,564.44  1,688.03 14,000 17.58  9.11  1,514.30  1,633.93 15,000 16.89  5.55  1,466.00  1,581.81 16,000 16.22  1.99  1,418.70  1,530.78 17,000 15.58  –1.58  1,373.34  1,481.83 18,000 14.95  –5.14  1,328.13  1,433.05 19,000 14.35  –8.70  1,284.89  1,386.39 20,000 13.76  –12.25  1,241.84  1,339.94 21,000 13.20  –15.81  1,200.85  1,295.72 22,000 12.65  –19.37  1,160.12  1,251.77 23,000 12.12  –22.93  1,120.57  1,209.10 24,000 11.61  –26.49  1,082.24  1,167.74 25,000 11.12  –30.05  1,045.15  1,127.72 1. Pressures and Temperatures taken from U. S. Standard Atmosphere Supplements, 1966, ESSA,  NASA, USAF; Table 5.2, Geometric Altitudes, English Units 2. Tables assume no effects due to superheating or impurities in lifting gas supply. 3. Entire volume is assumed to be completely filled with lifting gas as would normally be the case on  initial ascent. 4. For all descending altitudes, or for partially full envelopes, use the gross lift shown for the altitude at which the envelope would be completely full. This is called the pressure altitude and is equal to the  maximum altitude achieved during the flight, if the envelope was full at that altitude. Gross lift does  NOT change as balloon descends unless additional lifting gas is lost. Notes F-1