Simon Thomas
Senior Airman
In the Aeronautical Research Council Reports & Memorandum Report No. 2756 "The Loss in Climb Performance, Relative to the Optimum, Arising from the use of a Practical Climb Technique" bу K. J. Lush dated August, 1949, there is a table in Appendix II that contains CDZ and πeA values for the Lancaster 1 that were obtained from flight tests.
From these figures, e and f for the Lancaster can be determined. A = aspect ratio = 8 for the Lancaster, and the wing area of the Lancaster = 1,297 ft², thus f = 37.613 ft² and e = 0.87933.
R&M No. 2212 "The Variation of Power with Height of the Merlin XX Engine as determined by Flight Tests on a Hurricane II", "Rating Certificate Merlins 28, 29 and 31" and "The Performance of a Supercharged Aero Engine", Hooker, S., Reed, H., and Yarker, A., Technical Series No. 3 together allow the performance of a Merlin 28 (American XX) to be determined for any altitude. It also a means for determining exhaust thrust, power loss due to intake air consumption and provides bsfc figures for climb and max continuous. The paper "Methods used in Preparing Engine Specifications" by E. F. Pierce 1939 of Wright Aeronautical is also helpful.
Propeller performance can be calculated from "Airplane Performance Stability and Control", Perkins & Hage, 1949. Section 3-4, particularly Figure 3-20b. TAF was taken as 420. A sensitivy check was done of this figure and the prop efficiency does not change appreciably.
With the above data, a copy of "Aerodynamics For Naval Aviators" by H. H. Hurt, Jr. particularly p.89 for drag and p. 154 for rate of climb, and a spreadsheet, a calc can be put together fairly easily.
The results match rather closely the A.&A.E.E. report below as well as the Pilot's Notes for the Lancaster.
Report A.&A.E.E./766 "A review of the performance and handling trials of ten production Lancaster Mk.III aircraft" provides much useful data to not only cross check the above calculations but also to gain an appreciation of the variations in performance of Lancasters. The variations of calculation results is rather similar to the performance variations in the ten production examples.
"Development of the Rolls-Royce Merlin from 1939 to 1945" by Mr. A. C. Lovesey, Figure 9 provides power vs altitude for the Merlin RM16SM for both combat and max. cruising conditions. The high altitude performance of a Lancaster fitted with these engines provides an interesting case study in carrying a 10,800 lb bomb for 1,369 nm then a 408 nm return leg, with a suitable reserve.
The R&Ms can be found in Hathitrust. The Merlin rating certificate, A&AEE report and Lovesy paper can be found on wwiiaircraftperformance.org . "Aerodynamics For Naval Aviators" is available on the FAA website. "Methods used in Preparing Engine Specifications" is on AEHS. The Hooker paper can be bought from the RRHT and the Perkins & Hage book can be found second-hand.
From these figures, e and f for the Lancaster can be determined. A = aspect ratio = 8 for the Lancaster, and the wing area of the Lancaster = 1,297 ft², thus f = 37.613 ft² and e = 0.87933.
R&M No. 2212 "The Variation of Power with Height of the Merlin XX Engine as determined by Flight Tests on a Hurricane II", "Rating Certificate Merlins 28, 29 and 31" and "The Performance of a Supercharged Aero Engine", Hooker, S., Reed, H., and Yarker, A., Technical Series No. 3 together allow the performance of a Merlin 28 (American XX) to be determined for any altitude. It also a means for determining exhaust thrust, power loss due to intake air consumption and provides bsfc figures for climb and max continuous. The paper "Methods used in Preparing Engine Specifications" by E. F. Pierce 1939 of Wright Aeronautical is also helpful.
Propeller performance can be calculated from "Airplane Performance Stability and Control", Perkins & Hage, 1949. Section 3-4, particularly Figure 3-20b. TAF was taken as 420. A sensitivy check was done of this figure and the prop efficiency does not change appreciably.
With the above data, a copy of "Aerodynamics For Naval Aviators" by H. H. Hurt, Jr. particularly p.89 for drag and p. 154 for rate of climb, and a spreadsheet, a calc can be put together fairly easily.
The results match rather closely the A.&A.E.E. report below as well as the Pilot's Notes for the Lancaster.
Report A.&A.E.E./766 "A review of the performance and handling trials of ten production Lancaster Mk.III aircraft" provides much useful data to not only cross check the above calculations but also to gain an appreciation of the variations in performance of Lancasters. The variations of calculation results is rather similar to the performance variations in the ten production examples.
"Development of the Rolls-Royce Merlin from 1939 to 1945" by Mr. A. C. Lovesey, Figure 9 provides power vs altitude for the Merlin RM16SM for both combat and max. cruising conditions. The high altitude performance of a Lancaster fitted with these engines provides an interesting case study in carrying a 10,800 lb bomb for 1,369 nm then a 408 nm return leg, with a suitable reserve.
The R&Ms can be found in Hathitrust. The Merlin rating certificate, A&AEE report and Lovesy paper can be found on wwiiaircraftperformance.org . "Aerodynamics For Naval Aviators" is available on the FAA website. "Methods used in Preparing Engine Specifications" is on AEHS. The Hooker paper can be bought from the RRHT and the Perkins & Hage book can be found second-hand.
