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Old 8th June 2025 | 23:29
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DrDennisJensen
 
Joined: Jun 2025
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From: Mandurah
Originally Posted by dynamite dean
Returning to Manchester today above the headwinds we were at FL490 (!) Lear 40; whilst with glazed eyes was wondering ... this question for a moment and it just popped into my head ... how much thrust on a 3500Ib rated engine is actually being produced at this sort of level?
Anyway whatsover to answer this or is it rocket science?
Not sure of the actual answer, but most of the answers here are attempts based on cruise thrust, not maximum thrust.
You could calculate how much maximum thrust the engines of an aircraft has knowing absolute ceiling at a certain weight and speed, and knowing the lift over drag ratio at that speed.
For example, take a theoretical airliner that at a weight of 200,000lb, having a lift over drag ratio of 20:1 at its absolute ceiling would have 10,000lb of thrust in total. Any less thrust, and it would lose altitude, any more and it could gain either altitude or speed.
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