...................will the airlines count jet glider time towards gas turbine time they are interested in for the young guys and girls building hours and applying for the airlines.
................will all of you who have not passed BGT have to? SDF -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Peter Creswick Sent: Monday, 26 March 2007 9:03 AM To: Discussion of issues relating to Soaring in Australia. Subject: Re: [Aus-soaring] Jets A good "rule of thumb" for take off calculations is (0.7 x static thrust) / AUW, which gives acceleration in "g" (which is a very small figure) The 0.7 is to average thrust during the ground roll, since increasing ram drag reduces net thrust with increasing speed, making the calculation easier. Then of course you have to factor in slope, rolling resistance, and increasing aero drag and don't forget induced drag at rotation. ----- Original Message ----- From: "David Lawley" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; "'Discussion of issues relating to Soaring in Australia.'" <aus-soaring@lists.internode.on.net> Sent: Monday, March 26, 2007 8:52 AM Subject: RE: [Aus-soaring] Jets > Hi all, > > Let me rephrase the question, what is the conversion for thrust to > horsepower assuming 0 airspeed, idea being what acceleration a jet powered > glider will have from a standing start, ie takeoff? > > Regards > > Dave > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Anthony > Smith > Sent: Monday, 26 March 2007 7:50 AM > To: 'Mike Cleaver'; 'Discussion of issues relating to Soaring in > Australia.' > Subject: RE: [Aus-soaring] Jets > > Actual Thrust = prop efficiency x power / speed. > > Working out the prop efficiency is the interesting bit. > > -----Original Message----- > From: Mike Cleaver [mailto:[EMAIL PROTECTED] > Sent: Sunday, 25 March 2007 10:32 PM > To: [EMAIL PROTECTED]; Discussion of issues relating to > Soaring in Australia. > Subject: RE: [Aus-soaring] Jets > > At 21:36 25/03/2007, you wrote: >>Yes, but it isn't straightforward, which is why people keep refering to >>either thrust for jets and horses for props. >> >>It is probably easier to convert horsepower to thrust - but you will >>need a chart of your propeller efficiency. >> >> >> >>-----Original Message----- >> Anyone know the relationship between thrust and horsepower? > > > The old Physics teacher in me (yes, me too!) says > thrust = force > work = force x distance > speed = distance / time > power = work / time = force x distance / time > therefore power = thrust x speed > > with appropriate factors to convert from various units, but if you > use the old imperial units then 1hp = 550 ft-lbf/sec > but then the aerodynamicists went and stuffed it all up by requiring > the density of air to be expressed in slugs per cubic foot to make > the imperial system work. (actually the error is using a pound as a > force unit when it is really a mass unit - a slug is 32.2 lb mass!) > > Wombat > > > >>_______________________________________________ >>Aus-soaring mailing list >>Aus-soaring@lists.internode.on.net >>To check or change subscription details, visit: >>http://lists.internode.on.net/mailman/listinfo/aus-soaring > > _______________________________________________ > Aus-soaring mailing list > Aus-soaring@lists.internode.on.net > To check or change subscription details, visit: > http://lists.internode.on.net/mailman/listinfo/aus-soaring > > _______________________________________________ > Aus-soaring mailing list > Aus-soaring@lists.internode.on.net > To check or change subscription details, visit: > http://lists.internode.on.net/mailman/listinfo/aus-soaring > > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.5.446 / Virus Database: 268.18.18/733 - Release Date: > 25/03/2007 11:07 AM > > _______________________________________________ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring _______________________________________________ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
