JUSTNUZZA Posted June 8, 2014 Posted June 8, 2014 Just wondering what reference people use when they quote aircraft speeds for performance figures ? What is the altitude for reference and is the speed Indicated, True or Calibrated airspeed ?
rgmwa Posted June 8, 2014 Posted June 8, 2014 Depends who you're trying to impress. Seriously though, I'm not sure that there's any consistent standard. Cruise speeds at about 7,500' are often quoted, but it's usually not clear whether that's IAS or TAS, although I assume it's TAS. rgmwa
metalman Posted June 9, 2014 Posted June 9, 2014 It depends mostly on whether you're flying somewhere or selling the aircraft, ;-) 2 2
poteroo Posted June 9, 2014 Posted June 9, 2014 It depends mostly on whether you're flying somewhere or selling the aircraft, ;-) Wide open throttle at 6000 ft (in km/hr) for 'normal' cruise, and stalling speed with 10L fuel and a jockey as pilot, (in kts). happy days, 3 1
metalman Posted June 9, 2014 Posted June 9, 2014 Wide open throttle at 6000 ft (in km/hr) for 'normal' cruise, and stalling speed with 10L fuel and a jockey as pilot, (in kts).happy days, A salesman is born, good luck on the future sales of the latest 180 knot RAA plane with an approach speed in the low forties 1
Yenn Posted June 9, 2014 Posted June 9, 2014 Wide open throttle at 6000 ft (in km/hr) Not in Australia. 6000' is IFR level and they don't fly using km/hr. Anyone who knows anything knows that speeds can be highly inflated, so they will be taken with a pinch of salt. I say my Corby cruises at 100kts, that is at about 3500' part throttle and indicated speed. no doubt if I took it up to 6500 or higher and calculated TAS it would be greater, but what would that achieve, it may still be unbelievable to some people. More believable is the fact that at wide open throttle it can exceed Vne straight and level and would probably still be consuming about 18l/hr at most
robinsm Posted June 9, 2014 Posted June 9, 2014 Since when is 6000ft an IFR limited area. Cant we go to 10,000 nowadays as VFR?
Keenaviator Posted June 9, 2014 Posted June 9, 2014 Since when is 6000ft an IFR limited area. Cant we go to 10,000 nowadays as VFR? I think you'll find it's a possible IFR flight level. Above 5000' isn't there a requirement to fly hemispherically? Many moons ago I departed Orange and anounced on the area frequency that I was at 5000' heading north. Melbourne Centre piped up and informed me that I was at an IFR level so I climbed to the correct hemispherical level. Laurie 2
robinsm Posted June 9, 2014 Posted June 9, 2014 I always fly hemispherically anyway, didn't realise it was an ifr thing...
Ultralights Posted June 9, 2014 Posted June 9, 2014 not a good idea to fly hemispherically unless you add 500ft. , if VFR, its Hemispherical levels +500 ft. eg, 1500, 3500, 5500, 7500,9500 or 2500 4500 6500 8500 If flying headings from 000 to 180 degMag then is Odds +500, and evens +500 for 181 deg to 359 deg Mag. Not mandatory below 5000ft, (but avisable) and mandatory above 5000ft. IFR levels are Odds and evens 1000's CASA used to hand out little stickers displaying hemispherical levels for both VFR and IFR, and were small enough to not look out of place on your panel. 3
Bruce Robbins Posted June 9, 2014 Posted June 9, 2014 not a good idea to fly hemispherically unless you add 500ft. ,if VFR, its Hemispherical levels +500 ft. eg, 1500, 3500, 5500, 7500,9500 or 2500 4500 6500 8500 If flying headings from 000 to 180 degMag then is Odds +500, and evens +500 for 181 deg to 359 deg 0 - 179 is Odds (plus 500 for VFR) 180 - 359 is Evens
Bruce Robbins Posted June 9, 2014 Posted June 9, 2014 0 - 179 is Odds (plus 500 for VFR)180 - 359 is Evens And it is Magnetic Track, not heading.
nickduncs84 Posted June 10, 2014 Posted June 10, 2014 a lot of confusion here in an area where there really isn't any excuse for there to be any. not a good look for the training standards of RA Aus and not one of those areas you can afford not to understand and practice. 5
cherk Posted June 10, 2014 Posted June 10, 2014 a lot of confusion here in an area where there really isn't any excuse for there to be any. not a good look for the training standards of RA Aus and not one of those areas you can afford not to understand and practice.
frank marriott Posted June 10, 2014 Posted June 10, 2014 Also it applies above 3000, not 5000 Yen Where is the 3000ft mentioned? CAR173 only says "Must, whenever practicable" below 5000ft + must above 5000ft. I have heard this stated (the 3000ft bit) before but I am unable to see where it is legislated outside CAR173. 1
poteroo Posted June 10, 2014 Posted June 10, 2014 Wide open throttle at 6000 ft (in km/hr) Not in Australia. 6000' is IFR level and they don't fly using km/hr.Anyone who knows anything knows that speeds can be highly inflated, so they will be taken with a pinch of salt. I say my Corby cruises at 100kts, that is at about 3500' part throttle and indicated speed. no doubt if I took it up to 6500 or higher and calculated TAS it would be greater, but what would that achieve, it may still be unbelievable to some people. More believable is the fact that at wide open throttle it can exceed Vne straight and level and would probably still be consuming about 18l/hr at most My illustration wasn't meant to say 'fly at 6000 ft'........ it was meant as an approx. altitude where you can fly W-O-T and just achieve 75% or max continuous power. (I do happen to know the hemispherical rules). The 3000 - 5000 thing: I understand the confusion to be in regards to maintaining VFR criteria....nothing to do with cruising level selection. It is recommended that we fly hemispherical at any level provided we are 500 or 1000 agl according to what's under us.
frank marriott Posted June 10, 2014 Posted June 10, 2014 I suspect the 3000ft thing comes from FAA rules not Australian, hence my question. When you could fly "full SAR" VFR (in Australia) it was the norm to nominate a cruising altitude above 5000 (i.e. AO65) and below was BO50 . As far as I am aware CAR173 is the only rule as applies is Australia and there is no mention of 3000ft there. 1
nong Posted June 14, 2014 Posted June 14, 2014 Just wondering what reference people use when they quote aircraft speeds for performance figures ? What is the altitude for reference and is the speed Indicated, True or Calibrated airspeed ? "Indicated, True or Calibrated" You forgot to mention......"Fabricated". ! 2
JUSTNUZZA Posted June 14, 2014 Author Posted June 14, 2014 "Indicated, True or Calibrated"You forgot to mention......"Fabricated". ! I expect that is used commonly also to boost ones ego.
AVOCET Posted June 14, 2014 Posted June 14, 2014 "Indicated, True or Calibrated"You forgot to mention......"Fabricated". ! what about a pinhole in the static line?
metalman Posted June 14, 2014 Posted June 14, 2014 what about a pinhole in the static line? That would be "perforated airspeed" ! 4
ozbear Posted June 14, 2014 Posted June 14, 2014 If you fly at 3000ft where I come from you would be AGL at ground level or very close 1
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