Hi Bob and Richard,
On page 4.48 of the printed BT Perf manual issue 6, it states up near the top of the page just under the diagram "From Page 10 chart 5 of the Echo Mk 4 manual, TAS = 185kt."
When I go to the supplement, page 10 is all about loading system Charlie (nothing to do with Echo) and when I leaf through the supplement I can only find speeds on page 13 (Operating Limitations - which are in IAS or Windspeed) and on pages 14 and 16 which are Max rate of CLIMB (with associated TAS speeds) and also page 16 (TAS knots) based on pressure height, temp, weight and throttle setting.
I cant find this 185 kt tas the book is asking for however, and I dont have enough other data to use the chart on page 16, so where is this data sourced from?
Brook
Hi Brook,
That's a glitch 🙂 The question stem tells you the TAS and fuel flows and there is not enough information to use the cruise tables anyway. I suspect this is a long "hidden in plain sight" errata left over from a previous edition which did get you to do a look-up.
How about we pad out the stem and say:
An Echo aircraft cruises at 65% power at 10000 ft where there is an OAT of -5 degree Celsius. The tailwind component on the flight planned track is 25 kt and start up is with 120 gal. If 3 gal is allowed for start-up and taxi, and 15 gal is allowed for the fixed reserve, find the time to the PNR [ignore climb and descent].
That'll fix it. Thanks for pointing it out - much appreciated 🙂
Cheers,
Rich
Actually the only thing that needs to be done is to delete the line that refers to Page 10 of the supplement. All of the information required to solve the problem is given at the bottom of Page 47. Page 48 is simply a continuation of the example given on Page 47. The TAS of 185 knots is given in the question along with the fuel flow, wind and total fuel on board and reserves.
I think the question originally required you to look up the TAS and fuel flow tables on Page 16 of the supplement. The question was reworded to avoid the need to use the supplement at all. The reference to Page 10 of the supplement should have been deleted - which is what I have done now.
Thanks for your feed-back Brook
Bob
Aw Bob, don't spoil the fun. I wanted to give Brook some hard sums. Having said that, I should have specified an 8-way interpolation 👿
Thanks Guys - loving the Online Performance Module 🙂 I am fairly certain I have now got past the point of no return (ETP) which appeared to be moving away from me due to a 200 knot health headwind which I just spooled the turbine up for and got through, but the PNR looks like its getting closer 😉
I get it now Richard - you are going to get CASA in Canberra to bring out the Echo mk 5 which has 4 engines....just for some fun!
