Originally Posted by
FlightDetent
Dear John.
You keep missing the point where AF447 crew failed to maintain the normal pitch of 1-2.5, deg and a hefty dose of thrust (makes no difference if 80 or 95 N1), failed to do nothing just keep the ESSENTIAL two parameters the same. Giving them an Excel graph, forcing to memorize it, would greatly help them - I think not. Quite on par with the act where you could not add up HW and TW correctly, and thus the precision GS method to reach IAS = Vref = 100 at touchdown would put your followers into a stall with IAS of 60 kts at 2500 ft.
If the traits you claim to have are true, surely you see that a method which has its proponent fail to calculate correctly, (let alone explain it over a few days), from the comfy space in front of a computer screen, is of absolutely no use to a crew in distress.
Adding overlay mumbo-jumbo procedures only makes things worse for the next unfortunate lot. Severely worse as a matter of fact.
Dear Flight Detent
You have referred before to my appalling mathematical ability when in bed using an iPhone to respond to these forums, which I have admitted to. Mea Cupla. I give in. Indeed since then I have now resorted to responding wide awake and in front of my large screen with a keyboard. Like now.
And I have pointed out that on a real flight deck with real instruments in front of me, failed or otherwise, I would not have any trouble sorting out wheat from chaff. It is not so easy when trying to picture HW/TW etc and putting it down on paper remotely in a theoretical setting. But now armed with paper and pencil, I will try again.
And in your QUOTE above you don't
memorise the
graph. It is carried at hand for reference and can be used in seconds. But you do memorise the 50 its per 10,000 feet increase in TAS with altitude, which isn't too hard because I can do it.
First I must object to you repeatedly using my maths errors in a previous post, which I have since corrected, to suggest that the use of GS in UAS is a not worthy of consideration. Either it is a good idea or it is not, and Boeing have it in Line 4 of the QRH for UAS. What I am trying to get going here is a discussion about HOW it might be used effectively, which it most certainly can. I know that from training if you ask a pilot what line 4 in the QRH means, you get some very divergent answers! And that is not good at all , at all, as they say in my part of the world.
BOEING QRH 737-400 Line 4. CROSS CHECK IRS AND FMC GS AND WINDS TO DETERMINE AIRSPEED ACCURACY...................
If I had suggested the world was round and not flat, but made an error in part of the discussion, using your logic, you can reject the entire argument on the basis of an error in one part. Tackle the ball - not the man.
From various replies here you can see that many pilots do indeed find GS useful and I find it more than useful. So do Boeing. Otherwise it wouldn't be in the QRH.
It is useful all the time and particularly on the approach when GS +/- the wind is more or less the same as IAS, so it is absolutely accurate in that situation. Likewise after takeoff. On one or two previous types we flew the approach using a minimum GS, and the Airbus does it automatically using GS mini, I think it is called. But let's not go there.
At altitiude there is a very simple table which I know you don't like, which resolves the issue of not being at MSL.
On a point here, have you ever actually done any of this for real? It sounds to me as if you haven't. I have flown using GS alone umpteen times in the sim. in all sorts of situations (was trained this way on the 737-200 which had doppler GS before GPS) and it transforms what was always a difficult exercise into something entirely manageable.
And as someone else has pointed out. PITCH/ POWER tables are set for a particular airspeed and configuration, and if you set the pitch and power while at a totally different speed, it won't work. GS sorts this out for you.
Example. 737-400 from QRH tables Straight and level flight at 52 tonnes 737-400. 210 knots is 6 deg NU and 60% N1. The "six and sixty rule known by most 737 guys I know).
Now, if you are at 340 knots that won't work and you will be in a climb of about 2000 fpm with rapidly decreasing airspeed and very confused indeed.
I am really trying to engage politely here in what is a very serious matter and I hope we can continue the discussion calmly and tackle the core issues of how are we going to fly our plane in wide range of situations using the GS as a reference as given to us in the QRH.
Over, but not out, yet!! Off to see my therapist now...........
Cheers
Y