tag:blogger.com,1999:blog-431515400045975752.post6127218540131316472..comments2023-09-18T05:28:37.097-07:00Comments on surroundedbyair: Heat on Pitot TubesDr.ATPhttp://www.blogger.com/profile/10577827249492491854noreply@blogger.comBlogger4125tag:blogger.com,1999:blog-431515400045975752.post-31342719331777809882010-01-14T13:41:33.136-08:002010-01-14T13:41:33.136-08:00Claus,
Thanks for reading. I'm sorry to say ...Claus,<br /><br />Thanks for reading. I'm sorry to say that I have no experience in ATC modeling. As a rule, though, engineers write at the necessary level of complexity.Dr.ATPhttps://www.blogger.com/profile/10577827249492491854noreply@blogger.comtag:blogger.com,1999:blog-431515400045975752.post-45558267007985534452010-01-12T00:43:06.392-08:002010-01-12T00:43:06.392-08:00May I ask you a general question, please?
I am loo...May I ask you a general question, please?<br />I am looking for mathematical models/modelers of air traffic control. For example, how to adjust speeds or trajectories (vectors) such that certain constraints are satisfied.<br />There are some engineers writing on such things, but they generally make the things more complicated than they are.<br /><br />Thank you in advance,<br /><br /><br /><br />P.S. An example of an fine analysis of car-traffic is<br /><br />On traffic flow at a T-junction: a sufficient condition for a left-turn lane. Mathematical and Computer Modelling 24, No. 7, 53-57 <br />Mr. Mesterton-Gibbons.<br /><br />P.P.S.<br />I found your blog following traces of Mr. Horonjeff's book on airport planning, which has the same publisher than your own book.Clausnoreply@blogger.comtag:blogger.com,1999:blog-431515400045975752.post-82974307613851651752010-01-08T08:25:24.403-08:002010-01-08T08:25:24.403-08:00Thank you for your comments. I forgot all about th...Thank you for your comments. I forgot all about the B-2 accident, which seems more complex because of its complex flight control system. As I understand it, the wet sensors provided BOTH false airspeed AND false angle of attack information. In such a case PITCH+POWER=AIRSPEED doesn't work.<br /><br />Another disturbing part of this accident was that only some crews knew that the B-2 needed pitot heat on while operating in humid conditions. Where was the mechanism to pass this crucial information on to everyone?<br /><br />As for whether we still need pitot tubes, I think we'll have to disagree, at least in part. While in most conditions, airspeed can be computed from other parameters (descent angle, power, AoA,...), these computations may not handle transients (ie, gusts) well. You still need to have an input from the dynamic air pressure.<br /><br />What's really a mess is barometric altimetry. This is the root cause of cold temperature errors, among other things. But barometric altimetry is great for separation purposes; GPS altitude is not, unless you base separation on which satellites each aircraft is using. Altitudes derived from different satellite constellations might have different errors, which might lead to a loss of separation.Dr.ATPhttps://www.blogger.com/profile/10577827249492491854noreply@blogger.comtag:blogger.com,1999:blog-431515400045975752.post-72088243642525444012010-01-07T16:33:24.936-08:002010-01-07T16:33:24.936-08:00Some excellent thoughts here, and thanks for the p...Some excellent thoughts here, and thanks for the pint out on the ASWT article, I'm going to enjoy reading it.<br /><br />Yeasr ago when I worked for the USAF I had the privilege of spending some time with one of the earliest scientific advisors to the GPS program. He was hard over on the idea that GPS could go much further into the real of the cockpit, including replacing the "archaic" (his word) pitot static system. He couldn't believe, and I can't either, that with the instrumentation technologies available today we would still even be thinking of pitot/static systems.<br /><br />Perhaps from a pilot's perspective (anything that can go wrong will go wrong), his thinking was a bit too impractical ... but he certainly was on the right track. <br /><br />We shouldn't even be thinking of the problems of deicing pitot tubes at -70C. That would be like spending research dollars to study the NACA radial engine cowling's performance at Mach two.<br /><br />There are so many other methods we could use, redundant methods, that could measure speed and lift/angle of attack(a primary reason we want to know airspeed in the first place) that I truly think the industry is barking up the wrong tree ... stuck in a Pandora's box from the 1920's.<br /><br />Let's get rid of pitot tubes now, certainly on high performance aircraft ... they are the wrong tool for the job.<br /><br />(by the way, the USAF lost a 1.2 billion dollar super-sophisticated B-2 on Guam less than 2 years ago due to the pilots' following faulty airspeed data caused by, what else, moisture in the pitot/static system.)Dave Starrhttps://www.blogger.com/profile/05853160665847969116noreply@blogger.com