If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#21
|
|||
|
|||
At 07:30 01 June 2005, Stefan wrote:
I'd like to add that for aerobatic flight, it is common to use QFE, for obvious reasons. But then, aerobatic flights are usually strictly local. Stefan Precisely! And that is the attitude of hundreds of glider pilots for the last 40 years. Strictly local. I was taught that way of thinking in a J-3 cub back in 1953, and then we used it in a glider club in the 60s. It works fine if you are in an uncomplicated area and stay local, but it is OLD THINKING! Hardly anyone travelled to another site those days - even the Cessna pilots stayed within 25 miles of the home airport (flat country). We have a few of those in our club -- guys who never venture more than 10 miles away in flat land, but the instructors don't allow it for students. |
#22
|
|||
|
|||
I'm surprised at the number of US respondents using
the letters QFE, QNH and that third one, which I have already forgot. I'm even more surprised that no one has asked what they mean. QFE = field elevation QNH = pressure level indicating altitude above sea level Q__ = pressure altitude for a standardized pressure to use for high altitudes (above 18K in the US) Now, What does the Q mean? What are the words for NH and for that other one? |
#23
|
|||
|
|||
For some real fun if you have a large fleet of gliders, go out one
morning and set all the altimeters to 29.92 (or the current setting) and see how much variation there is in the altitude read outs. You may be surprised. I certainly was when I did it. |
#24
|
|||
|
|||
Nyal Williams writes:
.... QFE = field elevation QNH = pressure level indicating altitude above sea level Q__ = pressure altitude for a standardized pressure to use for high altitudes (above 18K in the US) Now, What does the Q mean? They come from morse code days, and there are hundreds of them covering all sorts of radio, marine, met, and aviation conditions. Defined by the ITU way back. -- Paul Repacholi 1 Crescent Rd., +61 (08) 9257-1001 Kalamunda. West Australia 6076 comp.os.vms,- The Older, Grumpier Slashdot Raw, Cooked or Well-done, it's all half baked. EPIC, The Architecture of the future, always has been, always will be. |
#25
|
|||
|
|||
|
#26
|
|||
|
|||
The original topic is one with some real merit. I learned to fly with
the field = 0. The field was only about 600' MSL so it wasn't a real big deal, or so I thought at the time. I have just gotten back into soaring and I am doing my very best to break that habit, and use field elevation, which for me is now 300 or so. It is taking a while to break a 19-year habit, but I'm about there. The people that taught me to fly didn't think they were doing anything wrong. They have nothing to be ashamed of, that's for sure. I'm proud to say I know all but one of them... the one that told me I needed to give up, and that I'd never learn to fly... a real morale builder. My point is that maybe instructors should be teaching students to add the field elevation in their decision making. If they're expected to do that, they will. If you expect them to be stupid, they will. Some have stated that they don't have a choice because their airports are too high. They have to teach this the right way. Their students have to learn this and all do. If I were an instructor, I would not solo a student that couldn't do this with proficiency. That student will then know this as instinct, rather than having to unlearn a bad habit. This is important in our mobile society. I've been moved twice in 8 years. I expect to move again this coming winter. I am now comfortable using the MSL field elevation as a start point, and my opinion is that this should be universal for all students. Just my nickels worth... and you thought I just had 2 cents... Jack Womack |
#27
|
|||
|
|||
|
#28
|
|||
|
|||
As a newly certified glider pilot, Hurray!!! I am accustomed to using
field zero because this is how I was taught, BUT... I fly in Florida. Our place is only 200'. However, the thought of eventually going cross country has me considering dumbing this QFE setting, but a few complications entered my mind. Not to mention the accuracy of the instuments in club and commercial planes. Nothing that simple math can't solve of course, but nonetheless important when trying to operate with others in the flying environment. Examples: Cloud base reported by other pilots as 4000',what are they determining that on? QFE or QNH. Signal to tow pilot to release me at 2000'. I pop off sooner. Towing out and looking out for the magic 200'mark to turn back to field in a rope break. Granted, communication with tow pilot, incorporating the math, and of course using good old "That looks about right" may solves these mentioned scenarios, but I just thought, would it not be nice if QNH was universally used by everyone even if my home field is a measley little 200'MSL.? |
#29
|
|||
|
|||
First, congrats and welcome to the sport.
Some suggestions per your questions (with the caveat that a discussion with a CFIG that you trust is undoubtedly a much better source of guidance!): The cloud base question gets to the very heart of this issue, however really only on a theoretical basis - cloud bases have been known to vary quite a bit, cloud to cloud! And here it gets interesting, because ceilings are given AGL for the field in question - because instrument approaches have minimums based on how low the clouds are - AGL! But cloud heights are given in MSL. Hopefully we aren't in the situation of shooting an approach to mins in our gliders! Tows are usually billed in altitude gained on tow - so it's really difference between takeoff and release altitude. You got to do the math - but since most pilots seem to like nice even tow numbers (odd, since the good lift always seems to be at either 900 ft or something like 1700 ft) it really isn't a demanding calculation to make. Anyway, just release, and trust me the tow operation will figure out a way to bill you! Seriously - at a strange field with an odd altitude, just do the math before hooking up, and when you see that number, you are there.\\ The "magic" 200 ft - if you still use it, instead of TLAR - is the same thing, do the math before hooking up as part of your checklist (the E of CBSIFTCBE, for example) and it will work anywhere. For those who like a visual reminder, there are moveable "bugs" that can be attached to the altimeter face that can be set at the field elevation. Cheap and easy. Kirk 66 |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Reading back altimeter settings? | Paul Tomblin | Piloting | 31 | April 12th 05 04:53 PM |
ATC Altimeter Settings | O. Sami Saydjari | Instrument Flight Rules | 81 | April 11th 05 08:07 PM |
Local altimeter at BFM | Dan Luke | Instrument Flight Rules | 3 | June 15th 04 02:01 PM |
Altimeter setting != Sea Level Pressure - Why? | JT Wright | Piloting | 5 | April 5th 04 01:04 AM |
Altimeter experience | HankC | Piloting | 2 | July 25th 03 09:43 PM |