Tests at New York?s MacArthur and Kennedy Airports compared ground-based visibility estimates to the actual pilot contact distance with runways (a TV camera-equipped aircraft flew 468 ILS approaches into radiation fog). Touchdown zone transmissometers provided a lower average difference from pilot visibility than station observers, although transmissometers were associated with larger maximum differences. The average and maximum variation from pilot visibility was considerably larger during the day for all ground based estimating sources, which is consistent with expected impacts from sunshine (bright light and glare may decrease pilot visibility below machine calculation).
Two studies suggest that 90 percent of the visibility estimates from automated weather systems will be within a half-mile of ground observer figures, when visibility is three miles or less. The studies compared transmissometers with runway end observers, and ASOS with station observers, with similar results for both studies.
ASOS and AWOS base daytime visibility calculations on the sighting distance to a large black object held up against the horizon, and night estimates compute sighting distance to a 25 candela light. Ground observers use prominent landmarks during the day, and a variety of light sources at night. Pilots flying daytime approaches in snowstorms to light colored runways, or night approaches to runways equipped with 2,500+ candela REILS, HIRLS or visual glide slopes, might expect variations from reported visibility. (see box below.)
Comparisons of automated weather systems with ground observer characteristics can become rather complex, and pilots may need to interpret visibility reports from all sources, particularly when runway conditions are significantly different from the basis of the visibility estimate.
Lorrin Bird
Ballston Spa, New York
Do schools hire older CFIs?
Thanks for December?s ?Opportunity Knocking.? It?s the first article I?ve read that encourages ?older pilots? to think about teaching. Music has been my career for 45 years, but in five years as a commercial pilot I?ve accumulated more than 4,000 hours.
I was 38 when I got my first job flying cargo but after two years I starved out. During this time I passed the CFI written but never went further. I re-entered aviation in 1985 and flew charter until late ?87. Again, I starved out. I didn?t fly again until three months ago, when I got my flight review and instrument proficiency. I turned 58 in October.
I?d like to get my CFI, but I need a livable wage because I don?t have a pension. I?ve had a lot of experience with FBOs and I know they are the worst place for a CFI to make that livable wage. My question is, do large schools, such as Air Staff in Bakersville, California, hire older instructors? Would appreciate any advice on this matter and, again, thanks for a great article.
Keith McCormack
Via the Internet
Welcome back to aviation! The pilot market has changed so much since your last involvement that you?re simply not going to believe it. Those larger flight schools, as well as university programs, are going to be delighted to have you. And if some of your impressive flight experience is in turbine aircraft, the big contract recurrent training outfits are going to be interested, too, as will, perhaps, airline training departments.
With current demand for pilots so high, young people aren?t instructing for long before moving on. Your maturity and solid flight and instrument experience are going to make you very desirable. So go for the top ? select the places where you?d really like to work, pursue them, and prepare for the dilemma of deciding between multiple job offers!
You will find excellent professional positions around the country listed in publications such as Trade-A-Plane and Business and Commercial Aviation, and on Web sites, such as the National Association of Flight Instructors (www.nafinet.org) and the Universal Pilot Application Service (www.upas.com).
But the shortage is significant enough that I can pretty well assure you that almost any larger flight training operation you choose is either looking for CFIs now, or will be soon. So don?t let a lack of want ads discourage you from applying anywhere that looks interesting. We need you!
? Greg Brown
I?ve got it!
I enjoyed December?s ?Helicopter Controls, First-Lesson Fundamentals,? by David A. Borrows, and I?m really thankful for the way he explained gyroscopic precession. I finally really got it!
I?ve been pursuing a helicopter rating for about three months now, and I already know that I would like to be a CFI because I believe that it would be a fun and rewarding career. You have an informative magazine, but I sure would like to see more articles about helicopter aspects of flight training.
Billy Payne
Belton Texas
Correcting torque
December?s ?Helicopter Flight Controls? said the tail rotor pedals are used to counter the effects of engine torque. The tail rotor actually counters main rotor torque. The difference is significant. When the collective is used in autorotation the tail rotor pedals must still be applied to counter the resultant torque of the main rotor. If a piston helicopter is sitting on the ground without the main rotor engaged and the engine is operating, the pilot can rev the engine throughout the power spectrum without using the tail rotor pedals. Try making a rapid power increase and see what happens if the rotor is engaged. If you?re on a slick surface, be prepared for a couple of wild 360s about the mast.
Dale W. Hemman, ATP, CFII
Steilacoom, Washington
Looking into CFI training
A private pilot with just under 200 hours, I?ve been thinking about becoming a CFI for sometime. December?s ?Opportunity Knocking? made me want to look into this a lot more. Thank you.
Dave Thorpe
Little River, California
Student perceptions
While observing in a sixth-grade history class at Hunt-Mapp Middle School (an Aerospace Magnet School), students were beginning a unit on the flying adventures of Amelia Earhart, getting ready for a related field trip to Kitty Hawk, North Carolina, to the Wright Brothers? Memorial.
As a ?thought-provoker? to introduce the material, the teacher made the following assignment: ?Fold your paper in half, side to side. Write the word ?women? at the top of the first half and list everything you think women would have to learn in order to fly a plane.?
After a few minutes, the teacher made the same assignment this time asking, ?What would men have to learn in order to fly a plane??
When the students finished their lists, the teacher instructed them to open the sheet of folded paper and compare the two lists. ?Look carefully at both lists. Is there anyone who has anything different on one list from the other?? the teacher asked.
A young girl raised her hand and upon being recognized said, ?Men would need to learn more navigational skills than women.?
Puzzled, the teacher asked, ?Why??
?Because men are always getting lost, and they never stop to ask for directions,? she responded. The teacher commented later to colleagues ? ?I?ve never been caught in such a crosswind!?
As a result, our principal, who has his private pilot?s certificate, asked the young lady to help him plot his flight from Norfolk International Airport to First Flight Airport at Kitty Hawk, where he did a ?fly-in? demonstration for the students on the field trip. He didn?t want to get lost, and have to stop to ask for directions!
Mrs. L. D. Ridenour, Magnet Program Facilitator
Hunt-Mapp Middle School
Portsmouth, Virginia
Equipment and systems
In the December ?Flight Forum,? the editor?s response to the question about pitot heat for IFR operations is simplistic and misleading. FAR Part 23 specifies the regulatory requirements, including aircraft equipment needed, for a manufacturer to obtain type certification for an aircraft certified under that part. FAR Part 91 specifies general operating and flight rules for all aircraft operating under that part. It covers aircraft operations and equipment required for those operations. It covers aircraft certified prior to and subsequent to the adoption of Part 23.
FAR Part 91 does not require heated pitot tubes for IFR flight operations, and it is misleading to imply that there is a FAR that does. Also, note that the terms IFR, IMC, and ?icing conditions? are not equivalent. I?d appreciate it if you would publish a clarification of your response. Obviously a wise and prudent pilot would equip his airplane properly and use that equipment appropriately when flying in IMC when there is a possibility of ice.
Owen C. Baker
Fairfax Virginia
You?re correct that Part 91 does not require heated pitot tubes for IFR operation, but it does require, in FAR 91.203, that an aircraft have an ?appropriate and current? airworthiness certificate. Also, Part 91 defines the required equipment, but a heated pitot tube is a system, which is, in the FAA?s eyes, different. The systems required to earn the appropriate aircraft certification, such as flight under instrument flight rules or in icing conditions, are specified in Part 23, among others, depending on the aircraft type. To earn certification for instrument flight rules, which allows an aircraft to fly in instrument meteorological conditions legally, or to fly in icing conditions, an aircraft certificated under Part 23 must have, among other things, a heated pitot tube system. ? Editor
Related Articles
