Issue 9
June 6, 2002

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NATA Safety 1st e-Line Service News

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Welcome to the NATA Safety 1st e-Line Service newsletter,
a quarterly summary of the latest NATA Safety 1st news
and education, dedicated to line service staff. Please
make copies available to all line service technicians,
both full and part-time.

---------------------------------------------------------------------------------------
In this Issue of NATA Safety 1st e-Line Service ...

****NATA Safety 1st Program and Other NATA News
****Featured Safety Article... GAMGRAM NO. 32 VENTURI AND NOZZLE PRESSURE
****FAQ --- NATA Safety 1st and Fueling Issues
---------------------------------------------------------------------------------------

---------------------------------------------------------------------------------
****NATA Safety 1st Program and Other NATA News
---------------------------------------------------------------------------------
~~~~~~~~~~~~~~~
NATA NEWS
~~~~~~~~~~~~~~~
NATA recently purchased two Sandpiper Publications. One publication is the Aircraft Ground Service Guide and the other is an Aircraft Towing Guide. Both publications make excellent reference materials for your line crews.

The Aircraft Ground Service Guide includes information on pistons, jets and turboprops concerning fuel requirements and capacity; aircraft performance criteria; ground power locations and requirements; tire pressure requirements; plus pertinent aircraft weights and dimensions. Graphic information inludes detailed locations of most serviceable requirements for each aircraft.

The Aircraft Towing Guide contains reference material provided by aircraft manufacturers on recommended towing guidelines. In-depth towing information is provided by Beechcraft, British Aerospace, CASA, Cessna Aircraft, Dassault Aviation, Galaxy Aerospace, Gulfstream Aerospace, Lockheed Aircraft, Piper Aircraft and Sabreliner Corporation.
Currently, the pricing structure is as follows;

AGSG is Aircraft Ground Service Guide

ATG is Aircraft Towing Guide

AGSG black & white, Print, $19.95

AGSG black & white CD Rom, $19.95

AGSG Color Edition, CD Rom, $39.95

AGSG Managers Edition (AGSG & ATG in color), Print, $59.95

AGSG Managers Edition (AGSG & ATG in color), CD Rom, $49.95

ATG black & white, Print, $19.95

ATG black & white, CD ROM, $19.95
You may order these by credit card on our website
-----------------------------------------------------------------------------------------------------
Have you heard about the latest NATF scholarship offering? It may apply to you...read on

NATA is dedicated to promoting education and training as a means for individuals to advance their careers and to increase the safety and professionalism in their positions. The annual NATA Business Scholarship Award of $2,500 is to be used for continuing education for employees of NATA member companies. All applicable studies should be directly related to furthering the skills applicable to working at a FBO, charter company, maintenance facility or flight school.
Specific details and applications are available on our website.

~~~~~~~~~~~~~~~
PROGRAM NEWS
~~~~~~~~~~~~~~~
-----------------------------------------------------------------------------------------------------
NATA Safety 1st information is available online. We have a new telephone number dedicated to the NATA Safety 1st Program. Please call (703) 575-2045 and ask for Amy Koranda, Jennifer Sword or Louis Soares. Our FAX number is still the same at (703) 845-8176.
----------------------------------------------------------------------------------------------------------------------------
Part of being a NATA Safety 1st Program participant is having your company's website listed on our participant's page. If you are not, please email Jennifer Sword with this information. On the other hand, if you do not want to have your company listed with a link, please let us know. We continue to update the website so that every NATA Safety 1st participant is recognized.

We sent a direct mail promotion to many FBOs that conduct line service operations. We thought it wouldn't hurt to repeat it. The following message is important to remember when you think training exceeds your current resources.

"Since announcing the new NATA Safety 1st Professional LIne Service Training (formerly ATI in January, aviation businesses just like yours have taken advantage of our introductory offer.

In less than sixty days, more than forty-four companies, pumping an average of 600,000 gallons of jet fuel a year took advantage of the new line training program. These companies range in size from 2 line technicians to more than forty-five. In addition, several corporate flight departments have ordered the program to train their employees. Participants are excited about the program and the new prices!

Everyone realizes the need for training. But let’s talk costs for a moment.

Ø NATA Safety 1st PLST training program cost = $100 per line technician
Ø Training time per new employee = $1,000 (80 hours @ $12/hr)
Ø Trainer’s time = $500 (25 hours @ $20/hr)
Ø Total = $1,600 for one line technician

Now let’s consider the costs of incidents.
Ø Insurance deductibles at $10,000 = $10,000
Ø 15% increase in insurance premium = $7,500 annually
Ø Margin on lost fuel and hangar business = $15,000 annually
Ø Cost of advertising, training, uniforms and overtime for other line techs when new line tech quits or is fired = $5,000 per employee
Ø Total = $37,500

At these prices, training is certainly the cost-effective way to do business."
Details on the new NATA Safety 1st PLST

The 9-module training program covers videos on Ground Servicing, Ramp Safety, Refueling Piston Aircraft, Refueling Turboprop Aircraft, Refueling Jet Aircraft, Fuel Farm Management, Towing, Customer Service and Fire Safety. A new, tenth module will be developed with the FAA on Facility and Ramp Security when guidelines and regulations have been determined.
In addition to the 9-series videos above, the program includes three manuals. One manual, the Employee Career Reference Guide, contains the written curriculum that compliments each video. Another manual, the Trainer's Guide, contains additional training information for maximum learning plus all the tests for each module. In addition, it outlines the requirements to become fully certified once training is complete. The third manual, the Aircraft Service Guide, contains important information all line technicians should be familiar with concerning the varying general aviation aircraft. All three manuals are on CD ROM for easy retrieval and print.
The introductory cost to NATA members is $100 per line service technician and $200 per line tech for non-NATA members . With this pricing, you really can't afford not to train.

If you'd like additional details on the training program, please email Amy Koranda.

~~~~~~~~~~~~
SEMINAR NEWS
~~~~~~~~~~~~
Saying good-bye to a colleague and a friend...

On June 3, 2002, Rick Waite, Product Manager at Velcon Filters, Inc., announced his retirement. Although Rick had been talking about retiring in 2004, he decided to retire earlier than planned.

Most of you reading this newsletter know Rick for his filter presentation at the Line Service Supervisor Training Seminar. Rick knows filters inside and out. His presentation has always been widely acclaimed for being technically informative.

We wish Rick the best in retirement. He will be sorely missed, as a friend and one of the best aviation experts in the industry.
Please remember the Line Service Supervisor Training Seminar (LSST) is a required part of the NATA Safety 1st Program. If you have already sent someone from your business, please feel free to skip to the next paragraph. If not, it is required that one person from your line service, usually the supervisor, attend an LSST. And remember, as long as that person remains with your company, the LSST requirement has been met for Safety 1st.

The next LSST will be held in Orlando, Florida on June 10 & 11, 2002.
In addition to the LSST, Excellence in Customer Service will be held in Orlando, Florida on June 10 & 11, 2002. The first day is spent on all aspects of customer service. The second day is combined with the LSST supervisory and management skills.

The next Train the Trainer will be held on September 25, 2002. It will be taught by two well-known and popular NATA presenters, Walter Chartrand and Frank Surface. It is a very interactive seminar with many training tips and techniques followed up by hands-on exercises specific to aviation training. It also gives you a better idea on what kind of trainer you are and why.

Financial Management Tools and Techniques for Aviation Service Businesses, will be held October 3 & 4, 2002 in Denver, Colorado. Phil Botana and Mark Chambers, experts in the financial aspects of running FBOs, will lead the seminar. All information is aviation specific with hands-on exercises that compliment and reinforce your learning experience. Details will be available on our website at a later date.
~~~~~~~~~~~~~
MEMBER NEWS
~~~~~~~~~~~~~
Did you hear about the following NATA Safety 1st Participants...

Wilson Air Center has recently been honored with three separate awards highlighting various aspects of their business and operational standards!
• Aviation International News has named Wilson Air Center as the #1 North American FBO (Fixed Base Operator) for the third straight year.
• Professional Pilot PRASE Pilot Survey has named Wilson Air Center as the #2 Overall Best U.S. FBO.

• AIG Aviation Inc. (the aviation division of American International Group), one of the world's largest aviation insurance companies, has selected Wilson Air Center to receive the 2002 AIG Medallion Award for Operational Excellence.

Million Air SLC is proud to announce that on May 2, 2002, our charter fleet received Wyvern recommendation! We are excited about this opportunity to better serve you and your customers.

NetJets recently issued a Safety Alert. It reads as follows;

"Recently there has been an increase in ground handling incidents involving NetJets aircraft. In light of these incidents, we find it necessary to distribute this Safety Alert highlighting several important ground handling procedures.

Each time a tug, golf cart or other ground vehicle encounters a NetJets aircraft there is a minimum of 24 hours down time. We ask that your staff pay close attention when moving a NetJets aircraft or driving a vehicle with the AOA. NetJets ask that all FBO's comply with the following:

Ø Place orange safety cones at each wing tip, nose and/or tail of all parked NetJets aircraft
Ø Use a minimum of 2 wing-walkers for all ramp towing procedures
Ø Use 2 wing-walkers and a tail guide when moving aircraft into and out of a hangar
Ø Use a minimum of 2 ground guides for all taxiing NetJets aircraft"

For more information please contact: vendorstandards@netjets.com tel. 614-239-5290"

Tom Slavin, Million Air - Cleveland, recommended NATA put together program information for safety meetings. We will be working with Tom, Jim Price and his line crew on subject material and format. If you'd like to participate, please email Amy Koranda or call (703) 575-2045 to assist on this very worthwhile project.

Let us hear from you...If you’d like to share something with other NATA Safety 1st participants, send an email to Amy Koranda with information and/or pictures for the NATA e-Line and website.

-----------------------------------------------------------------------------------
****Featured Safety Article...GAMGRAM NO. 32
VENTURI AND NOZZLE PRESSURE APRIL 1987

------------------------------------------------------------------------------------

As part of this e-Line, we will include an educational article.
Most of the articles will provide continuing education on issues
of importance to line service. In addition, if you are currently
taking the NATA Safety 1st written and practical exams, these
articles will make great study material. Feel free to copy them
and maintain a book for future reference.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
GAMGRAM NO. 32 VENTURI AND NOZZLE PRESSURE
By: Gammon Technical Products
Email: Jim Gammon
Website: www.gammontech.com
<a href="http://www.gammontech.com">AOL users, click here</a>
Tele: (732) 223-4600
Fax: (732) 223-5778
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
GAMGRAM NO. 32: VENTURI AND NOZZLE PRESSURE in pdf version
On nearly every refueler truck and hydrant cart which is capable of underwing (pressure) refueling there is a gauge marked nozzle pressure. Since it is not connected to the nozzle, how can it really show actual nozzle pressure? There is no magic involved. Actually, it does not show nozzle pressure. What it shows is simulated nozzle pressure. The gauge is connected to a device called a VENTURI. The venturi is usually mounted at the inlet of the hose reel. Few people understand what the venturi does or how to adjust it properly. A large number of the venturis in the world are not properly adjusted.

To understand a venturi, we have to understand energy. In a flowing pipe, the energy at any point depends on velocity and pressure. The energy level regains the same except for gradual decreases caused by friction as the fluid passes through valves, fittings and pipe. In Figure 1, the pressures at A, B and C will be exactly the same if there is no flow. If flow takes place, the pressure at C will be nearly the same as at A, less a friction
loss. However, the pressure at B will be much lower than at C. The reason is that we turned some of the pressure energy into velocity energy to get the fluid through the small opening. After the restriction, the velocity energy decreases so the pressure energy must increase accordingly.

Giovanni Venturi, the Italian scientist, discovered 200 years ago that he could make an excellent flow meter with very little pressure loss if he carefully designed the outlet from the restriction to avoid turbulence and friction. See Figure 2. The pressure recovery zone is a long gradual taper back to the original pipe size. The pressure drop (energy loss due to friction) in his design is much less than in Figure 1.

The purpose of a venturi in a fuel system is not to measure flow rate but to provide a simulation at B of nozzle pressure and to use that pressure as the control signal for the pressure control valve. When fuel is pumped to an aircraft, you want maximum flow, but pressure must be kept below 50 psi to protect the aircraft. Because every filter, meter, hose reel, hose and nozzle causes pressure drop, supply pressure must be above the 50 psi maximum aircraft fueling pressure to achieve maximum flow rate into the aircraft. See Figure 3. A typical system may require 80 psi at point C in order to result in 50 psi at the aircraft (D). The problem is that when the aircraft is full, there is no flow and therefore no pressure drop. Without a venturi such a system would, at no flow, put 80 psi on the aircraft. This could cause damage to the aircraft fuel system. If set at 50 psi, the actual fueling rate would be very slow, no where near the design rate because the presure drop between points C and D would use up much of that 50 psi.

The venturi system (Figure 4) solves this problem. By locating the venturi just before the hose reel, pressure drop across the filter and meter is ignored by the pressure controller. The venturi's job is to compensate for pressure drop in the hose reel, hose and nozzle. As flow increases, the venturi 'fools' the pressure control valve into delivering enough pressure so that there is 50 psi at the low pressure point (B). The venturi is 'tuned' so that B and D match. Under full flow conditions, supply pressure (C) may be 90 psi and pressure at point A may be 70 psi, but pressure at the nozzle and at point B is 50 psi. When the aircraft is full and flow stops, pressure A, B, C and D return to 50 psi.

ADJUSTMENT OF THE VENTURI
Venturis are not designed to match each system because it would be far too expensive to custom machine each one. Instead, a venturi is selected that has too much compensation. The Thiem F505 provides up to a 34 psi pressure depression at 600 gpm. If you only need 27 psi of depression to compensate for the pressure drop through the hose reel, hose and nozzle, you must 'bleed off' some of the signal. This is done by adjusting a needle valve (Figure 5) so that some fuel from the high pressure zone at the venturi inlet will flow to the venturi throat. The resulting 'mixed' pressure signal (27 psi below system pressure) is then fed back to the control valve as its 'command'. When correctly adjusted, the pressures at gauges B and 0 read the same. This should be checked at no flow and at full system flow rate.

When properly adjusted, the system allows maximum flow rate without danger to the aircraft. If you change to a different hose length or size (diameter), the venturi must be re-adjusted. We recommend that this adjustment be checked at least once a month. In this way, a possible problem with the pressure control system may be detected and maximum safe flow rate is assured.

If a hose-end pressure control valve is mounted on the nozzle, it must be either removed or 'blocked out' to adjust the venturi 'nozzle pressure' (see our Bulletin 75-47). When finished testing the system, remove the block-out device and re-test the system. (The HECV vent will spray some fuel when next used after hydraulic blockout!) Bear in mind that if the valve is unmounted and removed for this test, its own pressure drop will not be compensated for by the venturi.

Most specifications for fueling equipment now require dual pressure controls, one primary and one secondary or 'back up'. This can be achieved by various combinations of inline, bypass and hose-end controls. (We will address this subject in a future Gamgram) A common method has the deadman valve serve as a primary pressure controller with the bypass valve as a secondary controller. Figure 6 shows how this is done. Both valves mist not be adjusted to control the same pressure because they will 'fight' one another with resulting instability. In any system, the primary regulator controls pressure 5 to 15 psi lower than the secondary. This may be done either by setting the regulators at different pressures, or by sending the regulators differently tuned venturi signals. In this example, the in-line (primary) controller is set at 45 psi, (pressure E). The bypass (secondary) controller is set at 50 psi (pressure B). With this arrangement, if the aircraft valve closes suddenly, the secondary valve backs up the primary valve by opening quickly to relieve pressure on the primary. (Primary pressure may be set as high as 55 psi.)

Many systems on refueling trucks use air pressure as a reference using an air pressure regulator. It is a good idea to use a locking regulator (see our Bulletin 79-70) to prevent unauthorized or 'accidental' adjustment. On a Whittaker-Theim (Parker) regulator, this will be 10,16 or 25 psi higher than the desired fuel pressure. This difference is called the 'bias' pressure. The purpose of this bias pressure is to allow smooth operation of the controller. To better understand this system, think of it this way: The air reference pressure is on one side of a sensing pilot piston with the venturi pressure on the other side with a bias spring. If the total of spring force and venturi pressure is greater than the air reference pressure, the piston moves slightly toward the air side; this results in the control valve closing slightly to reduce system pressure and make the sensing piston return to a balanced position.

-----------------------------------------------------------------------------------------
****FAQ (Frequently Asked Questions) --- NATA Safety 1st
and Fueling Issues
-----------------------------------------------------------------------------------------

This section will help you with the paperwork and study process.
In addition, we will include other questions about fueling issues
that are frequently asked. If you have any tips to share, please
submit them to us and we will include them in upcoming e-Lines.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The following question concerns a test question on the NATA
Safety 1st PLST (formerly ATI). We will be releasing a change
notice in the near future but thought you might share this information
with your line technicians in the meantime. (Please note: this
question is only on the Safety 1st PLST, formerly ATI. It is NOT
contained in the NATA Safety 1st test binder of the original test
program.)

"...I have a question regarding the PLST and a test question.
In Module 4, Pg 3, Section 4.4, Paragraph 5, the manual
states, "the maximum allowable pressure for single point refueling
operations is 50 pounds per square inch (psi). The video also
confirms it is 50 psi. My background is the Fuels career field (Air Force)
and it was 55 psi. Actually, the correct term was 50 (+/- 5).
The test for Module 4, in question 15, says 55 and the correct
answer in the answer key says 'True'. My problem is my students
are answering 'False,' based on the video/reading and they are
correct, yet wrong because the answer key says 'True." Can you
please clarify this question?"
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Industry expert Brian Hahle, Senior Engineer QC for Air BP says...
"Nozzle pressure at the manifold is based upon aircraft manufacturers
specifications. Generally speaking a commercial aircraft is 50 psi
max at the manifold. ATA 103 3.6 (b). states "nozzle pressure should
not exceed 40 psi under conditions of constant flow. Pressure should
not fluctuate more than +/- 10 psi under conditions of constant flow.
(c) Immediately remove unit from service if pressure exceeds 50 psi.
"Nozzle pressure is checked on a daily basis and adjusted when
necessary on a test stand. Gamgram 32 and Gamgram 33 are an excellent source of information on this subject. (Note: Gamgram 32 is
this month's continuing education article.)

I know the Air Force and Navy purchase hose end pressure
control valves that are set at 55 psi and these aircraft manifolds
are designed to withstand higher constant flow and surge pressures.
Surge pressures occur when there is a loss of power on the aircraft and
the manifold valves abruptly shut down or a single tank is full and the
VTO closes the valve for that tank automatically.
Aircraft manifold systems are designed to withstand moderate surge
pressures but the pressure control on the refuleing vehicle will throttle
the nozzle pressure back to its originally set pressure. It's safe to say
that 50 psi max is the standard for GA, corporate and commercial
aircraft."

In the each e-Line, we ask you to share safety information or statistics about how the NATA Safety 1st Program has impacted your business. Please keep information coming our way! We really think you are doing a great job of keeping those lines safe.
-----------------------------------------------------------------------------------------------------
The NATA Safety 1st e-Line Service newsletter is distributed quarterly. We welcome your feedback on this newsletter and any topics you would like to see discussed. Send articles/email to Amy Koranda.

Thank you for your commitment to line service safety...
keep those ramps safe.