Y 

c- 

-c,. 

.’ x , 

c \. 

DATE: 7/a/74 

ADVISORY 

CIRCtiGmAR 

DEPARTMENT OF TRANSPORTATION ' FM mm CEHTEB c' 

; , 

RECEWED 

FEDERALVIATION ADMINISTRATION ( SEPl 01973 

.; 

SUBJECT: AIRCRAFT GROUND HANDLING AND SERVICiNG : LlBRARy 

t ( 

1. PURPOSE. This advisory circular contains inq,ormation and guidance for the 

servicing and ground handling of aircraft. . .I I 

. . 

*2. J CANCELLATION. Advisory Circular 00-34, dated April 12, 1972, is cancelled. 

3. GENERAL. The aviation industry has found through experience that firm 

safety practices deter accidents. This advisory circular contains 

generally accepted information and safety practices which may help 

prevent injuries to personnel and damage to aircraft. Revised information 

regarding fueling procedures has been included. * 

4. DIRECTING MOVEMENT OF AIRCRAFT. The person directing an aircraft that is 

being taxied should stay far enough ahead and to the left of the aircraft 

for 

a. 

b. 

C. 

the pilot to have an unobstructed view of him. 

Use the standard hand signals illustrated in Figures 1 or 2, as 

applicable, of Appendix 1 of this circular. 

l&en directing aircraft during darkness or inclement weather, the 

guideman should use illuminated or reflective wands. 

Movement of aircraft in congested areas should be avoided. However, 

when necessary, a dditional guidemen should be stationed near the 

aircraft wing-tips to assure that adequate clearance is maintained. 

5. PARKED AIRCRAFT. When an aircraft is parked, the main gear wheels should 

be chocked fore and aft. If the aircraft is to remain overnight or if 

winds are expected, flight control locks should be used. 

a. While turbine-powered aircraft are not in service or being worked 

engine plugs should be installed to prevent damage from dust, 

::6ris, nesting birds, etc. 

r Initiated by: ~~~-340 

_I ..,, ,. “. . . . . _ 
AC 00-34A 7129174 

b. Ground personnel should develop a habit of making a visual check of 

the aircraft as soon as it is parked and secured. Before the flight 

crew departs, advise them of any unsafe condition that may have been 

observed and determine the nature of services that will be required 

for the next flight. This procedure may prevent unwarranted delays 

of the next departure or possible in-flight failures. Exampies of 

conditions that may be observed are: low or flat tires; cracked 

windows; nicked propeller blades; loose propeller spinners; oil and 

fuel leaks; damaged flight surfaces; etc. 

CAUTION: Many people have been injured by propellers in 

a moment of carelessness. When it becomes necessary to 

position propellers, they should be handled as if the engine 

is going to start. Before moving a propeller, always check 

to be sure the ignition switches are in the lloffll position, 

and the throttle and mixture control levers are in the 

tlclosedll position. Always stand clear of propeller blade 

path, particularly when moving the propeller, because of a 

possible inadvertent engine start. Particular caution 

should be practiced around warm engines. 

6. TIE-DOWN OF AIRCRAFT. Information relating to aircraft tie-down 

techniques, equipment, and anchor installations is provided in Federal 

Aviation Administration Advisory Circular 20-35B, Tie-Down Sense. It 

is a good practice to always tie-down small aircraft after each flight 

and large aircraft when unusually high winds are expected. When not in 

use, wheel chocks, tie-down ropes, or chains,and other equipment, may 

be stored safely near the wing tie-down anchor points on the ramp. 

These are usually located outside of the aircraft wheel traffic pattern. 

Wheel chocks should be painted a bright color so they can be easily seen. 

7. TOWING OF AIRCRAFT. When towing aircraft, the proper tow-bar must be 

used. The.wrong type of tow-bar, or makeshift equipment, can cause 

damage to the aircraft. Persons performing towing operations should be 

thoroughly familiar with the procedures that apply to the type of 

aircraft to be moved. Particular care must be exercised when pulling or 

pushing an aircraft with a tow vehicle. 

a. One should never tow an aircraft in congested areas without guidemen 

to assist in determining that there is adequate clearance. 

b. No less than two people should be used to tow large aircraft, including a qualified person in the cockpit to operate the aircraft 

b?iikes,~and a qualifried tow vehicle operator. One man should be 

able to safeiy move a light aircraft with a hand-operated powertowing device or tow-bar provided for the aircraft. 

71 

pi 

/ 

T-l 8 

3 

Page 2 Par 5 
7129174 

:. ee.-.-.- - -... -__- 

AC 00-348 

C. 

d. 

h. 

f. 

g* 

The man operating the tow vehicle should assure that the nose 

wheel scissors or tail wheel lock is disengaged, when applicable, 

before attempting to move the aircraft. He should also make 

certain that the nose wheel swiveling limits are not exceeded 

during the towing operation. 

The aircraft engines should not, under normal circumstances, be 

operated during towing operations. However, the procedure of 

pushing transport aircraft away from terminal gates, used by 

airlines for dispatch, is an exception. If engines are operated 

during towing operations, p rocedures will be needed to keep 

personnel away from rotating propellers and away from the danger 

zones of jet engines. 

Prior to movement of any aircraft, all landing gear struts and 

hires should be properly inflated and brake pressure built up 

when applicable. 

The tow vehicle operator should avoid sudden starts and stops. 

The aircraft brakes should be applied only in an emergency, on 

coxmnand from the tow vehicle operator or his clearance man. 

Clearance must be obtained from the airport control tower, either 

by appropriate radio frequency or by prior arrangement through 

other means, before moving aircraft across runways or taxiways. 

8. TAXIING OF AIRCRAFT. Only rated pilots or other qualified persons 

should be authorized to taxi aircraft. Persons authorized to taxi 

9. 

aircraft should be familiar with the airport control cowunications 

procedures and radio frequencies. 

AIRCRAFT FUELING. Improper fueling procedures may cause aircraft 

accidents'and in-flight incidents. If operators of fueling facilities 

establish procedures for safe and proper fueling of aircraft and 

fueling personnel follow these procedures, many aircraft accidents 

or incidents will be prevented. Fueling personnel should be familiar 

with the fuel requirements for the models and types of aircraft they 

are servicing. The following paragraphs contain a description of 

problems that may be encountered in fueling aircraft and recommended 

procedures for combating these problems. 

a. Water in the Fuel. 

(1) Water occurs in aviation fuels in three forms: 

(a) Dissolved water occurs similar to the humidity in the 

atmosphere that converts to droplets and settles out as 

the fuel temperature decreases during flight. 

Par7 Page 3 
-s 

AC OO-34A 

b. 

C. 

Page 4 

(2) 

(3) 

(4) 

7129174 

7/29/r 

cd 

(b) Suspended water appears in the form of droplets that 

reflect light. High concentration of droplets will cause 

fuel to have a cloudy or hazy appearance. 

(c) Solid bodies of water may be caused by leakage of storage 

tanks, leaking filler neck seals, or the settling out of 

suspended water droplets. 

Accumulation of water. There is no way of preventing the 

accumulation of water formed through condensation in fuel 

tanks. The accumulation is certain, and the rate of accumulation 

will vary; so it is reconnnended that storage tanks, fuel truck 

tanks and aircraft fuel tanks be checked DAILY for the presence 

of water. Any water discovered should be REMOVED immediately. 

In addition to the daily water check, fuel tanks should be 

CHECKED AFTER EACH DELIVERY as insurance against inadvertent 

water contamination. 

The minimum settling time. Adequate settling time is NECESSARY 

for accurate testing. The minimum settling time for aviation 

gas is 15 minutes per foot-depth of fuel and 60 minutes per 

foot-depth of turbine fuel. 

Water checks of storage tanks and fuel trucks may be made by 

attaching water detecting paste,or litmus paper,to the bottom 

of the tank dip stick. 

(a) Push the dip stick to the bottom of the tank and hold 

for 30 seconds. When the stick is removed, the detecting 

paste or litmus paper will have changed color if water is 

present. 

(b) The source of excessive amounts of water must be determined and corrected before further use of fuel from the 

tank. 

Rust and scale dislodged from the inside of fuel storage tanks may 

enter the aircraft fuel tanks and clog systems. Turbine fuel tends 

to dislodge rust and scale and carry the particles in suspension. 

Because of this, fuel dispensing equipment filters should be serviced 

frequently. Aviation gasoline should not be stored in tanks or 

equipment that have been used for turbine fuel storage. 

Micro-organic growth thrives in turbine fuel and appears as a soapy, 

slippery slime on the inside surfaces of fuel storage tanks. Microorganisms of bacteria and fungi multiply rapidly and may cause 

serious corrosion in aircraft fuel tanks, as well as clog fuel 

filters, screens, and control units. Therefore, turbine fuel storage 

tanks should be checked frquently for the presence of slime or 

micro-organic growth. If found, the tank should be cleaned thoroughly 

to assure removal of the micro-organic growth and prevent further 

contamination. 

Par 9 

Par 

‘-- 
7129174 AC 00-34A 

d. Dirt, lint, and dust may collect on fuel dispensing hose nozzles 

when proper storage receptacles are not used. Fuel hose nozzles 

should not be stored in such a manner that dirt or moisture will 

collect in them. Always check the nozzle for dirt and water before 

using it. 

e. Contamination with other types or grades of fuel can cause aircraft 

engine damage and possible failure in flight. Turbine fuels mixed 

with aviation gasoline reduce the antiknock and volatility of 

fuels required for reciprocating engines. Quantities of aviation 

gasoline mixed with turbine fuels will cause damaging lead deposits 

to collect in jet engines when used indiscriminately. Transportation 

or storage of turbine fuel in tanks previously used for storage or 

transportation of aviation gasoline is not recommended as contamination from rust and scale, or a possible change of fuel specification, 

may result. 

f. Additives. Certain turbine-engine-powered aircraft require the 

use of fuel containing anti-icing additives. Therefore, fuel 

personnel must know whether or not the fuels they dispense contain 

additives. When anti-icing additives are to be added to the fuel, 

the manufacturer's instructions (usually printed on the container) 

should be followed to assure proper mixture. Anti-icing additive 

content in excess of 0.15% by volume of fuel is not recommended 

as higher concentration can cause the aircraft fuel capacitance 

system to give erroneous indications. Concentrations of at least 

0.05% additive by volume of fuel are effective in eliminating 

microbial growth. 

g* Fuel-Dispensing Equipment. Fuel-servicing vehicles should be 

conspicuously and legibly marked to indicate the type and grade 

of fuel. 

(1) Markings should be displayed on each side and on the rear of 

the vehicle in CONTRASTING colors. 

(2) Fuel hydrants and pit installations should be identified 

similarly, according to type of fuel and grade. 

(3) Turbine-fueling vehicles should be marked to show whether or 

not anti-icing additives are contained in the fuel being 

dispensed. 

(4) Leaking or otherwise defective pumping equipment, plumbing, 

hoses, nozzles, and grounding cables of fuel-dispensing 

vehicles and stationary facilities should be repaired before 

further use. Fuel-nozzle-lever stop notches should be 

removed to avoid the possibility of an inadvertent blockingopen of the valve. 

Par 9 

L 

Page 5 
AC 00-34A 7/29/74 

f-7 -1, 

(5) Fuel-dispensing vehicles, and stationary facilities, should 

be equipped with appropriate fire extinguishers, fire blankets, 

static grounding cables, explosion proof flashlights, and 

ladders. Fire extinguishers should be located so they are 

accessible from either side of the vehicle and remote from 

probable fire hazard. 

(6) Fueling vehicles should be positioned as distant from the 

aircraft as permitted by the length of the fuel dispensing 

hose. Mobile units should be parked parallel to or heading 

away from the aircraft wing leading edge, so it may be moved 

away quickly in the event of an emergency. When the fueling 

operation is completed, the fueling vehicle should be parked 

at least fifty feet from aircraft or buildings and positioned 

in a manner to permit removal from the area without delay. 

h. 

Page 6 

Fueling procedures. Fueling personnel should first check with the 

flight crew to determine the type and grade of fuel required, 

including additives for the aircraft. It is a good practice to 

have the pilot sign a request for service, identifying the grade 

and quantity of fuel desired. In the absence of the flight crew, 

fueling personnel should check the placard located near the aircraft 

fuel tank filler port, or the aircraft owner's manual that is 

usually carried in the aircraft, to determine the type and grade of 

fuel required. 

(1) Check to ensure that: 

(a) No electrical or radio equipment in the aircraft is 

energized or being maintained while fuel is being 

dispensed into the aircraft, except those switches that 

may require energizing to operate fuel selector valves 

and quantity gauge systems. 

(b) Qualified personnel should be stationed at the aircraft 

fuel control panel during pressure fueling operations. 

(c) Fueling personnel should not carry objects in the breast 

pockets of their clothing when servicing aircraft or 

filling fuel service vehicles because loose objects may 

fall into fuel tanks. 

(d) Matches or lighters should never be carried during 

fueling operations. 

(e) Because of the high lead content, direct fuel contact with 

skin or the wearing of fuel saturated clothing should be 

avoided. Skin irritation or blisters may result from 

direct contact with fuel. 

(f) Immediate medical attention should be sought if fuel 

enters the eyes. * 

Par 9 ,--Y - 
- __L1I’ 

7129174 AC 00-34A 

J w 

* 

I 

L .- 

(g) In the event of fuel spillage, discontinue fueling 

operations until the spill can be removed, using proper 

safety precautions. 

(2) Fueling from mobile equipment. The following sequence should 

be followed by the fueling crew. 

(a) 

(b) 

cc> 

Cd) 

(e> 

Connect a grounding cable from the fueling vehicle to a 

satisfactory ground. Grounding posts usually consist of 

pipes or rods driven far enough into the ground to result 

in a zero potential. * 

Connect a ground cable from ground to the aircraft (on 

landing gear axle or other unpainted surface). Do not 

attach ground cables to the propeller or radio antenna. 

Connect a grounding cable from the fueling vehicle to the 

aircraft. The fueling vehicle may be equipped with a 

I~Tl~ or IlYll cable permitting ground attachment first and 

grounding of the aircraft with the other end. 

Connect a grounding cable from the fuel nozzle to the 

aircraft before removing the aircraft tank cap. This 

bond is most essential and needs to be maintained throughout the fueling operation and until the fuel cap is 

replaced. 

CAUTION: Conductive-type fuel hose does not provide a 

satisfactory method of bonding. 

The fuel-dispensing equipment grounding cables should be 

removed in the reverse order of the sequence outlined 

above. 

(3) Fueling from hydrants, pits, and cabinets. 

(a) Connect the grounding cable from the dispenser to the 

aircraft. 

(b) Connect the grounding cable from the hose nozzle to the 

aircraft before removing the fuel cap. 

(4) Overwing fueling. The fuel-filler hose should be draped over 

the wing leading edge. Never lay the fuel-filler hose over the 

wing trailing edge because aircraft structural damage may result. 

A simple rubber shower mat may be used to provide protection 

for wing leading edges during fuel operation. Step ladders or 

padded upright ladders may be used to provide easy access to 

high-wing and large aircraft. Standing on wing surfaces should 

be avoided and never stand on wing struts. Hold the fuel 

nozzle firmly while it is inserted in the fuel tank filler neck 

and never block the nozzle lever in the open position. Be sure 

that fuel filler caps are replaced and securely latched when 

fueling is completed. 

Page 7 
AC 00-34A 7129174 

(5) Underwing fueling. Discharge possible static buildup in the 

fuel dispensing hose by touching the pressure nozzle to an 

unpainted part .of the aircraft, such as a landing gear axle, 

before attaching to the aircraft filler receptacle. No static 

ground wire between the filler nozzle and the aircraft is 

necessary. 

(6) The aircraft fuel tank sumps should be drained before each 

fuel servicing to remove water that may have accumulated 

from condensation or entered the tank during fueling operations. 

Draining fuel sumps immediately after fueling serves little 

purpose because the agitation action of fuel entering the tank 

may suspend water and contaminants - which can remain suspended 

for many minutes and may not settle out until the aircraft is 

airborne. 

10. SERVICING OF OXYGEN SYSTEMS. Certain precautions should be observed 

whenever aircraft oxygen systems are to be serviced. 

a. 

b. 

C. 

d. 

e. 

f. 

Before servicing any aircraft with oxygen, consult the specific airzt service manual to determine the type of equipment required and 

procedures to be used. 

Oxygen system servicing should be accomplished only when the aircraft 

is located outside of hangars. 

Personal cleanliness and good housekeepin& are imperative when 

working with oxygen. Oxygen under pressure and petroleum products 

create spontaneous results when they are brought in contact with each 

other. Service people should be certain to wash oil and grease 

(including lip salves, hair oil, etc.), and dirt from their hands 

before working around oxygen equipment. It is also essential that 

clothing and tools are free of oil, grease, and dirt. 

Aircraft with permanent3 installed ox Etanks usually require two 

persons to accomplish servicing of the systae man should be 

stationed at the service equipment control valves, and the other 

stationed where he can observe the aircraft system pressure gauges. 

Oxygen system servicing is not recotmnended during aircraft fueling 

operations or while other work is performed that could provide a 

source of ignition. 

Oxygen system servicing while passengers are on board the aircraft is 

not recommender 

---- 

Page 8 Par 9 

- 
_ __._ _uI*_--_.. -. 

7/29/74 AC 00-34A 

Appendix 1 

k 1 .-I 

FIGURE 1. AIRCRAFT OPERATING SIGNALS 

FLACMAN DIRECTS PILOT TO 

SICNALhlAN IF TRAFFIC 

CONDITIONS REQUIRE 

0 7-r 

STOP 

0 

T 

START ENGINES 

0 

ii 

ALL CLEAR (O.K.) 

SIGNALMAN’S POSITION SICNAl,hlAN DIRI<:CTS 

TO\VIN(: 

-0 K 

COME AllEAD EMERGENCY STOP CUT I’NCINES 

0 

9 

PULL CHOCKS INSERT CIIOCKS 

LEFT TURN RIGHT TURN 

0 

t t 

9 

8 8 

SLOW DOWN 

NIGHT 

OPERATION 

t , Page 1 
AC 00-34A 

Appendix.1 

0 

T 

START ENCIN’E 

MOVE BACK 

FIGURE 2. HELICOPTER OPERATING SIGNALS 

ENCAGE ROTOR 

MOVE FORWARD 

0 0 5 r 8 

TAKE OFF I.ANDING 

DIRECTION 

SWING TAIL 

TO RICH-I 

STOP ROTOR 

0 IT 

MOVE RIGHT MOVE LEFT 

II 0 

II 

If 

GO UP 

SWING TAIL 

.TO LEFT 

7129174 

"-7 

I ‘\ 0 ’ 

F 

STOP 

0 

-77 

JJ”n 

+P 

GO DOWN 

-,, 

Page 2 
t 

Ground Coble Attach Point 

NOTE: 

A 20-FOOT MINIMUM DISTANCE 

SHALL BE MAINTAINED BETWEEN 

EXHAUST OUTLET AND FILLER 

POINT OR VENTS. 

,N IO FT. 

L FULL STOP AT 20 FT 

THEN DIRECTED INTO 

POSITION FOR 6 

SERVICING OPERATION w 

NOT LESS THAN IO FT 

FROM AIRCRAFT.