ICS 83.160.20 
G 41  
 
 
National Standard of the People’s Republic of China 
GB 9745 －×××× 
Superseding GB 9745—1995 
 
 
    
 
      
 
 
 
Aircraft Tyres 
（ISO 3324 －1：1997 Aircraft tyres and rims—P art 1: Specifications, NEQ ） 
(Draft for Approval) 
 
            
Issued on ××××-××-××       Implemented on  ××××-××-××  
 
 
 
Issued by the General Administration of Quality Supervision, Inspection, and Quarantine of the People’s Republic of China 
GB 9745 -××××  
 
Foreword 
 
 
The provisions stated in Chapters 4 and 7 of this Standard are compulsory while the rest of 
the chapters are recommendatory.  
This Standard supersedes GB 9745-1995 Aircraft Tyres .   
This Standard is not equivalent to the International Standard ISO 3324-1:1997 Aircraft Tyres-
Part 1: Specifications and the Technical Standard TSO-C62e Aircraft Tyres  issued by the 
Federal Aviation Administration.  Major changes in this Standard compared to GB 9745-1995 are:  -  modified the applicable scope (Chapter 1 of  the 1995 version; Chapter 1 of this version);  
-  added 1 definition (Chapt er 3 of this version);  
-  added requirement and testing methods on the bead  fit pressure of inner tube tyre attached on 
the skidproof wheel rim ( 4.5 a nd 5.5 in this version);  
- deleted requirements and test methods on materi al suitability, resistance of materials to 
high/low temperature, tyre weight and physical performa nce (4.2, 4.4, 4.10, 4.14, 5.2 and 5.9 
of the 1995 version);  
- modified the requirements on tyre static unbala nce (item 4.12 in the 1995 version; 4.6 of this 
version);  
-  adjusted Chapter 6 to Informative Appendix A (Chapter 6 of the 1995 version; Chapter 6 of 
this version);  
- deleted the provisions on packagin g (item 7.2 of the 1995 version);  
- modified the tyre markings, storage, and usag e (Chapter 7 of the 1995 version; Chapter 7 of 
this version).  This Standard is proposed by the China Petr oleum and Chemical I ndustry Association.  
This Standard falls under the jurisdiction of the National Technical Committee for the 
Standardization of Aircraft Tyres.  This Standard is subject to the interpretation of National Technical Committee for the Standardization of Aircraft Tyres.  The unit responsible for the drafting of this Standard: Shuguang Rubber Industry Research and 
Design Institute of China Rubber Group.  Major drafters of this Standard: Deng Haiyan, Zhou Birong, Zhang Hong, Qi Liping.  
Previous versions supers eded by this Standard:  
——GB 9745 －1988、GB 9745 －1995。 
 
 
 
    
   
 
GB 9745 -××××  
Aircraft Tyres 
 
1 Scope  
 
This Standard sets the requirements, testing met hods, rules for inspection, markings, storage, and 
usage of aircraft diagonal tyres.  This Standard applies to various new civil aircraft diagonal tyres.  
 
2    Normative References  
The provisions of the following documents become provisions of this Standard after 
being referenced. For dated reference documents, all later amendments  (excluding corrigenda) 
and versions do not apply to this standard; however, the parties to  the agreement are 
encouraged to 
study whether the latest versions  of these documents are applic able. For undated reference 
documents, the latest versi ons apply to this Standard.
 
 
GB/T 6326    Tyre Terminologies and Definiti ons (GB/T 6326-××××, ISO 4223-1: 2002 NEQ)  
GB/T 9746    Series of Aircraft Tyres  GB/T 9747    Testing Method for Dynamic Simulation of Aircraft Tyres  
GB/T 11191  Testing Method for Burst Pressure of Aircraft Tyres   
                       (GB/T 11191-2004, ISO 3324-2: 1998 NEQ)  GB/T 11192   Testing Method for Static Load Performance of Aircraft Tyres                          (GB/T 11192-2004, ISO 3324-2: 1998 NEQ)  GB/T 11193   Measurement method for Outer Rim Dimensions of Aircraft Tyres                          (GB/T 11193-1998, neq ISO 3324-2: 1979)  
GB/T 11194   Testing method for Air-tightness of Tubeless Aircraft Tires  
                        (GB/T 11194-2004, ISO 3324-2: 1998 NEQ)  GB/T 11195   Testing Method for Bead Fit Pressure of Aircraft Tyres with Inner Tubes                          (GB/T 11195-1998, neq ISO 3324-2: 1979)  GB/T 13652   Surface Quality of Aircraft Tyres  
GB/T 13653   X-ray Inspection Method for Aircraft Tyres  
GB/T 13654   Holographic Inspection Method for Aircraft Tyres  GB/T 13655   Testing Method for Static Unbalance of Aircraft Tyres  HG 2195         Usage and Maintenance of Aircraft Tyres   3 Terminologies and Definitions  
 
The following terminologies and definitions as well as those set by GB/T 6326 applies to this 
Standard.  
 
 
3.1 
Rated inflation pressure  
This pertains to the inflation pressure value of ty res, which correspond to the static load radius, under 
rated loads.  
 
GB 9745 -××××  
 
4.    Requirements   
4.1    Specifications and dimensions, rated value, and static load radius  
4.1.1   The formula for specifications, inflation dimensi ons for the new tyre,  rated load, rated inflation  
pressure and static load radius must conform to the standards set in GB/T 9746.  
   For tyres whose specifications are not included in GB/T 9746 or tyres whose tread shoulder 
dimensions are not stipulated, the maximum tr ead shoulder dimensions must be determined 
according to formulas (1) and (2):  
                                  W s=0.9W …………………………………………………(1) 
                                  H s=0.9H………………………………………………….. (2) 
In the formula:  
Ws- the maximum tread shoulder width of the inflated tyre;  
W- the maximum width 1of the inflated tyre;  
Hs- the maximum tread shoulder height of the inflated tyre;  
H- the maximum height of the inflated tyre  
 
4.1.2   When ordinary aircraft tyres are used in helicop ters, their rated load will be determined by the rated 
load of ordinary aircraft tyres multiplied by 1.50,  the corresponding inflation pressure must also be 
multiplied by 1.50. There is no need to carry  out any additional assessment tests.   
4.2  Dynamic performances  
4.2.1   Low speed tyres must undergo 200 times of landing tests, including 100 times each of low speed  
landing and high speed landing tests.  
4.2.2   High speed tyres must undergo 50 times of rated load  take-off tests, 1 overloaded take-off test with 
1.5 times of the rated load, 10 times of coastdown tests including 8 rated load coastdown tests and 
2 times of coastdown tests with 1.2 times of the rated load.  
4.2.3    After completing the tyre tests, the following requirements must be met:  
                                                        
1 The maximum width includes the raised height of the logo, kerbing rib, and decorative rib etc. on the tyre side but 
does not include the chine height of the tyre in the frontwheel.  
 After completing its landing, take-off, and coastdown tests, the tyre must not burst or thrown off; 
there must be no cracks in the groove pattern of the rubber tyre. In addition, the depth of the crack or 
breakage of the groove pattern of the reinforced tread  must not exceed the tyre’s outer cord; the maximum 
area of any part must not exceed 6.25cm2 while its depth must not exceed 75% of the groove pattern of the 
rubber tyre; the block area in the 2.50 cm2-6.25cm2 portion of the tyre must not exceed 3 or 10 places, and 
the total area must not exceed 25.00 cm2 (blocks around the tread marking won’t be calculated, unless the 
block area exceeds 6.25cm2).  The groove contains reinforced cord s in its base hence the cracks or damages 
of the cords must not be found in any of the requirements set in Table 1. Tyres with inner tubes that have  completed the overloaded take-off test must not burst but may be thrown off; tubeless tyres that have 
completed the overloaded take-off test must, besides meeting the same requirements as those tyres with 
inner tubes, cool down to an ambient temperature and adjust its pressure to rated inflation pressure, with the 
drop in the rate of pressure after 24h not ex ceeded 10% of the rated inflation pressure.  
GB 9745 -××××  
 
 
Table 1  Permitted scope of cracks a nd damages for reinforced treads  
No. Name  Number of cord cracks and damages 
found in the groove pattern Percentage of the tyre 
circumference  
1 Cord cracks Cord crack in one groove pattern 30 
2 Cord cracks Total of cord cracks in two or more 
groove patterns 40 
3 Cord damages Cord damage in one groove pattern 65 
4 Cord damages Total number of cord damages in two or 
more groove patterns 95 
5 Cord cracks and damages Cord cracks and damages reside one 
groove pattern   65 
6 Cord cracks and damages Total number of cord cracks and 
damages in two or more groove patterns 95 
 
4. 3 Excess pressure performance  
When the tyre is inflated to 4 times its rate d pressure and the pressure remains 3s, it must 
not burst, produce bubbles, delaminated, or have broken steel wires or cords.  
4.4 Air tight performance for tubeless tyres  
Fix the tyre onto the targeted wheel rim, inflate it with the rated inflation pressure, and place it in 
room temperature for at least 12h; after this, adju st the pressure to the rated inflation pressure, and 
place it in room temperature for at least 24h, the drop  in the inflation pressure must not exceed 5% of 
the rated inflation pressure.  
4.5  bead fit pressure of tyres with inner t ubes attached to the skidproof wheel rim  
For tyres with rated inflation pressure less than or equal to 275kPa, the bead fit pressure value must 
reach 170kPa~280kPa;  For tyres with rated inflation pressure of 275kPa~6 90kPa, the bead fit pressure value must reach 
170kPa until the rated inflation pressure;  For tyres with rated inflation pressure over 690kPa, the bead fit pressure value must reach 350kPa or 
above, but must not exceed the rated inflation pressure value of the tyre.  
4.6  Static unbalance  The maximum static unbalance  M of the main tyre must not ex ceed the calculated value in formula 
(3):  
M=0.00383D2 ………………………………………(3) 
        The maximum unbalance M of auxiliary tyre must not exceed the calculated value in formula (4):  
M=0.00274D2 
………………………………………(4)  
        In formulas (3), (4):  
M——the set static unbalance value of the tyre, unit: N·cm;   
D——the maximum inflated outside diameter of the tyre, unit: cm. 
4.7  Surface quality  
The surface quality of the tyre must conf orm to the standards set in GB/T 13652.  
4.8  Internal defect s 
No defects must be found inside the tyre such as air bubbles, delamina tion, steel wire cracks, 
broken cords, etc.  
GB 9745 -××××  
 5   Testing Methods 5.1    Specifications & dimensions and static load radius 
5.1.1 Tyre dimensions  
The outer rim of the inflated tyres must be  measured according to the dimension set in 
GB／T 11193.  
5.1.2 Static load radius  
The static load radius must be measured according to the standard  set in GB/T 11192.  
5.2 Dynamic performance  
The dynamic performance of the tyres mu st be tested based on GB/T 9747.  
5.3  Excess pressure performance   
The excess pressure performance of the ty res must be tested based on GB/T 11191.  
5.4  Air-tightness of tubeless tyres  
Air-tightness of tubeless tyres must be te sted based on the requirements in GB/T 11194.  
5.5  Bead fit pressure of tyres with inner tube s attached on the skidproof wheel rim   
Bead fit pressure of tyres with inner tubes attached to the skidproof wheel rim must be 
tested based on the requirem ents set in GB/T 11195.  
5.6 Static unbalance  
Static unbalance must be tested based on the requirements set in GB/T 13655.   
5.7 Surface quality   
Tyres will be checked and measured visually and with instruments such as steel ruler, 
metallic tape (without radian, accuracy±1.0m m), vernier caliper (accuracy±0.02mm).  
5.8 Internal defects  
Internal defects must be insp ected based on the re quirements set in GB/T 13653 or GB/T  
13654.  
 
6   Rules for Inspection  
 
      Please refer to Appendix A 
7    Markings, storage and usage  7.1 Markings  
7.1  Air-escape hole 
After being retreaded, tubeless tyre s and those with inner tubes a nd with an inflation pressure 
higher than 686kPa, an air-escape hole must be placed in the tire again if the old one is 
covered. The new air-escape hole must be marked  with a white colour. The depth for tubeless 
tyres must not reach the layer of air tightness.  
7.1.2 Balance  
There must be a “balance” marking placed on th e tyre. Put a red dot on the lightest portion on 
the side of the tyres, close to the bead. The sa id marking must be seen clearly on the original 
tyre within its storage period and usage. 
7.1.3 Other markings  
 Aside from the air-escape hole and balance marking ，there must be at least the presence of 
the following markings on the side of the tyres, among which, items a) ～j) are permanent 
markings:   
 GB 9745 -××××  
 
a) specifications;  
b) ply rating (or actual number of layers);  
c) manufacturing date a nd product serial number;  
d) name of the materials used in the tyre body frame;  
e) tubeless tyres must be marked  with the word ‘tubeless”;  
f) fabric reinforced tread shall be  marked with “reinforced tread”;  
g) rated speed, rated load and patte rn depth of the simulated model;  
h) manufacturer’s name and trademark;  
i) implemented Standard Number;  
j)    Accessories No.;  
k)   Seal of Inspection.  
7.2  Storage and usage  
 Tyres must be stored and used according to  the standards set in HG 2195. The sum of their 
storage and usage time must not exceed 5 years from the date of manufacture.  
 
   
 
  
 
      
    
  
 
  
GB 9745 -××××  
 
Appendix A 
(Informative Appendix) 
Rules in Inspection 
 
1   Approval of Product Batches  
 
Tyres will be grouped and approved according to  specifications and ply ratings. Every 500 or 
1000 tyres with the same specifications and pl y ratings, which are manufactured within a 
succeeding date and under similar manufactur ing conditions, will make up one batch. 
However, volume in excess of 500 or 1000 will form another batch.   
 
 2  Inspection and Classification 
Inspection  is divided into out-of-factory  inspection and comprehens ive inspection. Out-of-
factory inspection refers to the various in spections done when products are delivered. 
Comprehensive inspection means carrying out a complete assessment of the quality of the 
product, which is to inspect the tyre accord ing to requirements set by this Standard.  
 
3   Comprehensive Inspection  
    Comprehensive inspection shall be d one when one of the following occurs:  
-  an evaluation of the trial manufacturing proc ess when new products are put in production or 
when old products are transferred to a nother factory and produced there;  
-  when large changes are made in the structur e, major raw materials,  and techniques after 
formal production has begun;  
-  when there is a big discrepancy between the results of the out-of-f actory inspection and the 
previous comprehensive inspection;   
-  when government quality monitoring institutio ns require a comprehensive inspection to be 
carried out.  
4   Out-of-factory Inspection  
      Out-of-factory inspection is composed of  100% inspection and sampling inspection.  
4.1  Items for 100% inspection  
a) static unbalance;  
b) surface quality.  
4.2 Items for sampling inspection  
a) dimensions of the inflated tyre’s outer ri m (excluding dimensions of the tyre shoulder);  b) excess pressure performance;  
c) air-tightness of tube less tyres attached to th e skidproof wheel rim;  
d) bead fit pressure of tyres with inner tubes;  
e) internal defects 
5   Sampling Plan  
A random sampling method is used to draw samples.  This is to ensure the consistency of the 
samples with the rest of the products. Products that have surface defects but do not affect the 
test results are allowed to be sampled; how ever they cannot be named as samples.  
 
GB 9745 -××××  
 
5 .1 Comprehensive inspection   
       Draw 2 tyres from the product batch, 1 tyre undergoes a dynamic perf ormance test while the 
other tyre undergoes other specified inspections. In case the samples are insufficient to carry out all the inspections, d ouble sampling may be done. 
5.2 Out-of-factory inspection  
Samples for the inspection of the tyres’ internal  defects will be draw n from the 5%-10% of 
each product batch; remove 1 tyre from each pr oduct batch for other sampling inspections.  
 
6   Rules for Re-inspection  
When substandard products are found durin g a sampling inspection, a double sampling is 
allowed for re-inspection. Rules for re-inspection are as follows:  
a) when the air-tightness or inflated outer rim di mension of the retreaded tyre do not fulfil 
the requirements, two more samples may be  randomly drawn for re-inspection in the 
same product batch. Based on the results, wh en both of the two samples qualify, this 
product batch will be judged as having passed the inspection; otherwise, it has failed.  
b) if the retreaded tyres fail to pass the insp ection after double sampling and a re-inspection 
of their internal defects, a 100% inspection shall be carri ed out for all the products.