Airframe Part Number Identification
The 125 was the 125th aircraft design of the de Havilland Aircraft Co. All early Hawker airframe part numbers were prefixed with the number 25 which designates the part as for the 125 aircraft. As a note the 121st aircraft design was the Trident and some 21 prefixed part numbers still exist today on the Hawker through interchangeability with the original Trident aircraft drawings over 50 years ago!!
After the initial "25" digits there follows a two digit "alpha" code which represents the area of the aircraft for which that part belongs. The remaining digits form the drawing number for the part e.g.
25WS619 - Designed part for early Hawker 125, detail of wing structure.
As the Hawker developed, new or modified parts took on a prefix reference of up to 4 digits to reflect the Hawker aircraft series e.g.
25-8WB9-2A - Part designed for the 800 series Hawker, airbrake assembly.
"S" prefixed part numbers - "Spares" condition, part supplied with additional items for installation. Some consumable items supplied undrilled or unfinished for final assembly on the aircraft e.g.
S25-7DP53 - "Spares" part for the 700 series Hawker, trim item in the passenger cabin.
"A" suffix denotes "assembly", additional alpha digits identify modification status, eg AB, AC etc, e.g.
S25-9WG50001AB - Part designed for the 1000 series Hawker 125, flap assembly supplied in "spares" condition, mod status "B".
Spare parts for repair to the aircraft structure are designated with a letter "R" after the dual alpha area code Items are oversized bushings, bolts and brackets etc, e.g.
25-8UMR296-1 - Part designed for the repair of 800 series main gear.
Hawker 125 Aircraft Type, Series and variant codes as reflected in Part Number prefixes.
- 25
- Hawker 125 series 1,3 & 400
- 25-2
- Hawker "Dominie" aircraft (RAF)
- 25-6
- Hawker 125 series 600
- 25-7
- Hawker 125 series 700
- 25-8
- Hawker 125 series 800
- 25-9
- Hawker 125 series 1000
- 25-F1
- Hawker 125 series 1 Garrett retrofit
- 25-F3
- Hawker 125 series 3 Garrett retrofit
- 25-F4
- Hawker 125 series 400 Garrett retrofit
- 25-F6
- Hawker 125 series 600 Garrett retrofit
- 25C8
- Hawker 125 Carbon Fibre Wing Variant
- 25F8
- Hawker 125 C29A (C-FIN) Variant
- 25G8
- Hawker 125 U125 Variant
- 25H8
- Hawker 125 U125A Variant
Part Number Identification Codes
B. Structural test and wind tunnel, not used in part numbering.
- BST
- Structural test drawing.
- BWT
- Wind tunnel model drawing.
C. Controls.
- CA
- General arrangements of controls in aircraft.
- CF
- Flying controls in fuselage.
- CT
- Flying controls in tail.
- CW
- Flying controls in wing.
- CX
- Ancillary controls in fuselage, wing & tail.
D. Decor and passenger service.
- DA
- General arrangements of decor and passenger services.
- DC
- Crew cabin- furnishing, trimming and sound proofing.
- DP
- Passenger cabin- furnishing, trimming and sound proofing.
E. Engine installation.
- EK
- Systems in engine pods (Hydraulics, fuel, air supply fire extinguisher etc.
- ES
- Structure of pods, including mounting, cowlings, doors intake etc.
- EZ
- General arrangements of engine installation, basic geometry.
F. Fuselage structure.
- FA
- General arrangements of fuselage structure, main assemblies.
- FC
- Centre portion, all structure between nose and aft pressure bulkheads.
- FN
- Nose portion- nose cone, nose wheel bay forward pressure bulkhead etc.
- FR
- Rearpressure bulkheadto, but not including front fin & bulkhead pod.
- FT
- Tail fuselage - all structures aft of and including front fin bulkhead.
G. General.
- GA
- General arrangements of aircraft.
- GF
- Final assembly components eg bolts, attaching fillets & control surfaces etc.
- GR
- Rigging diagrams.
- GT
- Protective treatment charts.
H. Hydraulics.
- HA
- General arrangements of hydraulic systems in aircraft.
- HC
- Hydraulic components- valves, reservoirs etc.
K. De-icing system.
- KA
- General arrangements of de-icing system in aircraft.
- KF
- De-icing systems components, ducting etc in fuselage.
- KT
- De-icing systems components, ducting etc in tail.
- KW
- De-icing systems, ducting etc in wing.
M. Equipment.
- MA
- General arrangements of equipment in aircraft.
- MC
- Crew cabin instrument panels, piping etc.
- MM
- Miscellaneous stowages (First Aid kit etc).
- MS
- Crew cabin seating.
N. Electrical system.
- NA
- General arrangements of electrical services in aircraft.
- NF
- Electrical systems in fuselage.
- NT
- Electrical systems in tail.
- NW
- Electrical systems in wing.
- NX
- Drawings for electrical tests and functioning rigs.
P. Fuel System.
- PA
- General arrangements of fuel system in aircraft.
- PF
- Fuel feed system in fuselage and wing.
- PJ
- Fuel jettison system in fuselage and wing.
- PT
- Fuel tanks.
- PV
- Fuel venting system in fuselage and wing.
Q. Interchangeability data sheet - all units.
R. Radio and radar.
- RA
- General arrangements of radio and radar in aircraft.
- RF
- Radio and radar installation in fuselage, wing and tail.
S. Plumbing services (hydraulic, oxygen A.S.I. fresh and waste water systems, piping).
- SA
- General arrangements of piping services in aircraft.
- SF
- Piping in fuselage.
- ST
- Piping in tail.
- SW
- Piping in wing.
T. Tail unit.
- TA
- General arrangements of tail, basic geometry and surface drawings.
- TE
- Elevator assemblies and details.
- TF
- Fin assemblies and details.
- TP
- Tailplane assemblies and details
- TR
- Rudder assemblies and details.
U. Undercarriage.
- UA
- General arrangements of main and nose undercarriage.
- UM
- Main undercarriage - Oleo leg, retraction and locking for leg and doors.
- UN
- Nose undercarriage - Oleo leg, retraction and locking for leg and door.
V. Air conditioning and pressurisation.
- VA
- General arrangements of air conditioning system in aircraft.
- VF
- Assemblies and details in fuselage, wing and tail.
W. Wing structure and moveable surfaces.
- WA
- general arrangements of wing, basic geometry and surface drawings.
- WB
- Airbrake assemblies and details.
- WF
- Flap assemblies and details.
- WG
- Aileron assemblies and details.
- WS
- Assemblies and details of wing structure.
X. Preliminary layouts, mock up.
- XL
- Preliminary layouts (use 25XL numbers from the 800 and 1000 register)
- XM
- Drawings for mock up.
Y. Ground equipment. (external to aircraft)
Z. Trial installations.
- ZT
- Trial installations for preliminary flight test.
The above "alpha digit" codes do not reflect in any way the ATA standard chapter headings for aircraft systems, these are listed later on.
Other Hawker 125 Airframe part prefixes include the following;
- 125REFxxxxxxxxx
- BAe Pt/No for a Hawker item, where original Pt/No is over 15 digits.
- 125REFUXxxxxxxx
- BAe Pt/No for Hawker unit exchange item, original Pt/No is over 15 digits.
- BAEREF00000xxxx
- BAe Pt/No for an over length Pt/No, not exclusive to Hawker 125.
- DHS (de Haviland Spares)
- General hardware, some but not all exclusive to the Hawker 125.
- DOI prefixed part numbers
- Drawing Office Instruction, later superseded by 140- Pt/No's.