STC SR00252LA

SR00252LA

WSH LLC 3255 S. Bodenburg Loop Palmer, AK 99645 Part 21.25 Title 14 CFR H12NM Western International Aviation, Inc.

UH-1P, Serial Number 63-13163 only The limitations and conditions of the Type Certificate Sheet (TC) No. H12NM apply, except as outlined in this STC. This approval is limited to the rotorcraft model and serial number identified above. A copy of this STC must be included in the permanent records of the rotorcraft when modified in accordance with this STC.

(See Continuation on Page 3) 11/24/1995 06/10/1999 06/11/2026 08/29/1996 05/01/2003 for Manager, West Certification Branch 6 Installation of a Honeywell (Lycoming) T53-L-13BA Engine in a Western International Aviation, Inc. helicopter in accordance with Tamarack Helicopter Master Drawing List Report No. TAM002, Revision B, dated August 21, 1996, with associated photographs and sketches. Tamarack Helicopters’ FAA Approved Rotorcraft Flight Manual Supplement to the U.

S. Air Force T.O. 1H-1(U)F-1 for the Installation of the Lycoming T53-L-13BA Engine in the Model UH-1P, Document No.

TAM 006, dated August 29, 1996, or later FAA Approved revision is also required as part of this installation

SR00252LA 06/11/2026 6

SR00252LA 06/11/2026 Limitations and Conditions Continued:

Engine Honeywell (Lycoming) T53-L-13BA

Engine Limits

Torque Pressure: 50 p.s.i Maximum

Horsepower: 1,100 h.p.

Exhaust Gas Temperature: 400 *C to 610 *C Continuous 610 *C to 625 *C 30 minutes 625 *C Maximum (625 *C to 675 *C 10 second limit for starting and acceleration) (675 *C to 760 *C 5 second limit for starting and acceleration)

Oil Pressure: 25 p.s.i. Minimum 80 to 100 p.s.i. Continuous 100 p.s.i. Maximum

Oil Temperature: 93 *C Maximum Below 30 *C FAT 100 *C Maximum Above 30 *C FAT (See Note 4)

Oil Capacity: 3.8 Gallons (0.8 Gallons unusable)

SR00252LA 06/11/2026 Limitations and Conditions Continued:

Engine Limits (Continued)

Gas Producer Tachometer (N[F1.1]1): 101.5 % Maximum

Engine Tachometer (N2): 6000 to 6400 r.p.m. Transient 6400 to 6699 r.p.m. Continuous 6700 r.p.m. Maximum Continuous above 15

p.s.i. torque 6900 r.p.m. Maximum Continuous at 15 p.s.i.

torque or less 6900 r.p.m. Maximum Transient (3 seconds) above 15 p.s.i. torque 6900 r.p.m. Maximum

Rotor Limits: 294 to 324 r.p.m. Continuous 399 r.p.m. Maximum

Fuel: Mil-T-5624 (JP-4) Mil-T-5624G (JP-5) ASTM Type B (Jet B) ASTM Type A-1 (Jet A)

Fuel Quantity: 224 Gallons (3.0 Gallons unusable)

Airspeed Limits: Consult Rotorcraft Flight Manual

SR00252LA 06/11/2026 Certification Basis:

Basis: 14 CFR part 29, sections: 29.27, 29.29, 29.31, 29.39, 21.45, 21.65, 29.143,

29.171, 29.175, 29.177, 29.251, 29.549, 29.601 through 29.609, 29.611, 29.873,

29.907, 29.908(b), 29.917(a)(b)(2), 29.939, 29.993, 29.1011, 29.1013, 29.1017,

29.1043(a)(1)(2), 29.1091, 29.1121, 29.1141, 29.1143(a)(c), 29.1191, 29.1193(a)

(b)(d)(e)(f), 29.1305, 29.1337(a)(b)(d)(e), 29.1351, 29.1353, 29.1519, 29.1521,

29.1529, 29.1541, 29.1543, 29.1549 and 29.1581 through 29.1585(a)(c)(d) through amendment 38.

14 CFR part 36 through amendment 21, 14 CFR part 34 through amendment 2.

NOTES

Note 1. The helicopter shall be maintained in accordance with USAF T.O. 1H-1(U)F-2-1, Organizational Maintenance and Inspection program as modified as follows:

The Honeywell (Lycoming) T53-L-13BA engine assembly and applicable sub-assemblies are to be maintained in accordance with U.S. Army T. M. 55-1520-210-23.

The main drive shaft, part number KSCP2281-103, is to be maintained in accordance with U.S. Army T.M. 55-1520-210-23.

The main transmission, assembly part number 204-040-016-5 is to be maintained in accordance with U.S. Army T.M.

55-1520-210-23.

Note 2. The helicopter shall be operated in accordance with USAF T.O. 1H-1(U)F-1 as supplemented by Tamarack Helicopters FAA Approved Rotorcraft Flight Manual Supplement, Document No. TAM 006.

Note 3. Limited life schedule for the helicopter components is included in the USAF T.O. 1H-(U)F-6 as amended as follows:

SR00252LA 06/11/2026 Certification Basis Continued:

The Honeywell (Lycoming) T53-L-13BA engines component life limits and overhaul intervals are to be complied with in accordance with Honeywell Service Bulletin T53-L-13B-0020, Revision 3, dated October 25, 2001.

The main transmission, assembly part number 204-040-016-5 component life limits and overhaul intervals to be complied with U.S. Army T.M. 55-1520-210-23.

Note 4. At ambient temperatures below 30 *C and the maximum "Oil In" temperature is 93 *C, inspect oil filter when oil temperature exceeds 93 *C for more than 10 minutes. At ambient temperatures of 30 *C and above a steady state engine "Oil In" temperature of 100 *C is acceptable provided the following requirements and limitations are observed: Inspect oil filter after 50 hours of engine operation for excessive accumulation of carbon or metal particles

Note 5. Airworthiness Directives pertaining to General Electric model T-58 series engines do not apply with installation.

Note 6. Airworthiness Directives pertaining to Honeywell (Lycoming) T-53-L-13 series apply to this installation.

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