# TCDS ATC 39: Pratt & Whitney Division

- Type: Type certificate data sheet
- Status: Current
- Holder: Pratt & Whitney Division
- Revision: 0
- Product: Engine
- Data sheet PDF: https://openairdocs.org/files/sha256/8f/09/8f093e13c7d1065fcc2fb42bb7a33cc00fe7f1e5a5154318df7def6057755ca2
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/41FFECB71E9B0BB88525670D004C87E1.0001
- Page: https://openairdocs.org/tcds/ATC%2039

## Models (1)

As the data sheet lists them.

- Wasp Jr. A

## What the data sheet says

From the PDF's text layer, line by line; tables lose their columns. The PDF is the record.

```text
PRATT & WHITNEY AIRCRAFT DIVISION OF UNITED AIRCRAFT CORPORATION
MODELS:  Pratt & Whitney Wasp Jr. A
T.C. NUMBER:  ATC 39
Model Wasp Jr. A
Type 9RA - Direct drive
Rating:
   Maximum continuous, hp,
   rpm, at S.L. pressure altitude 300-2000-S.L.
   Take-off (one minute),
   hp, rpm, at full throttle 300-2000
Fuel (minimum octane
   aviation gasoline) 68
Bore and stroke, in. 5-3/16 x 5-3/16
Displacement, cu. in. 985
Compression ratio 5: 1
Weight (dry), lbs. 565
Supercharging
   (impeller gear ratio) 7: 1
Carburetion Stromberg NA-R9B carburetor
Ignition, dual Scintilla VAG-9D magnetos
Certification basis Approved Type Certificate No. 39
NOTE 1.    Approval expired 1/8/36.  No engines of this model manufactured after this date or
with numbers above 121 eligible for use in certificated aircraft.
```

## ADs (7, in force first)

- [AD 78-08-07](https://openairdocs.org/ad/78-08-07): Cylinder Head Separation · Pratt & Whitney Division Military R-985 Series, Wasp Jr. A, Wasp Jr. B-4 and 10 more. Effective May 2, 1978
- [AD 68-09-01](https://openairdocs.org/ad/68-09-01): Crankshaft Flyweight Liners · Pratt & Whitney Division Military R-985 Series, Wasp Jr. A, Wasp Jr. B-4 and 10 more. Effective Jan 17, 1973
- [AD 70-10-02](https://openairdocs.org/ad/70-10-02): Gerotor Pump Drive Pin/Fuel Injector Filter · Pratt & Whitney R-985 engine and ATI fuel injection (Staggerwing Museum Foundation STC SE1-391). Effective Jun 9, 1970
- [AD 66-14-04](https://openairdocs.org/ad/66-14-04): Cam Reduction Drive Gear Assembly · Pratt & Whitney Division Military R-985 Series, Wasp Jr. A, Wasp Jr. B-4 and 10 more. Effective Jul 9, 1966
- [AD 56-06-02](https://openairdocs.org/ad/56-06-02): Cylinder Flange Attaching Stud · Pratt & Whitney Division Double Wasp CA15, Double Wasp CA17, Double Wasp CA18 and 115 more
- [AD 57-05-04](https://openairdocs.org/ad/57-05-04): Crankshaft · Pratt & Whitney Division Military R-985 Series, Wasp Jr. A, Wasp Jr. B-4 and 10 more
- [AD 56-26-03](https://openairdocs.org/ad/56-26-03) (historical): Crankshaft · Pratt & Whitney Division Military R-985 Series, Wasp Jr. A, Wasp Jr. B-4 and 10 more

## STCs approved under this data sheet (1)

- [STC SE04651CH](https://openairdocs.org/stc/SE04651CH): To allow use of l00R grade aviation fuel meeting Swift Fuel, LLC specification SPEC-l00R-22. Swift Fuels LLC

## PMA parts (OpenAirDocs) (10)

Current parts manufacturer approvals (PMA): parts the FAA has approved companies to make as replacements or modifications. Each record lists its models as free text; OpenAirDocs matched them to this data sheet's models, so check the FAA record before relying on it. Newest first.

- [72-231114-2](https://drs.faa.gov/browse/excelExternalWindow/DRSDOCID152913847920260722204353.0001): TAG-Engine. Swift Fuels, LLC · PMA PQ04423CE · Modification part · For Wasp Jr. A · Jul 17, 2026
- [URHB32E](https://drs.faa.gov/browse/excelExternalWindow/E479EEF57CC2917B86257760004A62FE.0001): Spark Plug. Aero Accessories Inc · PMA PQ1206CE · Replaces Make Allied Signal (Autolite) Part No… · For Wasp Jr. A · Jun 10, 2010
- [URHB37E](https://drs.faa.gov/browse/excelExternalWindow/D515F4D4AC4E4B2B86257760004A640B.0001): Spark Plug. Aero Accessories Inc · PMA PQ1206CE · Replaces Allied Signal (Autolite) Part No. SL… · For Wasp Jr. A · Jun 10, 2010
- [UREB37E](https://drs.faa.gov/browse/excelExternalWindow/2D0A9D412CCEF30B86257760004A63DF.0001): Spark Plug. Aero Accessories Inc · PMA PQ1206CE · Replaces Make Allied Signal (Autolite) Part No… · For Wasp Jr. A · Jun 10, 2010
- [URHB32E](https://drs.faa.gov/browse/excelExternalWindow/E065BAE329C5D68C8525704C00570B93.0001): Spark Plug. Slick Aircraft Products, Division of Unison Ind · Replaces SL 350 Allied Signal (Autolite) · For Wasp Jr. A · Jul 1, 1999
- [UREB37E URHB37E](https://drs.faa.gov/browse/excelExternalWindow/C2F2D61F0CDCC1D58525704C00570B8F.0001): Spark Plug. Slick Aircraft Products, Division of Unison Ind · Replaces SL 30A SL 300A Allied Signal (Autolite) · For Wasp Jr. A · Jul 1, 1999
- [UREM40E URHM40E](https://drs.faa.gov/browse/excelExternalWindow/1E40C481546604768525704C00570B91.0001): Spark Plug. Slick Aircraft Products, Division of Unison Ind · Replaces SL 20A SL200A Allied Signal (Autolite) · For Wasp Jr. A · Jul 1, 1999
- [AS6515](https://drs.faa.gov/browse/excelExternalWindow/8445F591CF9197B38525703B0055E2E5.0001): Aircraft Supplies Gear. Aircraft Supplies Inc · Replaces Pratt & Whitney Gear 6515 · For Wasp Jr. A · Mar 26, 1997
- [SOL 3503](https://drs.faa.gov/browse/excelExternalWindow/C393E97F032E1DE78525704C005707E0.0001): Exhaust Gasket. SOL Company · Modification part · For Wasp Jr. A · May 19, 1991
- [SOL0524AK10](https://drs.faa.gov/browse/excelExternalWindow/74EA1E5D02FF3E468525704C005707E1.0001): Retaining Nut. SOL Company · Modification part · For Wasp Jr. A · May 19, 1991

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