# TCDS ATC 681: Ryan Aeronautical Company

- Type: Type certificate data sheet
- Status: Current
- Holder: Ryan Aeronautical Company
- Revision: 0
- Product: Aircraft, Small Airplane
- Registered aircraft: 9, by the registry models matched to it (OpenAirDocs)
- Data sheet PDF: https://openairdocs.org/files/sha256/87/cc/87cc19d93436c67ea4b222687686e309083538ad80054ac75f6d9f4f70b83963
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/A3D2DDFA25C59B048525673D00631233.0001
- Page: https://openairdocs.org/tcds/ATC%20681

## Models (1)

As the data sheet lists them.

- ST-A Special

## What the data sheet says

This is OCR from the scanned FAA data sheet. OCR can misread letters and numbers.

```text
MODELS: Ryan ST-A Special, 1 or 2 PO-CIM
T.C. NUMBER: ATC 681
Engine  Manasco Pirate C4S
Placard limits  Maximum, except take-Off 28.5 in.Hg., 2260 rpm (125 hp). Take-off 1  Timinute (31.0 in. Hg., 2260 xm (125 hp) 106 inches
Propeller  Maxinum permissible diameter -
Placard speeds  Level flight or climb -  123 moh True Ind.
Glide or dive -  156 mph True Ind.
Fuel capacity  24 gallons (fuselage tank at 24 gallons)  (-10.5)

T.C. NUMBER: 681
Oil capacity  3 gallons (-27)
No. passengers  None or 1 (+14.5) (crew 1 or 2 (+14.5, +65)) (See NOTE 6)
Baggage  40 lbs. (single compartment between cockpits) (+31)
Weights Empty  Use actual (approximately 1046 lbs. (+6) as 2 POLM with Class I
C.G. limits  (+10.5) and (+14.7) (measured horizontally with engine bearers
level) (See NOTE 7)
Specification basis  Approved Type Certificate No. 681 Serial numbers 121, 141 and up
manufactured prior to 7/24/41 eligible. Approval expired as of
Equipment:  (Datum is wing leading edge) (* Means net increase)
Class I
101. Wheel streamlines (See NOTE 9) 15 1bs. (+3)
102.  3-inch wheels (Goodyear 3MBA, 3IMBA or 3LMBM) with brakes and 18x8-3
103.  Front seat cushion  (+14.5)
(+65)
104.  Wiring for position lights
105.  8-inch streamline tail wheel (+170)
106.  Partial span split trailing edge flaps, manually operated
103. Elevator trail edge tabes manually operated  Oil radiator (G & O No. 326511)  (-26)
109. Propeller - wood  (-62)
Class II
201. Carburetor air heater
(Ryan Drawing 7-167)  4 lbs.  (-41)
301. Fuel capacity increased 18 gallons - auxiliary fuel tank installed on front seat
(eliminates provision for passenger)
Fuel pump, hand wobble
Extra fuel systen, etc.
Front cockpit cover
(+39.5)
Electric (Eclipse Y-150)
(-21)
Bonding and shielding
Booster and solenoid
307. Extra instruments (manifold
pressure, bank and tum, climb, altimeter)  (+41.5)
308. Dual controls (removable type)  (-8)
Battery (Reading 6ARL9)  (+31)
Radio receiver (RCA AVR-7 series)  (+31)
311. New type wheel streamlines
(+3)
NOTE 1. Placard fuel selector valve as follows:  Always take off and land with fuel feeding
fran reserve.
NOTE 2. When item 301 is installed, installations of itens 302(a) and (b) and 303 are
required.
NOTE 3: This model same as model ST(ATC-541) except for change in engine and items of equipment
NOTE 4. Deleted 5/26/38.
NOTE 5. Eligible for export, as follows, subject to inspection for equipment specified in
Chapter XII of Inspection Handbook (5/26/38):
Canada - Landplane - Skiplane - not eligible.
(b) All other countries except Australia.
NOTE 6. Placard front cockpit, as follows: "when operated as a single place airplane, pilot
must occupy rear seat.
NOTE 7. All aircraft also eligible with C.G. limits of (+10.5) and (+16.3) provided an
elevator bungee is installed in accordance with Ryan Drawing SK-257, change C, and
the elevator cables are adjusted to provide exactly 29 degrees up travel and
approximately 26 degrees down travel.
NOTE 8. Item 101 is considered optional equipment which may be installed or renoved, subject
to inspection and check of C.G. limits.
```

## ADs

None name its models.

## Registered aircraft by registry model (OpenAirDocs)

- [Ryan Aeronautical ST-A SPECIAL](https://openairdocs.org/model/ryan-aeronautical-st-a-special): 9 aircraft (registry code 7830404)

## STCs approved under this data sheet (3)

- [STC SA00680SE](https://openairdocs.org/stc/SA00680SE): Installation of Electronics International model UBG-16 or UBG-16T bar graph engine analyzer.. Electronics International
- [STC SA1626NM PAGE 2](https://openairdocs.org/stc/SA1626NM%20PAGE%202): Installation of Electronics Int'l Digital EGT/CHT Instruments and accessories. (201 Series). Electronics International
- [STC SA4302NM](https://openairdocs.org/stc/SA4302NM): Installation of Electronics Int'l digital automatic engine analyzer.. Electronics International

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