SEABORNE AIRLINES DATE: 03-31-14 

EXTENDED OVERWATER – PARTIALLY EQUIPPED PROGRAM REVISION: Original

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Introduction 

The following manual is a guide to Extended Overwater Operations. It includes the single 

engine descent profile, drift down charts, regulations and limitations with excerpts from the 

Saab 340 Company Flight Manual Volume 1. 

Regulatory Compliance 

14 CFR 121.161 Airplane limitations: Type of route.

(a) Except as provided in paragraph (e) of this section, unless approved by the Administrator in 

accordance with Appendix P of this part and authorized in the certificate holder's operations 

specifications, no certificate holder may operate a turbine-engine-powered airplane over a 

route that contains a point— 

(1) Farther than a flying time from an Adequate Airport (at a one-engine-inoperative cruise 

speed under standard conditions in still air) of 60 minutes for a two-engine airplane or 180 

minutes for a passenger-carrying airplane with more than two engines; 

NOTE: Seaborne Airlines Extended Overwater Operations are conducted within thirty 

(30) minutes of a suitable airport at all times. A list of suitable airports for each 

extended overwater flight segment will be included in the “Adequate Airports” section 

of the dispatch release package for the flight. 

121.565 Engine inoperative: Landing; reporting.

(a) Except as provided in paragraph (b) of this section, whenever an airplane engine fails or 

whenever an engine is shutdown to prevent possible damage, the pilot in command must land 

the airplane at the nearest suitable airport, in point of time, at which a safe landing can be 

made. 

Extended Overwater

Definition: 

With respect to aircraft, an operation over water at a horizontal distance of more than 50 

nautical miles from the nearest shoreline. 

Seaborne Airlines will conduct extended overwater operations – partially equipped with the 

Saab 340 aircraft up to thirty (30) minutes flying time from land. This distance will be 

considered to be 98 nautical miles at an expected single engine still air speed of 197 knots at 

28,000 pounds and 9,000 feet. This is based upon Saab AOM data for single engine operations 

and represents the worst-case performance from an engine failure during cruise. 
SEABORNE AIRLINES DATE: 03-31-14 

EXTENDED OVERWATER – PARTIALLY EQUIPPED PROGRAM REVISION: Original

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Operations Specifications (OpSpecs) and Deviations 

Extended Overwater – Partially Equipped Operations: Deviation to FAR 121.339(a) as granted in 

OpSpec A005

Seaborne Airlines is authorized to conduct Extended Overwater – Partially Equipped with the 

Saab 340 aircraft. Operations will be conducted as follows: 

• A list of aircraft approved for Extended Overwater – Partially Equipped operations will 

be maintained in the Seaborne Airlines Dispatch Center and will show the same tail 

numbers approved by the FAA on Seaborne Airlines Operations Specifications. 

• All Extended Overwater – Partially Equipped flights may operate at more than 50 

nautical miles from any shoreline, however the flight must remain within 98 nautical 

miles from any shoreline 

• Authorized area of operation for this program includes the airspace contained by the 

following coordinates: 

o 20N 68W, 20N 64W, 19N 62W, 17N 60W, 14N 59W, 11N 59W, 10N 60W, the 

shoreline of South America from 10N west to 63W, 15N 63W, 16N 64W, 17N 

68W. 

o Any direct or published routes within the above airspace 

• Temporary excursions outside of the operating area may be made for weather 

avoidance, however the flight must return to the operating area as soon as practical. 

• Extended Overwater – Partially Equipped operations are restricted to a planned cruise 

altitude of 11,000 feet MSL or above. 

• The primary means of navigation on Extended Overwater – Partially Equipped routes 

will be GPS. In the event of a loss of GPS navigation, the flight must revert to 

conventional navigation. Notify ATC and Dispatch for rerouting to re-enter Class I 

Navigation Airspace. 

• Long Range Navigation must be fully functional on any aircraft dispatched into Extended 

Overwater operations: 

o GPS must be operable with a current navigational database. 

o GPS coupling to the autopilot/flight director (LRN selection on Captain’s EHSI and 

NAV mode) must be operable. 

IFR Enroute Navigation Using Area Navigation Systems (OpSpec B034) (GPS Authorization)

Seaborne Airlines is authorized to conduct IFR Class II navigation (including operations outside 

positive radar control) using approved aircraft and area navigation systems. Such operations 

shall be conducted only within the areas of enroute operations where this paragraph is 

referenced in OpSpec B050. 
SEABORNE AIRLINES DATE: 03-31-14 

EXTENDED OVERWATER – PARTIALLY EQUIPPED PROGRAM REVISION: Original

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Authorized Areas of Enroute Operation (OpSpec B050)

Seaborne Airlines is authorized to conduct operations in the following geographic areas: 

• Caribbean Sea excluding Havana FIR 

• 48 Contiguous United States 

Class II Navigation Using Single Long-Range Navigation System (OpSpec B054)

Seaborne Airlines is authorized to conduct GPS Class II Navigation using a single long range 

navigation system. Seaborne Airlines Saab 340 aircraft are authorized to use systems as listed 

in OpSpec B054. 

The following Limitations and Provisions apply: 

• Class II Navigation is only authorized in areas of operation as listed in OpSpec B050 

above. 

• Navigation must meet the minimum degree of accuracy required by ATC. If not 

specified, the error may not exceed 25 nautical miles. 

• Prior to entering Class II Navigation, the aircraft position shall be accurately fixed using 

ATC or land based navaids. After exiting class II navigation the position shall be fixed. 

Any GPS error must be logged. All GPS malfunctons shall be noted in the discrepancy 

section of the aircraft logbook. 

• Ground based navigation facilities which are temporarily out of service may be 

substituted by GPS navigation. 

• In the event of a loss of GPS navigation, the flight must revert to conventional navigation. 

• Prior to conducting Class II navigation the Pilot-in-Command must receive a line check or 

conduct a leg under the supervision of a qualified Check Airman. 

Extended Overwater Operations – Procedures

On Extended Overwater – Partially Equipped aircraft, there is a lifevest located under each 

passenger seat. There are additional lifevests located in the last overhead bin. These can be 

used for last minute replacement of a missing or damaged lifevest. A minimum of three (3) 

additional lifevests must be carried. 

Infant lifevests are also located in the last overhead bin and will be distributed by the flight 

attendant if an emergency situation occurs. 

The total number of occupants onboard the aircraft may not exceed the number of lifevests 

available. In the event of missing life vests in excess of the seating capacity, a deferred 

maintenance item will be opened using the NEF item for extra life vests. 

All Extended Overwater – Partially Equipped flights may operate at more than 50 nautical miles 

from any shoreline, however the flight must remain within 98 nautical miles from any shoreline 
SEABORNE AIRLINES DATE: 03-31-14 

EXTENDED OVERWATER – PARTIALLY EQUIPPED PROGRAM REVISION: Original

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Authorized area of operation for this program includes the airspace contained by the following 

coordinates: 

• 20N 68W, 20N 64W, 19N 62W, 17N 60W, 14N 59W, 11N 59W, 10N 60W, the shoreline 

of South America from 10N west to 63W, 15N 63W, 16N 64W, 17N 68W. 

• Any direct or published routes within the above airspace 

Temporary excursions outside of the operating area may be made for weather avoidance, 

however the flight must return to the operating area as soon as practical. 

Extended Overwater – Partially Equipped operations are restricted to a planned cruise altitude 

of 11,000 feet MSL or above. 

The primary means of navigation on Extended Overwater – Partially Equipped routes will be 

GPS. In the event of a loss of GPS navigation, the flight must revert to conventional navigation. 

If the flight is outside of Class I airspace, Notify ATC and Dispatch for rerouting. 

Figure 1: Overwater Operations Area 
SEABORNE AIRLINES DATE: 03-31-14 

EXTENDED OVERWATER – PARTIALLY EQUIPPED PROGRAM REVISION: Original

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Driftdown Procedures

In the event of an engine failure during Extended Overwater – Partially Equipped operations, 

the following flight crew procedure must be used: 

• Aircraft Driftdown Procedure: 

o One engine operating at MAX CONTINUOUS POWER and the other inoperative 

with the propeller feathered. 

o Flaps and Landing Gear retracted 

o ECS ON above 10,000 ft. and ECS OFF below 10,000 ft. 

o Speed VCLEAN +5 unless in icing conditions, then VCLEAN +15 

• Advise ATC 

• Divert to nearest suitable airport 

• Contact Dispatch for diversion weather and single engine cruise/speed information 

• Maintain fuel balance via fuel crossfeed procedures 

• Descend to the net level-off altitude as shown in Table 1 (Following Page) 

ENG A/I OFF

PRESSURE ALTITUDE (ft)

WEIGHT Temperature (C°)

(lb) ISA – 20 ISA ISA +10 ISA +20

22,000 19500 18500 16800 15000 

23,000 18200 17200 15700 13200 

24,000 17000 16200 14500 11800 

25,000 16000 15000 13100 10200 

26,000 15000 13800 12000 9500 

27,000 14000 12500 10800 9000 

28,000 13000 11500 10200 7800 

29,000 12200 11200 8800 6500 

ENG A/I ON

PRESSURE ALTITUDE (ft)

WEIGHT Temperature (C°)

(lb) ISA – 20 ISA ISA +10

22,000 17500 16200 14500 

23,000 16500 15000 13700 

24,000 15500 13900 11900 

25,000 14400 12200 10200 

26,000 13500 11500 10000 

27,000 12500 10000 9500 

28,000 11500 10000 8000 

29,000 11000 9100 6500 

Table 1: One-Engine Service Ceiling
SEABORNE AIRLINES DATE: 03-31-14 

EXTENDED OVERWATER – PARTIALLY EQUIPPED PROGRAM REVISION: Original

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Extended Overwater Operations – Limitations 

Certain MEL/CDL/NEF items affect the ability of the aircraft to meet the requirements of 

Extended Overwater – Partially Equipped operations. Operations may not be conducted with 

any of the following items deferred/inoperative: 

SYSTEM ITEM DESCRIPTION 

MEL 21-31-1 Cabin Pressure Control System 

MEL 21-31-1-1 Manual Pressurization Control System 

MEL 21-31-2 Pressure Dump System 

MEL 21-31-3 Outflow Valves 

MEL 21-33-4 Cabin altitude/Differential Pressure Warning System

MEL 21-50-1 Air Conditioning Packs 

MEL 21-60-1 Compressor/Duct Overtemperature Indicators 

MEL 23-10-5 FlightCell DZM Satellite Phone 

MEL 25-60-2-1 Observer Seat Oxygen Masks 

MEL 27-21-1 Rudder Limiter 

MEL 32-33-1 Landing Gear Extension/Retraction System 

MEL 34-11-2 Standby Pitot-Static System 

MEL 34-23-2 Standby Magnetic Compass 

MEL 34-42-1 Weather Radar System 

MEL 34-60-1 Global Positioning System (GPS) 

MEL 34-60-1-1 Global Positioning System (GPS) Database 

MEL 35-12-1 Cockpit Oxygen Pressure Indication 

MEL 35-20-1 Passenger Oxygen System 

MEL 36-10-2 Bleed Valves 

MEL 36-20-2 Bleed Fault Caution Indications 

MEL 36-20-3 Bleed Closed Caution Indications 

MEL 36-20-5 Bleed Leak Caution indications 

CDL 53-30-001 Landing Light Aerodynamic Cover 

Table 2: Inoperative Components 

Single Engine Operation Checklists

Refer to Seaborne Airlines Saab 340 Quick Reference Handbook.