Flight Manual: Saab 35 Draken 5.0Updated: 2020-11-01
About this simulation
Flight dynamics
The simulated flight characteristics, or flight dynamics engine (FDE), of this add-on is the result of many years of development by Bookmark in close collaboration with a number of former Draken pilots.
The FDE has been tested on everything from laptops to full-scale cockpit simulators, but since there are endless possible combinations of hardware and program settings out there it will always be a compromise. You may therefore need to customize the FDE by editing the aircraft.cfg file to suit your own particular hardware setup.
At the moment there are a handful of cockpit builders in Sweden that are using real Draken hardware in their simulators. The FDE:s for these are slightly different from the publically released version, and they are usually modified further by the cockpit builders. If you are planning a cockpit project (non-profit or commercial), please contact Bookmark for further information about customization, licensing, and technical support.
Fig. 8 - Draken cockpit simulator in development at the Ängelholm Air Museum, Sweden
Limits and restrictions
Draken is an excellent aerobatics performer provided that you understand its limits. The double delta wing has good characteristics throughout the speed range but it creates an exceptional amount of drag at high angles of attack. At AOA >15 the aircraft will not accelerate even on afterburner!
Do not attempt split-S maneuvers above M 0.9 or 700 kmh, as you may not be able to achieve enough angle of attack to recover from the dive.
Transsonic
In the transsonic speed range (~0.95–1.05 M) control response will be sluggish because of the high dynamic pressure on the large elevons, and you may be unable to pull more than 3 G at low altitude.
Do not manoeuver close to the ground at transsonic speed.
Inverted flight
Flying inverted or with negative G is restricted to max 15 seconds to prevent fuel flow problems. The buffer fuel tanks will aid in keeping the fuel flow uninterrupted, but after prolonged inverted flight you may experience flameout.
Superstall
Draken can go from stationary to supersonic in less than a minute. On the downside, speed bleeds off just as fast with rising angle of attack. Always keep an eye on the AOA gauge: when approaching 15 you will lose speed and gain alpha at an alarming rate and may eventually end up in superstall.
Superstall or deep stall
basically means an unrecoverable condition
where all lifting surfaces on the aircraft have stalled (lost lift). It is most common
on, but not restricted to, delta winged aircraft.
A delta wing does not stall gradually like a straight wing; at a certain angle of attack the whole wing area will lose lift without much warning. Hence the Stall warning system, which starts to rattle the stick before the critical AOA. When the stall warning alerts you, pitch down immediately to reduce AOA and prevent superstall.
Fig. 10 - Draken filmed during superstall recovery training
Superstall could not be realistically simulated here due to limitations of the Prepar3D flight model, it is more a sort of tumbling spin. But close enough.
Superstall recovery
To recover from superstall, try this procedure:
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Extend gear.
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Counter the spin component by adding left yaw and right roll if you are spinning to the left, and vice versa.
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When reasonably stable, point the nose down to increase airspeed and reduce angle of attack.
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Retract gear.
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Raise the nose smoothly. Do not exceed AOA = 15.
Do not attempt recovery from superstall below 5000 m (15000 ft) altitude.
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