# Tag Info

49

No, the helicopters are standard production versions. The Eurocopter AS350 is a common model used for these operations. In 2005, Didier Delsalle landed a Eurocopter AS350 B3 on the summit of Mt. Everest at 29,029 feet (8848m) (twice). The only changes he made to the standard version were removing a few things like extra seats to reduce the weight, and of ...

16

No because if stick force per G is too low, when maneuvering it becomes too easy to pull a lot of G and that's bad. It's like having power brakes in your car that don't build up more resistance in the pedal the harder you brake; it becomes difficult to regulate braking effort and too easy to lock the brakes (assuming no ABS). Like with brakes, it's ...

7

I'll do this without most of the math since your target audience won't want to read equations in your story. In the simplest terms, the maximum speed of an airship occurs when the maximum thrust generated by its engines is equal to the drag it experiences while being pushed through the air at that speed. That drag depends on the diameter and length of the ...

6

As mentioned in this answer: stick forces are designed into the control feel. The best feedback for the pilots on how large their control input is, is haptic feedback: push/pull force as detected by the force transducers in our hands. While looking out of a cockpit window, we don't exactly know where our hands are, but we don't have to look at our hands to ...

5

For an estimate, we can use the Brequet range equation: $range = V\cdot t_f = \frac{L}{D} \times I_{sp} \times \ln\left(\frac{W_i}{W_f}\right)$ with: $V$: optimal velocity $t_f$: flight time $L$: lift $D$: drag $I_{sp}$: propulsion efficiency $W_i$: initial weight $W_f$: final weight Assuming the lift to drag ratio $\left(\frac{L}{D}\right)$ and the ...

5

Reading the heated discussion between Robert and JZYL makes me sad. Both are right and still they cannot agree. Maybe a longer and more detailed description might help. 1) When the aircraft is taking off, is the tail down force required to pitch up the aircraft high? Because the aircraft always has a natural tendency to pitch down. The aircraft should ...

4

The top speed depends on the type of the airship. While the first designs were non-rigid, it became soon obvious that useable speeds could best be achieved with rigid designs because the higher dynamic pressure at higher speeds required more internal pressure to maintain the hull's shape. Given the low strength of early hull materials, the internal pressure ...

4

This is going to involve a lot of speculation! I'd guess that White Knight Two will have to fly at approximately airliner speeds once it reaches altitude, otherwise it will stall in the thin air. Total flight time of the combination is expected to be 2.5 hours, which gives a range of about 2500km (if we optimistically assume it does Mach 0.8 the whole time,...

4

Rather than put up with one us speculating and pontificating on what to do, just read this terrific account of the Air Canada Gimli Glider incident, where a '67 did exactly that. They pretty much did it right, helped by a Capt that really knew how to fly as opposed to just being competent at running the machinery.

3

To answer the other part of your question, in a scenario where you lose all 3 speed indications, you are left with pitch and power. If you know the airplane really well and are sufficiently skilled at flying, this should be enough. For example if you've been flying some jet for a while you will know that at Vref on a 3 degree glide slope flaps and gear ...

3

No, there isn't any single rule of thumb for airframe shape. Just look at the huge variety of airframes that have been built and flown over the years. One way to scratch-build is to start with a cardboard glider that's roughly the shape you want. Tape the wings and tail to the fuselage in different places, tape on some noseweight, give it a toss, deflect ...

3

If the airfoil profile does not change along the span, then we can expect the entire wing to enter a stall condition at the same time. This means the stall break will be sudden and sharp. If instead we transition between several different airfoil profiles along the span of the wing, we can get different portions of the wing to stall at different airspeeds/...

3

Comparison of two giants from the golden age of airships LZ 127 Graf Zeppelin and LZ 129 Hindenburg provides some useful information on your proposed scaling. Both airships were around 800 feet long and cruised at 80 - 85 mph. Hindenburg was 35 feet wider, with more than double the lifting capacity, but required 4 x 1200 hp compared with 5 x 550 hp of the ...

2

As for the weight vs. speed: a rigid or semirigid airship has a max takeoff weight, which depends on it's size (because the size pretty much determines the max lift). If this airship was to fly, say, only half of the max weight, it would not go any faster, as the drag would be the same because the size does not change. An airship may lift a load heavier ...

1

"What would happen if the thickness...are same throughout the wing". This is known as a "Hershey bar" wing, and is an excellent general purpose, easy to build wing for models and full scale aviation aircraft alike. Aircraft designers add twist or "washout" to wings to prevent the entire wing from stalling at once. Washout lowers the angle of attack of the ...

1

1) When the aircraft is taking off, is the tail down force required to pitch up the aircraft high? Because the aircraft always has a natural tendency to pitch down. For rotation, yes. Aft stick increases elevator/stabilator trailing edge up, which increases the downward force on the tail, thereby producing a positive pitching moment and increasing pitching ...

1

It can travel 4259 kilometers or 2647 miles loaded, but I am not sure if Airbus would have a need to publicly document the information of the unloaded range - I doubt this information is accessible.

1

I don't know why but this configuration has always appealed to me. Fits my eyes. I have been tinkering with this design making my own adjustments and there is a lot that can be done. Just a thought. Good luck!

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