57
votes
Accepted
Why does camouflage make some planes fly slower?
Same reason gliders keep their wings waxed. It wasn't the camo per se, it was the dull matte field-applied paint finish that included all sorts of imperfections, and to a small degree, the weight of ...
- 126k
36
votes
How did planes measure their speed relative to the ground before GPS?
The other answers seem to make a simple thing way too complicated. Yes there are DMEs or TACANs, that are sometimes used to get a ground speed, but it's only accurate if you're tracking exactly to or ...
- 11.8k
30
votes
How does it feel like to be outside a flying airplane?
It won't be pleasant. The main result of being exposed outside at altitude, besides the obvious hypothermia, frostbite and hypoxia, will be bruising from the 280-ish knot slipstream (it's the ...
- 126k
26
votes
Accepted
How much leverage do commerial pilots have on cruise speed?
There is something called the "Cost Index" - it is basically how you choose between speed and fuel economy. Company dispatchers, after knowing that a flight has been delayed, will calculate this value,...
- 39.7k
24
votes
Accepted
Why don't small aircraft produce tyre smoke when landing, but big aircraft do?
It is not only the speed, but the combination of several effects:
Landing speed: The much higher wing loading of airliners, even at the end of their trip, results in touchdown speeds in the area of ...
- 229k
23
votes
What is wrong with a high-speed landing for an ultralight or GA aircraft?
Keeping too much speed in an approach in any airplane can be risky depending on how much runway you have as it all has to bleed off before you can stop. It's a great way to end up in a hedge. Extra ...
- 52.9k
22
votes
Why does the speed of commercial airliners fluctuate, sometimes as high as 1,060 km/h or as low as 800 km/h?
There are three different speeds that are of relevance here:
Groundspeed- This is probably the speed indicated to the passenger. For them, this is the most relevant as it determines the time taken ...
- 100k
21
votes
Accepted
What could cause an irregular climbing pattern on takeoff?
The brief period of leveling off is not unique to the flight on that day. Looking at track logs for previous days, it always levels off at around 7,000 feet for some period.
As Terry commented, this ...
- 71.8k
21
votes
How does it feel like to be outside a flying airplane?
This is from Irish Luck - Surviving Partial Ejection from A-6 Aircraft. In this incident, the bombardier/navigator's ejection seat came part way out of an A-6, leaving the head and upper body exposed. ...
- 3,219
19
votes
Accepted
Why do we need to know both groundspeed and airspeed?
Airspeed is critical for pilots, because it is what the airplane "feels" when it's flying. Too little airspeed and the wings won't generate enough lift to fly, too much and the plane can be damaged. (...
- 306
19
votes
Why does camouflage make some planes fly slower?
It's primarily all about matte vs glossy finish. Normally a camo paint scheme would not be finished in a glossy finish as this might flash in the sunlight. A matte finish is rougher and thus has ...
- 21.8k
17
votes
How did planes measure their speed relative to the ground before GPS?
There's one method that has been successfully used since long-distance flights became available - you took out your map, and tried to match it to features under your plane. This allowed you to correct ...
- 271
17
votes
What ground speed reference is used for anti skid control?
On the Airbus A320, the ADIRU (Air Data Inertial Reference Unit) data is used for the reference speed of the anti-skid system:
The system compares the speed of each main gear wheel (given by a
...
- 54.3k
16
votes
Accepted
What is wrong with a high-speed landing for an ultralight or GA aircraft?
You can, in theory, fly a faster landing speed than the default Vref of 1.3*Vso. But it’s wasteful in the round out and potentially very dangerous on short field landings.
When an airplane lands, ...
- 72.8k
14
votes
What ground speed reference is used for anti skid control?
The answers would be incomplete without mentioning the 'original' ABS. It was used very widely on civil and military aircraft alike throughout the world until at least the 1970s.
The system employed a ...
- 9,013
13
votes
Accepted
How do pilots manage the speed during the approach?
The Boeing chart you reference appears to use for the approach speed column the Vref speed of the aircraft at its max landing weight in the landing configuration. This is the speed you want to be at ...
- 39.2k
12
votes
What could cause an irregular climbing pattern on takeoff?
Looks like an intermediate altitude assignment from atc. A look at the standard instrument departure plates (SID's) for Stansted shows that the final altitude on some of the procedures is 6000 ft. ...
- 28.4k
12
votes
Accepted
What special tyres (tires) are needed for high altitude takeoff and landing?
The higher takeoff speeds might exceed the speed rating of the usual tires. As a tire is rolling it deforms in two directions.
As each section comes in contact with the runway it is pressed inward ...
- 28.4k
12
votes
How does it feel like to be outside a flying airplane?
A skydiver in free fall is fully supported (i.e. no longer accelerating, but falling at constant velocity) at about the same speed as your example motorcycle.
Wind resistance is generally proportional ...
- 17k
11
votes
How did planes measure their speed relative to the ground before GPS?
According to a story I read about the SR71, planes used to be able to ask ATC for a "ground speed check", i.e. ask "What's my speed on the ground?" ATC would measure it using their ...
- 3,094
10
votes
How do head- and tailwinds affect airspeed?
I'm wondering how to calculate the actual speed based on that.
Which actual speed? All of the speeds you mentioned are actual speeds. None of them is in any way artificial, virtual, or otherwise ...
- 5,700
10
votes
How do head- and tailwinds affect airspeed?
How do head- and tailwinds affect airspeed?
They don't. Airspeed is the aircraft's speed relative to the air it's travelling through. The aircraft doesn't care whether that air is moving relative to ...
- 11.9k
10
votes
What determines the maximum ground speed of hot air balloons?
Balloons travel with the wind, so all their motion over ground comes from air movements.
do hot air balloons have the ability to control their ground speed? If so, how?
This was a burning question ...
- 229k
9
votes
How to calculate the real Ground Speed from True Air Speed?
First calculate horizontal component of airspeed, then add the wind:
$$v_{GS} = cos(\theta) * v_{TAS} + v_{wind}$$ with $\theta$ being the angle between the horizon and the path of the aircraft in ...
- 3,020
9
votes
Accepted
Calculating Ground Speed - E6B vs Pythagorean Theorem
Course and heading are not the same. Course is the direction of your path over the ground. Heading is the direction you are pointed (and the direction you would travel through a still airmass).
In ...
- 5,551
9
votes
What is wrong with a high-speed landing for an ultralight or GA aircraft?
Depends.
With tricycle gear airplanes the limitation is mainly pitch attitude in the landing flare so you don't come down nosewheel first, which is very bad on the nosewheel and ultimately on the ...
- 126k
8
votes
Is it centrifugal force that allows a non-aerodynamic body to achieve lift purely because of thrust?
Basically, you're asking 'Can you achieve orbital velocity in atmospheric conditions?'.
Orbital velocity is approximately equal to
$$v_o \approx \sqrt{\dfrac{GM}{r}}$$
which, if we fill it in at ...
- 12.9k
8
votes
Why does the speed of commercial airliners fluctuate, sometimes as high as 1,060 km/h or as low as 800 km/h?
It is all about the wind. If you check schedules, you'll see that for example USA-Europe flights are way shorter (about an hour, say) than Europe -USA. This is due to the jetstream. I found it even ...
- 2,070
Only top scored, non community-wiki answers of a minimum length are eligible