Questions tagged [high-altitude]
Regions on or above the earth's surface located higher than 8,000ft or 2,500m above sea level.
76
questions
1
vote
1answer
139 views
How was the AeroVironment Helios able to fly to the edge of space at no more than 23.5 kn?
The NASA/AeroVironment Helios holds the FAI record for the highest sustained horizontal flight at 96,900 ft (29.5 km) MSL. It reportedly spent more than 40 min above 96,000 ft. It could fly no faster ...
0
votes
0answers
93 views
Is the L-39 Albatros able to go above 40,000 ft in steep flight?
The L-39's service ceiling is 36,100 ft / 11 km but would it be able to easily reach and surpass 40,000 ft MSL if flying a parabola?
14
votes
2answers
5k views
Why are planes required to cruise at round flight levels only above 18000 ft of altitude?
AFAIK, planes flying at up to FL180 (18,000 ft pressure altitude) are allowed to fly at both round and semi-round altitudes (e.g. 15,000 ft or 15,500 ft). Planes flying above FL180 must fly at a round ...
17
votes
1answer
3k views
Are there any gliders that can fly over the Himalayas?
Do gliders (sailplanes) use ridge and wave lift in the Himalayas to go to extreme altitudes, possibly above Everest's peak?
3
votes
0answers
209 views
What is the highest operational ceiling for a nuclear scramjet?
A similar question is:
What is the highest operational ceiling for an air-breathing jet engine?
The answers point to scramjets. Cited reports focus on combustion kinetics.
The Wikipedia Scramjet page:
...
21
votes
3answers
8k views
What prevents a small plane like a Cessna or Piper from flying as high as a jet?
Obviously taking oxygen in consideration. What prevents a small plane from being able to fly at a much higher altitude? I know some business jets can fly up to 40,000 ft. Does it have to do with the ...
0
votes
2answers
217 views
Is it possible to file for a flight level ABOVE an Airway altitude limitation (for high en route airways)?
I'm just curious if it's ever possible to file for, and/or fly, an altitude that is above an airway restriction. Say if the airway has an altitude restriction of FL410 or less. Is it ever possible to ...
1
vote
2answers
160 views
Are there any high altitude flying options for a private pilot?
I would like to ask: if you are a private pilot that wants to fly really high, what are their options?
I know that for gliders it's not uncommon to reach FL160. Beechcraft Baron can reach FL190. ...
6
votes
1answer
354 views
What is the straight-and-level altitude record for a heavier-than-air winged/lifting-body aircraft?
There are many variants of the flight altitude record. The highest on the list is SpaceShipOne but rocketry isn't really "flight" in the sense of aerodynamic lift. What is the highest ...
5
votes
2answers
665 views
What is the altitude record for the F/A-18 Hornet?
Does anyone know how high (above MSL) the F/A-18 ever went? Its service ceiling is 50,000 ft, but when going up steeply, is it able to surpass 100,000 ft altitude?
1
vote
1answer
114 views
Could the Perlan II glider be used for nearspace tourism?
I asked the same question about the SR-71 Blackbird, and I'm also curious about the Perlan II sailplane which travelled above 70,000 ft, and is planned to be flown to 90,000 ft, if it could be used ...
1
vote
1answer
144 views
How high can manned subsonic planes go?
What is the maximum altitude a manned plane that flies subsonically can reach? Subsonic airplanes can't go as high as super- and hypersonic ones of course, so record holders are the latter ones. But ...
22
votes
3answers
6k views
Could the SR-71 Blackbird be used for nearspace tourism?
The Blackbird had two seats onboard. Could it be reactivated for nearspace tourism, placing a paying tourist in the other seat? If no, why not or why isn't it being proposed? In leveled flight, the ...
2
votes
1answer
153 views
What limits high altitude powered paragliders other than the engine?
Due to their extremely low wing loading, powered paragliders stall at very low indicated airspeeds compared to other airplanes. A typical paraglider can continue flying all the way down to 10-15 ...
0
votes
0answers
164 views
What's the highest altitude ever achieved by a (rocket-?)plane for level flight?
As probably most of us know, the SR-71 Blackbird holds the altitude record for leveled flight for (manned) jet planes (and ground-launched planes) at 90,000 ft MSL. However, the very altitude record ...
2
votes
1answer
181 views
Did every X-15 pilot become weightless when flying into the upper strato- and mesosphere?
The North American X-15 was aimed at breaking airspeed and altitude records. The flights that sought to achieve new airspeed records (Mach 5+) were rather leveled but the flights into the upper ...
-1
votes
1answer
162 views
Are there jet aircraft for whose flights astrodynamics must be taken into account? [duplicate]
Civilian jet airliners don't need to push their yokes down to follow the curvature of the Earth because within the atmosphere the curvature is accounted for by automatical systems, right? I wonder ...
14
votes
2answers
574 views
Could one see stars from the Concorde in daytime?
The Concorde flew to an altitude of 60,000 ft (18.3 km) where stars should be visible at noon, aren't they? This question asks on how high stars become visible, and it is said Blackbird pilots could ...
32
votes
2answers
3k views
How is altitude reached by aircraft flying above the stratosphere measured?
Aircraft flying above the stratosphere (above 30km) are rare, but there is still the X-15 and the spaceship two. For those aircraft, maximal altitude is measured to within 500 ft.
As described in this ...
9
votes
2answers
318 views
What is the maximal altitude at which an emergency slide can be deployed?
If I understand correctly, the mechanism to inflate an emergency slide relies on a tank of inert gas and on an "aspirator" that sucks ambient air. This aspirator works thanks to depression ...
0
votes
1answer
387 views
How does 'standalone' propeller efficiency change with altitude?
I've seen questions regarding propeller aircraft and altitude and their interaction. But I'm wondering what the relationship between just the propeller and altitude (changing air density) is. How does ...
-1
votes
1answer
283 views
What happens in an F-16 once the aircraft exeeds its service ceiling?
What exactly is the sequence of events that would unfold as an F-16 attempts to exceed its service ceiling? The scenario is simply full afterburner and attempting to simply climb higher and higher (at ...
0
votes
3answers
463 views
What happens if an aircraft goes above maximum altitude? [duplicate]
We all know what happens when a plane goes overspeed... but what happens when a plane goes above their max. altitude? And why are planes certified maximum altitudes anyway? Is it because there won't ...
2
votes
2answers
192 views
How to adjust time of useful consciousness for pilots acclimatised to high altitudes?
The time of useful consciousness (TUC) is the length of time an average pilot, breathing ambient-pressure air without supplemental oxygen, is capable of functioning usefully at a given altitude. For ...
5
votes
1answer
575 views
Does high density altitude affect your landing speed?
So I had this question asked in my recent commercial-pilot checkride:
The DPE asked me about high-density-altitude airports; he specifically asked me if I should add airspeed when I'm on landing ...
10
votes
2answers
4k views
Which aircraft can fly at FL600 or above?
I would like to know some examples of aircraft (specific models) which can fly at FL600 or higher.
I am interested in aircraft which can or could fly at that altitude on a regular basis (service ...
9
votes
3answers
3k views
How does latitude affect the air temperature at 8 km altitude where planes fly?
Is the air temperature (at 8km) above the North or South poles colder than the same altitude above the equator? Why?
Ground level air temperature difference between coldest and warmest places on ...
36
votes
1answer
7k views
Do the Mt. Everest rescue helicopters have modified engines to operate at high altitudes?
There are so many climbers on Mt. Everest today that there is now a helicopter rescue service there. They operate rescue up to 21,000 + ft. Because this is essentially stationary service it seems that ...
1
vote
1answer
284 views
Where and when would a 737-700 be taking off at an altitude of 19 kft?
Another question triggered by reading the 737 technical site; according to this section of the page on the 737's pressurisation system, the 737-700 comes with an option that allows it to safely take ...
5
votes
2answers
717 views
What kind of drone might be able to fly so high that it "operate(s) outside national boundaries"?
In the question What is a propellant burner trailer? I mention that
CNN and NPR have pointed out that the US president recently tweeted a surveillance photo of an explosion of a rocket on a launch ...
37
votes
4answers
18k views
Why do private jets such as Gulfstream fly higher than other civilian jets?
I heard in a TV show that private jets such as Gulfstream can fly at about 50,000 ft, higher than other civil jets.
Is it an aerodynamic reason (lighter aircraft to be sustained in a less dense air) ...
1
vote
4answers
227 views
Could a hybrid electric steam plane be more efficient at altitude than at sea-level, and how to optimise it to frigid air?
In the thirties a steam powered plane was built.
video
Could a hybrid electric steam plane be more efficient at altitude than at sea-level, and how could such a steam engine be optimised to benefit ...
5
votes
3answers
2k views
How do carbureted and fuel injected engines compare in high altitude?
I couldn't find enough information on the internet for this topic. What I found can be paraphrased as:
Carburetor means easy engine start while fuel injected means manual fuel start up and ...
1
vote
0answers
193 views
What lights to use for a high-altitude weather balloon?
I am designing a high-altitude weather balloon for a college project. The balloon may fly at night, which means that, per FAA regulations, I need a light that is visible for 5 miles.
Does anyone ...
1
vote
1answer
75 views
Proportionally, what is more affected by a hot and high takeoff - a electrically driven propeller or a turbofan?
My assumption would be the electrically driven propeller would be less affected compared to turbofans at high altitudes and take off as although the air would be less dense at these ambient conditions,...
14
votes
4answers
6k views
How do planes know what altitude they're cruising at?
I know that when planes enter the aerodome containing the airfield of destination, the ATIS will tell them an altimeter setting so the system knows how to calculate their altitude above their field; ...
4
votes
0answers
315 views
What will happen to a modern high bypass engine at 80 000 feet with cruise speed of 0.8 Mach?
While keeping the typical cruise speed of 0.8 Mach, will the engine shut down due to "air starvation" at such high altitude? Is it possible to design a turbofan engine, which is able to provide thrust,...
6
votes
1answer
501 views
Has fuel boiling ever been an issue for high altitude aircraft?
Are special measures being taken to prevent fuel from boiling inside the fuel systems at high altitudes? If so, when (with what aircraft) did this practice start?
(question is pertaining to air-...
1
vote
1answer
2k views
Difference between Mach buffet and shock stall
What is the difference between Mach buffet and shock stall?
3
votes
4answers
437 views
Why do suborbital planes feature H-tail and/or large wingtips?
Spaceplanes that are suborbital are mostly supersonic and feature H-tail or rather large wingtips. This looks to be similar to a H-tail configuration but I'm unsure abut how it works, which is why I ...
7
votes
2answers
1k views
Why does aircraft stability increase when it transitions from subsonic to supersonic flight?
I am puzzled why would the aircraft be more stable at high speed flight at high altitudes. Given that the Centre or Pressure moves gradually towards the 50% MAC region, once past Mcrit.
Has this got ...
3
votes
2answers
1k views
What forces act on an airplane's door from the outside in cruise?
The inside cabin pressure from what I understand is pressurized to the values found at 6000-8000 feet high (11.34 psi at 7000 feet), at which point we can find the amount of force can be found acting ...
2
votes
1answer
161 views
Why do high altitude air-launch plane designers choose to use two fuselages?
We see double fuselages in both the huge Stratolaunch vehicle and in Virgin Galactics high altitude launch vehicle. What about this design makes it desirable?
7
votes
2answers
832 views
If maximum speed was a priority for modern military fighter jets and bombers, approximately how fast would they likely be?
Burt Rutan talks rather passionately about the lack of innovation in space flight, but also mentions how fighter jet (maximum) speed performance has stalled:
In fact,...
3
votes
1answer
2k views
Is there a limit to the possible altitude for electric jets?
So I was thinking about Elon Musk's supersonic electric jet idea. Assuming we have sufficiently energy-dense batteries, where would the limits be in terms of speed and altitude.
His logic seems to ...
6
votes
1answer
412 views
What special tyres (tires) are needed for high altitude takeoff and landing?
I just watched this video of AA922 taking off from El Alto (LPB) to Santa Cruz. The video's author mentions that the aircraft needs "... special tyres" due to the high altitude.
While I do ...
7
votes
2answers
3k views
What is the highest operational ceiling for an air-breathing jet engine?
An air-breathing jet engine can only operate at relatively low altitude, where the atmosphere is dense enough. However, some jet-powered aircraft can operate at an altitude higher than 20 Km (e.g., ...
20
votes
4answers
7k views
Is there a height limit to national airspace?
Given the following facts:
satellites can operate at an altitude of 200km without triggering frontier violation incident
aircraft can trigger diplomatic protestations if they cross a frontier at an ...
2
votes
2answers
584 views
Could an airliner get better fuel efficiency at higher altitude? [duplicate]
By higher I mean like 60k feet instead of 30k.
Seems like the rate limiting step is engine performance at 60k feet.
Are people working engines that can operate at higher altitudes? How close are we ...
2
votes
1answer
188 views
Are artificial magnetic fields used or proposed to be used to shield high altitude pilots and astronauts from charged, high energy radiation?
If not for the earth's magnetic field our atmosphere would be bombarded by high energy plasma (ionized gas) from the sun and other space sources. At very high altitudes and orbital altitudes this ...
