Questions tagged [high-altitude]

Region on the earths surface beginning at 2,400 meters (8,000 ft)

Filter by
Sorted by
Tagged with
0
votes
4answers
175 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
1k 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
63 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
55 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
273 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
256 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
346 views

Difference between Mach buffet and shock stall

What is the difference between Mach buffet and shock stall?
1
vote
2answers
240 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 ...
3
votes
1answer
448 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
744 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
126 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?
4
votes
2answers
389 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,...
4
votes
1answer
1k 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
334 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 ...
6
votes
1answer
1k 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., ...
16
votes
3answers
3k 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
398 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 ...
1
vote
1answer
165 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 ...
15
votes
3answers
4k views

What are the limiting factors for high altitude planes (e.g: U2 or SR71) preventing them from going higher?

I'm curious as to why planes like the U2 Dragon Lady and the SR71 Blackbird couldn't fly higher. What physical constraint set their operational ceiling? Pilots wore spacesuits, so that wasn't the ...
1
vote
1answer
1k views

Why is the ratio of TSFC at altitude vs. sea level different for hi-bypass vs. lo-bypass turbofan engines?

I've read up on how the thrust-specific fuel consumption of turbofan/turbine engines increases with altitude, and the Georgia Institute of Technology plot in particular seems to indicate that, for ...
2
votes
1answer
443 views

Which small, light aircraft are suitable for operating at very high elevations?

I live in Jammu and Kashmir, in an area with an average elevation of 4,500m / 14,700ft MSL . I would like to know what would be a good and cheap light aircraft to carry 3-4 people for a 3-4 hour ...
11
votes
1answer
654 views

Why is tethered hover testing performed on helicopters?

The KGUC website notes that they have a tether for helicopter testing. From what I can tell this testing has something to do with hot and high conditions, but I don't know what the purpose is of ...
-1
votes
4answers
928 views

What is a blimp called if it is designed not to be lighter than air?

I have not found a name for a this type of vessel what class a vessel is it? Could it operate similar to a parasail if dropped from a high altitude or orbit with air far thinner then operational ...
3
votes
2answers
6k views

What are the ground and flight requirements for high performance endorsement?

I'm told ground is proficiency based but that in the plane you have to fly up to 25,000 feet! I don't know anything short of a turboprop capable of doing that, let alone have the ability to rent it. I'...
5
votes
4answers
685 views

Can a light glider without thermal protection land from the orbit, starting from the orbital speed?

I ask about a glider without any special thermal protection (pilot in the space suit), so both answers to the other question do not cover the topic. When the glider enters the atmosphere, it starts ...
1
vote
3answers
2k views

Could a plane with an electric turbine engine generate enough lift to provide a electric areodynamic lift and runway to space?

This question is similar to my previous ones but configuration is different and so is the question. Could a modified electric turbine engine (E-Fan) plane create enough of its own lift not to burden ...
4
votes
4answers
805 views

Is it possible for a modified hang glider to land safely coming from orbit? [closed]

Can a glider be dropped from geosynchronous or other orbits and safely land?
5
votes
2answers
2k views

Is there a maximum airfield elevation in which a Cessna 172P can operate?

The title says it all: is there a maximum airfield elevation in which a Cessna 172P can operate? Or a maximum density altitude at which take off shouldn't be considered?
7
votes
1answer
593 views

Passenger hypoxia in a small plane at 11,000 feet: what is the pilot's responsibility?

An acquaintance of mine visiting western U.S. was recently a guest passenger in a small plane flying from Santa Fe, New Mexico to Colorado reaching an altitude of 11,000 feet. She related that she ...
5
votes
2answers
619 views

Do airliners adjust altitude for latitude?

According to this NASA article, the troposphere extends from about 5 miles at the poles to about 9 miles at the equator. Though the height of the troposphere is defined by the height of the tropopause ...
6
votes
2answers
3k views

How are aircraft separated at high altitude?

When cruising at high altitude, a fixed-wing aircraft has less margin for adjusting its speed, due to the convergence of the stall "speed" and the overspeed limit: If and aircraft has to be separated ...
9
votes
1answer
602 views

What is considered “high altitude”?

The AFM for DA40 states in 4A.3.9 CRUISE checklist: Electrical fuel pump . . . . . . . . . . . . . . . . . . . ON at high altitudes CAUTION Operation at high altitudes with the electrical ...
9
votes
2answers
650 views

Are there any aircraft designed to operate between an altitude of 50-80km?

Aircrafts operating at high altitude falls into several categories: Wings with high aspect ratio (Global Hawk, TR-1, Scaled Composite Proteus,...) High velocity aircraft (Concorde, A-12, X-51,...) ...
7
votes
2answers
321 views

What is minimal altitude that aircraft (rocket?) can fly above any country without any permission?

What is minimal altitude that aircraft (rocket?) can fly above any country without any permission? I mean, at what altitude ends country's airspace?
6
votes
1answer
145 views

What are the FAA regulations concerning controlled descent of a light payload?

I'm part of a High Altitude Ballooning club. Our main goal for this year is to achieve controlled descent of our payload. We plan to use Magnus force cylinders to go about this. I have found nothing ...
15
votes
3answers
36k views

Can commercial airliners fly over hurricanes?

When Patricia was making landfall yesterday I opened up Flight Radar 24 to see if there were any planes flying around or near it. As I had expected, there were a couple of storm watching planes near ...
16
votes
5answers
9k views

Are sun's UV rays more harmful on an airplane at high altitude?

Most airplanes fly at >30k feet, way into the stratosphere / mesosphere where sun's UV rays aren't filtered by lower atmosphere layers. If the windows of the plane are open and the sun is shinning ...
9
votes
2answers
2k views

What keeps an aircraft engine from flaming out at high altitude?

High altitude atmosphere has lower oxygen level. How do aircraft, especially the military ones, prevent engine flameout?
10
votes
3answers
5k views

How did aviation industry come to know about the drastic difference in air pressure in high altitude?

After watching many documentaries about air plane crashes, it seems that aviation industry learned many of its lessons from disasters. For example, from the 2 mid-air explosion of de Havilland DH 106 ...
1
vote
1answer
1k views

How does altitude affect sound? [closed]

So I know that altitude affects the speed of sound because of temperature differentials in the atmosphere, but I am curious what else affects how we hear planes overhead? When a plane flies overhead, ...
23
votes
4answers
6k views

How should I deal with a passenger experiencing hypoxia over the Grand Canyon?

I am taking my mom for a trip over the grand canyon. My mom lives at sea level, whereas I live at 5000ft, and workout at 8000ft daily. The VFR lowest route over the Grand Canyon is 11,500ft MSL. If I ...
35
votes
5answers
6k views

How does an airliner deal with cabin altitude at an airport above 8000 ft?

There are a number of airports above 8000 ft altitude. FAR 25.841 states: Pressurized cabins and compartments to be occupied must be equipped to provide a cabin pressure altitude of not more than ...
17
votes
2answers
3k views

Is there a ceiling on weather patterns?

I know there are winds and other effects at very high altitudes but how high can storms with lightning and rain be? Bottom line, let's say you are flying a craft with the ceiling of a U-2, can't you ...