Aircraft without wings! (NASA M2-F1)

Wingless Aircraft NASA M2-F1

Image from: - Wikimedia

The wing is most important part of the aircraft. From my post, How Aircraft Fly, we know that Wing gives a lift to the Aircraft. To know about how Aircraft wing produces a lift, look at my this post. But in 1963 NASA developed an aircraft which had no wings. The Aircraft was NASA M2-F1.  Here M stands for Manned & F stands for flight. (So Manned 2 Flight 1).

M2-F1 was developed by NASA engineers at the Ames Research Center. It was developed as an alternative to a capsule spacecraft. So it can re-enter in earth's atmosphere.

Image from: - Wikimedia

The M2-F1 was made of wood, had an internal framework of steel tubes, looked like a bathtub sitting on a tricycle. M2-F2 didn't use wings to produce lift. Aircraft was designed in such way that it used air flowing over its body to produce lift. This design allowed it to re-enter in earth's atmosphere and land on a runway like a conventional airplane. 

The wingless, M2-F1 aircraft design was initially conceived as a means of landing a spacecraft horizontally after atmospheric reentry. The absence of wings would make the extreme heat of reentry less damaging to the vehicle. M2-F1 took its first flight on 16 August 1963. But this design was rejected & retired on 16 August 1966.

General characteristics (From Wikipedia)

Crew: one
Length: 20 ft (6.1 m)
Wingspan: 14 ft 2 in (4.32 m)
Height: 9 ft 6 in (2.89 m)
Wing area: 139 ft² (12.9 m²)
Empty weight: 1,000 lb (454 kg)
Loaded weight: 1,182 lb (536 kg)
Max. takeoff weight: 1,250 lb (567 kg)
Powerplant: 1 × Solid fuel rocket, 250 lbf (~1.1 kN)

Performance (From Wikipedia)

Maximum speed: 150 mph (240 km/h)
Range: 10 mi (16 km)
Wing loading: 9 lb/ft² (44 kg/m²)

For more posts visit

Like us on facebook

Mail us your queries & doubts on

Russian Plane Tupolev Tu-154 Crashed in Black Sea!

Tupolev Tu-154 Crash

Image From: - Wikimedia

A Russian military plane Tupolev Tu-154 has crashed in the Black Sea near Sochi. There are apparently no survivors, according to the Russian Defense Ministry. A Tupolev Tu-154 plane was carrying 92 people, including 84 passengers and 8 crew members. Tu 154 was an old model, no longer flown by airlines in Russia but still used by the military. It was 33 years old.

The plane took off from Moscow and was headed to the Russian Hmeymim airbase in Latakia, Syria. Coming from Moscow, the plane had landed in Sochi for refueling. It disappeared from radar 2 minutes after taking off from Adler airport, Sochi at 05:25 AM (Local Time) on Sunday. The flight data recorder has been recovered and brought to Moscow. Flight Data recorder was found by a Seaeye Falcon underwater remotely operated vehicle at a depth of 17m & 1,600m from the shore. The recorder was in a satisfactory condition. Investigators are searching for second black box & it is believed that it could be recovered shortly. According to BBC news reports, A plane was unable to gain height and for some reason - possibly overloading or a technical fault. According to the reports, the plane had made a U-turn back towards the coastline shortly after take-off, before disappearing off the radar. But in an audio recording of a final conversation between air traffic controllers and the plane, there was no sign of any difficulties. Voices were normal until plane disappear.

The cause of the disaster is still being investigated but there is no suggestion of a terror attack.

Information Courtesy: - BBC News, CCN News

For more posts visit

Like us on facebook

Mail us your queries & doubts on

Why Do Air Traffic Control (ATC) Towers Have Slanted Windows?

Air Traffic Controller slanted windows

Image from: - Wikimedia

While waiting for a flight at the airport you must have seen a tall tower at every airport. That tall tower is called as Air Traffic Controller. Air traffic control (ATC) is a service provided by ground-based controllers who direct aircraft on the ground.

Each airport has its own ATC Tower. Even if different airports have different ATC towers you will see one thing common in all which is their slanted windows. Slant angles vary but most of the time slant angle is 15°.  But why are ATC towers windows are slanted?

There are various reasons one of which is, Many people assume that they are designed that way to prevent the sun's reflection or glare from disturbing incoming pilots. But its not valid explanation. Because not all the windows surrounding ATC tower have slanted windows, so if that's the reason then even buildings surrounding ATC tower which are having flat windows can disturb pilot!

Here are some of the valid reasons,

Slanted windows collect much less rainwater & wind-blown dust that sticks to drops of water as compared to flat windows. So this provides a much better look through windows. So person inside ATC tower can get good vision through such windows. 

we see reflections in a glass all the time, for example from computer monitors or car windows. But air traffic controllers must not have any distracting reflections as they monitor flights. By slanting windows, any other light from inside the tower such as Computer screens, etc. is reflected up onto the ceiling, which is painted black.

So these are some valid reasons for slanted ATC tower windows.

For more posts visit

Like us on facebook

Mail us your queries & doubts on

shortest International Flight in the world

The World's shortest International Flight!

Image from:- wikimedia

In my Previous post, I mentioned about world's shortest flight. It is shortest domestic flight. This flight is between two islands in Scotland. But today I am going to tell you guys about world's shortest international flight.

Austrian Airline People's Viennaline provides world's shortest international flight. This flight is just eight minutes long. Just think about it, you will be in the another country just after flight of 8 minutes. This flight connects St. Gallen-Altenrhein in Switzerland to Friedrichshafen in Germany. Vienna Airline operates Embraer E170 for this shortest flight. The flight distance is just 20 km. Passengers can book this shortest journey between the two countries for around 40 euros.

(Route between two airports if traveling by car)
Courtesy: - Google maps

So, you can travel from Switzerland to Germany either by this flight in 8 minutes or by taking a train ride for two hours. If going by car it takes an hour to travel this distance of 63 km between two airports.

(Route between two Airports if travelling via train)
Courtesy: - Google maps

Previously, the world’s shortest international flight was a ten-minute journey between the Austrian capital Vienna and the Slovakian capital Bratislava.

For more posts visit

Like us on facebook

Mail us your queries & doubts on

Shortest flight in the world

World's Shortest flight

Courtesy: - Google Maps

The world’s shortest commercial flight is between the two Orkney Islands, Westray and Papa Westray. These islands are just at north of Scotland. These two islands are separated by a distance of only 1.7 miles. This shortest flight is operated by Loganair Scotland's Airline.
Loganair operates this flight with one of its two Pilatus Britten-Norman BN2B-26 Islander aircraft.

Courtesy:- Wikimedia

The flight duration is officially two minutes, but under ideal wind condition can be completed in only 47 seconds. Pilot Stuart Linklater flew the short hop a record more than 12,000 times, more than any other pilot, before he retired in 2013. Linklater set the record for the fastest flight between the islands at 53 seconds

Courtesy: - Wikimedia

Tickets are priced at about $30 per passenger with no in-flight service.
It’s used by teachers, doctors, policemen and school pupils, helping them to go about their daily routines with ease and simplicity.

For more posts visit

Like us on facebook

Mail us your queries & doubts on

What if aircraft door opened in mid flight?

What if aircraft door opened in mid flight?

Image from:- Wikimedia

Just think about it? what if aircraft door opened in mid flight?

First of all it is not Possible!
As we know air pressure decreases as we go higher. Air pressure inside aircraft cabin is maintained so that passengers won't face any kind of problems due to low pressure. There is a huge pressure difference inside and outside of the cabin. Aircraft doors are fixed from the inside. Air inside aircraft cabin applies internal pressure force on the door. And that's really a very massive force. And its not possible to open aircraft door.

Now consider hypothetical situation, some miracle happened & aircraft door opened in mid flight.

Due to high air pressure difference between aircraft cabin & atmosphere, everything near Aircraft door will suck out until pressure inside cabin becomes equal to atmospheric pressure.

Image from:- Wikimedia

Something like this happened in 1988, an Aloha Airlines flight Boeing 737 with 90 people on board was on route to Honolulu, cruising at an altitude of 24,000 feet, when a small section of the roof ruptured. Rapid decompression caused large section of roof tore off & flight attendant Clarabelle Lansing was sucked out of it. But all passengers were safe.

10 June 1990 British Airways Flight 5390,
Pilot Tim Lancaster was sucked out of aircraft as windshield of the aircraft broke. Check out the video for full story.

Also if aircraft door opened in mid flight temperature inside aircraft cabin will drop at massive rate. Amount of oxygen in aircraft cabin will drop.

But don't worry as I said earlier it is not possible that aircraft door will open in mid flight!

Thanks for reading!

What happens when Lightning strikes an aircraft?

Lightning strike on Aircraft

Aircraft lightning strike
Aircraft Lighting strike: - Wikimedia

Imagine you are in flight. And suddenly weather turns stormy. A lightning bolt struck on your aircraft. What will happen? Will you aircraft blast and crash?

Lightning is just electric current with a massive amount of energy. Lightning can be 5 times hotter than the surface of the sun. Lightning contains 5 billion joules of energy. And such massive energy containing bolt of lightning struck on your aircraft. But no need to fear. Today's aircraft can survive a lightning strike. Every aircraft experiences lightning strike at least once a year. Things which you will experience is just bright light and loud noise.

Pan Am flight 214 Boeing 707
Pan Am flight 214 - Wikimedia
But on 8th December 1963, Lightning struck on Pan Am flight 214(Shown in the picture above). And this flight with 81 on board crashed near Elkton, Maryland. This crash killed all 81. Actually what happened was lightning stricken on the fuel tank of the aircraft, causing burning of the fuel and wing broken. Aircraft lost its control. So after that incident aircraft, fuel tanks are protected by thick layer so lightning cannot damage it.

(Pan Am flight 214 Crash)
Pan Am flight 214 Boeing 707 crash
Pan Am flight 214 crash - Wikimedia
There are many modifications in today's aircraft. Today aircraft are manufactured in such a way that they can survive a lightning strike. Do you know even Aircraft itself produces lightning when it travels through clouds?

Static electrical buildup due to the friction between air and surface of the aircraft. The air friction separate electrons from atoms. It is same as rubbing balloon produces a static charge. Hence, the static wicks are used which provides pointed structure where air flow leaves aircraft surface. And additional charge flows away from the aircraft into the air.

Aircraft static wicks
Aircraft Static wicks - Wikimedia
Aircraft are mostly made up of Aluminum & its alloy. Aluminum & its alloys are a good conductor of electricity. Lightning usually strikes on the extremity of aircraft such as nose & wing tips.  So when Lightning strikes on aircraft it travels through conducting a body of aircraft. And continues to air.

Modern aircraft are made up of non-conducting material Carbon Fibre. So when Lightning strikes on such material this material resist current from flowing through it. And such massive electrical energy of lightning gets converted into heat energy & material burns. Hence such material is embedded with conducting material such as Aluminum. So when Lightning strikes, it flows through this material & protects aircraft from burning. This principle is same as that of Faraday's cage.

To protect aircraft electrical circuits from lightning, Aircraft circuits are grounded. Also, surge suppression device is used for protection.

So don't worry about a lightning strike on Aircraft while traveling in stormy weather.

Check out: - How are Airbus planes named?

Source: - Boeing

How does stealth technology work? (Stealth Technology behind B2 Spirit)

Stealth technology

Image from: - Wikimedia

RADARs are used to detect aircraft. But there are some aircraft which are designed in such a way that they get ignored by RADAR. Those aircraft are known as stealth aircraft. Those aircraft are not actually invisible but they are somewhat ignored by RADAR.

But how stealth aircraft get ignored by RADAR?

In my previous post, I told about how RADAR works? 
RADAR uses reflection & Doppler effect (Doppler shift) property of Radio waves to detect aircraft. Radio waves after reflection from aircraft go back to the RADAR receiver. If we modified our aircraft in such a way that after reflection, Radio waves won't reach back to Radio receiver of RADAR Then our aircraft will remain undetected.
Stealth aircraft do something like this only to remain undetected!

Let's talk about world's most expensive stealth bomber aircraft B2 Spirit & stealth technology behind it.
B2 spirit is most expensive stealth aircraft in the world. The production cost of 1 unit of B2 spirit including its designing, engineering, etc. is $2.1 billion.

Check out Cool B2 Spirit model kit on Amazon!

B2 Spirit Model kit - Amazon

Stealth technology behind B2 Spirit

B2 Spirit - Wikimedia

All the parts of B2 spirit are blended. So that this aircraft reflects the very little amount of Radio waves.
For maneuverability, this aircraft has two pair ailerons. One for normal flying & other for stealth flying. So that in a case of stealth flying reflection due to ailerons will be less.
Wings of the B2 Spirit are designed in such a way that whatever Radio waves aircraft will reflect back they will go away from Radio receiver of RADAR. Wings are angled backward.
The surface of B2 Spirit was coated with an alternate high-frequency material (AHFM). This material absorbs some amount of radio waves striking on aircraft.
The combination of these all features B2 spirit is low observable. B2 spirit is not 100% ignored by RADAR. But a number of Radio waves reflection is very low. Hence less observable.

Check out Cool B2 Spirit model kit on Amazon!

B2 Spirit Model Kit - Amazon

For more posts visit

Like us on facebook

Mail us your queries & doubts on

How RADARs are used to detect an aircraft?

How RADARs work?

Image from:- wikimedia

RADARs are used to track an aircraft. RADAR stands for RAdio Detection And Ranging. Radio waves are used in RADAR for detection purpose. Radio waves are electromagnetic waves. Mainly two properties of radio waves are used for detection purpose. One is reflection property and other is doppler effect.
Let's discuss about these two properties of Radio waves!

Radio waves reflect back when they come in contact with any obstacle. It is same as reflection of sound waves. Echo is the best example for reflection of sound waves. Sound waves produced by sound source will reflect back when they collapse on obstacle kept in front of them. In this case we will hear an echo. Sound waves & Radio waves are completely different wave forms. But property of reflection is same in both the cases. Of course you cannot hear Radio waves. Then how can we find that radio waves are reflected back?
Transmitter of RADAR will transmit Radio waves. And receiver of RADAR will detect the reflected Radio waves.
In such a way Aircraft can be detected by using reflection property of Radio wave. Radio waves will reflect back from aircraft. Reflected waves are detected by Radio receiver. According to amount of radio waves received & time taken for reflection even type of aircraft can be detected.

Now we have detected that aircraft is flying! What about its speed? How can we obtain its speed?
For that second property of Radio waves i.e. Doppler effect(doppler shift) is used.

Doppler Effect
Speed of aircraft can be obtained by this property of radio waves. When radio waves collapse on fixed obstacle (obstacle which is not moving) radio waves will simply reflect back without any change. But when radio waves collapse on moving object, the frequency of radio waves will change according to motion of an object. If object is moving towards the RADAR, Frequency of Radio waves reflected back will increase. On the other hand if object is moving away from RADAR frequency of  Radio waves reflected back will reduce.
So based on change in frequency of radio waves computer automatically detects the speed of an Aircraft.

In such a way using two properties of Radio wave Aircraft can be detected.

For more posts visit

Like us on facebook

Mail us your queries & doubts on

Aircraft into Space?

Aircraft into Space?

Aircraft into Space?

In my previous post, I mentioned that escape velocity is the maximum velocity of aircraft within earth's atmosphere. Escape velocity is minimum velocity required for any object to leave planet's atmosphere. On our earth 11.2 Kmps or 32 mach is escape velocity for any object.

When aircraft flies, its the earth's gravitational pull which keeps aircraft in earth's atmosphere. So aircraft can't go straight into space. Earth's gravity will pull aircraft into circular path as aircraft don't have much energy to escape from gravitational pull. So if we provide our aircraft energy to escape from earth's gravity our aircraft will leave earth's atmosphere. So we provide aircraft this energy in terms of kinetic energy.

Kinetic Energy= 1/2(mv^2)
M= mass of aircraft
V= Velocity of aircraft

Gravitational potential energy to leave earth's gravity= (Gm)/R - 0
G= Universal gravitational Constant
m= mass of earth
R= distance of aircraft from earth's centre.

(Gm/R is gravitational potential energy on earth's surface, 0 is gravitational potential energy at infinity (here, at infinity R becomes infinity so (Gm)/R becomes zero)

So, we will provide same energy to our aircraft which any object will have at infinite distance from earth.


1/2(mv^2) = (Gm)/R

So, velocity becomes

V= sqrt[(2Gm)/r]

So here, V is known as escape velocity which any object should have to  leave earth's atmosphere.
For earth it is 11.2Kmps or 32 Mach.

At such a high speed it is not possible to keep aircraft in earth's atmosphere. So what if we tried to keep aircraft in earth's atmosphere by turning aircraft nose down?

At present we use elevator to turn aircraft nose up & down.  if we use  elevator to turn aircraft nose down air impact will produce massive force of more than 11200N on elevator which will probably break elevator. Suppose if we make very strong elevator which can withstand such a massive force then is it possible to stay in earth's atmosphere at speed of escape velocity?
My answer is No!!
Because suppose aircraft is flying with speed exactly equal to speed of escape velocity & if we turn down aircraft nose using  elevator it will produce resistance to airflow & reduce speed of aircraft less than escape velocity.
If speed of  aircraft is little bit equal to or greater than escape velocity then aircraft will leave earth's atmosphere!!

Conclusion:- Escape velocity is maximum velocity of aircraft on earth!!!