Slitherine

quote:

ORIGINAL: Dixie

quote:

ORIGINAL: Apollo11

Hi all,

Few questions for Martin and the rest of you guys...


Why modern civilian aircraft still rely on pitot tubes and static ports for speed readings (IAS, TAS) and altitude?

Was there any civilian aircraft that used radar as a tool to measure speed over surface and altitude?

Why aren't modern GPS devices used as (backup) speed indicators and altitude in civilian aircraft?


Leo "Apollo11"


P.S. [Edit]
Fixed sighted typos.

As well as what the other guys have posted I'll try and add in a little of what I know, but pitot statics and the like are avionics based and I've only had a very basic training in that area. Plus I've not worked on anything except 1960s/70s airliners

GPS cannot give you your true airspeed, in theory an aircraft flying into a big enough headwind could have a groundspeed of 0mph across the earth but an effective airspeed of Mach 1. An aircarft's speed is best desribed as the rate of airflow over the wings and using pitot pressure is the best way to do it. In a similar idea to the first point, an aircraft with a strong enough tailwind could in theory stall due to a lack of airlow across the wings even though it's being pushed along at several hundred miles an hour.
I believe that radio altimeters were used on aircraft that were expected to fly low and fast, that's probably the closest you'd get to a radar based height detection system.

quote:

ORIGINAL: HMS Resolution

In about fifteen hours, my girlfriend and I will be heading up to Traverse City. I should not be this excited about going to Traverse City.

I feel like I'm Han Solo, and you're Chewie, and she's Ben Kenobi, and we're in that bar.
Member Texas Thread Mafia.

Sig art by rogueusmc

quote:

ORIGINAL: Dixie

quote:

ORIGINAL: AW1Steve

quote:

ORIGINAL: Dixie

Evening chaps.  My head hurts   I managed to smash it on an engine cowling (again) 8 hours ago   

Oweeeeeeeee! Have some beer! Beer , single malt scitch and duct tape can fin almost anything! But not in that order!

I don't drink. And cocodomol isn't helping Never mind, I'll just sleep it off and feel better in the morning

quote:

ORIGINAL: Dixie

quote:

ORIGINAL: AW1Steve

quote:

ORIGINAL: Dixie

Evening chaps.  My head hurts   I managed to smash it on an engine cowling (again) 8 hours ago   

Oweeeeeeeee! Have some beer! Beer , single malt scitch and duct tape can fin almost anything! But not in that order!

I don't drink. And cocodomol isn't helping Never mind, I'll just sleep it off and feel better in the morning

I feel like I'm Han Solo, and you're Chewie, and she's Ben Kenobi, and we're in that bar.
Member Texas Thread Mafia.

Sig art by rogueusmc

quote:

ORIGINAL: AW1Steve

quote:

ORIGINAL: Dixie

quote:

ORIGINAL: Apollo11

Hi all,

Few questions for Martin and the rest of you guys...


Why modern civilian aircraft still rely on pitot tubes and static ports for speed readings (IAS, TAS) and altitude?

Was there any civilian aircraft that used radar as a tool to measure speed over surface and altitude?

Why aren't modern GPS devices used as (backup) speed indicators and altitude in civilian aircraft?


Leo "Apollo11"


P.S. [Edit]
Fixed sighted typos.

As well as what the other guys have posted I'll try and add in a little of what I know, but pitot statics and the like are avionics based and I've only had a very basic training in that area. Plus I've not worked on anything except 1960s/70s airliners

GPS cannot give you your true airspeed, in theory an aircraft flying into a big enough headwind could have a groundspeed of 0mph across the earth but an effective airspeed of Mach 1. An aircarft's speed is best desribed as the rate of airflow over the wings and using pitot pressure is the best way to do it. In a similar idea to the first point, an aircraft with a strong enough tailwind could in theory stall due to a lack of airlow across the wings even though it's being pushed along at several hundred miles an hour.
I believe that radio altimeters were used on aircraft that were expected to fly low and fast, that's probably the closest you'd get to a radar based height detection system.

I'm not sure that a tailwind could cause an aircraft to stall, as it's still generating lift (airflow) do to forward momentum. Any more than the B-29's over Japan stalled when encountering jet streams from behing that nearly doubled their speed. Or fell when they entered jet stream and were actually flying Backward! It's all lift.

Bigger boys stole my sig

(in reply to AW1Steve)

quote:

ORIGINAL: AW1Steve

quote:

ORIGINAL: Dixie

quote:

ORIGINAL: Apollo11

Hi all,

Few questions for Martin and the rest of you guys...


Why modern civilian aircraft still rely on pitot tubes and static ports for speed readings (IAS, TAS) and altitude?

Was there any civilian aircraft that used radar as a tool to measure speed over surface and altitude?

Why aren't modern GPS devices used as (backup) speed indicators and altitude in civilian aircraft?


Leo "Apollo11"


P.S. [Edit]
Fixed sighted typos.

As well as what the other guys have posted I'll try and add in a little of what I know, but pitot statics and the like are avionics based and I've only had a very basic training in that area. Plus I've not worked on anything except 1960s/70s airliners

GPS cannot give you your true airspeed, in theory an aircraft flying into a big enough headwind could have a groundspeed of 0mph across the earth but an effective airspeed of Mach 1. An aircarft's speed is best desribed as the rate of airflow over the wings and using pitot pressure is the best way to do it. In a similar idea to the first point, an aircraft with a strong enough tailwind could in theory stall due to a lack of airlow across the wings even though it's being pushed along at several hundred miles an hour.
I believe that radio altimeters were used on aircraft that were expected to fly low and fast, that's probably the closest you'd get to a radar based height detection system.

I'm not sure that a tailwind could cause an aircraft to stall, as it's still generating lift (airflow) do to forward momentum. Any more than the B-29's over Japan stalled when encountering jet streams from behing that nearly doubled their speed. Or fell when they entered jet stream and were actually flying Backward! It's all lift.

I feel like I'm Han Solo, and you're Chewie, and she's Ben Kenobi, and we're in that bar.
Member Texas Thread Mafia.

Sig art by rogueusmc

quote:

ORIGINAL: bobogoboom

maybe you should start

i get to sit maybe 100yards from the b24 when it take off tomorrow. i figured that would make you head feel better

Bigger boys stole my sig

(in reply to bobogoboom)

quote:

ORIGINAL: Dixie

quote:

ORIGINAL: bobogoboom

maybe you should start

i get to sit maybe 100yards from the b24 when it take off tomorrow. i figured that would make you head feel better

Been there, done that. I was drifting away from drinking by the time I joined the RAF and I didn't miss it for my 9 weeks basic training. Since then I've drank (and been drunk) three times in 5 years.
What didn't help my head was the TIn Triangle taxying past, taking off and doing some low flypasts shortly after I hit my noggin

I feel like I'm Han Solo, and you're Chewie, and she's Ben Kenobi, and we're in that bar.
Member Texas Thread Mafia.

Sig art by rogueusmc

quote:

ORIGINAL: bobogoboom

depends if the aircrafts wing generates enought lift with the air flowing from behind. but at a cartian point if you were going as fast as the air flowing from behind then technicaly the wing wouldn't generate lift.......i think, my physics is a little rusty. ugg and i need to take another semester once i start college back up.

Bigger boys stole my sig

(in reply to bobogoboom)

quote:

ORIGINAL: Dixie

quote:

ORIGINAL: AW1Steve

quote:

ORIGINAL: Dixie

quote:

ORIGINAL: Apollo11

Hi all,

Few questions for Martin and the rest of you guys...


Why modern civilian aircraft still rely on pitot tubes and static ports for speed readings (IAS, TAS) and altitude?

Was there any civilian aircraft that used radar as a tool to measure speed over surface and altitude?

Why aren't modern GPS devices used as (backup) speed indicators and altitude in civilian aircraft?


Leo "Apollo11"


P.S. [Edit]
Fixed sighted typos.

As well as what the other guys have posted I'll try and add in a little of what I know, but pitot statics and the like are avionics based and I've only had a very basic training in that area. Plus I've not worked on anything except 1960s/70s airliners

GPS cannot give you your true airspeed, in theory an aircraft flying into a big enough headwind could have a groundspeed of 0mph across the earth but an effective airspeed of Mach 1. An aircarft's speed is best desribed as the rate of airflow over the wings and using pitot pressure is the best way to do it. In a similar idea to the first point, an aircraft with a strong enough tailwind could in theory stall due to a lack of airlow across the wings even though it's being pushed along at several hundred miles an hour.
I believe that radio altimeters were used on aircraft that were expected to fly low and fast, that's probably the closest you'd get to a radar based height detection system.

I'm not sure that a tailwind could cause an aircraft to stall, as it's still generating lift (airflow) do to forward momentum. Any more than the B-29's over Japan stalled when encountering jet streams from behing that nearly doubled their speed. Or fell when they entered jet stream and were actually flying Backward! It's all lift.

As I understand it, that wouldn't work too well. Aerofoils are designed to work in one direction, a helicopter's rotors won't work if they rotate in the wrong direction.

PS: I could be wrong, theory of flight was a long time ago and we all wanted to finish early so questions like this were left well alone Feel free to ask me one about engines though

quote:

ORIGINAL: thegreatwent

I think a greater issue is air density. Here in Colorado planes get in trouble when they just don't have the air they need to avoid stall speed.

Bigger boys stole my sig

(in reply to thegreatwent)

quote:

ORIGINAL: thegreatwent

Well I would rather ride in a Tupolev than an Airbus. Check out the flight records, Tups had less catastrophic failures, rather they had pilot error most times.

quote:

ORIGINAL: thegreatwent

Well I would rather ride in a Tupolev than an Airbus. Check out the flight records, Tups had less catastrophic failures, rather they had pilot error most times.

Bigger boys stole my sig

(in reply to thegreatwent)

quote:


IIRC, lift is generated by a wing because the shape makes air flow more slowly over the top of the wing than under it.

quote:

ORIGINAL: AW1Steve

Your all wrong! Magic fairys (Called "liffties") push on the wing and give it lift. And others called "Thrusties" push it forward.

" Gentlemen, you can't fight in here! This is the War Room. " President Muffley

quote:

ORIGINAL: JWE

quote:

ORIGINAL: gladiatt
Wow...i've just learned one of my collegue know a young couple among the casualties . The child of this couple is still in holliday with his aunt, and nobody told him what happend because nobody know how to do it.
Know, each time we ear a plane or someone talk about some plane, his eyes stare in the "empty" (sorry about bad english)....i feel pain for her, but how to give support??????

I am so sorry. I too have lost people. Light a candle; or maybe have a requiem Mass. Invite your friend, let them know you care, even if it's just the 2 of you. The priests won't care if you kneel or not, but it's a cathartic experience. Afterwards, you can talk about the things that need to be talked about. Hold them. Let them weep. To weep is to be human.

quote:

ORIGINAL: thegreatwent

Morning Gladiatt although I should be soon to bed :)