Lockheed Connie was an efficient airliner

[fdcg27]

Clue us in.
None of that stuff would be classified now, in an age where a hundred buck smart phone has more capability then anything installed in that vintage Boeing.
Well, that AF1 would have at least had INS over any cell handset, but that's pretty much obsolete these days.

 

[Astro14]

INS is far from obsolete. In many areas, it is essential. In many operational scenarios, it is essential.

 

[fdcg27]

You'd certainly know better than I.
In what areas or operational scenarios would INS be essential?
Are any current airliners delivered with it?
I had thought that these costly systems were mainly a thing of the past in an age of GPS.
As backups in mission critical applications like AF1, sure, but anywhere else?

 

[BusyLittleShop]

Originally Posted By: MolaKule


If you only knew about the plethora of avionics and classified electronics in that plane you would be even more impressed.


I was impressed... I got the full tour on board Balls 26 when I was stationed at Norton AFB...

 

[Astro14]

Originally Posted By: fdcg27
You'd certainly know better than I.
In what areas or operational scenarios would INS be essential?
Are any current airliners delivered with it?
I had thought that these costly systems were mainly a thing of the past in an age of GPS.
As backups in mission critical applications like AF1, sure, but anywhere else?


GPS coverage, and accuracy, varies with the constellation visible. So, in mountain canyons, it can degrade to the point that it's unsuitable for use in aircraft navigation. One of our required checks before flying a GPS-based approach, is the RAIM (Receiver Autonomous Integrity Monitoring) prediction for accuracy. It has to be "good enough" to fly the approach.

So, a perfectly functioning GPS constellation, may not meet accuracy requirements for aircraft navigation.

That's why every new airliner built has a triple ring-laser gyros. ADIRU is the vernacular on an Airbus (each is integrated with an air-data unit). They provide both platform (attitude and heading reference) and dead-reckoning position to the flight management system.

Further, we can fly a non-precision approach using only INS data for position...as long as it meets accuracy requirements. TEH FMS will use GPS, ILS ranging (if available) VOR ranging, ILS ranging, VOR bearing, and dead-reckoning to calculate the aircraft position. GPS is merely one input. A good one.

But not perfect.

It's not hard to imagine a scenario in which conflict with a major power, one capable of space denial, would result in destruction of sufficient elements of the GPS constellation that GPS would no longer work. Simply: the US cannot allow the GPS constellation to be the single point of failure that causes us to lose a war.

China, for example, was sending a very clear message in 2007 when they shot down their own satellite. Pundits and newscasters couldn't understand why the Chinese would fill low earth orbit with debris, which increased navigation challenges with increased chances for collision...

But people who were paying attention got the message: China can hold earth orbit assets at risk. In a conflict, they could deny the use of space, which includes GPS...and communications... A very, very serious and unambiguous statement.

China claims that their military exists only for defense. Whether or not you accept that statement, in a defense of China scenario, China has stated that they are willing to use all available options to defend their homeland.

Whether you operate an airplane, or are planning military contingencies, you would be a fool to ignore a "world without GPS" scenario.

 

[MolaKule]

Originally Posted By: Astro14
Originally Posted By: fdcg27
You'd certainly know better than I.
In what areas or operational scenarios would INS be essential?
Are any current airliners delivered with it?
I had thought that these costly systems were mainly a thing of the past in an age of GPS.
As backups in mission critical applications like AF1, sure, but anywhere else?


GPS coverage, and accuracy, varies with the constellation visible. So, in mountain canyons, it can degrade to the point that it's unsuitable for use in aircraft navigation. One of our required checks before flying a GPS-based approach, is the RAIM (Receiver Autonomous Integrity Monitoring) prediction for accuracy. It has to be "good enough" to fly the approach.

So, a perfectly functioning GPS constellation, may not meet accuracy requirements for aircraft navigation.

That's why every new airliner built has a triple ring-laser gyros. ADIRU is the vernacular on an Airbus (each is integrated with an air-data unit). They provide both platform (attitude and heading reference) and dead-reckoning position to the flight management system...

The RockwellCollins NAV system (as do many others) updates the NAV database when GPS is visible.

When GPS is not available, the system defaults to INS and the INS provides updates from the last known GPS position, and then updates the navigational database from that point on until GPS comes back on line.

 

[fdcg27]

Thanks to you and Astro for the education.
I guess I'm stuck in the light piston world, where we had for navigation without following the airways first the expensive RNAV and later LORAN and finally GPS.
If you don't need legal IFR capability, GPS is pretty foolproof and you can probably navigate with your phone.
There's an app for that. LOL!

 

[CT8]

From 2003 until 2008 the most fun I have ever had is when my was a boy Scout . The Scout Master was a back seater in an F4 and the troop was well trained in navigation

These Scouts were more at home in the wilderness than at home. we logged 31 days a year under the stars.Snow camping was freezing !!!

 

[billt460]

No Lockheed Constellation thread would be complete without a flaming twilight takeoff! Here it is:

 

[BusyLittleShop]

Don't you miss the days filled with blapty blat blat receps spitting flames???

Rare Bear's modified 3350...

 

[JetStar]

Originally Posted By: BusyLittleShop
Don't you miss the days filled with blapty blat blat receps spitting flames???

Rare Bear's modified 3350...


Nice! Whats the white smoke at the tail during the final taxi and shutdown? Crankcase vent?

 

[BusyLittleShop]

Originally Posted By: JetStar


Nice! Whats the white smoke at the tail during the final taxi and shutdown? Crankcase vent?


Not crankcase venting... Rare Bear sports a new drag reducing boil-off oil cooling system which produces a steady stream of vapor from the tail cone...

 

[JetStar]

Interesting!