Thursday, December 8, 2016

Communications Assistance for Law Enforcement Act (CALEA)

Sunday, December 4, 2016

LMI2933 LAMIA AVRO RJ85 Medellín Deadstick

LMI2933 approach to SKRG.  The airplane position is plotted as a function of time (where it effectively flows to the left). The airplane initially arrived with conceivably enough fuel to complete the approach and landing safely.  The airplane entered a holding pattern and on the back side of the second circuit departed the holding pattern with apparently total engine failure.

Wednesday, November 9, 2016

Galloping Gertie

The Tacoma Narrows Bridge opened to fanfare in July, 1940 having been constructed over the previous two years as a Public Works Administration Project.  The bridge donned the name "galloping gertie" during construction, giving to its narrow profile and insufficient stiffness. The bridge famously collapsed on Nov. 7, 1940.

“Pence Plane” EA3452 Overrun

Wednesday, October 12, 2016

FCC 15.247 (c) 2 Smart Antenna Systems - Powering Line-of-Site Aeronautical Communications

The FCC issued Report and Order 04-165 on July 12, 2004.  The Smart Antenna System (SAS), capable of forming multiple antenna beams, forged a pathway to frequency reuse and ultimately powers the unlicensed air-to-ground networks being developed by SmartSky Networks and Gogo.  A review of the FCC 15-247 offers an understanding of an overall system architecture and performance estimates.

Wednesday, September 28, 2016

Using Unlicensed Spectrum for Air-to-Ground Networks

Gogo has announced an initiative to utilize unlicensed spectrum to power an new Air-to-Ground (ATG) network.  They profess a beam-forming network deployed to their 200 plus ground stations will deliver 100 Mbps.  I believe that it is possible both Gogo and SmartSky are pursuing a similar technology.  The following is my analysis on SmartSky, to which it may relate to Gogo ATG as well.

Monday, September 26, 2016

Bluetooth Low Energy - Guiding our Way in the Future

Bluetooth Low Energy (BLE) refers to a low power broadcast mode commonly referred to as a beacon (Bluetooth beacon, iBeacon).  BLE broadcast is a limited protocol intended to be received only by proximate user devices (less than 100 meters).  The beacon presents "effectively" a unique serial number.  An application can lookup the location of a beacon by its serial number.  An application can use the BLE beacon-derived position to trigger appropriate actions.

Saturday, September 24, 2016

Aircraft Tracking using ADS-B - We've come a long ways!

Automatic Dependent Surveillance - Broadcast, or ADS-B, is revolutionizing Air Traffic Control.  With some minor enhancements to the aircraft transponder, space-based ADS-B can become the cornerstone of an ICAO Autonomous Distress Tracking service, mandated for new aircraft starting in 2021.  Such an installation may also allow the removal of one of the required Emergency Locator Transmitters.   The use of satellite data link and navigation together with ADS-B are powering emerging Performance Based Navigation initiatives as well.
Aireon Space-based ADS-B

Wednesday, August 3, 2016

ADS-B Telemetry from EK521

Within minutes of the incident, published a time history of the ADS-B transponder transmissions from EK521.
REVISED with a closer look at the last 32 seconds and adding in position data.
REVISED with a summary plus a look at earlier arrivals wind effects
REVISED with the revelation that EK545, arriving ahead of EK521, had similar speed profile
REVISED with Boeing 777 procedures at end

Friday, June 24, 2016

Cybersecurity and Phased Arrays - PP848 and PP792

The Ku/Ka satcom subcommittee met the last two weeks to progress the latest AEEC standards and characterstics defining secure broadband connections and satcom equipment.  Airbus expects to use PP848 for securing non-safety communications, bringing an unexpected urgency to completion of IPSec end-end functional definitions. PP848 will offer an optional means to segregate both passenger and non-safety aeronautical communications with a commercial broadband radio, such as Ku/Ka satcom.  PP792 builds upon ARINC 791 to characterize emerging flat-panel antennas, especially phased array antennas, as well supplier-specific guidance for installing antenna systems using either 791 or PP792.

Wednesday, June 8, 2016

Aviation Data Link - Security, Segmentation, QoS

Beginning in 1978, aircraft data link emerged using a VHF network named ACARS (Aircraft Communication, Addressing and Reporting System).  ACARS is a purpose-built, store-and-forward, character-based, messaging service.  Within just over ten years, ACARS was extended to Inmarsat L-band satcom and HF radio.  Five years later (1995) ACARS was delivering Air Traffic clearances. Today Iridium SBD (short-burst data) and even cellular radios communicate ACARS messages. How is the industry migrating to embrace and secure IP networks, and will ACARS ever go away? How are broadband radios being applied to support airplane health monitoring or EFB?

Saturday, May 21, 2016

Air Safety Investigation

The first and foremost response to any incident is rapid rescue and for sympathy to victims, survivors, and those that loved them.

Timely alerting and accurate aircraft position is the key to rapid response.

Moving beyond rescue becomes recovery.  At this point the motivation is to collect the remains of those lost and as much of the airplane itself.  Assembly of the airplane parts into a skeleton gives a foundation to check and verify various failure scenarios.

Regardless of the cause of catastrophe, airplane structure and systems are designed to be fault tolerant.  Crash survivability is a paramount endeavor.  Materials are evaluated for their contributions to post-crash fire and smoke.  While the first objective is to understand what led to the catastrophe, just as important is to understand what can be improved to enhance prevention and survivability.

Thursday, May 12, 2016

Friday, April 22, 2016

Aero Antennas: Bigger is Better!

ThinKom and QEST are both promoting Ka-band flat panel antennas that use about a 25" aperture for receive.  ARINC 791 provisions can support at least a 30" aperture, as shown by Gogo with 2Ku.  Should a Ka antenna be built as big as possible, or is there any size that is "big enough"?

As time moves forward, will service levels going up (due to evolving user behaviors) outrace the cost of services going down (due to expanding capacity and lower costs to launch capacity)?

How valuable will a larger antenna be if trends run away from expectations?

Monday, April 4, 2016

It Takes a Village

Delivering a consistent Internet experience to an airline passenger demands adequate provisioning for the peak periods (highest contention ratios).  It may take many satellites with overlapping coverage to aggregate sufficient capacity to meet the demands in any "hotpot".

Tuesday, March 29, 2016

Show Me the Gbps: When 1 + 1 > 2

Some airlines offer passengers connectivity for free, others make the passengers pay, and in the end most will offer a mix of free and pay services.  Will the airplane radio be able to meet the needs of the passenger?  What about the radio network?  How will that evolve over the next ten years?  This feasibility analysis takes a look at the US market to reveal the technical requirements for a satellite network to meet the demand from a "typical" large US airline and from four such large US airlines.

Both Ku-band satellites and Ka-band satellites can serve any foreseeable airline passenger connectivity market.  Because of concentrated demand, a single large US airline under the heaviest demand cannot be served from a single orbital slot by 2026.  It takes a family of orbital slots with satellites offering overlapping coverage to aggregate the spectrum needed at the busiest airports.  A family of satellites offers a robust and scalable solution to grow as demand grows, applying the newest technology incrementally along the way.

Tuesday, March 22, 2016

Average Data Rate and Usage - Use Cases

Every Internet access session is a unique experience generating a unique amount of usage (as measured broadly in MBytes). Light, average, heavy and future make up four categories. For each usage scenario, there are three use cases: all streaming, all Internet access, or split evenly between the two. The session duration and the amount of time off-line is another dimension. A short session will have less off-line time than a longer session.

Monday, March 7, 2016

Satellite 2016 - Day 1

Software defined payloads, beam-forming arrays, and unfurling antennas are just a few of the technologies to power the digital satellite revolution.  The challenge is to reach a price point that is competitive with terrestrial alternatives and with enough capacity to serve the addressable markets.

Wednesday, March 2, 2016

Reflecting on the Boeing 727

The first flight of the Boeing 727 began with a center-engine surge after takeoff.  It settled down quickly.  In any case, the tail-mounted configuration made engine-out handling much easier than wing-mounted engines. The outer leading-edge slats got stuck deployed (symmetric) as the aero loads overwhelmed the actuator.  It was going to take more than a few hiccups to keep Lew Wallick and his crew from two plus hours inflight, including landing configuration stalls, using flaps 40, using less than 2000 feet of ground roll in the first landing - and a big thumbs-up!  The first flight was on Feb. 9, 1963, fifty three years ago. I was almost five years old, living about 150 miles north in Vancouver and completely oblivious.  Yet my own personal first flight would be on a 727 just six years later.

Sunday, February 28, 2016

Beam Hopping, Beam Forming, Frequency Reuse, and the Quest for Maximizing Satellite Throughput

Satellite communication is amazing in so many ways.

Start with launching a machine into space and expect it to operate precisely while managing to harvest solar energy and hold attitude and position.

Add to the mix operating at frequencies that frankly are absurd.

Wide-band transponders got us this far, but their utility now is just a gateway to the future of spot beams.

Spot beams are formed by higher gain antennas with smaller beam widths than continental wide beam transponders.  The beam width is a function of aperture and of frequency.  A given aperture delivers a smaller beam width with higher frequency.  A given frequency delivers a smaller beam width with a bigger aperture.

The last piece of the puzzle is the part that is in play, that of how to switch the information between the beams, and how many beams can you use?

Friday, February 26, 2016

A Broadband User Average Throughput is 150 kbps, not 25 Mbps

The following are all clipped excerpts driving the point that a good broadband experience averages only 150 kbps...the contended data rate...not the headline "advertised rate of 25 Mbps.

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