Thursday, November 15, 2018

737 MCAS - Failure is an Option

The 737MAX introduced a new feature, Maneuvering Characteristics Augmentation System (MCAS). MCAS commands the stabilizer to trim down (only while flaps are up) in steps.  From reports, the aft column cutout switch is disabled while MCAS is active.  MCAS commands nose down trim at 0.27 deg/sec for about 10 seconds at a time. It then pauses briefly (duration not known, but presumed five seconds).  The time history of a fabricated scenario, starting at a stabilizer position of 8 units, shows it would take about 55 seconds to reach the nose-down limit (starting at a more nose down position would take less time).

MCAS Commanded Stabilizer Trim Without Stopping

Monday, November 12, 2018

Stabilizer Trim

LionAir JT610 plunged into the sea from what may have been the result of runaway stabilizer trim.  The details are not released, but the FAA has issued an Airworthiness Directive drawing attention to the recovery from such an event.  What is stabilizer trim and why would it runaway?

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/83ec7f95f3e5bfbd8625833e0070a070/$FILE/2018-23-51_Emergency.pdf

Saturday, October 13, 2018

Coverage Along a Route - Europe

Airlines flying routes connecting European airports fly far enough north to limit satellite elevation to less than 45 degrees. Installing a Ku/Ka band satellite antenna in the Airbus-nominated position for A320 series creates a blockage from the tail (shadowing) that can extend more than 30 degrees in elevation and about 4 degrees wide. This combination can lead to loss of service when the airplane is flying directly away from the servicing satellite. The problem is made worse by using satellites that are not well situated.

Friday, October 12, 2018

Close Calls Coming (TG679) and Going (IX611)

ADS-B OUT data broadcast coupled with machine learning can create a great enhancement to aviation safety. Flight Operations Quality Assurance (FOQA) was conceived as an anonymous means to reveal unsafe trends. The post-flight evidence would guide training and awareness, not personal vendetta. With ADS-B, the alerting can be done in real-time; the trends recognized as they are occurring.

IX611 Takeoff normal (A) and accident (X)

Friday, September 28, 2018

Using True Time Delay to Increase Instantaneous Bandwidth in a Phased Array Antenna

The progression towards High Throughput Satellites is enabled by frequency reuse using larger and larger bandwidth signals.  Bandwidths exceeding 100 Mhz are commonplace, with 250 MHz and larger bandwidths evident. A phased-array antenna belies the concept of using phase control to form a beam (or inherently, steer the beam electronically.) 

Tuesday, September 25, 2018

APEX 2018 Midway Report

APEX EXPO 2018 got started a day earlier than I expected.  My report from the first two days looking at VR headsets, satcom partnerships and agreements, seeking profit, and emerging technology.

Thursday, September 20, 2018

Panasonic adds Inmarsat GX to the Routing Table

Panasonic and Inmarsat have jointly announced an agreement to work together.
  • Panasonic will offer Inmarsat as their exclusive Ka-band satcom supplier
  • Panasonic will continue to operate and grow their Ku-band network 
  • Inmarsat will be able to bundle in Panasonic IFE and support as a part of their offerings
  • Panasonic and Inmarsat will jointly develop a new Inmarsat GX terminal
"Customer airlines will be able to select a product that represents the best that Inmarsat and the best that Panasonic offer together" declared Ian Dawkins, Panasonic Senior VP of Network Operations. "This is far more than a simple reseller agreement." 

Thursday, June 7, 2018

Aviation Cybersecurity 101

Thanks to Woodrow Bellamy III and Mark Holmes for inviting me to present at the Global Connected Aircraft Summit 2018.

Here is my slide deck (with notes). I have revised and added a slide to address how an iPad can host type B EFB messages.

Monday, April 30, 2018

Lion Air PK-LOO JT-892 Departed runway after touchdown

Joining final approach very late may have contributed to a Boeing 737-800 departing the runway 27 at GTO/WAMG Gorontalo Jalaluddin Airport in Indonesia at about 18:35:30L (10:35:30Z).


Monday, February 26, 2018

Seamless Air Alliance - Who Owns the Customer?

Delta, Airbus, OneWeb, Sprint, Airtel, and Gogo announced the formation of the Seamless Air Alliance.  

Equipment, certification, satellite coverage, billing and overall service is included as a one-stop offering.

A participating airline picks parts from a catalog, installs per a cookie-cutter, turns it on, and the passengers connect to the Internet.

Friday, February 9, 2018

Malfunction in an Aero Ku/Ka-band Satcom System

Ku/Ka-band Satcom Systems offer no safety functions. 

No failure of the satcom system should create an unsafe effect.

Users of the satcom system do so at their own peril, as they would with any Internet access provider.

Discovery of cybersecurity vulnerabilities should emphasize rapid response to close the threat and a cooperative approach to sharing information privately, with an agreement to share enough information publicly to raise awareness of best practices.

Details and a checklist in the following paper.

Sunday, January 28, 2018

PP792 Mark 2 Satcom Advanced Features

PP792 defines the form and fit characteristics of the Mark II Aviation Ku-band and Ka-band Satellite Communication (satcom) System, intended for installation in all types of commercial air transport aircraft. The satcom system described in PP792 represents the next evolution from the Mark I system defined in ARINC Characteristic 791, Part 1.

Significant advancements include:
  • Single, standard installation, no customization, fully interchangeable
  • Smaller: no KRFU, Virtual APM
  • Lighter: smaller connectors, fewer wires, no hyper-critical wiring, coax, or waveguide
  • Flexible lug pattern accommodates two apertures, each up to 42"
  • High power supply (2000 Watts) for large, solid-state, phased-array antennas
  • Integrated Position, Attitude and Heading sensor
  • High performance IF interface supporting NGSO networks

Thursday, January 11, 2018

10 Years Later - Still Standardizing Aero Ku/Ka Satcom

With a two hour telecon in Jan 2008, the SAE/ITC AEEC Ku/Ka-band Satcom Subcommittee started to work together.  What ever happened?

10 years and 122 gatherings later, we are still at it!  Here we are today @ThinKom_Inc.

Tuesday, January 2, 2018

Regulating Radiated Emissions

https://transition.fcc.gov/Bureaus/Engineering_Technology/Documents/bulletins/oet56/oet56e4.pdf
Equipment installed on aircraft must be designed and tested to be compatible with other equipment and with the airborne environment.  Notably, radio frequency (RF) radiated emissions from one system may disrupt other aircraft systems such as radio receivers or present hazards to human health.