My opinion about displaced thresholds and landing

Most of my friends who are pilots will not touch down prior to a displaced threshold.  Even if it means leaving more than 3,000 feet of runway behind them.  Runway 31 left at JFK is a good example.

 I recall my very first flight instructor repeating the axiom of the three things a pilot cannot use.  They are the altitude above you, the gasoline in the gas pit and the runway behind you.
There is no regulation that prohibits landing touch down prior to the displaced threshold. Most pilots apparently believe there is one.  I personally, have touched down prior to many displaced thresholds at many different airports in the USA.

My opinion about touching down prior to a displaced threshold had its beginnings many years ago.  I was awaiting departure on runway 31 left at JFK when I watched a British Airways Lockheed L-1011 take off.  Shortly after lift off, he announced he had an engine failure and declared an emergency.  The weather at the time was 5,000 feet overcast with light drizzle.

He proceeded to fly a left down wind leg to runway 31L which has a marked displaced threshold 3,324 feet from the end of runway 31L.  He touched down well beyond the displaced threshold at about point I estimated to be 5,000 feet from the end of the runway.  I watched as he applied the brakes and smoke began to emanate from them early in the landing roll.  Apparently he was landing at a weight in excess of maximum landing weight.

He was successful in stopping just before he reached the end of the runway and turned off to go to the gate.  I thought sure I was going to be witness to an over run and possibly an accident and was much relieved as a result.  That incident started me to wondering why an airline pilot would leave so much good runway behind him in this situation?

After much discussion with my fellow pilots and thought, I concluded he was conditioned to landing beyond the displaced threshold without giving any serious thought about doing it.  This conditioning occurred as a result of observing so many pilots doing that every day.  If you go out to JFK today and runway 31L is the active landing runway you will get a chance to watch pilot after pilot doing the same thing.

One of my first considerations was to ask the question "Why is the runway 31L threshold displaced for landing?  The answer is for noise abatement reasons.  Isn't noise abatement supposed to take a back seat to safety? Of course it is.  I also discovered in my research the present displaced threshold was put in place many years ago prior to the present much quieter jet aircraft being placed into operations.

See Part II above.

Google Analytics is working on the Blog

Well, my big effort to get Google Analytics to function with my Blog site was successful!
It sure delivers a lot of information concerning traffic to it.  As a result, I have decided my site is mostly ready to go public.  If you have any suggestions as to how it may be improved, please let me know.
Thanks!
Dick

Installed Google Analytics

I spent all evening installing an application called Google Analytics.  This application is designed to help me track my website traffic. It was not easy.  It took me more than 5 hours and the use of two computers and required printing 21 pages of text. Sure hope it works....24 hours have to pass before I will know whether it works or not.
Wish me luck and I will report tomorrow whether it worked or not.

Part 6 WGS-84 Versus PE-90.02 update

As a result of questions I e-mailed to Eric Gakstatter the editor of the magazine GPS World I can update the previous posts. Here is the e-mail I sent him this afternoon.

I am a pilot instructor.  Could I trouble you for guidance on how to determine the differences in location that use of the WGS-84 ellipsoid versus PE-90 ellipsoid would result if using the the US SatNav satellites location information?

Many of the pilots who attend my training presentations are flying to Russia and the Commonwealth of Independent States.  As PE-90 is the ellipsoid used by the GLONASS satellites, what is the maximum difference in locations it the SatNav system is used while flying in Russia and the CIS?

Most of the pilots have been instructed to disable their GPS sensors while flying in countries not using the WGS-84 datum.  I think it may be time to reconsider this restriction due to the nearly identical PE-90 and WGS-84 datums as described in the paper by Misra, Abbot and Gaposchkin.

It states "The difference between the coordinates of points on earth in WGS 84 and PZ-90 has been found to be less than 15 m (average: 5 m). The two coordinate frames are brought substantially into coincidence by a small rotation (0.4") of the Z-axis of either. An additional improvement, though only slight, is obtained by displacing the origin by 2.5 m along the Y-axis of WGS 84."

This paper was written 10 years ago.  Are you aware of any updated papers on the subject of PE-90 versus WGS-84?

I was surprised by the promptness of his answer about 45 minutes later.  It said:

The last I checked, the GLONASS folks made a major adjustment to PZ-90 (named PZ-90.02) in 2007 (Sept. 20) to improve its alignment with ITRF00/WGS-84 to under a 1/2 meter (Delta X = -36cm, Delta Y = +8cm, Delta Z = +18cm) and then one or more minor adjustments since then. Offhand, I don't know the precise current relationship between the two. However, I just emailed a colleague in Russia who would know the current status and hopefully he will email me a technical paper you can reference.

From GLONASS scientists I've listened to and conversed with over the past few years, it is my understanding that Russia's intent is to bring GLONASS into precise alignment with ITRF/WGS-84, if they haven't done it already.
To sum up his answer, there is just one half meter difference between WGS-84 and PE-90.02 and in some parts of Russia it is less than 6 inches difference.

New Mandatory National Transportation Safety Board (NTSB) Reports

Effective March 8, 2010, the National Transportation Safety Board has added new mandatory reports.  This is the first significant change in about 10 years to Part 830.  One of these new reports covers loss of more than 50% of the multi-function displays. Included are the following: Engine Indication and Crew Alerting System loss, Primary Flight Displays, Primary Navigation Displays or other displays of this kind.

Colgan Air Pilots poorly treated by NTSB summary statements

The following statements are just my opinions.
I feel the National Transportation Safety Board (NTSB) recent release of summary statements treat the pilots poorly.
Could a three man crew have influenced the outcome?

Part 5 Integrity and Current World GPS status

The integrity of any radio signal a pilot uses may be more important than the accuracy of the signal.  As we operate in a "safety of life" enviornment it is imperative we become aware as soon as possible when ever the signal becomes unreliable or is  lost.

Prior to augmented GPS signals being available, we relied upon the GPS receivers built in Receiver Autonomous and Integrity Monitoring (RAIM) and Fault Detection and Exclusion (FDE) to supply warnings.  These warning may take as long as 10 minutes before it is delivered to the pilot.  This is not acceptable for most of our operations.

Both Ground Based Augmentation Systems (GBAS) and Satellite Based Augmentation Systems (SBAS) are able to warn the pilot with almost no time delay. It should be clearly apparent to the pilot the superior advantage of having an augmented signal. As the WAAS capability does not add to the cost of the receiver, I am astonished how few corporate aircraft are equipped with it.

Many older airliners are still not equipped with GPS, let alone WAAS GPS as there is no regulatory requirement to do so. The superiority of the GPS signal to provide navigational information should insure that it is installed on all aircraft. The increased integrity of the augmented signal along with the increased accuracy also should insure it is installed on all aircraft.

I have been suggesting that all pilots carry their own personal battery powered portable GPS receiver to cover the possibility of encountering an event where the loss of the aircraft's GPS receiver happens. A GPS has the ability to deliver us aircraft ground speed. In the event of the loss of pitot and static instruments or loss of indicated airspeed information, you can apply and wind speed estimate and use the ground speed as a substitute for indicated air speed.

If the GPS receiver has at least 4 satellites in view, it will calculate our altitude giving us a chance to substitute for our altimeters.  The GPS will also calculate the aircraft track angle and update that information at least once per second.  This will permit us to use the GPS for turn information as well.

Have you ever viewed the GPS calculated altitude in your aircraft?  Does the Flight Management System (FMS) on your aircraft permit you to view the GPS calculated altitude?  Most FMS systems will allow you to view it on the sensors page but some older units do not allow it. Assure your self you have the ability to view it and you know how to access it.

Back in 1996, an Aero Peru Boeing 757 with 75 crew members and passengers took off at night in Instrument Meteorlogical Conditions (IMC) over water with duct tape covering the pitot and static ports. The crew suffered from unreliable incorrect instrument indication as well as numerous aural warnings and warning lights.  The resulting confusion of the flight crew ended 30 minutes later when the aircraft stalled and crashed into the water with all on board killed.

If the crew had available a portable GPS receiver , they would have had enough information to avoid stalling the aircraft and would be alive today. Do you carry a portable GPS receiver on board your aircraft today?