"New York Approach, Falcon 900, I am canceling my IFR flight plan - request traffic advisories."

Is there ever a good reason to cancel your Instrument Fight Rules (IFR) flight plan? Is it possible to operate under Visual Flight Rules (VFR) and not compromise the safety of flight? I believe the answer to both questions is yes.

Based upon many discussions with other pilots, I believe most pilots think flying is safer while operating under Instrument Flight Rules.  When I ask them to explain why they think it is safer, the answer most pilots will offer the explanation of having an Air Traffic Controller watching over their flight is the reason.

The fact so many pilots think this may in fact contribute to a less safe situation. Their belief will result in a much less thorough traffic watch as well as a more relaxed overall operation. I have taken the opportunity to cancel my IFR flight plan while flying with a both a co-pilot and a flight engineer.  Their reaction was almost uniform with both of them almost coming to attention and becoming very interested in looking out the windows. You might say the safety of our flight was enhanced by the canceling of the IFR flight plan.

I must add the conditions under which I would cancel the IFR flight plan had been very carefully considered.  First of all, the weather would always include excellent visibility and clearance from clouds.  We had to be in radar contact and receiving traffic advisories from the controller as well.

Now let me ask you this question. Specifically, what service does a pilot receive while under Instrument Flight Rules that he does not receive while under Visual Flight Rules operations?

Answer: The air traffic controller is obligated to assure separation from other "known" IFR traffic. This is his first priority. Traffic advisories are only given to IFR traffic if workload on the part of the controller permits.

This is true also of VFR traffic receiving traffic advisories.  They are only provided on a work load permitting basis on the part of the controller.  Many pilots may be operating on the incorrect belief that flights operating on an IFR flight plan receive priority for traffic advisories over flights operating under VFR.

This may be the primary reason why so many pilots think flying under IFR is safer than flying under VFR.

Another question, does the air traffic controller have an option to refuse your IFR cancellation?  The answer is no.  He neither approves nor disapproves an IFR cancellation.  He only has the option to acknowledge it.  The pilot in command is the sole determiner and is responsible for choosing which set of rules either IFR or VFR he follows for his operation.

Displaced Thresholds and Landing - Part II

JFK Has Five Displaced Thresholds 

What are the reasons a permanent displaced threshold will be established for a specific runway? There are only two reasons.  The first one is if an obstacle penetrates the obstacle clearance plane.  A displaced threshold will be established to assure clearance from the obstacle while making an approach in Instrument Meteorological Conditions (IMC). The second reason is for noise abatement. As far as I know, there is no way to tell them apart.    

I made an attempt in 1997 to get the FAA to consider re-locating the five different displaced thresholds in place at JFK in light of the newer, quieter stage II and stage III aircraft using JFK.  The FAA actually did do a study to see what the cost of moving the displaced thresholds would be.  The cost of the computer time to move the thresholds was estimated to be in excess of $100,000.

The reason for the high cost was the need to re-survey the heights and locations of all the man made obstacles that had been built in the obstacle clearance planes for the approaches.  As a result of the high cost of doing this, the displaced thresholds will most likely remain in their current locations. I doubt if we ever see them change.

Once again, I want to re-state the fact there is nothing that prevents you from touching down prior to the displaced threshold.  You will note upon inspection of the actual runway there are many tire marks prior to almost all of the painted threshold markings.

Consider the situation of a requirement for a no flap landing.  Without the use of wing flaps, the approach and touch down speeds are going to be much higher than normal.  Add to the situation a high gross weight condition along with a 9 knot tail wind and the actual touch down speed may exceed 230 knots. I recognize this set of conditions may be highly unlikely but it still remains a possibility.  If you are landing at JFK on runway 31L, I doubt very much if you would choose to land on or beyond the displaced threshold.

If there is an operational need for you to use all the runway, use it!

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.