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Domestic RVSM

by Jeremy Cox 1. March 2005 00:00
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A friend of mine was attending his annual Aircraft Type Recurrency Training, at Simu-flite in Dallas in February of this year. He is a captain for a large household chemical corporation that owns and operates an aircraft in the support of their business. The instructor asked the class: "What is the Rated Ceiling of the Dassault Falcon 20 dash Five?" He was expecting the attendees to throw back the answer of: "Forty Two Thousand Feet, or FL 420." My friend's hand shot high up with a vigor that forced the instructor to call upon him to respond. The answer thus offered came as a surprise to all: "The Rated Ceiling of our Dassault Falcon 20 dash Five is FL 280, or Twenty Eight Thousand Feet!" An un-conventional, but thoroughly accurate response to such a benign question (His aircraft is undergoing the RVSM STC now); Why is this so? Well, since the early hours of January 20th, 2005 all flight operations within the Airspace block between FL 290 and FL 410 in this country has been controlled by the new regulation: Domestic Reduced Vertical Separation Minimum (DRVSM.) Even though the majority of the rest of the World have been living under these regulations for many months or even years longer than we Americans, what this means is that many of today's Turbine Powered Aircraft are now forced to cease most operations above FL 280 unless they have been equipped and approved for operations above this level. What is DRVSM? This a standard change that mandates a reduction of the vertical separation down to 1,000 feet from 2,000 feet between aircraft relative to each other in flight between FL 290 and FL 410. This change was originally touted as a way that fuel could be saved (mainly by the Airlines) by supposedly allowing up to twice as many aircraft to operate within the same block of airspace than what was allowable with a 2,000 foot separation standard. In addition to increased volume, this standard is also meant to allow greater operating flexibility for aircraft to maneuver around thunderstorm activity at altitude in the summer months. Are the benefits touted by the architects and proponents of this reform implementation, truly being reaped by as many Flight Level users as possible? Only time will tell. Unfortunately any publication of the experience by users outside of the US has given little enough guidance in answering this question. I think that this is mainly because close to 70% percent of the world's General Aviation Fleet (according to GAMA) are based in the US, and the pilot population in our country equals more than 600,000 individuals. Statistically the bulk of the feed-back attributed to the implementation of RVSM has yet to be recorded.

Recently I downloaded the March 21st, 2005 US DRVSM Approvals/IGA Document from the FAA's RVSM website. This document keeps track of which aircraft have full DRVSM Approval, and which do not. After spending some time totaling up each page, I came up with the following statistics:

Approximate Number of Business/General Aviation Aircraft Listed and Tracked by the FAA for the purpose of RVSM = 4,860.

Approximate Number of Business/General Aviation Aircraft that are performance capable of flight in the DRVSM Altitude Block = 13,199 (Per a Fleet Report that I ran from my Amstat database.)

Approximate Number of Business/General Aviation Aircraft that are currently DRVSM Approved and listed in the FAA document = 3,780.

I have summarized these numbers as follows: Less than 37% of the Aircraft that are physically capable of flight in the ‘RVSM Airspace Block,' are expected to receive DRSM Approval. Of these 4,860+ aircraft, almost 88% of these aircraft are now DRVSM Approved.

Several issues that I have heard about recently include: Long delays in the processing and issuance of a Letter of Authority (LOA) to qualified operators; Delays and Re-Routings due to Traffic Density Saturation in certain areas of the country; and many ‘Gee-Whiz' comments from both Crew and Passengers regarding visual sightings of passing aircraft.

I will expand each topic separately: First ‘LOA-s.' To obtain RVSM Approval, an operator must under-go a ‘four-step' process. Step-One; Each aircraft has to be approved and fitted with the following: two independent, cross-coupled altitude measurement systems; one automatic altitude control system, to within ±65 feet; one altitude alert system; one SSR altitude reporting transponder; and RVSM-compliant avionics. Also the static port and pitot-static probe installations have to be inspected and conformed to a known standard. Step-Two; Next the integrity and function of the equipment that was installed in the aircraft to meet the airworthiness requirements of RVSM approval must be functionally tested, either by flying with a Static Source Trailing Cone (if you are obtaining your own STC); or flying with a portable Global Positioning System Monitoring Unit (GMU) on board; or (this will soon become the most prevalent testing method) Flight over a permanent Height Monitoring Unit (HMU). The HMU is a passive, ground-based system that gauges the altitude of aircraft flying within its coverage area. It consists of a set of ground stations arranged as a central site, with four additional receivers arranged in a square. Each site receives aircraft secondary surveillance radar (SSR) transmissions, from which the aircraft's three-dimensional position is derived. The HMU calculates altimetry system error using meteorological information and the Mode-C/S height data. Remember how I said that this will become the most prevalent method of verification, well the FAA has promised that HMU sites will be located in Atlantic City, New Jersey; Wichita, Kansas; Cleveland, Ohio; Roanoke, Virginia; Ottawa, Ontario; Lethbridge, Alberta and somewhere in Arizona. Unfortunately so far, Atlantic City is the only site that is currently up and running (March 2005.) Step-Three; All of the operators Crew Members that are to be assigned to fly in RVSM airspace must have been trained in RVSM operations. The operator has the option to either train in-house or contract with outside sources such as Simu-flite, Flight Safety International or anyone else that can show that their Training Program is FAA approved. Many operators choose to incorporate this RVSM training in a class for Int'l operations. And finally Step-Four; The operator must prove to its local Flight Standards District Office (FSDO) that it has written and implemented a logical and eventually approved system to maintain their aircraft and flight crews to RVSM standards. The operator proves this by writing a manual that logically states what steps it is going to follow to become certified and then stay certified. The responsibility is placed entirely on the operator to convince the FAA that its plan is legal, practical, and workable. Now here is where the first problems occur that I have heard about. DRVSM Applications are taking three months or more to process. This is not a standard problem, but it is FSDO dependent depending on the amount of backlog at each office. It is amazing to talk to many operators that are trained, have brand-new aircraft that are fully RVSM compliant and have bought a manual off-the-shelf from a proven compliance consultant and yet they are unable to fly between FL 290 and FL 410 because they have yet to receive an FAA stamp of approval. I have been given the impression by several people I know that fly internationally, including a friend who is a Falcon 900 driver, that the LOA approval process in Europe is also subject to delay. Specifically he is DRVSM approved and is still seeking the LOA from Eurocontrol for approved RVSM operations in European Airspace. This is after he has flown over the NAT HMU in Strumble, Wales. He tells me that he submitted all of the required documentation that details the Date, Time and Altitude of passage over Strumble, and yet he still waits, even after holding multiple telephone conversations with the Eurocontrol ‘powers-that-be.'

Second Problem Topic: Delays and Re-Routings due to Traffic Density Saturation in certain areas of the country. I have a friend who is a Beechjet 400A driver in Florida, he has told me of several instances where he needed to get up to altitude (he is an RVSM approved operator) and get en-route, and yet he has been forced to racetrack between Tampa and Cape Canaveral until he was sequenced to climb and proceed, because of all of the lower non-RVSM compliant traffic filed at FL 280 and below. Another friend, who is based in Atlanta and who drives a Falcon 50, tells me that on trips out to the West Coast he gets cleared to FL 430 pretty quickly. However when he makes a run up to the North East or down to Florida, he still meets with the same delays that he experienced before DRVSM was implemented. I have heard that the Center air traffic controllers supposedly tout how much DRVSM frees up airspace and gets the system flowing. Meanwhile, the approach controllers continue to shake their heads and say that Atlanta for instance, can still only handle the same number of arrivals as they did prior to DRVSM. The complaint here is that the bottleneck is still at the arrival/departure phase. It is admirable to be able to put more aircraft in cruise airspace, but there's still only so many runways that you can land on and there's a limit to the amount of traffic those runways can hold. I have further heard that before DRVSM, Air Traffic Control issued airspeed restrictions hundreds of miles out for traffic coordination into high density traffic airports. Now flight crews still get the same airspeed restrictions and vectors....only now they can get them at a greater variety of Flight Levels.

My last Problem Topic is the many ‘Gee-Whiz' comments from both Crew and Passengers regarding visual sightings of passing aircraft. Even though Air Traffic Control are reportedly proactive at reporting converging or crossing traffic, the view from a Gulfstream cockpit of a Boeing or Airbus converging at a 1,000+ KTAS and a 1,000 foot separation can be very un-nerving. I wonder how many passengers swear that they were nearly involved in a mid-air collision and have narrowly cheated death?

There are still strategies available to non-RVSM compliant operators. One of which is to request a transition through and above the RVSM Block Levels. However, this option may often not be suitable. The DRVSM rule does allow ‘climb-throughs' but non-compliant aircraft must be able to make a steady climb from FL 280 to FL 430, with no level-offs. Even if payloads or performance allow such a maneuver to be accommodated, traffic density may forbid it. The amazing thing to me, about DRVSM is the cost to an operator who cannot, or will not, seek approval and instead continues to operate with a FL 280 Ceiling. I will use the example of a Dassault Falcon 20F to illustrate my point of view. For a Falcon 20F that weighs 26,000 pounds, at FL 280 with an indicated Mach of 0.790 at ISA -10˚F, its pair of GE CF700-2D-2 Engines will manage to convert approximately 462 gallons of Jet A into Heat and Noise every hour. At the same weight, speed and temperature lapse rate at FL 370 these illustrious powerplants perform the same conversion at a rate of 302 gallons every hour (Obviously the consumption rate for each scenario is higher for the first hour, but as the aircraft weight becomes reduced, so does the fuel-burn.. work with me on this, okay.) Now let's say that the owner of this Falcon 20 is used to paying an average of $3.50 per US Gallon of Jet A, and the Falcon flies an average of 400 flight hours per year. If you figure that 65% of the annual utilization of this example aircraft is spent at altitude, i.e. 260 Flight Hours. The owner of this non-compliant Dassault Falcon 20F will pay $145,600 US Dollars more every year as punishment for not getting RVSM approved. That quoted cost of $180,000.00 USD for the RVSM STC now looks mighty attractive doesn't it, especially when you realize that it will only take 15 months of fuel savings to offset the cost to incorporate the DRVSM STC? So, what feed-back can you share with your fellow readers here at GlobalAir? I have personally ‘surfed' the web looking for forums where people like you and I are discussing these everyday issues and problems that appear to be occurring as a result of DRVSM. I have still yet to find a site that carries these comments, hence this article on this site. Please allow me to challenge you to write in, speak up and be heard. Best of all, your comments will not fall on deaf ears, as the Operations staff in charge of DRVSM have indicated their interest in receiving any and all comments that result from this piece. So go ahead and give us your ‘good, the bad and the ugly' comments because you might be able to make a difference and be instrumental in getting the system improved.

Cell Phones in the Cockpit

by Greg Reigel 1. March 2005 00:00
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Cellular Telephones And PDA's In The Cockpit

Can you use a cellular telephone in a private, general aviation aircraft? What about personal digital assistants ("PDA's")? MP3 players? CD players? Laptop computers? With the proliferation of cellular telephones and portable electronic devices ("PED's"), these questions are more and more frequent. This article will give you some answers to these questions based upon the law as it stands today. However, as you are reading this article, keep in mind that it will focus on private, general aviation operations operated under FAR Part 91. Although I may briefly address FAR Part 121 airline operations or FAR Part 135 charter operations, I will not focus on them specifically.

Portable Electronic Devices

PED's such as PDA's, laptop computers, CD players and MP3 players etc. are addressed in 14 CFR 91.21. 14 CFR 91.21(a) provides that "no person may operate, nor may any operator or pilot in command of an aircraft allow the operation of, any portable electronic device on any of the following U.S.-registered civil aircraft: (1) Aircraft operated by a holder of an air carrier operating certificate or an operating certificate; or (2) Any other aircraft while it is operated under IFR". The FAA issued this rule back when VOR's were the primary navigation aid because the FAA was concerned that PED's may interfere with the VOR receivers and navigation/communication equipment aboard aircraft. Although 14 CFR 91.21(a) appears to be a blanket exclusion, 14 CFR 91.21(b) does contain some exceptions including portable voice recorders, hearing aids, heart pacemakers, electric shavers, or the catch-all exception: "Any other portable electronic device that the operator of the aircraft has determined will not cause interference with the navigation or communication system of the aircraft on which it is to be used."

This catch-all exception gives the operator of the aircraft, who is usually the pilot in command under FAR Part 91 operations, the authority to determine what PED's may be used on his or her aircraft. Fortunately, the FAA provides some additional guidance to be used in making this determination. AC 92.21-1A, Use of Portable Electronic Devices contains information and guidance to assist operators and pilots to comply with FAR 91.21. As with most advisory circulars, the AC provides one means, but not the only means of compliance.

The AC states that the operator and/or pilot in command must make a determination regarding the non-interference and safety of each PED to be operated in the aircraft. This determination can be as simple as turning each PED on at cruise altitude and noting whether any interference occurs. If interference is experienced, the conditions of operation at the time of the interference should be noted and the PED should be turned off. The AC also suggests that the operator and/or pilot in command can obtain professional assistance, presumably from a reputable avionics shop, to make the non-interference determination. If PED's are to be allowed on the aircraft, AC 92.21-1A recommends establishing specific procedures to govern the use of PED's such as passenger briefings, determining non-interference, limitations on use etc.

Cellular Telephones

If you have flown on an airline, you should be familiar with the section of the flight attendant's pre-flight briefing in which you are instructed to turn off your cellular telephone. This instruction is consistent with federal law promulgated by the Federal Communications Commission ("FCC"). 47 CFR 22.925 states that all cellular telephones carried aboard an aircraft must be turned off before the aircraft leaves the ground. Although the FAA has not expressly prohibited the use of cellular telephones in flight, it has indicated its support of the FCC regulation in AC 92.21-1A. It is important to note that 47 CFR 22.925 does not prevent the use of cellular telephones while the aircraft is on the ground. As long as the wheels are still touching the ground, the regulation does not prevent you from using your cellular telephone (Note: Airline or charter operator procedures may be more restrictive). However, even if the operator and/or pilot in command allows the use of cellular telephones on the ground, he or she is still required to make a non-interference determination before they may be used. Also, procedures similar to those relating to PED's should be adopted to govern the use of cellular telephones on the ground.

Cellular telephones definitely add convenience when you want to obtain an IFR clearance from flight service prior to departing from an uncontrolled airport without a FSS RCO or if you can't otherwise reach FSS via radio. Simply call from your cellular telephone either before or after your run-up and obtain your clearance and void time. This is a definite improvement over the old days when you sometimes had to rush through pre-flight and run-up to make sure you met your void time. Calling for a ride after landing is also more convenient: You can call while taxiing to the ramp. Additionally, with the current lobbying and the FCC's reconsideration of the ban on using cellular telephones in flight, you may also legally be able to use a cellular telephone in flight in the not too distant future.


In addition to the convenience, not to mention the pleasure, of flying an aircraft, portable technology can provide additional convenience and pleasure. With the proper planning and investigation, PED's and cellular telephones can be used to make flying more convenient and more enjoyable without sacrificing safety.

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Greg Reigel

Upgrading Older Aircraft

by David Wyndham 1. March 2005 00:00
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Upgrading an older aircraft can be one way of enhancing performance or functionality while delaying the cost of replacing the aircraft. Even so, the costs can be substantial and they may outweigh the benefits.

Upgrades are different from conversions. An upgrade enhances what is already there while a conversion results in major changes to the systems or design of the aircraft hopefully improving the aircraft substantially. Replacing the engines with newer, different engines such as Honeywell has done with the Falcon 20 and Falcon 50 would be a conversion. Adding an aft fuselage baggage locker to a Lear is an upgrade.

Upgrades can be divided into several different areas – airframe, interior cabin & comfort, avionics and other systems. Engine & propellers tend more to the conversion category. An airframe upgrade will include things such as winglets to increase climb or cruise performance or ventral fins to improve handling. Interior cabin & comfort upgrades include better soundproofing, added baggage compartments and enhanced cabin entertainment systems. Avionics upgrades include safety related ones such as terrain awareness and warning systems (TAWS) or GPS for navigation. Other systems would include air conditioning and de-icing systems (mostly piston models).

Some upgrades are actually mandated by law. Due to the cost and or complexity of some of these modifications, some operators of much older aircraft may elect not to upgrade and will sell their aircraft or "part it out" for the value of its spare parts.

The basic issue involved when evaluating whether to upgrade an older aircraft involves the cost versus the benefit. For example, a set of winglets for a Gulfstream II costs about $495,000. They save fuel and improve climb performance. The 7% fuel savings is about a $125 per hour savings. It would take nine to ten years' normal flying to earn back the cost of those winglets from fuel savings alone. However, with the improved fuel burns, you add range and with the enhanced climb performance and thus will be able to better utilize high altitude airports. For a GII operator who flies short distance trips from long runways at sea-level, the winglets may not be worth the expense. For a GII operator who flies long trips and needs the flexibility to get fly out of many different airports, the winglets are well worth evaluating.

Upgrades also can add value. They key issue there are (1) whether the aircraft is desirable by the buyer and (2) whether the upgrade is desirable by the buyer. While it is doubtful you will get every dollar back, you could see 30% to 90% of the money "back" in resale value depending on the age of the upgrade and its desirability.

Back to our GII with Winglets example. Winglets will add value to the GII. While neither Vref nor the Aircraft Bluebook Price Digest list an "adjust for winglets" price, those items are mentioned. A recent winglet installation to a GII will most definitely will add to the aircraft's value. According to AMSTAT's list of aircraft for sale, there are 42 GII currently for sale or lease – or 22% of the active fleet. Given that percentage, it is a buyer's market for the GII. The GII faces aging, RVSM and noise issues and that is part of why so many used GII's are for sale. Selling a GII with winglets may add some value, but given the number for sale, the added resale value may not be much but it may reduce the time it takes the aircraft to sell.

If an upgrade can pay for itself in added performance, comfort or functionality, then it is clearly worth the expense.


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