Significant Regulatory & Related Activity

Mon, Jun 23, 2008 — David Evans

Regulatory & Other Items

Significant Regulatory & Related Activity


Eclipse 500 very light jet. Note the straight wing with the small wingtip fuel tanks. Provisional FAA type certification was granted in July 2006.

12 June 2008

Federal Aviation Administration (FAA)

Emergency Airworthiness Directive

AD # 2008-13-51

Applicable to all Eclipse Aviation Corporation Model EA500 airplanes, a new ultra-light jet, the AD is effective upon receipt. This AD results from a 5 June incident in which an EA500 attempting a landing at Chicago’s Midway Airport experienced uncontrollable maximum power engine thrust, the pilots were forced to go-around and land at a high rate of speed, blowing two tires as the airplane screeched to a stop on the runway.

The two pilots and two passengers on the flight were uninjured.

Before further flight, the AD requires inspection of the throttles for anomalies and to see if any engine control messages occur. If necessary, the throttle quadrant must be replaced and the test repeated. The evaluation results must be reported to the FAA; this is a twist, as usually the FAA requires reports of AD-mandated inspections to be reported to the manufacturer. As such, this AD reflects an unusually high level of FAA interest.

As part of the throttle evaluation, the testing pilot must do the following:

  • Move both throttle levers slowly from idle to the maximum position.
  • Look for the following throttle anomalies:

a. Restricted, erratic or binding movement.

b. Unusual noises, such as grinding or scaping.

  • Note if any of the following crew alerting system messages are displayed at any time during this evaluation:

a. L or R ENG CONTROL (white)

b. L or R ENG CONTROL FAIL (amber).

The FAA said the Chicago incident showed that the throttles could remain stuck at full power if pushed forward with enough force, depriving the pilot of the ability to control the airplane’s landing and touchdown speed.

The National Transportation Safety Board (NTSB) is investigating the landing emergency, and it issued urgent recommendations on 12 June for an inspection of Eclipse 500 airplanes and development of an emergency procedure for a dual engine control failure. The FAA issued the emergency AD within hours of receiving the NTSB recommendations, prompting Mark Rosenker, the chairman of the NTSB, to issue on 13 June congratulations and thanks to the FAA for prompt action:

“ ‘The quick FAA response to the urgent recommendation we issued could save lives,’ Rosenker said. ‘Additionally, the NTSB is looking forward to reviewing the results of the FAA-required inspections of these aircraft.’

“Next week, the FAA and Eclipse will be conducting further evaluations and tests on the throttle quadrant from the incident aircraft.”

According to the NTSB letter to the FAA:

“During this incident, the fault in the right engine was cleared when the crew shut down that engine. However, because the FADEC [full authority digital engine control] was programmed so that the left engine would mirror the throttle position of the no-fault engine, which was positioned at idle, the power to the left engine was reduced to idle. So, after the pilots shut down the right engine in an attempt to regain engine control, it is likely that the left engine rolled back to idle immediately. Thus, the pilots were flying with one engine that was shut down and another that would not advance past idle – and they had no emergency procedures to address the situation.

“The Safety Board notes that the dual-channel failure of both throttle levers occurred after the airplane had accumulated only 238 hours and 193 cycles since new. The throttle levers are part of the throttle quadrant assembly. The Board is concerned about the reliability of an assembly that fails in such a short time. Moreover, when the failed throttle quadrant assembly was replaced, pushing the throttle levers on the replacement unit against the maximum power stops caused a R ENGINE CONTROL FAIL message to appear on the CAS [crew alerting system] display. The immediate failure of the replacement part suggests that there may be a design or quality problem in the Eclipse 500’s throttle quadrant assembly.”

In a statement released that day, Eclipse decried the NTSB’s recommendations as “premature.”

There is an unconfirmed report that FAA certification engineers filed a grievance against FAA management for pressure to speed the certification of the Eclipse. Certainly, the process by which the throttle quadrant was approved will be a subject of the NTSB investigation. The obvious question was whether this failure mode was discovered during certification, and if not, why not?

(The emergency AD may be viewed at


_Emergency.pdf. The NTSB recommendation letter may be viewed at, and NTSB preliminary accounts of the incident may be viewed at two websites:

6 June 2008               FAA

FR Doc E8-12752      Docket No. 2008-M-351-AD

Applies to Boeing 737-300, -400 and -500 airplanes

Affects 669 airplanes in U.S. registry

Other Docket Numbers issued the same day affect different Boeing aircraft but contain virtually the same language:

FR Doc E8-12685     Docket No. FAA-2008-0617

Applies to Boeing 737-600, -700, -800, -900 and -900ER airplanes

Affects 825 airplanes in U.S. registry

FR Doc E8-12692     Docket No. FA-2008-0619

Applies to Boeing 747-100, -200, -300 and SR and SP airplanes

Affects 166 airplanes in U.S. registry

FR Doc E8-12725     Docket No. FAA-2008-0620

Applies to Boeing 747-400 and -400F airplanes

Affects 79 airplanes in U.S. registry

FR Doc E8-12749     Docket No. FAA-2008-0615

Applies to Boeing 757 aircraft

Affects 673 airplanes in U.S, registry

FR Doc E8-12684     Docket No. FAA-2008-0616

Applies to Boeing 767 airplanes

Affects 416 airplanes in U.S. registry

FR Doc E8-12691     Docket No. FAA-2008-0618

Applies to Boeing 777 airplanes

Affects 676 airplanes in U.S, registry

Notice of Proposed Rulemaking (NPRM)

The action affects some 3,500 Being aircraft of all models, proposing regular inspections for possible air leaks that “could result in multi-engine flameout” with “an inability to restart the engines, and consequent forced landing of the airplane.”

The FAA said the move was prompted by engine stoppages on six different Boeing aircraft between 2002 and 2004. Some of those incidents occurred during flight, while others took place during ground taxi operations.

It is somewhat unusual for the FAA to issue multiple, identical inspection mandates at the same time, via multiple proposed rulemakings. The inspections could have been mandated under one proposed NPRM, since they all require the same action by the same deadlines: inspections within 7,500 flight hours (about two years worth of flying) and comments to the proposed ADs due 21 July.

The multiple regulatory initiatives tend to dilute the impact, by breaking the entire effort into smaller pieces. This is an apparent ploy to avoid calling undue attention to the problem.

Comments on the NPRMs are due 21 July 2008.

6 June 2008               FAA

FR Doc E8-12272      Docket No. FAA-2008-0613

Notice of Proposed Rulemaking (NPRM), propounding an airworthiness directive (AD) for Airbus A300-600 airplanes

The FAA proposes wiring modifications to avoid a short circuit that could lead to overheating of the fuel level sensors and possible explosion of the airplane. The FAA action emulates that taken 5 March by the European Aviation Safety Agency (EASA):

“Degradation of the electrical insulation sleeves of the low-level indication lamps on the MTI [Multi Tank Indicators] on the flight deck can cause a short circuit that might result in high voltage being conveyed to the high- and low-level sensors in the outer [fuel] tanks. This might cause the level sensor to heat above acceptable limits.

“For the reasons stated above, this airworthiness directive requires the accomplishment of wiring modifications to protect the FLSA [Fuel Level Sensor-Amplifier] and the Flight Warning Computers from 115V AC and 28V DC short circuits within the Multi Tank Indicators.”

Requires accomplishment of an Airbus service bulletin within 3 months of the effective date of the AD.

Comments on the proposed rule are due 7 July.

8 May 2008                    FAA

FR Doc E8-10246          Docket No. FAA-2007-29281

Notice of Proposed Rulemaking (NPRM), Removal of Regulations Allowing for Polished Frost on Wings of Airplanes

The FAA is proposing to remove provisions in its regulations that allow flights of private airplanes with “polished frost” (i.e., frost polished to make it smooth) on the wings.

By this change, the regulators have decided, after almost 50 years, that it’s no longer safe for private airplanes (Part 91) and cargo aircraft (Part 135) to fly with polished frost on their wings. Since 1960, the FAA has allowed some planes – not commercial passenger planes – to fly with ice on the wings as long as the ice was smooth. That left it up to the operators to clean off the wings themselves and decide whether it was safe to fly.

The regulatory action comes after several fatal crashes of business aircraft that were attributed to ice on the wings and an increase in the use of corporate and fractional-ownership jets in the last decade.

A January 2002 crash in Birmingham, England that killed two business executives and three pilots illustrated the dangers of ice on aircraft. British investigators pointed out that the plane had been flying under the “polished frost” regulation and they recommended that the FAA delete all reference to polished frost.

In 2004 and 2005, fatal crashes in Colorado, attributed to ice on the wings, provided further impetus for change.

In addition, the FAA said there are at least 11 known incidents in which aircraft with polished frost did not generate sufficient lift and crashed after takeoff.

Commercial aircraft operate under rules that call for a “clean wing” before take-off and de-ice treatment at the airport before departure under certain weather conditions.

While the old rule said pilots could take off “with frost adhering to wings or stabilizing or control surfaces if that frost had been polished to make it smooth,” the consensus now is against any ice on the wing. The FAA concluded that any ice on the wing poses a number of problems. As indicated in the NPRM:

  • A contaminated wing’s maximum lift may be reduced by 30% or more.
  • The angle of attack for maximum lift may be reduced by several degrees.
  • Drag may increase significantly.
  • The airplane’s handling qualities and performance may change unexpectedly from that of the uncontaminated aircraft.

The FAA discovered numerous inventive, though sometimes disastrous, ways to clean ice, snow and frost off the surfaces of aircraft. For example, running a rope against the wing surface to remove frost, brushing it off by hand or with a broom, using a paper towel, of even using a credit card as a scraper.

Under the NPRM, operators would have four ways to comply with the proposed rule:

1) Wing covers

2) Waiting for the frost to melt.

3) Storing the aircraft in a heated hangar.

4) De-icing the wing surface.

Of these choices, the FAA believes wing covers “are the lowest cost alternative” According to the FAA, wing covers meet the test of cost-benefit, costing the industry about $164,000 over the ten year period 2009 to 2018, while benefits (presumably accidents avoided) over this same period amount to $460,000. It is not entirely clear how these costs and benefits were calculated, as the cost of a single fatal accident can run to the millions of dollars.

The National Transportation Safety Board (NTSB) has been asking the FAA since the 1990s to revise its rules on icing conditions and the certification of airplanes to fly in those conditions. The NTSB has maintained, based on past investigations, that the wings need to be free of ice, frost or snow.

The FAA now concludes:

“Complete removal of frost from critical surfaces to achieve uncontaminated surface smoothness is necessary to ensure acceptable airplane airworthiness. If all wing surfaces, other than those under the wing in the area of the fuel tank, and control surfaces are not uniformly smooth upon take off, the FAA believes an unsafe condition exists.”

Comments on the NPRM are due 6 August 2008.

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