[Federal Register Volume 59, Number 233 (Tuesday, December 6, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-29921]


[[Page Unknown]]

[Federal Register: December 6, 1994]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-174-AD; Amendment 39-9087; AD 94-25-03]

 

Airworthiness Directives; Fokker Model F28 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to all Fokker Model F28 series airplanes. This action 
requires a revision to the Airplane Flight Manual that prohibits 
takeoff in certain icing conditions unless either a tactile inspection 
is performed or specific takeoff procedures are followed. This 
amendment is prompted by several accidents in which Fokker Model F28 
series airplanes lost aerodynamic lift when attempting takeoff with ice 
contamination on their wings. The actions specified in this AD are 
intended to prevent degradation of aerodynamic lift during takeoff when 
icing conditions exist.

DATES: Effective December 21, 1994.

    Comments for inclusion in the Rules Docket must be received on or 
before February 6, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-174-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    Information concerning this amendment may be examined at the FAA, 
Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.

FOR FURTHER INFORMATION CONTACT: Timothy J. Dulin, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-2141; fax (206) 227-1320.

SUPPLEMENTARY INFORMATION: The FAA has received reports of at least 
three accidents involving Fokker Model F28 series airplanes in which 
the probable cause has been attributed to wing ice contamination prior 
to takeoff. The FAA has determined that airplanes with wings that do 
not have leading edge high lift devices, such as the Fokker Model F28 
series airplanes, are particularly susceptible to loss of lift when 
attempting to take off with minimal amounts of ice accumulation 
(contamination) on the wings. Further, the FAA finds that airplanes 
with this configuration account for a disproportionate number of the 
total number of accidents attributable to wing ice contamination. In 
light of this, the FAA has determined that, for airplanes with this 
configuration, an extra degree of protection is necessary beyond 
reliance solely on operation in accordance with the current 
requirements specified in section 121.629 (``Operation in icing 
conditions''), amendment 121-231, of the Federal Aviation Regulations 
(14 CFR 121.629).
    The FAA has determined that one acceptable (interim) method of 
addressing icing problems associated with airplanes having this 
configuration is a physical (tactile) and visual check of the leading 
edge and upper wing surfaces to verify that there is no accumulation of 
ice, frost, and snow prior to takeoff. The FAA previously issued AD 93-
11-01 [amendment 39-8593 (58 FR 33898, June 22, 1993)], which requires 
such a tactile check of McDonnell Douglas Model DC-9-10 series 
airplanes; those airplanes, like the Model F28, do not have leading 
edge high lift devices. The intent of checks such as these is to 
prevent takeoff with wing ice contamination, which can result in the 
degradation of wing lift, and can result in the airplane stalling at 
lower than normal angles-of-attack during takeoff.
    Additionally, the Rijksluchtvaartdienst (RLD), which is the 
airworthiness authority for the Netherlands, issued Netherlands 
Airworthiness Directive (BLA) 93-167/2 (A), dated April 29, 1994, 
applicable to Fokker Model F28 series airplanes operating in the 
Netherlands. This BLA describes an ``alternative'' takeoff procedure 
that can be followed to improve stall margins whenever icing conditions 
exist. [This ``alternative'' takeoff procedure was developed in 
response to the U.S. National Transportation Safety Board's (NTSB) 
Safety Recommendation A-93-023.] The ``alternative'' takeoff procedure 
requires the availability of 120 percent of the minimum takeoff 
distance for the actual gross weight. Additionally, the 20 percent 
increase in takeoff distance must be accounted for in the obstacle 
clearance analysis. The BLA specifies that the ``alternative'' takeoff 
procedure is an optional procedure that is available for use when 
sufficient runway length and obstacle clearance margin are available.
    The FAA has reviewed and approved this ``alternative'' takeoff 
procedure as an interim measure that will acceptably address the 
problems associated with takeoff and operation of Model F28 series 
airplanes in icing conditions. Although the RLD has classified the 
procedure as optional, the FAA has determined that it must be mandated 
as one method to ensure that these airplanes have adequate lift to 
effect a safe takeoff when icing conditions exist.
    As indicated previously, the FAA has determined that the 
accomplishment of these types of additional actions is necessary in 
order to provide an extra degree of protection for Model F28 series 
airplanes, beyond that provided by the current operating requirements 
specified in part 121 of the FAR.
    Fokker has advised the FAA that it is currently developing a 
modification to the thermal anti-ice system on all Fokker Model F28 
series airplanes. This modification would allow the thermal anti-ice 
system to operate on the ground, which would prevent reformation of ice 
on the wing leading edges after ground equipment has been used to 
properly de-ice/anti-ice the airplane, and would minimize the effect of 
undetected ice/frost/snow contamination. Fokker has indicated that this 
proposed modification will be similar to the one required by AD 93-11-
01 for McDonnell Douglas DC-9-10 series airplanes. (That AD requires a 
modification of the wing leading edge bleed air anti-ice system on so 
that it can operate on the ground to prevent the reformation of ice 
after de-icing procedures have been accomplished.) However, because 
this proposed modification for Model F28 series airplanes currently is 
under development, any associated modification instructions or required 
parts are not available at this time.
    This airplane model is manufactured in the Netherlands and is type 
certificated for operation in the United States under the provisions of 
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and 
the applicable bilateral airworthiness agreement. The FAA has 
determined that AD action is necessary for products of this type design 
that are certificated for operation in the United States.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design registered 
in the United States, this AD is being issued to prevent degradation of 
the aerodynamic lift during takeoff due to wing ice contamination, 
which could result in the airplane stalling at lower than normal 
angles-of-attack during takeoff. This AD requires a revision to the 
Limitations Section of the FAA-approved Airplane Flight Manual (AFM), 
which requires that, whenever icing conditions exist, one of the 
following actions must be accomplished:
    1. A physical (tactile) check to detect ice, frost, and snow 
accumulation on the leading edge and upper wing surfaces must be 
performed prior to takeoff. (This check is similar to that required by 
AD 93-11-01 for McDonnell Douglas Model DC-9-10 series airplanes). Or
    2. The airplane must be operated in accordance with the 
``alternative'' takeoff procedure developed by Fokker that improves 
stall margins. Use of the ``alternative'' takeoff procedure would 
require weight to be off loaded, if necessary, to meet the revised 
takeoff distance and obstacle clearance requirements. -
    This AD also provides for the termination of these requirements if 
the airplane's thermal anti-ice system is modified and operated in 
accordance with a method approved by the FAA. -
    This is considered to be interim action. As stated previously, 
Fokker currently is developing a design modification that will 
positively address the unsafe condition that is the subject of this 
rulemaking action. Once this modification, as well as its associated 
operating procedures and an implementation schedule, are developed, 
approved, and available, the FAA may consider additional rulemaking 
action. -
    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited -

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this rule by 
submitting such written data, views, or arguments as they may desire. 
Communications shall identify the Rules Docket number and be submitted 
in triplicate to the address specified under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed. -
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments submitted will be 
available, both before and after the closing date for comments, in the 
Rules Docket for examination by interested persons. A report that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket. -
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 94-NM-174-AD.'' The postcard will be date stamped and 
returned to the commenter. -
    The regulations adopted herein will not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment. -
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, may be obtained from the Rules Docket at the 
location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39 -

    Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment -

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES -

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended] -

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

94-25-03 Fokker: Amendment 39-9087. Docket 94-NM-174-AD.

    -Applicability: All Model F28 series airplanes (all Marks and all 
serial numbers), certificated in any category. -
    Compliance: Required as indicated, unless accomplished previously. 
-
    To prevent degradation of aerodynamic lift during takeoff when 
icing conditions exist, accomplish the following: -
    (a) Within 10 days after the effective date of this AD, incorporate 
the following into the Limitations Section of the FAA-approved Airplane 
Flight Manual (AFM). This may be accomplished by inserting a copy of 
this AD in the AFM.

``Wing De-Icing/Anti-Icing Prior To Takeoff

CAUTION

    The Model F28 series airplane has a wing design with no leading 
edge high lift devices, such as slats. Wings without leading edge high 
lift devices are particularly susceptible to loss of lift due to wing 
icing. Minute amounts of ice or other contamination (equivalent to 
medium grit sandpaper) on the leading edges or upper wing surfaces can 
cause significant reduction in the stall angle-of-attack. This can 
increase stall speed up to 30 knots. The increased stall speed can be 
well above the stall warning (stick shaker) activation speed.
    Takeoff shall not be attempted unless the pilot-in-command has 
ensured that the aircraft surfaces are free of ice, frost, and snow 
accumulation, as required by sections 91.527 and 121.629 of the Federal 
Aviation Regulations (FAR).
    In addition, takeoff shall not be attempted when the Outside Air 
Temperature (OAT) is below 6 degrees C (Centigrade) [42 degrees F 
(Fahrenheit)]; and either the difference between the dew point 
temperature and OAT is less than 3 degrees C (5 degrees F), or visible 
moisture (rain, drizzle, sleet, snow, fog, etc.) is present, unless the 
operator complies with either OPTION 1 or OPTION 2, below:
OPTION 1
    The leading edge and upper wing surfaces have been physically 
checked for ice/frost/snow and the flight crew verifies that a visual 
check and a physical (hands-on) check of the leading edge and upper 
wing surfaces has been accomplished and that the wing is clear of ice/
frost/snow accumulation.

OR
OPTION 2
    The following takeoff procedure is used:

WARNING:

    The following technique cannot be used unless the pilot-in-command 
has ensured that the aircraft surfaces are free of ice, frost, and 
snow, as required by sections 91.527 and 121.629 of the FAR.
     (All Marks, except Mark 0100 and Mark 0070) When using 
flight director for takeoff, select HDG mode and 10 degrees pitch 
attitude.
     Select the largest flap setting that is permissible for 
the takeoff weight/altitude/temperature conditions.
     (All Marks, except Mark 0100 and Mark 0070) Use rated 
takeoff thrust.
     (Mark 0100 and Mark 0070) Use takeoff/go-around (TOGA) 
thrust.
     Do not use FLEXIBLE thrust.
     At VR rotate slowly (less than 3 degrees per second) 
to 10 degrees pitch attitude.
     When positively climbing, select gear UP.
     DO NOT EXCEED 10 DEGREES PITCH UNTIL AIRSPEED IS ABOVE 
V2+20 KTS.
     When above V2+20 KTS, slowly increase the pitch 
attitude, keeping the speed above V2+20 KTS.
     Retract the flaps at or above VFR + 20 KTS.

Notes to Option 2

    1. The available field length must be greater than or equal to 120 
percent of the takeoff distance required by regulation for the actual 
gross weight. Also, the 20 percent increase in takeoff distance must be 
accounted for in the obstacle clearance analysis. WEIGHT MUST BE OFF-
LOADED, IF NECESSARY, TO MEET THESE CONDITIONS.
    2. (Mark 0100 and Mark 0070) Do not follow the Flight Director 
pitch command during rotation for takeoff and initial climb, as this 
will result in exceeding the recommended maximum pitch angle of 10 
degrees before reaching the speed of V2+20 KTS.
    3. (Mark 0100 and Mark 0070) Do not engage the auto-pilot until 
leaving the Automated Flight Control and Augmentation System (AFCAS) 
takeoff (TO) mode.
    4. For the case of an engine failure, refer to the applicable 
procedure in Section 4.17.01 SINGLE ENGINE OPERATION of the F28 Mark 
0100 (Fokker 100) and F28 Mark 0070 (Fokker 70) AFM, or Section 1.7.4 
OPERATION UNDER ABNORMAL CONDITIONS of the F28 FHB, as applicable.
    5. During takeoff, the first indication of wing contamination will 
probably be airframe buffet when the pitch angle is increased above 10 
degrees, followed by wing drop and insufficient climb rate. DO NOT 
EXCEED 10 DEGREES PITCH UNTIL AIRSPEED IS ABOVE V2+20 KTS.''

    Note 1: If an operator elects to implement in its fleet only one 
of the two OPTIONS specified in this paragraph, the other OPTION 
does not have to be included in the Limitations Section of the AFM. 
However, the OPTION that is implemented must be incorporated in the 
AFM verbatim as it appears in this paragraph.

    -(b) Modification of the thermal anti-ice system so that it can be 
operated on the ground, in accordance with a method approved by the 
Manager, Standardization Branch, ANM-113, FAA, Transport Airplane 
Directorate, constitutes terminating action for the requirements of 
this AD.

    Note 2: Incorporation of the leading edge thermal anti-ice 
modification and associated operating instructions does not relieve 
the requirement that aircraft surfaces are free of ice, frost, and 
snow accumulation as required by sections 91.527 and 121.629 of the 
Federal Aviation Regulations (14 CFR 91.527 and 121.629).

    -(c) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be used 
if approved by the Manager, Standardization Branch, ANM-113. Operators 
shall submit their requests through an appropriate FAA Principal 
Operations Inspector, who may add comments and then send it to the 
Manager, Standardization Branch, ANM-113.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

     -(d) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 
21.197 and 21.199) to operate the airplane to a location where the 
requirements of this AD can be accomplished. -
    (e) This amendment becomes effective on December 21, 1994.

    Issued in Renton, Washington, on November 30, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-29921 Filed 12-5-94; 8:45 am]
BILLING CODE 4910-13-P