Airworthiness Criteria: Airship Design Criteria for Zeppelin Luftschifftechnik GmbH Model LZ N07 Airship, 16924-16944 [E8-6600]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 73, Number 62 (Monday, March 31, 2008)]
[Notices]
[Pages 16924-16944]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-6600]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration


Airworthiness Criteria: Airship Design Criteria for Zeppelin 
Luftschifftechnik GmbH Model LZ N07 Airship

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of issuance of final design criteria.

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SUMMARY: This document announces the issuance of final design criteria 
for the Zeppelin Luftschifftechnik GmbH model LZ N07 airship. The 
German aviation airworthiness authority, the Luftfahrt-Bundesamt (LBA), 
forwarded an application for type validation of the Zeppelin 
Luftschifftechnik GmbH Company KG (ZLT) model LZ N07 airship on October 
1, 2001. The airship will meet the provisions of the Federal Aviation 
Administration (FAA) normal category for airships operations and will 
be certificated for day and night visual flight rules (VFR); 
additionally, an operator of this airship may petition for exemption to 
operate the airship in other desired operations.

EFFECTIVE DATE: March 21, 2008.

FOR FURTHER INFORMATION CONTACT: Federal Aviation Administration, 
Attention: Mr. Karl Schletzbaum, Project Support Office, ACE-112, 901 
Locust, Kansas City, Missouri 64106; telephone: 816-329-4146; e-mail: 
karl.schletzbaum@faa.gov; facsimile (816) 329-4090.

SUPPLEMENTARY INFORMATION: 

Background

    Under the provisions of the Bilateral Aviation Safety Agreement 
(BASA) between the United States and Germany, the German aviation 
airworthiness authority, the Luftfahrt-Bundesamt (LBA), forwarded an 
application for type validation of the Zeppelin Luftschifftechnik GmbH 
Company KG (ZLT) model LZ N07 airship on October 1, 2001. The LZ N07 
has a rigid structure, 290,330 cubic foot displacement and has 
accommodations for twelve passengers and two crewmembers. The airship 
will meet the provisions of the FAA normal category for airships; 
additionally, an operator of this airship may petition for exemption to 
operate the airship in other desired operations. The airship will be 
certificated for day and night visual flight rules (VFR).

Discussion of Comments

    On April 10, 2007, the Federal Aviation Administration issued a 
notice of availability of proposed airworthiness design criteria for 
the ZLT model LZ N07 airship. The criteria was the certification basis 
accepted for the U.S. validated of the airship according to 14 CFR part 
21, Sec.  21.17(b). This criteria consisted of the German national 
standard Luftt[uuml]chtigkeitsforderungen f[uuml]r Luftschiffe der 
Kategorien Normal und Zubringer (LFLS) [Airworthiness Requirements: 
Normal and Commuter Category Airships] and equivalent requirements 
identified by the national aviation authority of Germany, the LBA.
    The notice was published for public comment on May 3, 2007 (72 FR 
24656). The comment period closed on June 4, 2007.
    A commenter from the airship design industry requested that we 
extend the comment period for the proposed design criteria. We agreed 
and issued the reopening of the comment period on July 7 and published 
a notice on July 16, 2007 (72FR 38858).
    Three commenters provided their comments on the notice. While the 
notice was not a notice of a regulatory change or requirement, the FAA 
is responding to the comments.
    Two commenters came from firms that proposed to operate airships. 
These comments were supportive of the standard and the process.
    The third commenter came from an airship manufacturer, which 
provided extensive comments as discussed below in the sections of the 
LFLS.

General Comment

    In its decision to accept the German LFLS certification 
requirements, the FAA has stated, ``the LFLS requirements are at least 
equivalent to and, in many cases, more conservative than the 
requirements for the normal category contained in the ADC.'' The LFLS 
requirements are for an airship designed to meet a ``commuter'' 
category for carrying passengers, hence a higher level of safety is 
appropriate. [Note: ADC means Airship Design Criteria.]
    By this statement, it is implied that the ZLT airship will meet a 
higher standard of certification, where in fact, the airship does not 
currently meet several critical safety requirements in both the LFLS 
and FAA-P-8110-2 Design Criteria. It has, therefore, been designed and 
accepted to a lesser standard.
    More importantly, several of the claims by ZLT to demonstrate an 
equivalent level of safety are not supported by reasonable argument but 
are really requests for exemption. They are also at odds with FAA 
determinations in previous U.S. airship certification programs in 
critical areas affecting safety of flight and in FAA efforts for 
standardization.
    In reviewing the ZLT exemptions, it also became apparent that the 
Zeppelin airship design is a significant departure from a conventional 
non rigid design. The industry and the FAA understand that the 
designation of conventional non rigid design implies a certain level of 
capability, especially in emergency conditions, and, therefore a 
certain level of operating environment has been granted. If the 
applicant continues to seek exemptions or if these exemptions are 
granted, it is more appropriate to call this airship a hybrid and, 
thus, issue special operating limitations, which limit the regime it 
can fly in.
    Generally, it is not understood why such latitude is being 
contemplated. In previous U.S. airship certification programs, the FAA 
has rigidly applied, and the airship industry has rigidly complied with 
certain fundamental airship certification requirements with no 
exemptions being granted. The ZLT airship certification program in 
Germany does not appear to have met some of these basic requirements. 
In addition, the FAA would appear to be

[[Page 16925]]

accepting the airship on the basis of the LFLS certification program 
without close scrutiny of the merits of the ZLT arguments for an 
equivalent level of safety.
    By accepting the ZLT claims, a precedent would be set. To compound 
the matter, the claims for a dispensation against the requirements are 
numerous in these critical safety areas, thereby having a cumulative 
affect and potentially compromising safety.
    FAA Response: The FAA reviewed the LFLS and the differences from 
this standard as applied by the LBA. We then, compared them to the 
currently accepted airship design criteria, the FAA-P-8110-2 Airship 
Design Criteria. The LFLS, with the additional or equivalent 
requirements applied by the LBA to the Zeppelin N07-100 (now referred 
to as the certification basis), was determined to provide the level of 
safety specified in 14 CFR part 21, Sec.  21.17(b).
    The certification basis criteria, as summarized in the notice, is 
accepted by the FAA as providing an equivalent level of safety, as 
specified by the 14 CFR part 21, Sec.  21.17(b), and is the accepted 
airworthiness criteria for the ZLT LZ N07-100 as defined in that part. 
In accepting this certification basis, the FAA considered the entire 
proposed certification basis, and does not consider equivalent levels 
of safety (for specific regulations), special conditions, or exemptions 
in this process, as the need to issue such regulatory processes are not 
required when accepting an airworthiness criteria in total for a 
special class aircraft. In this case, a criterion that had not been 
previously accepted, along with equivalencies granted by the local 
authority, was accepted as the airworthiness criteria and is the 
certification basis for this special class aircraft.
    The ZLT N07-100 airship is a rigid type airship that is capable of 
operations that have been previously type certificated by the FAA; the 
rigid structure is the only design feature that has not previously been 
type certificated. The FAA considers the noticed criteria suitable for 
the ZLT LZ N07 airship and does not consider it a hybrid type.

Technical Comments

    The commenter continued with specific technical comments on the 
notice criteria:
    These fundamental certification requirements where ABC [American 
Blimp Corporation] considers that ZLT are claiming an unreasonable 
equivalent level of safety are identified as follows:
    1. LFLS Section 881(a) and ADC paragraph 3.4--Proof of Structure
    2. LFLS Section 76 and ADC paragraph 2.11 Engine Failure and 
Ballast Requirements
    3. LFLS Section 893(b) and ADC paragraph 4.49 Ballast Requirements 
during Normal Flight.
    4. LFLS Section 143(b) and ADC paragraph 2.14(b)--No Engines--Safe 
Descent
    5. LFLS Section 673(d) and ADC paragraph 4.14(d)--No Mech Linkage--
Dual Redundancy.
    6. LFLS Section 881 (f) and ADC paragraph 4.43 (f)(g) Emergency 
Deflation
    7. LFLS Section 883(e) and ADC paragraph 4.44(e)--Air to helium 
Provision
    8. LFLS Section 2498(b) and ADC paragraph 6.25 Position Lighting
    (1) Comment:
    With respect to item 1 above, the commenter stated:

LFLS Section 881(a) and ADC paragraph 3.4--Proof of Structure

    The LFLS section 881(a) Envelope design requirement states that 
``The envelope must be designed to be pressurized and maintain 
sufficient super pressure (amount of envelope pressure in excess of 
ambient pressure) to remain in tension while supporting the limit 
design loads for all flight conditions and ground conditions''. ZLT 
claims that they should be exempt from this requirement because the 
structural integrity of the LZ N07 airship is not dependent on the 
envelope tension but on the structural integrity of the rigid 
structure. The structure must, therefore, be subject to a full 
structural load analysis and full-scale structural tests to ensure it 
meets the requirement. We are assuming that the FAA will verify that 
full-scale structural tests were carried out. (The ADC paragraph 3.4 
Proof of Structure requirement is very specific in this regard and 
states, ``Compliance with the strength and deformation requirements 
must be shown for each critical load condition. Structural analysis may 
be used only if the structure conforms to those for which experience 
has shown this method to be reliable.'')

FAA Response

    Under the Bilateral Aviation Safety Agreement (BASA) between the 
FAA and the LBA, the FAA can accept the provisions of the proposed 
certification basis and the method of compliance accepted by the LBA. 
In this case, the alternate requirements imposed by the LBA for LFLS 
section 881(a) are considered acceptable; the method of compliance was 
also accepted. The corresponding LFLS section to ADC section 3.4 is 
LFLS section 307. Compliance for these sections was accepted as applied 
by the LBA. A review of the LFLS requirements shows that structural 
testing is required for certain parts of the structure.
    (2) Comment:
    With respect to items 2 and 3 above, the commenter stated:

LFLS Section 76 and ADC Paragraph 2.11--Engine Failure and Ballast 
Requirements and LFLS 893(b) and ADC Paragraph 4.49--Ballast 
Requirements During Normal Flight

    The ADC paragraph 2.11 states ``The airship must be capable of 
rapidly restoring itself to a state of equilibrium following failure of 
one or more engines during any flight condition. Only designated 
ballast may be used.'' The FAA states ``ZLT met this requirement with 
an equivalent level of safety'' by demonstrating that a zero vertical 
speed condition can be established for any flight condition, by using 
the thrust vectoring capability of the remaining engines. Being able to 
only do this on one engine not on more engines is not equivalent. This 
equivalent level of safety claim ignores the essential airship 
capability to conduct a free balloon safe landing as required by LFLS 
893(b) and ADC paragraph 4.49.
    This requirement is applied to not only single engine failure but 
also the all-engine failure condition. The FAA in all previous Airship 
Certification programs in the U.S. has rigidly applied the requirement 
primarily because it is based on the airship's inability to glide to a 
safe landing or conduct an autorotation as in a helicopter.
    FAA Response:
    LFLS section 76 is slightly different than the ADC, in that the 
LFLS allows for the failure ``of any engine'' and the ADC specifies the 
failure of ``one or more engines.'' As the goal of the requirement is 
interpreted to be attaining a zero descent rate, the use of vectored 
thrust, as accepted by the LBA, was also accepted by the FAA as an 
acceptable approach.
    The provisions of LFLS section 893 apply if a ballast system is 
installed. The LZ N07-100 airship has a water ballast system, but it is 
not approved for in-flight use. For this reason, this section was not 
applied to the LZ N07-100 by the LBA. The FAA has accepted this 
position.
    (3) Comment:
    With respect to item 4, the commenter stated:

[[Page 16926]]

LFLS Section 143(b)--Safe Descent

    Section 143(b) and ADC paragraph 4.49 state that ``It must be shown 
that without engine power, a safe descent and landing under the 
conditions of section 561 can be made'' In the ZLT narrative, it is 
stated ``With the airship heavy there is no means to modulate the 
descent * * *.'' This (flying heavy) is a choice made by the applicant 
to make the airship more economically viable.
    The equivalent level of safety argument that ``A qualitative safety 
analysis will be performed to show that the simultaneous occurrence of 
a loss of all engines (combined with worst case weight conditions) is 
extremely improbable'' is inaccurate. It is not unrealistic to expect a 
total engine failure at maximum heaviness, as could be the case with 
fuel contamination. Indeed, total engine failure was experienced in an 
airship in the U.S. leading to a free balloon landing. This accident 
occurred one hour into the cross-country flight with the airship in a 
heavy static weight condition.
    Once again, the provisions of this and the previous LFLS section 76 
and ADC paragraph 2.11 are a basic airship design requirement and based 
on the airships inability to glide or conduct an autorotation. It is 
required to also protect people and property on the ground and not just 
the occupants of the airship. If the applicant continues to choose to 
seek an exemption to the safety requirements of a blimp it is more 
appropriate to call this airship a hybrid and thus issue special 
operating limitations, which limit the regime it can fly in to 
unpopulated areas or at higher altitudes over populated areas.
    FAA Response:
    LFLS section 143 is the applicable requirement which was again 
subject to an equivalent level of safety issued by the LBA, which 
allowed an analysis to show that an all engine failure in conjunction 
with the maximum heaviness was extremely improbable. This approach was 
also accepted by the FAA. It should be noted that even with all engines 
inoperative, the airship is still in compliance with LFLS section 561, 
Emergency Landing Conditions, General. As previously stated, the FAA 
does not consider this airship a hybrid type.
    (4) Comment:
    With respect to item 5 above, the commenter stated:

LFLS Section 673(d) and ADC Para 4.14(d)--No Mechanical Linkage--Dual 
Redundancy

    The LFLS section 673(d) requires that airship without a direct 
mechanical linkage between the cockpit and primary surfaces, be 
designed with a dual redundant control system. ABC does not understand 
why the following statement is made ``dual redundant is considered 
ambiguous in that it does not clearly define the degree of redundancy 
required.'' A dual redundant flight control system is a relatively 
straightforward concept that has been incorporated in many aircraft and 
the requirement seems quite unambiguous.
    It is also stated that compliance will be shown as ``continued safe 
flight and landing is assured after complete failure of any one of the 
primary flight control system lanes.'' This ignores the requirements of 
LFLS section 683(c) for the ``hard over'' condition. Any demonstration 
must include one of the control fins in a hard-over condition and not 
just one failed lane. The argument that vectored thrust is part of the 
primary flight control system then means that it too must comply with 
Dual Redundancy. Any use of vectorable engines is going to compromise 
the ability to maintain forward speed and limit this recovery 
capability.
    FAA Response:
    LFLS section 673(d) is the applicable requirement, in this case the 
LBA referred to the requirements for analysis for the control systems 
as specified in LFLS 1309 as adequate substantiation to show that 
compliance with LFLS 673(d) had been met. The design of the fly-by-wire 
control system of the airship was found to be compliant with LFLS 
673(d) when considering that the control system was compliant with LFLS 
1309. The FAA concurred with the approach.
    (5) Comment:
    With respect to item 6 above, the commenter stated:

LFLS Section 881(f) and ADC paragraph 4.43(f)(g)--Emergency Deflation

    LFLS Section 881(f) requires that provisions be maintained to allow 
for rapid envelope deflation on the airship should it break loose from 
the mast. ZLT's airship does not meet this requirement. ZLT's claim 
that the masthead design is fail proof is irrelevant if the airship 
tears apart behind the nose section and departs the mooring mast. It is 
not understood why this important design feature is not incorporated 
for the other reason that it can be used to ensure the airship stays on 
the ground in any emergency egress of passengers. This again, is a 
basic design requirement that, coupled with concessions against other 
design issues, adds to an overall compromised design standard. There is 
no reason this cannot be incorporated.
    FAA Response:
    The ADC and LFLS sections fundamentally have the same requirement. 
As the LZ N07-100 is a rigid type, envelope deflation is not considered 
a possible option in meeting the safety requirement of these sections. 
The LBA accepted that an analysis showing the safe life design of the 
mooring mast and its systems would be adequate to meet this requirement 
on an equivalent basis. The FAA accepted this as equivalent, with the 
additional requirement that the applicant also provide additional 
ground procedures for handling the airship on the ground, transponder 
activation and notification procedures in the case the airship was lost 
from the mast.
    (6) Comment:
    With respect to item 7 above, the commenter stated:

LFLS Section 883(e) and ADC Para 4.44(e)--Air to Helium Provision

    LFLS section 883(e) and ADC paragraph 4.44(e) requires that 
provisions be maintained to blow air into the helium space in order to 
prevent wrinkling of the envelope. The other purpose is to prevent the 
ballonet from overfilling and possibly rupturing. The ZLT airship does 
not meet this requirement. In the case of the ZLT airship, one of the 
ballonets rupturing could bring about a large center of gravity shift. 
This again, is a basic and essential airship requirement that should 
have been met.
    FAA Response:
    Again, the ADC and LFLS sections fundamentally have the same 
requirement. As the LZ N07-100 is a rigid type, pressurization of the 
envelope to prevent envelope wrinkling is not applied, as the rigid 
structure eliminates the need for this requirement. With respect to 
ballonet rupturing and center of gravity issues, this issue is not 
identified as a compliance goal for this section.
    (7) Comment:
    With respect to item 8, the commenter stated:

LFLS Section 2498(b) and ADC Para 6.25--Position Lighting

    LFLS Section 2498(b) and ADC paragraph 6.25 specify the position 
lighting requirements for airships. It is not understood why a 
dispensation should be given for something that can be easily fixed 
with properly TSO'd LED or similar lighting. ABC had to go through a 
stringent certification of the lighting on the one model. This was 
revisited in a new model and the FAA

[[Page 16927]]

asked ABC to modify our position lighting by providing two sets of bow 
lights in slightly different positions to further ensure adequate 
brilliance in all sectors. It is not understood why any latitude is 
being given to this basic legal requirement affecting safe navigation 
of aircraft.
    FAA Response:
    The FAA notes that there is no LFLS section 2498(b) and that the 
comparable LFLS section to ADC section 6.25 is LFLS section 1385. The 
only section where an equivalent level of safety to the LFLS lighting 
requirements was granted by the LBA is LFLS section 1387(b). The LBA 
granted this equivalency based on what was considered compensating 
features of the lighting system installed on the LZ N07-100, and the 
FAA agreed.

Conclusion

    After review of the provided comments, the FAA sees no need to 
modify the proposed airworthiness criteria. Accordingly, the 
airworthiness criteria, as issued on April 10, 2007, is adopted as the 
certification basis for the ZLT LZ N07-100 airship under the provisions 
of 14 CFR part 21, Sec.  21.17(b).
    The design criterion is shown below:

Design Criteria

Applicable Airworthiness Criteria Under 14 CFR part 21

    The only applicable requirement for airship certification in the 
United States is FAA document FAA-P-8110-2, Airship Design Criteria 
(ADC). This document has been the basis of bilateral validation of 
airships between Germany and the United States for many years. However, 
in 1995, the LBA issued the initial version of the 
Luftt[uuml]chtigkeitsforderungen f[uuml]r Luftschiffe der Kategorien 
Normal und Zubringer, (hereafter referred to as the LFLS), which added 
a commuter category to German airship categories and also added 
additional requirements for normal category airships. Due to this, 
where the previously mutually accepted ADC can be considered to be 
harmonized in practice, the issuance of the LFLS created regulatory 
differences for normal category airships between the United States and 
Germany.
    In keeping with its bilateral obligations, the FAA has, with 
assistance from the LBA, determined that regulatory differences exist 
between the two requirements (ADC versus LFLS). This determination is 
the Significant Regulatory Differences analysis. In the case of the LZ 
N07 airship, the German certification was accomplished to the higher 
standard of the commuter category of the LFLS, with various LBA 
modifications and additions. The FAA desires to accept the Zeppelin 
airship model LZ N07 at the same airworthiness standard as it was 
certificated to in Germany, so we have decided to accept the 
requirements of the LFLS and the supplemental requirements issued by 
the LBA as the U.S. certification basis. With this decision, the bulk 
of the regulatory differences are not relevant, as the FAA is accepting 
the provisions of the German LFLS certification in the commuter 
category in its entirety. The FAA has, after comparing the normal 
category ADC to the commuter category LFLS requirements, determined 
that all of the LFLS requirements are at least equivalent to and, in 
many cases, more conservative than the requirements for normal category 
contained in the ADC.

Regulatory Differences

    The LFLS was developed considering the ADC at Change 1, but Change 
2 provisions were not considered. There will be one regulatory 
difference due to this; ZLT will show compliance to ADC Sec.  4.14 at 
Change 2.

Additional and Alternative Requirements

    The German aviation authority, the Luftfaht-Bundesamt (LBA) issued 
additional requirements, special conditions, and equivalent levels of 
safety to deal with certain design provisions and airworthiness 
concerns specific to the design of the LZ N07 that were not anticipated 
by the LFLS. These requirements will also become part of the U.S. 
certification basis for this airship.
    The U.S. certification basis for the LZ N07 was proposed as an 
entire certification basis, including those changes required by the FAA 
and the LBA. Based on the provisions of 14 Code of Federal Regulations 
(CFR) part 21, Sec. Sec.  21.17(b), 21.17(c) and 21.29, the following 
airworthiness requirements were evaluated and found applicable, 
suitable, and appropriate for this design, and they remained active 
until August 31, 2007, the FAA has now extended the project termination 
date to May 31, 2008 and the requirements will stay active until that 
date.
    The German regulation Luftt[uuml]chtigkeitsforderungen f[uuml]r 
Luftschiffe der Kategorien Normal und Zubringer, (referred to as the 
LFLS), effective April 13, 2001; except:
    (1) In lieu of compliance to LFLS Sec.  673 the LZ N07 will comply 
with ADC Sec.  4.14.
    (2) B-1 LBA, Equivalent Safety Finding for Sec.  76 LFLS, Engine 
Failure.

Discussion

    The LFLS requires that the airship restore itself to a state of 
equilibrium after the failure of any one engine during any flight 
condition. In the case of the LZ N07, a state of equilibrium using 
designated ballast cannot be achieved as required by the LFLS. ZLT met 
this requirement with an equivalent level of safety.
    In lieu of the provisions of LFLS Sec.  76 the following is 
required:
    In the case of failure of any one engine (of three) it must be 
shown that a zero vertical speed condition can be established for any 
flight condition by using the thrust vectoring capability of the 
remaining two engines and aerodynamic lift.
    The time to achieve this zero vertical speed will be demonstrated 
to be not more than when using a designated ballast system with a 
minimum discharge rate established in LFLS Sec.  893(d).
    (3) B-2 LBA, Equivalent Safety Finding for LFLS Sec.  143(b), 
Controllability and Maneuverability, General [all engines out].

Discussion

    LFLS Sec.  143(b) requires that the airship be capable of a safe 
descent and landing after failure of all engines under the conditions 
of LFLS Sec.  561. ZLT met this requirement with an equivalent level of 
safety.
    Even in the event of all engines failing, a limited means to 
control the descent of the airship is available, but only with the 
airship in equilibrium. With the airship heavy, there is no means to 
modulate the descent once speed has dissipated, since the descent rate 
is determined by heaviness only. However, descent will be stable and no 
unsafe attitude will result and the worst-case descent rate is still in 
compliance with the emergency landing conditions of LFLS Sec.  561. 
This fulfills the safety objective of LFLS Sec.  143(b).
    To satisfy the provisions of LFLS Sec.  143(b), the following is 
required:
    A qualitative safety analysis will be performed to show that the 
simultaneous occurrence of a loss of all engines (combined with worst 
case weight conditions) is extremely improbable.
    (4) B-3 LBA, Equivalent Safety Finding for LFLS Sec.  33(d)(2), 
Propeller Speed and Pitch Limits.

Discussion

    LFLS Sec.  33(d)(2) requires a demonstration with the propeller 
speed control inoperative that there is a means to limit the maximum 
engine speed to

[[Page 16928]]

103 percent of the maximum allowable takeoff rotations per minute 
(rpm). The LZ N07 is designed so that in case of a zero thrust 
condition in flight, the affected engine is shut off. The shutoff rpm 
is above 103 percent of the maximum allowable takeoff rpm.
    The LZ N07 airship is not equipped with a traditional propeller 
governor system. The propeller speed control function is provided by 
the AIU (engine control board). If the AIU fails, a means to shut down 
the engine is provided: called the Limiting System (Lasar). The 
limiting system provides two functional stages; the first stage limits 
rpm between 2725 and 2750, in case the AIU engine control board is 
unable to limit engine speed with the propeller in zero thrust pitch 
condition. The second stage shuts down the engine at 2900 rpm in case 
of limiting system first stage failure in order to avoid engine and 
propeller disintegration hazard to the airship. The shutdown of one 
engine is considered a major hazard. (Note: maximum rpm = 2700, 103 
percent maximum rpm = 2781.)
    In traditional governor systems during in-flight operation with 
zero thrust pitch selected, overspeed protection is not assured in case 
of a governor failure. The LZ N07 design is considered to provide 
equivalent or improved safety compared to previously certified 
(traditional) governor systems.
    To satisfy the provisions of LFLS Sec.  33(d)(2), the following is 
required:
    The proper function of the systems will be demonstrated by 
performing a system ground test simulation.
    The propeller overspeed capability of 126 percent of the maximum 
rpm will comply with the provisions of JAR P certification, (JAR P 
Sec.  170(a)(2)).
    (5) B-4 LBA, Equivalent Safety Finding for LFLS Sec.  145, 
Longitudinal Control.

Discussion

    LFLS Sec.  145 requires a demonstration of nose-down pitch change 
out of a stabilized and trimmed climb and 30 degree pitch angle at 
maximum continuous power and a nose-up pitch change out of a stabilized 
and trimmed descent and -30 degree pitch angle at maximum continuous 
power on all engines. ZLT met this requirement with an equivalent level 
of safety. The LZ N07 ballonet system limitations prevent stabilized 
climbs or descents above certain vertical speeds. The procedure 
required in LFLS Sec.  145 cannot be demonstrated by flight test 
without modification.
    ZLT demonstrated through flight test that sufficient control 
authority was available to recover from a steep climb or descent when 
the airship is trimmed for the appropriate climb or descent and is 
operated under maximum continuous power.
    Additionally, it was also shown that it is possible to produce a 
nose-down pitch change out of a stabilized and trimmed climbing flight 
and a nose-up pitch change out of a similar descent. The LZ N07 
ballonet systems limitations prevent this from being demonstrated at 
maximum continuous power and 30-degree pitch angle because the climb or 
descent rates are too high at the resulting airspeed.
    To satisfy the provisions of LFLS Sec.  145 the following is 
required:
    A flight test procedure will demonstrate that it is possible to 
produce:
    (1) A nose-down pitch change out of a stabilized climb with a nose-
up flight path angle as limited by the ballonet system for the relevant 
true airspeed or 30 degrees, whichever leads to a lower absolute value.
    (2) A nose-up pitch change out of a stabilized descent with a nose-
down flight path angle as limited by the ballonet system for the 
relevant true airspeed or -30 degrees, whichever leads to a lower 
absolute value.
    (6) C-1 LBA, Additional Requirement for a Reliable Load Validation; 
14 CFR part 25, Sec.  25.301(b).

Discussion

    The present LFLS does not include the requirement for the 
manufacturer to validate the load assumptions used for stress analyses. 
14 CFR part Sec.  25.301(b) requires that methods used to determine 
load intensities and distribution must be validated by flight load 
measurement unless the methods used for determining those loading 
conditions are shown to be reliable.
    The following is added as an additional requirement:
    The provisions of 14 CFR part 25, Sec.  25.301(b) will be complied 
with.
    (7) D-1 LBA, Additional Requirements for LFLS Sec.  853(a), 
Compartment Interiors [Flammability of Seat Cushions].

Discussion

    LFLS Sec.  853 does not provide requirements for flammability 
standards for seat cushions as introduced by Amendment 59 of 14 CFR 
part 25. The LBA requested a proof test for seat cushions with the oil 
burner as specified in 14 CFR part 25, Appendix F, part II or 
equivalent for passenger seats, except for crew seats.
    To satisfy the provisions of LFLS Sec.  853(a), the following is 
required:
    A proof test for seat cushions with the oil burner as specified in 
14 CFR part 25, Appendix F, part II or equivalent for passenger seats 
will be performed successfully.
    (8) D-5 LBA, Additional Requirements for LFLS Sec.  673(d), Primary 
Flight Controls.

Discussion

    LFLS Sec.  673(d) requires that airships without a direct 
mechanical linkage between the cockpit and primary flight control 
surfaces be designed with a dual redundant control system. The 
terminology ``dual redundant'' is considered ambiguous in that it does 
not clearly define the degree of redundancy required.
    To satisfy the provisions of LFLS Sec.  853(a), the following is 
required:
    Compliance with LFLS Sec.  1309 will show that continued safe 
flight and landing is assured after complete failure of any one of the 
primary flight control system lanes.
    (9) D-6 LBA, Equivalent Safety Finding for LFLS Sec.  771(c), Pilot 
Compartment [Controls Location with Respect to Propeller Hub].

Discussion

    LFLS Sec.  771(c) requires that aerodynamic controls and pilots may 
not be situated within the trajectories of the designated propeller 
burst area. Since a thrust vectoring (including a non-swiveling lateral 
propeller) system has been incorporated into the airship, with two 
engines forward and one aft engine, formal non-compliance in some cases 
cannot be avoided.
    To satisfy the provisions of LFLS Sec.  771(c), the following is 
required:
    A qualitative safety analysis will be accomplished that considers 
the mitigating effects of:
    (1) The relationship of overall swivel angle of propeller 
rotational plane versus crucial swivel angle of propeller rotational 
plane,
    (2) The distance between aft propeller and aerodynamic controls, 
and
    (3) The potential energy absorbing and deflecting structure between 
aft propulsion unit and controls and pilot.
    The analysis will consider the following:
    The lateral propeller is continuously operating in idle with the 
exception of ground maneuvering and approach phases.
    The rear propeller transitions through its crucial angle only, 
while swiveling from the horizontal to the vertical position from a 
takeoff/approach/landing/hover to a level flight configuration.
    Aircraft Flight Manual (AFM) procedures, cockpit placarding, and 
swivel lever markings shall be

[[Page 16929]]

established to restrict normal operation in the crucial swivel range.
    (10) D-7 LBA, Equivalent Safety Findings for LFLS Sec.  777(c), 
Cockpit Controls; 1141(a), Powerplant Controls: General; 1143(c), 
Engine Controls; 1149(a)(2), Propeller Speed and Pitch Controls; 
1167(c)(1), Vectored Thrust Controls.

Discussion

    LFLS Sec.  777(c), 1141(a), 1143(c), 1149(a)(2), and 1167(c)(1) all 
involve requirements governing the configuration and characteristics of 
throttle, propeller pitch, mixture, and thrust vectoring controls. Due 
to the constant speed throttle control concept allowing infinitely 
variable thrust vector control between maximum reverse and maximum 
forward thrust, a non-conventional control system was developed that is 
partially non-compliant with the requirements. The requirements and the 
configuration of the LZ N07 are summarized in Table 1 below.
    To satisfy the provisions of LFLS Sec.  777(c), 1141(a), 1143(c), 
1149(a)(2) and 1167(c)(1) the following is required:
    In the case of an identified non-compliance to the LFLS, as shown 
in Table 1, compliance will be by an evaluation of the airship and a 
finding that there are safe handling characteristics using the type 
design engine thrust control/thrust vectoring controls as described in 
Table 1.

                                                     Table 1
----------------------------------------------------------------------------------------------------------------
                                                      Compliant/non-         Description of equivalent level of
    LFLS paragraph            Requirement               compliant                     safety finding
----------------------------------------------------------------------------------------------------------------
 777(c)..............   throttle, propeller       1. non-compliant......   Propeller speed, thrust, and mixture
                        pitch, mixture            2. compliant..........   controls are arranged in this order
                        controls:.                                         from left to right. Propeller speed
                        1. order left to right.                            and mixture are grouped together
                        2. arrange to prevent                              forward of the THRUST levers because
                        confusion.                                         they are preset for individual
                                                                           operating conditions. The THRUST
                                                                           levers are located separately with
                                                                           the L/H and R/H THRUST levers and
                                                                           swivel controls grouped together in
                                                                           order to achieve convenient vector
                                                                           operation.
                                                                           Rear engine thrust control set is
                                                                           offset to the rear of the center
                                                                           pedestal, which makes its allocation
                                                                           to the rear engine obvious.
 1141(a).............   1. arrangement like 777   1. compliant as          See 777(c) above; compliant.
                        2. markings like          described above.
                        1555(a).                  2. compliant..........
 1143(c).............   1. separate control of    1. compliant..........   1. compliant
                        engines.                  2. simultaneous          2. simultaneous control of forward
                        2. simultaneous control   control virtually        engines allows for symmetric thrust
                        of engines.               compliant.               applications, which are essential for
                                                                           effective handling of the airship.
                                                                           The aft engine THRUST lever is not
                                                                           located between the forward THRUST
                                                                           levers because it requires individual
                                                                           control especially during take-off,
                                                                           hover, landing and ground
                                                                           maneuvering. Unintentional operation
                                                                           of the aft engine is prevented by
                                                                           this arrangement.
 1149(a).............   simultaneous speed and    Non-compliant for take-  In contrast to conventional propeller
                        pitch control of          off, hover, landing,     controls, a constant propeller pitch
                        propellers.               and ground maneuvering.  is commanded directly by the THRUST
                                                                           lever and propeller speed is
                                                                           preselected by the RPM lever and is
                                                                           automatically governed by means of
                                                                           throttle variation.
                                                                           In this operating mode, full RPM is
                                                                           selected and pitch control is
                                                                           commanded directly from the THRUST
                                                                           levers, which are not grouped
                                                                           together, thus not allowing
                                                                           simultaneous pitch control. The
                                                                           reason for this arrangement is
                                                                           explained in issue 1143(c) above, In
                                                                           FLIGHT configuration maximum pitch is
                                                                           preselected by the THRUST levers,
                                                                           speed control is now accomplished by
                                                                           movement of the RPM levers, which are
                                                                           grouped together allowing
                                                                           simultaneous speed control.
 1167(c)(1)..........   Thrust vectoring:......   1. compliant..........   1. compliant.
                        1.--independent of        2. non compliant......   2. simultaneous vectoring control of
                        other controls.                                    forward engines allows for symmetric
                        2.--separate and                                   vectoring. Asymmetric control of
                        simultaneous control of                            forward swivel angle is made
                        all propulsion units.                              impossible in order to prevent pilot
                                                                           confusion during vector control.
                                                                           Aft swivel adjustment is limited to 0
                                                                           for cruise and -90 for T/L. The aft
                                                                           swivel is separated due to the
                                                                           individual control requirement.
----------------------------------------------------------------------------------------------------------------

    (11) D-8 LBA, Equivalent Safety Findings for LFLS Sec.  807(d) and 
Sec.  807(d)(1)(i), Emergency Exits.

Discussion

    LFLS Sec.  807(d) and (d)(1)(i) for commuter category airships 
carrying less than 15 passengers requires at least three emergency 
exits. Refer to Table 2.

                                                     Table 2
----------------------------------------------------------------------------------------------------------------
      Category versus exits                First exit                Second exit               Third exit
----------------------------------------------------------------------------------------------------------------
Normal Category (Less than 10      External door/Main door:   One exit 19 x 26 inches   No requirement.
 passengers.).                      Sec.   783(a) (19 x 26     opposite of main door:
                                    inches).                   Sec.   807(a)(1).

[[Page 16930]]

 
 Commuter Category (Less than 15   Main door must be floor    Same as above...........   In addition one exit 19
 passengers.).                      level: Sec.   807(d)(1).                             x 26 required.
 Commuter Category Zeppelin LZ     Floor level main door      Second floor level main   Not provided. Equivalent
 N07. Design comprising 12          much larger as 19 x 26     door much larger as 19    safety requested for
 passengers.                        inches provided.           x 26 inches provided.     greater than 9
                                                                                         passengers.
----------------------------------------------------------------------------------------------------------------

    The design of the LZ N07 fully complies with the requirement for 
the Normal Category; however, the third exit required for compliance in 
the Commuter Category is not provided. This results in a formal 
noncompliance.
    To satisfy the provisions of LFLS Sec.  807(d) and 807(d)(1)(i), 
the following is required:
    Compliance for LFLS Sec.  807(d) and 807(d)(1)(i) will be shown by:
    (1) The first and second exits provided are both floor level exits 
and oversized compared to 19 by 26 inches.
    (2) The evacuation demonstration required in Sec.  803(e) shall be 
accomplished within 60 seconds, (with one exit blocked) instead of 90 
seconds.
    (12) D-9 LBA, Equivalent Safety Finding for Sec.  881(a), Envelope 
Design [Envelope Tension].

Discussion

    LFLS Sec.  881(a) requires that the envelope maintain tension while 
supporting limit load conditions for all flight conditions. The rigid 
design of the LZ N07 allows for limited wrinkling of the envelope under 
limit load conditions with no effect on airship handling and 
performance.
    Due to the unique kind of rigid structural design, the structural 
integrity of the LZ N07 airship is not dependent on the tension of the 
envelope, as rigid structure replaces the load-carrying envelope. The 
alignment of structure, engines, empennage, cabin and other components 
affecting handling qualities, performance, and other factors is 
independent of any wrinkling condition of the envelope.
    To satisfy the provisions of LFLS Sec.  881(a), the following is 
required:
    Safe handling characteristics will be demonstrated by flight test, 
the limit load carrying capability by analysis.
    (13) D-10 LBA, Equivalent Safety Finding for LFLS Sec.  881(f), 
Envelope Design [Rapid Deflation Provisions].

Discussion

    LFLS Sec.  881(f) requires that provisions be maintained to allow 
for rapid envelope deflation of the airship should it break loose from 
the mast while moored. The present design does not include such a 
provision. For German certification, ZLT had to demonstrate an 
equivalent level of safety. As part of this, ZLT presented that, due to 
the unique kind of rigid structural design of the airship, any rapid 
deflation provision will not significantly reduce the effective cross 
section of the envelope; thus, the uncontrolled drift of the airship 
due to surface winds once free of its moorings could not be brought 
under control. ZLT presented that the overall level of safety is 
negatively affected by the potential unwanted operation of the required 
rapid deflation provision when unintentionally operated or operated due 
to individual failure conditions, and that this could lead to a 
potentially severe failure condition.
    ZLT was required by the LBA to provide an equivalent level of 
safety by means of a qualitative safety analysis and by showing that 
the reliability of the mast coupling system design is significantly 
improved over typical non-rigid airship systems. It also provided proof 
of safe life design for the structural parts and to prove the fail-safe 
design of the hydraulically powered locking mechanism. These systems 
are part of the ground based mooring vehicle.
    We understand that the rigid structure of the airship complicates 
or eliminates the deflation design feature expected of non-rigid types 
of airships, and we believe that this requirement cannot be met without 
an equivalent level of safety. The rapid deflation feature of a non-
rigid airship is provided to allow emergency egress without the ship 
lifting and to deflate the envelope in case an airship is blown off of 
the mast and is subsequently uncontrolled. These concerns still apply 
to a rigid airship.
    We accept the evacuation procedure, described in the section 
discussion LFLS Sec.  809(e), as an acceptable equivalent feature for 
the evacuation requirement.
    In the event that the airship is blown off of the mast, we believe 
that a rigid airship will present the same or enhanced hazard as the 
requirement for non-rigid type airships was developed to mitigate, that 
being of an unmanned and, or, uncontrolled airship in controlled 
airspace in the proximity of persons, property, or other aircraft.
    To satisfy the provisions of LFLS Sec.  881(f), the following is 
required:
    Safe life design for the structural parts and fail-safe design of 
the hydraulically powered locking mechanism of the mooring vehicle will 
be shown.
    The Airship Flight Manual will contain mast procedures for all 
approved mast mooring conditions. These procedures will also include a 
requirement to have transponder equipment active when the airship is 
moored on the mast, and define conditions when a pilot must be in the 
airship.
    (14) D-11 LBA, Equivalent Safety Finding for LFLS Sec.  883(e), 
Pressure System.

Discussion

    LFLS Sec.  883(e) requires that provisions be maintained to blow 
air into the helium space in order to prevent wrinkling of the 
envelope. The present design of the airship does not include this 
provision; therefore, ZLT had to demonstrate equivalent level of 
safety.
    Due to the unique kind of rigid structural design, the structural 
integrity of the airship is not dependent on the tension of the 
envelope. Rigid structure replaces the load-carrying envelope. The 
alignment of structure, engines, empennage, and cabin, etc., affecting 
handling qualities and airship controllability is independent of any 
wrinkling condition of the envelope.
    To satisfy the provisions of LFLS Sec.  883(e), the following is 
required:
    Safe operation at reduced helium pressures will be demonstrated.
    (15) D-12 LBA, Interpretation of LFLS Sec.  785(b), Seats, berths 
and safety belts [Approval of].

Discussion

    The LFLS requires approval for seats; the LBA required approval of 
passenger and crew seats according to TSO C39b. The ZLT uses seats that 
are TSO C39b approved by a seat vendor; if this is not done, the seats 
used will demonstrate compliance to TSO C39b.
    To satisfy the provisions of LFLS Sec.  758(b), the following is 
required:
    Seats will comply with the provisions of TSO C39b.

[[Page 16931]]

    (16) D-13 LBA, Additional Requirement; LFLS Sec.  1585(a)(10), 
Operating Procedures [Ditching, Emergency Evacuation].

Discussion

    The LFLS does not provide requirements for ditching exits; the LBA 
requested a floatation analysis to be done, to analyze the case of an 
unplanned ditching. Helium loss during the emergency evacuation 
procedure was not considered. It was determined by calculation that the 
passenger cabin provides enough buoyancy for safe egress with the 
requirement that one emergency exit shall be usable above the static 
waterline for at least 90 seconds for emergency evacuation.
    To satisfy the provisions of LFLS Sec.  758(b), the following is 
required:
    It shall be demonstrated by test or analysis that an emergency 
evacuation exit will remain above the waterline for at least 90 seconds 
after finally settling on the water. Relevant instructions will be 
included in the Airship Flight Manual.
    (17) D-14 LBA, Interpretative Material; LFLS Sec.  803(e), 
Emergency Evacuation Demonstration.

Discussion

    LFLS Sec.  803(e) requires an emergency evacuation demonstration. 
This evacuation must be completed within 90 seconds. Compliance with 
LFLS Sec.  881(g) must be considered in conjunction with Sec.  803(a) 
through (e).
    This requirement demonstrates the ability of the entire cabin to be 
evacuated within 90 seconds using the maximum number of occupants, with 
flight crew preparation for the emergency evacuation. Normal valving of 
helium to provide emergency deflation on the ground during the 
emergency evacuation, according to Sec.  881(g), is assumed.
    To satisfy the provisions of LFLS Sec.  803(e), the following is 
required:
    (1) It will be demonstrated that the cabin can be emergency 
egressed within 90 seconds.
    (2) In addition, the evacuation method established will include the 
preparation of the airship for the ground phase of the emergency 
evacuation on the ground. The applicant will demonstrate by analysis 
supported by tests that the preparation for cabin emergency evacuation 
could be conducted within 30 seconds (from time of landing until start 
of cabin emergency evacuation). This technique will be published in the 
AFM. Refer to Figure 1, ``ZLT Emergency Evacuation Technique.'' 
[GRAPHIC] [TIFF OMITTED] TN31MR08.000

    (3) The evacuation method established will include four steps:
    (a) After the occurrence of the emergency situation, the pilot has 
to prepare the airship for an emergency landing.
    (b) The pilot has to land the airship.
    (c) The pilot has to prepare the airship for the evacuation. This 
includes providing enough heaviness so that the airship cannot leave 
the ground during the passenger evacuation. Also, the pilot must keep 
the airship in a safe position before starting the evacuation. By 
controlling the deflation, the pilot must try to prevent trapping of 
the envelope over the occupants during the evacuation.
    (d) The actual evacuation will only begin when a safe position of 
the airship can be maintained and when enough heaviness is provided.
    These steps will be reflected in the AFM.
    (18) D-15 LBA, Additional Requirements; 14 CFR part 23, Sec. Sec.  
23.859 and 23.1181(d), [cabin heating; fuel burner].

Discussion

    ZLT wishes to install fuel burner heating equipment for a cabin 
heating and ventilation system in the lower shell of the passenger 
cabin. The LFLS does not provide adequate requirements for the 
installation of fuel burner equipment. The LBA required the application 
of 14 CFR part 23, Sec. Sec.  23.859 and 23.1181(d), revised as of 
January 1, 1998, in addition to other applicable requirements of the 
LFLS. The LBA interpretation of Sec.  23.859(a) is such that the entire 
heater compartment will be considered a fire region and has to be of 
fireproof construction. Part 23 Sec.  23.859, paragraphs (a)(1) to 
(a)(3), will be complied with also. Other applicable FAA regulations 
introduced by reference to Sec. Sec.  23.859 and 23.1181(d) by

[[Page 16932]]

the LBA will be complied with by compliance to applicable LFLS 
sections.
    The airship will comply with the provisions of 14 CFR part 23, 
Sec.  23.859, Combustion Heater Fire Protection, and Sec.  23.1181(d), 
Firewalls.
    (19) E-1 LBA, Additional Requirements Remote Propeller Drive 
System.

Discussion

    The LZ N07 propellers of both forward and aft propulsion systems 
are not conventionally installed directly on the engine crankshaft. A 
remote propeller drive system consisting of torque shafts, swivel 
gears, friction clutches and a belt drive unit (on the aft engine only) 
is installed between engine and propeller to provide thrust and vector 
capability for the propellers. The LFLS does not contain requirements 
for such power transmission designs.
    The LBA required compliance as described in LBA guidance paper I-
231-87, applicable to components installed between engines and 
propellers. I-231-87(01) requires compliance with JAR 22H or 14 CFR 
part 33; however, instead of JAR 22H or 14 CFR part 33 compliance, 
compliance with applicable sections of JAR P (Change 7) as listed in 
Table 3 will be required.

                               Table 3.--Applicable Sections of JAR P and I-231-87
----------------------------------------------------------------------------------------------------------------
                               Section                                                  Summary
----------------------------------------------------------------------------------------------------------------
I-231-87............................................................  Remote torque shafts/Fernwellen.
I-231-87(01)........................................................  Alle Bauteile zwischen Motor und Propeller
                                                                       FAR 33.
I-231-87(02)........................................................  Kr[auml]fte auf k[uuml]rzestem Weg in
                                                                       tragende Bauteile.
I-231-87(03)........................................................  Konstruktive Ma[beta]nahmen gegen
                                                                       ungleiche Dehnung.
I-231-87(04)........................................................  Bei Drehgelenken ungleichf[ouml]rm.
                                                                       Drehbewegung meiden.
I-231-87(05)........................................................  Abstand Struktur zu rotierenden Teilen
                                                                       >13mm.
I-231-87(06)........................................................  FVB: Erweichungstemperatur TGA nicht
                                                                       [uuml]berschreiten.
I-231-87(07)........................................................  Nicht feuersichere Wellen: Feuerschutz zum
                                                                       Motor.
I-231-87(08)........................................................  Keine Gef[auml]hrdung durch angetr. Rest
                                                                       gebroch. Welle.
I-231-87(09)........................................................  Unterkritischer Lauf/Kritische Drehzahl
                                                                       1,5*nmax.
I-231-87(10)........................................................  Schwingungsversuch mit Anla[beta]-
                                                                       Abstellvorg[auml]ngen.
JAR-P...............................................................  Propellers: Change 7, dated 22.10.87.
JAR-P01.............................................................  Section 1--Requirements.
JAR-P01 1A..........................................................  SUB-SECTION A--GENERAL
JAR-P030(a)(1)......................................................  Specification detailing airworthiness
                                                                       requirements.
JAR-P040(b).........................................................  Fabrication methods.
JAR-P040(b)(1)......................................................  Consistently sound structure and reliable.
JAR-P040(b)(2)......................................................  Approved process specifications, if close
                                                                       control required.
JAR-P040(c).........................................................  Castings.
JAR-P040(c)(1)......................................................  Casting technique, heat treatment, quality
                                                                       control.
JAR-P040(c)(2)......................................................  AA Approval for casting production
                                                                       required.
JAR-P040(e).........................................................  Welded structures and welded components.
JAR-P040(e)(1)......................................................  Welding technique, heat treatment, quality
                                                                       control.
JAR-P040(e)(3)......................................................  Drawings annotated and with working
                                                                       instructions.
JAR-P040(e)(4)......................................................  If required, radiographic inspection, may
                                                                       be in steps.
JAR-P070............................................................  Failure analysis.
JAR-P070(a).........................................................  Failure analysis/assessment of propeller
                                                                       and control systems.
JAR-P070(b)(2)......................................................  Significant overspeed or excessive drag.
JAR-P070(c).........................................................  Proof of probability of failure.
JAR-P070(e).........................................................  Acceptability of failure analysis, if more
                                                                       on 1 of:
JAR-P070(e)(1)......................................................  A safe life being determined.
JAR-P070(e)(2)......................................................  A high level of integrity, parts to be
                                                                       listed.
JAR-P070(e)(3)......................................................  Maintenance actions, serviceable items.
JAR-P080............................................................  Propeller pitch limits and settings.
JAR-P090............................................................  Propeller pitch indications.
JAR-P130............................................................  Identification.
JAR-P140............................................................  Conditions applicable to all tests.
JAR-P140(a).........................................................  Oils and lubricants.
JAR-P140(b).........................................................  Adjustments.
JAR-P140(b)(1)......................................................  Adjustments prior to test not be altered
                                                                       after verification.
JAR-P140(b)(2)......................................................  Adjustment and settings checked/
                                                                       unintentional variations recorded.
JAR-P140(b)(2)(i)...................................................  At each strip examination.
JAR-P140(b)(2)(ii)..................................................  When adjustments and settings are reset.
JAR-P140(b)(3)......................................................  Instructions for (b)(1) proposed for
                                                                       Manuals.
JAR-P140(c).........................................................  Repairs and replacements.
JAR-P140(d).........................................................  Observations.
JAR-P150............................................................  Conditions applicable to endurance tests
                                                                       only.
JAR-P150(a).........................................................  Propeller accessories to be used during
                                                                       tests.
JAR-P150(b).........................................................  Controls (ground and flight tests).
JAR-P150(b)(1)......................................................  Automatic controls provided in operation.
JAR-P150(b)(2)......................................................  Controls operated in accordance with
                                                                       instructions.
JAR-P150(b)(3)......................................................  Instructions provided in Manuals.
JAR-P150(c).........................................................  Stops (ground tests).
JAR-P160............................................................  General.
JAR-P160(b).........................................................  Pass without evidence of failure or
                                                                       malfunction.
JAR-P160(c).........................................................  Detailed inspection before and after tests
                                                                       complete.
JAR-P170(c).........................................................  Spinner, deicing equipment, etc., subject
                                                                       to same test.

[[Page 16933]]

 
JAR-P190(c).................................