Manifold Pressure requirements.

Blip16

Well-Known Member
so the reason i bring this is up, is i have been looking thru the Data Cert for the PA44 under how it was certified; which i assume then is all the requlations that were met for certifciation AND for operation??????

91.205
(8) Manifold pressure gauge for each altitude engine.

23.1305 (b)(5)
(5) A manifold pressure indicator for each altitude engine and for each engine with a controllable propeller.
 
so the reason i bring this is up, is i have been looking thru the Data Cert for the PA44 under how it was certified; which i assume then is all the requlations that were met for certifciation AND for operation??????

91.205

23.1305 (b)(5)

Seminole does not have an altitude engine, and I am not familiar with part 23, (just looked it up). So does this mean the manifold pressure guage was required for certification but not for flight?
 
Seminole does not have an altitude engine, and I am not familiar with part 23, (just looked it up). So does this mean the manifold pressure gauge was required for certification but not for flight?

91.213 requires that everything required for certification is required for flight:

91.213 Inoperative instruments and equipment.
...

(2) The inoperative instruments and equipment are not—
(i) Part of the VFR-day type certification instruments and equipment prescribed in the applicable airworthiness regulations under which the aircraft was type certificated;
 
91.213 requires that everything required for certification is required for flight:

91.213 Inoperative instruments and equipment.
...

(2) The inoperative instruments and equipment are not—
(i) Part of the VFR-day type certification instruments and equipment prescribed in the applicable airworthiness regulations under which the aircraft was type certificated;
yeah, that is where i was going. so even though 91.205 says it is required for altitude engines (yes i know the PA44-180 does not have them), they are required then for flight?
 
91.205 says it is required for altitude engines (yes i know the PA44-180 does not have them), they are required then for flight?

Since they were required to get the initial certification, yes. Same reason you can't placard an aileron. ;) The 91.205 stuff is "extra".
 
Since they were required to get the initial certification, yes. Same reason you can't placard an aileron. ;) The 91.205 stuff is "extra".
yup, makes sense. this stuff is honestly not taught here, so i am teaching it myself. a good CFI is always learning, and even though i have a lot of dual given now (comparatively speaking to my coworkers) this is one concept i have never been taught, and i figured it out, i just wanted to clarify :) thanks
 
i am teaching it myself

Aren't we all?;)

Part of the information you don't have which makes the conclusion more obvious is the following letter of interpretation:
=============================================
May 11, 1992

Mr. Alan R. Kaufman

Dear Mr. Kaufman:

We have received your letters of September 10, 1991, October 14, 1991, and January 8, 1992, in which you questioned the source of the Federal Aviation Administration's interpretation that all installed equipment in the aircraft must be working before the aircraft may be dispatched. We have reviewed the referenced notice of proposed rulemaking (NPRM) with particular attention to the preamble discussion. That rulemaking action was subsequently published as a final rule on June 13, 1967 (32 FR 8405) with the rule language essentially unchanged. The rule remains in effect today and may now be found in Federal Aviation Regulation (FAR) Sec. 91.205.

The requirement that all installed equipment in the aircraft must be working starts with the original type certification of an aircraft. As an example, FAR Sec. 23.1385 requires that an aircraft that is presented for type certification in the normal category have position lights that meet certain design parameters. FAR Sec. 23.1301 requires that each item of installed equipment function properly when installed. Compliance with both of these FAR requirements must be demonstrated to the FAA before a type certificate is granted. When Sec. 23.1301 is read with Sec. 23.1385, the inescapable conclusion is that the aircraft must have a working set of position lights to receive Part 23 type certification.

An airworthiness certificate may be issued if the Administrator finds that a particular aircraft conforms to the type certificate issued for an aircraft of that design and that the aircraft is in a condition for safe operation (see 49 USC App 1423). Since an airworthiness certificate indicates that the aircraft conforms to a type certificate, the airworthiness certificate (for the above example) would require that the position lights be functioning since they were required to be functioning by the type certificate.

The FAR requires the possession of a current airworthiness certificate before an aircraft may be operated. The following regulations illustrate this requirement:
FAR Sec. 91.7 Civil aircraft airworthiness.
(a) No person may operate a civil aircraft unless it is in an airworthy condition.
FAR Sec. 91.203 Civil aircraft: Certifications required.
(a) Except as provided in Sec. 91.715, no person may operate a civil aircraft unless it has within it the following:
(1) An appropriate and current airworthiness certificate...
Thus, any equipment that is a certificated part of the aircraft must be installed and functioning in order to have a current airworthiness certificate. It then follows that the aircraft cannot be dispatched with
inoperative equipment.

FAR Sec. 91.205 (the section you question) provides additional minimum equipment requirements for certain types of operations. These additional requirements must be met for a specified type of operation even if an aircraft was not required to possess this equipment under its original type certificate. As an example, FAR Sec. 91.205(c) would require position lights for night VFR flight even if a particular aircraft was certificated for flight without position lights. These additional pieces of equipment must have their installation approved by the FAA and these pieces of equipment would become part of the certificated type design for that aircraft.

We have determined that the example given in the cited NPRM preamble is incorrect. The example was incorrect in 1966 as it was contrary to the plain language of the existing regulations. The FAA's position has always been that, absent an applicable minimum equipment list (MEL) provision, all installed items of equipment in the aircraft must be working prior to dispatch. The following regulation states that requirement:
FAR Sec. 91.213 Inoperative instruments and equipment.
(a) Except as provided in paragraph (d) of this section, no person may take off an aircraft with inoperative instruments or equipment installed unless the following conditions are met:
(1) An approved Minimum Equipment List exists for that aircraft...
Therefore, operation of an airworthy aircraft requires that any instrument or item of equipment that is part of the aircraft type certificate must be installed and in proper operating condition. Absent an applicable MEL provision, if a piece of equipment is missing or inoperative, the airworthiness certificate is ineffective.

Sincerely,

Donald P. Byrne
Assistant Chief Counsel
Regulations and Enforcement Division.
 
Since they were required to get the initial certification, yes. Same reason you can't placard an aileron. ;) The 91.205 stuff is "extra".

One of these I'm going to walk out to a plane and find a wing placarded... "ok for RTS" my derriere...
 
Well, lately, turbo problems. And plenty more. If you really want details, PM.
 
Back
Top