Post-Maintenance Test Flights

[African Eagle]

Would anyone be willing to share their procedures relating to PMTF's?

When we have a bit of nav kit which has been repaired or replaced we go out and verify that it is working as it should. But after scheduled maintenance and dynamic component repair or replacement we basically check T's and P's and general handling. When a turbine or components have been changed we will perform a power check and which we also perform after scheduled maintenance and on an ongoing regular basis.

Does anyone possess a specific checklist or follow prescribed PMTF procedures?

Some of the info I have is:

UK CAA:

Flight testing, referred to as check flights or in-flight surveys, can be carried out periodically on in-service aircraft as one of the processes to ensure that an aircraft continues to comply with the applicable airworthiness requirements. Additionally, maintenance check flights may be carried out following a maintenance activity on an aircraft to provide reassurance of handling characteristics, performance or to establish the correct functioning of a system that cannot be fully established during ground testing.

Flight Testing and Check Flights of UK Civil Registered Aircraft | Airworthiness | Operations and Safety (http://www.caa.co.uk/default.aspx?catid=1455&pageid=8913)

CAA Disclaimer on PMTF procedures (http://www.caa.co.uk/docs/1455/20130701FlightTestWebPageUseOfSchedulesV1.pdf)

Note: The PMTF procedures I am enquiring about are separate from those recommendations made in RFM's or specific manufacturers bulletins. It is also understood that there are separate and unique prcedures for rotor tracking and balancing. In other words I am looking for general PMTF procedures, if there is such a thing.

[Harry the Hun]

There should be specific procedures in they Aircrafts Maintenance Manual. For Nav equipment there might be some generic test procedure, but for the rest it is type specific.

[victor papa]

For most Eurocopters the when and how is in sect 8 of the Flight Manual. The maintenance manual refer to the flm.

[MightyGem]

For most Eurocopters the when and how is in sect 8 of the Flight Manual.
Not for our 135.

[victor papa]

Sorry Mightygem, should have said French EC's.

[Harry the Hun]

For the 135 everything is laid down in detail within the AAM.

[Harry the Hun]

Sorry, I meant The AMM

[[email protected]]

African Eagle, one would hope that your AMM should prescribe what manoeuvres and test points should be checked following specific component changes ie hover, spot turns,sideways and backwards, max power climbs and turns in auto following a TR change to confirm the rigging is correctly set.

The main teaching point in the UK mil for PMFT is of an incremental approach - ie if you are required to check the handling at 30 kts sideways then build up to it gradually rather than just going for it straight off.

Your general handling and Ts and Ps check doesn't sound very specific but you don't say what aircraft type you are flying - it sounds like an old-fashioned shake-down flight rather than a flight test to check specific parameters.

[African Eagle]

Thanks for the responses guys.

crab, I fly the B407 but this is for the company ops manual (we are having an audit later this year) and we've nothing covering PMTF's. In the final para of my original post I mentioned that I was looking for any general rules applying to PMTF's aside from what's in the aircraft manuals.

For the company ops manual I can simply write "follow procedures as per AMM" but wanted to put something more such as any general advice which would be useful for PMTF's. Obviously checking for left over tools as well as inspecting any specific work which has been done (as part of a detailed per-flight inspection) are notes you could make.

A lot of stories over the years of PMTF's which have gone pear shaped!

[[email protected]]

A lot of stories over the years of PMTF's which have gone pear shaped! that's for sure:ok:

We have a specific flight test qualification for our captains where the instructor takes them through the relevant documentation (military rules and the flight test schedule) and then flys specific manoeuvres with them highlighting potential pitfalls (low speed autos for example), suggested best profiles to achieve the required test points and emphasising the incremental approach to flight testing generally.

We do have some words of wisdom as an appendix to our flight test schedule which reinforces the procedures and culture.

For your ops manual, you would need to produce something similar, detailing the practicalities of conducting the flight test but written in pilot-speak - generally AMMs are written by engineers and are factually correct but not easily interpreted;)

[African Eagle]

generally AMMs are written by engineers and are factually correct but not easily interpreted

Well you hit the nail on the head Crab and in fact the reason I've been scouting for suggestions.

I'm going to go with the obvious reference to AMM's etc. but am also going to incorporate your suggestion of incremental introductions to any specific flight phase which requires testing. Presumably the "incremental approach" is what test pilots use in any case?

Thanks again.

[[email protected]]

Yes, the incremental approach is advocated by Empire Test Pilots School and it is they who provide the course we send our pilots on.

[RotaryWingB2]

generally AMMs are written by engineers and are factually correct but not easily interpreted

Incorrect. AMM's are written by morons in an office that struggle to remember what a helicopter looks like. Who fail to mention that removing part a. Requires the removal of parts b. to z. And part z. Requires new O rings, which we won't mention until the last paragraph, by which time the stores have all gone home.

Yours sincerely.

An engineer.