Wheel fairing conversion for a Piper Archer

[BoeingBoy]

Hi All. (I know, it's that bloke with his Archer again!)

Can I ask if anyone has knowledge of what is required to upgrade my P28A Serial 28-7790402 from one that cruises at 107kts to the later model spec that cruises at 120kts? The only difference seems to be that mine has simple spats and the later models have full leg fairings. Is it as simple as changing to fairings or is there a difference in airframe and/or prop as well?

If only the former can the conversion be made without a design change and STC? Looking at the EASA web site I can find no previously known STC that covers this subject so I presume it will be expensive to convince the CAA that it's safe to change. On the other hand since the type is already certified for fairings one hopes a simple conversion can be applied.

Also, I note there are several products available in the States that will seal the aileron and flap gaps, streamline the flap hinges and also there is a non standard shroud that goes between the leg fairing and simple spat to offer higher speed. All of these have FAA STC's but how easy is it to apply them here.

I have spoken to my maintenance company but they are not sure of the answer.

As always any help appreciated.

[NutLoose]

The manual for the Archer 11 just says wheel pants were an optional fit, though standard on the 111.

Oddly enough the TDC just covers taking them off.

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/14c3cccc5e5a2550862580280054db6e/$FILE/2A13_Rev55.pdf

[wrench1]

BB.

No clue if this helps--and a little out of my skill set--but a quick consensus at Club Octane points to your S/N having a max cruise of 121 knots per the FAA TCDS (2A13). It does show a reduced maneuvering speed though:

XV - A.- Model PA-28-181 (Archer II), 4 PCLM (Normal Category), 2 PCLM (Utility Category), 8, 1975, for S/N 28-7690001 through 28-8690056; 28-8690061; 28-8690062; and 2890001 through 2890205.

Airspeed Limits Never exceed 171 mph (148 knots) CAS
Maximum structural cruising 140 mph (121 knots) CAS
For S/N 28-7690001 thru 28-7690467:
Maneuvering 124 mph (108 knots) CAS
For S/N 28-7790001 thru 28-7990589, 28-8090001 through 28-8690056, 28-8690061, 28-8690062, and 2890001 through 2890205:
Maneuvering @ 2550 lbs. 128 mph (111 knots) CAS
Maneuvering @ 1634 lbs. 102 mph ( 89 knots) CAS
Flaps Extended 115 mph (100 knots) CAS

And as NL mentioned wheels pants can be removed, but I'm not sure if that note (24) is applicable to your aircraft.

But as you pointed out:
Piper Seneca & Cherokee Cruise Modifications - Laminar Flow (http://laminarflowsystems.com/)
Piper Main Gear Fairing Set (STC'd) (60-MGF-18D) - BuyPlaneParts.com is the Texas Aeroplastics online store (http://buyplaneparts.com/piper-main-gear-fairing-set-stcd-60-mgf-18d/)
Piper PA-28 Wheel Pants and Fairings by Knots 2U. (http://www.knots2u.net/wheel-pants-1/)

I might be totally wrong on this, but good luck.

How did your corrosion issue work out?

W1

[BoeingBoy]

Thanks for the replies.

Please see the attached page from the 1980 POH that shows the difference between the two wheel sets. On the left, the TAS with spats at 2000'/75% power in ISA is around 110 but on the right with fairings it's 120.

PA28 Cruise Speeds (http://i832.photobucket.com/albums/zz246/Boeingboy-767/Piper%20Manual%20Cruise%20Speeds.jpg)

I thought this might be solely due to the difference between spats and fairings but further research shows that there is also a prop difference on serial numbers of 789001 and up which I presume is a coarser pitch. If that's the case then whole exercise becomes too expensive to justify and trading up to a faster aircraft would seem the way to go. It would appear that it was the 78 model that commenced sales with fairings and a 62" pitch prop.

The other alternative is to spend a reasonable amount on gap seals and enhanced leg covers and get what I can out of the aerodynamics. The question there is whether the parts sold in the states on FAA STC's are able to be fitted here without a new EASA STC being raised? Any takers on that one?


Wrench: The corrosion settled down to be mostly on the inspection panels and elevator. The aircraft is booked in for repainting next month. Thanks for your help. It was deeply appreciated.

[NutLoose]

Can you not get the prop pitch reset?

Trouble with tweaking it to cruise performance is it will degrade climb performance.

http://www.sensenich.com/files/documents/Repairs_Trouble_Shooting_Repitch_Limits_1303228075.pdf

http://www.sensenich.com/support/documents

[BoeingBoy]

Thanks Nutloose.

I am not sure I would be happy sitting behind a prop that had been bent, even for two inches. I have never heard of a prop being reset to another pitch in the UK.

The climb performance is not critical as I tend to only operate from medium to large airports and I am based at sea level anyway.

BB

[NutLoose]

It is actually quite common for props to be set for cruise or climb, indeed, back when it was mandatory for aircraft to have a 3 yearly flight test, props would often be sent off to get the pitch corrected if they failed to achieve the book figures. You may also find that they are done when your prop is overhauled, over time they tend to lose some of their performance. Though it can increase fuel consumption etc, it's a bit more technical than jamming it in a door and giving it a twist ;)

https://www.aopa.org/news-and-media/all-news/2013/july/16/propeller-care-overhauls