Aircraft certification for Flight into KNOWN ICE

[AirAddict]

Wondering what the legal requirements are for an aircraft to be certified for flight into known ice, particularly the Navajo. I assume you need the following:

1. Wings, tail and stab boots.
2. Hot props.
3. Pitot heat.
4. Alternate air.
5. Heated windshield or Hotplate.

I see some advertised that have all of the above yet are placarded 'not certified for known ice'

Thoughts?

[CD]

Not sure if this will necessarily help you or not... Here are the basic regulatory references (I'm giving the CAR references but they are harmonized with the FARs) as well as the Advisory Circulars:

523.1419 Ice Protection (Normal, Utility, Aerobatic And Commuter Category Aeroplanes)
525.1419 Ice Protection (Transport Category Aeroplanes)

AC No: 23.1419-2D - CERTIFICATION OF PART 23 AIRPLANES FOR FLIGHT IN ICING CONDITIONS
AC No: 25.1419-1A - CERTIFICATION OF TRANSPORT CATEGORY AIRPLANES FOR FLIGHT IN ICING CONDITIONS

[tired of the ground]

There is also a serial number limitation for those Navajos. I think there is a TC policy letter or something out there.

Only Navajos after x serial number are certified for FIKI even if you have all of the required equipment. If you look at the AFM there is a section that will tell you what you need for FIKI.

[Mach .28]

I was going to give you this

http://www.tc.gc.ca/CivilAviation/comme ... s/menu.htm

0043R 1994.07.13 Notice to Operators of Piper PA-31 Navajo Aircraft Operation in Icing Conditions - (Limited Distribution)
(Cancelled)

But if you read the CBAAC it was cancelled Jan 1st.

Give TC a call and see what they superseded the information with.

[MB-AME]

Check the Type Certificate Data Sheet - certain serial numbers of PA-31's are certified for known ice, and certain serial numbers of Cheiftains are. I believe one of the changes is inboard wing deicers.
I've seen Navajos and Chieftains modified with hot plates, but they still include the limitation of not certified for FIKI.

[AirAddict]

Never seen a chieftain with inboard wing boots before. The serial numbers must have something to do with it, also thinking maybe the hot plate and heated window arent considered the same for certification because ive heard that hot plates dont work very well.

[twistedoldwrench]

In days gone by, we use to fly older (69 vintage) Navajo's around in lots of iceing conditions, as they were properly equiped per the flight manual for light to moderate icing.
When you started to fall out of the sky, thats when you exceeded the definition of moderate. The older aircraft were certified for icing before FAR 23, so the CAR requirements for certification for the time was what did and still applies. Later model s/n's certified under FAR 23 had some additional requirements imposed for those specific s/n's, however I don't believe that would invalidate the certification of the earlier models. The original flight manual for the specific aircraft should have the required equipment listed as installed if it was certified for icing or not- some had a specific installations per drawing number xxxx!!!, but only for a specific s/n range.

[86583]

the other issue with the PA-31 is that unless it left the factory with all the equipment installed it's not approved... aircraft that were modified at other shops after, even though identical equipment was installed don't cut it, you have to see the original equipment list to figure that out..one of the most over looked items to be legal is the installation of the sacraficial boot on the elevator horn. this normaly splits, gets thrown away and never replaced..also there is no such thing as a navajo with a hot plate that is certified for ice, even though the installation of the plate is approved by TC the certification for ice is not legal without the hot windsheild installed....one other item that is serial # specific but also required to be legal is the windsheild wiper...the other serial # issue that surfaces is the inboard boot on the 31-350

[oldtimer]

86583 has it correct. Most original Navajos were not and could not be certified into known ice. Mostly due to certification and the lack of sufficient air pressure from the air/vacuum systems. Also there was the liability problem where the factory had no control over the equipment installed by other sources but were still held liable in a court of law.
The windshield plate does not cut it because it was never certified specifically for the Navajo by Piper or New Piper. All that was required for certification was for the manufacturer of the windshield plate to prove that the installation had no adverse effect on installed equipment. Nothing said it had to work. This does not follow the requirements for FIKI. As an example, the stall characteristics were explored during certification and all the manufacturer had to prove was that the installation of de-ice boots did not have an adverse effect on the stall characteristics.
The inboard de-ice boots were part of the installed equipment on later model airplanes.
In 1978, the FAA started to have a look at de-ice/anti-ice equipment on smaller airplanes and adopted the FAR 25 Transport Category airplane certification requirements as to the severity of icing conditions and the airplanes ability to survive a short encounter with moderate ice. Prior to that, all that was required was certification that the installed equipment did not have an adverse effect on aircraft systems or flight characteristics. The de-ice equipment in use prior was designed so a pilot could stick his nose into ice, turn around, leave the area and shed the wee bit of ice collected.
The FAA, TC, Ames Research Center, ICAO and others are still working on the problem of flight into known ice and are still working on solutions.