WACO Type Certificate Data Sheet

Hi, I have a question regarding the certification of WACO ATO aircraft.

I have been looking to purchase a WACO ATO aircraft certified in the Standard Category.

Many of the restorations are fitted with an engine that is not the Wright J5 as indicated on the original ATO Type Certificate Data Sheet ATC 123.

Additionally these aircraft are usually fitted with a modern tailwheel arrangement such as one from Scott Industries and a constant speed prop. There is no propeller specifications listed on ATC 123. Obviously the WACO Company has been out of business for a long time and no one has updated the type certificate data sheet.

How can these aircraft be certified in the Standard Category?

Numerous people have told me that WACO had a few different engines certified for this airframe but I can't find any record of this. I also don't see how a constant speed prop would have been certified before the company went bust in the 40s.

I would really like to purchase one of these aircraft but these discrepancies bother me.

Can you point me in the right direction to find the information I seek?

Many Thanks.

ANSWERS: Your first question is a good one and I understand your concern. On the front of a standard airworthiness certificate there is a statement that says it remains effective as long as the maintenance, preventive maintenance and alterations are performed in accordance with FAR Parts 21, 43 and 91. I don’t have a copy of an old standard airworthiness certificate but it would be something similar.

I looked up several WACO’s including a few ATO’s on the FAA’s aircraft registration database and confirmed what you have said. The ones I checked all had standard airworthiness certificates.

If these aircraft are still being operated with a standard airworthiness certificate, they cannot be altered (engine, propeller or tail wheel change) without some type of approval. For example, a suppemental type certificate, FAA field approval, or designated engineering representative (DER) approval.

The types of alterations you are referring to would also be considered major alterations and would require the issuance of an FAA Form 337.

The FAA keeps copies of Form 337’s on file by registration number and serial number and you can access that information by clicking here. Of course it would depend on when the alteration was performed and if the information was forwarded to the FAA.

When I pulled up the type certificate data sheet you referred to I had to chuckle at how simple things were back then compared to todays type certificate data sheets. I thought I would post a copy of ATC 123 for everyone to see.


In reference to your second question, the EAA is always a great place to find information on vintage aircraft. Try visiting http://www.vintageaircraft.org/ to see if you can find someone who might have answers about specific WACO delivery configurations.

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