Straight 170 (Raqwing) Accident - Fuel Pump?

[GAHorn]

While researching the fuel pump/check-valve requirement for Straight (so-called “Ragwing”) 170 I’ve come upon a 2017 accident some might recall in Fl which was very strange for several reasons.

It was a “Ragwing”. It was operated by an experienced ATC Controller/Pilot. It killed all four aboard (husband, wife, 2 children), it was good weather with only slightly gusty winds, and at least 20 aircraft overflew the wreck while departing without noticing it despite the ELT working properly. The flight departed on a clear day at 3:10 PM but the wreck was not noticed until the next day.

At the bottom is the link and pics of the sad tragedy.

What caught my attention and causes me to bring it up is the fact that only this last week ... for the umpteenth time.... I’ve come across another 170 which has been flying for some time and numerous annual inspections with no fuel pump and no approval for it’s removal. The airplane had a fairly recent engine replacement yet because the replacement engine came off a 170-B having no fuel pump.... it was installed on the Ragwing with no fuel pump. What could possibly be wrong?

Anyway, the history of this problem is rife with errors. Some will recall the time I was contacted by a 3-way partnership in a Ragwing, the partnership being made up of FAA Inspectors in OKC... who had flown their ragwing for years with no fuel pump. They had no idea....

A&P/AI types often overlook the fact that the TCDS item 104 requires that pump, ... Every Annual Inspection is supposed to confirm that the aircraft conforms to it’s Type Certificate....and contributing to the error, the Aircraft Illustrated Parts Catalog (IPC) doesn’t list or show it!.... NOR does the ENGINE IPC! If one were to restore a Ragwing and go looking for the required pump GOOD LUCK finding the correct part number for the pump so you can order it. It’s NOT going to be listed in either IPC. And Continental correctly thinks it’s an AIRFRAME part, While Cessna thinks it’s on the ENGINE... and FAA is unfamiliar with the issue... and NTSB reports the pilot must have simply STALLED the airplane on takeoff.

WHY would an experienced commercial rated pilot stall an airplane on takeoff? ... perhaps out of SHOCK when the engine suddenly loses power in a steep climb, ya’ think? (Anyone ever practice this maneuver? If you are in a high angle-of-attack and the engine suddenly loses power you’d better be QUICK to get that NOSE DOWN or you WILL stall! And, BTW, the ragwing is not required ..and none I know of.... have a stall indicator.)

If this accident airplane did not have the required pump and check valve and plumbing I seriously doubt the Engine and Airframe Reps at the investigation or the FAA or the NTSB would ever think to look for it. No mention of a fuel pressure gauge either which might accompany a pump installation.... And the condition of that engine compartment after the crash is not likely to draw attention to that issue. As the old Navy Aviator song ends....”So What could be Fairer, than to call it Pilot Error..?”

http://www.kathrynsreport.com/2017/04/c ... 0462801053

[GAHorn]

CLICK. To Enlarge for readability:

Engine Photo

[GAHorn]

Nathan Enders Gone West

[cessna170bdriver]

The included photos don’t show whether or not the engine had a fuel pump installed, but perhaps there are others not included in the report that could resolve that speculation. There might also be others that might show whether or not the fuel lines had been rerouted so as to not require one. Also I thought it curious the the NTSB report, while it did mention fuel being found in both tanks, didn’t say whether or not the tanks (or gascolator or carburetor) had been checked for water. I also thought it odd that they didn’t mention loss of engine power as being a factor in the accident.

[3958v]

I found the accident quite disturbing as the plane looked identical to mine. I would also suspect a chance that the check valve was in backwards or was not opening properly because it did not have a low enough cracking pressure. Like you George I am also suspicious that the NTSB failed to find the real cause. Bill K

[bugs1961]

Looking at the AOPA carb ice chart, the temperature/dew point put the conditions in the “severe icing-glide power” region. Time on the ground in idle could have built up ice to the point of trouble. I get carb icing nearly every time I taxi for takeoff that I clear with 20 seconds of heat during the runup. There are very few days in in the Anchorage area where carb icing isn’t a threat—only when it’s very cold outside.

[GAHorn]

Looking at the AOPA carb ice chart, the temperature/dew point put the conditions in the “severe icing-glide power” region. Time on the ground in idle could have built up ice to the point of trouble. I get carb icing nearly every time I taxi for takeoff that I clear with 20 seconds of heat during the runup. There are very few days in in the Anchorage area where carb icing isn’t a threat—only when it’s very cold outside.

I hope that EVERYONE, when applying take-off power, looks at the tachometer to assure that at the very least “static RPM” is met. If not... then you DON’T HAVE TAKE-OFF POWER. Carb ice would be clearly indicated by the lack of meeting that RPM.

The TCDS specifies the “static RPM” for your airplane dependent upon the engine/prop combination you have installed, (see TCDS Item 1) but generally speaking, C145/O300 equipped 170’s should see 2250-2350 RPM (approx) at the beginning of the takeoff roll. I teach my students for normal ops to align for takeoff, check DG agrees w/Runway No’s., apply full power checking static RPM and oil pressure, before continuing the takeoff.

[gobrien]

Not to blow smoke anywhere uncomfortable, but ... I would have had no idea about this problem with my aircraft but for this forum.

The airframe and engine were purchased separately as Serial# 18513 had her engine (an O-300D) removed and sold separately after a minor incident in Florida.
The engine I have is an O-300A from an early 172 which rolled over in a storm while not tied down properly. The replacement crank is from an O-300D which makes the newly rebuilt engine an O-300ACC. (A converted to C)
The engine has no pump installed and as George mentions the airframe didn't have anything to indicate it is necessary. Deep in the airframe IPC there is a single mention of "Fuel-line pump to tee" but seriously ... ?!
There is a 337 showing an earlier installation of an electric boost pump, but no electric pump on the firewall so no idea where that went.

I'm putting the electric boost pump scheme back in place rather than attempt to find an original mechanical pump for $1.2 gazillion.

The nature of my project has meant examining (almost) every inch of every system and I've been surprised by a few things I've found (or not found): a pound (I weighed them) of loose nuts, bolts, etc. in the belly of the beast; the primer line has been removed and replaced with a second drain fitting screwed into the gascolator's tee fitting, so it seems she may not have been priming for some time despite having a primer in the panel!!?

Anyway the point is thank you all for your contributions. They are very helpful and definitely improving safety in the fleet!

Gareth.

[GAHorn]

Gareth, there is only one ragwing (to my knowlege) that has FAA approval for an electric pump installation in lieu of the mechanical pump, and that airplane is the winner of many many many convention trophies... it belongs to past president Duane Shockey in CA. He is also an A&P and I suggest you contact him (contact info in the Directory) to obtain copies of his installation details that might be helpful. (Even tho’ you are operating under different rules there’s no need to re-invent the wheel when we have a good design already capable of approval.).

Otherwise, if I owned a ragwing, I think I’d re-route the fuel lines down the aft doorpost like the A and B models to solve the problem. We have one Member I’m working with now who is doing this under the approval basis of a DER (designated engineering rep) and who will be producing an article for 170 News which will hopefully be helpful for future such alterations. (But he’s got a job over near you actually, and might be a couple months for completion.)

[gobrien]

Thanks George,

I have Duane's docs which I am following closely and I made the call not to pull the floor and reroute up the B post.

Gareth.

[Poncho73]

I modified my 48 to the A and B fuel line system a couple of years back. My 48 170 had been operating without a pump since the 80’s and had accumulated 1500 hrs as such. I figured I would finally address the issue. I also installed two belly fuel drain ports to remove any water (lowest point). I usually check them every month or so.

[Poncho73]

I don’t think the fuel pump played any issue in the event if you look at the NTSB Electronics report it appears it was a performance issue. Low speed at lift off very little climb rate if any, there were a few pitch changes and subsequent G loss.

[GAHorn]

I don’t think the fuel pump played any issue in the event if you look at the NTSB Electronics report it appears it was a performance issue. Low speed at lift off very little climb rate if any, there were a few pitch changes and subsequent G loss.

The NTSB Electronics report is defective in that regard due to the fact the GPS groundspeed does not equate to IAS, especially when the quartering headwind is taken into consideration.

[Poncho73]

I don’t think the fuel pump played any issue in the event if you look at the NTSB Electronics report it appears it was a performance issue. Low speed at lift off very little climb rate if any, there were a few pitch changes and subsequent G loss.

The NTSB Electronics report is defective in that regard due to the fact the GPS groundspeed does not equate to IAS, especially when the quartering headwind is taken into consideration.

None of them do. Same problem with FDR and positioning errors. In one of the NTSB reports they have the acceleration reversed. The error the pilot made was he left a ton of runway behind him. Never really had any energy regardless of the obvious GPS speed error. The G trace including a super low VS got him. Plus he was heavy