AvWeb blog ref Ghost

[Lockheed Bob]

Re: AvWeb blog ref Ghost

Great Post. A lot to be learned from this. Thanks.

[BuckyD]

Re: AvWeb blog ref Ghost

Big Thanks (again) to Michael Luvara, f/posting the NTSB link to their 20-page summary narrative on the GG accident. -'Very illuminating', to say the least.

One thing I do find baffling fm a research perspective: With the NTSB's (& FAA) investigative reputation of being extremely-thorough & going to great lengths to obtain their findings results f/their reports (-we used to quip about how they'd go the extra-mile to- "dig-up the name of the miner who'd dug up the ore f/the metal that was used to make the plane part" ),~in the beginning of this document where they give a thumbnail of NX79111's racing history noting the racer's turtledeck assy's in-flight departure (-while Leeward was "racing"), the author states the specific incident date/year 'wasn't able to be determined'. Plenty of available published refs. & air race historians/buffs out there f/ready contact to retrieve that timeline data for the report prior to the report release.

Date: Tue. 9/11/84-UNL Qualifying & Practice Session~ T-deck came-off when Leeward was attempting his Q-run w/NX79111 & going about 410-mph. New tail parts were flown-in to effect repairs to the damage & Leeward was able to successfully-Q (@425+mph) & race after the fix & re-installing the Candace/Jeannie turtledeck unit.

Michael~ Maybe you could fwd this info on to the author-Clinton R. Crookshanks/NTSB, to revise his draft to include the date info & remedy the ambiguity of that slight omission. (?)

Appreciate all your thoughtful postings & keepin' us all well-informed on these timely official govt. documentary studies covering last year's tragic crash.

DBD

[Big_Jim]

Re: AvWeb blog ref Ghost

BigOne thing I do find baffling fm a research perspective: With the NTSB's (& FAA) investigative reputation of being extremely-thorough & going to great lengths to obtain their findings results f/their reports (-we used to quip about how they'd go the extra-mile to- "dig-up the name of the miner who'd dug up the ore f/the metal that was used to make the plane part" ),~in the beginning of this document where they give a thumbnail of NX79111's racing history noting the racer's turtledeck assy's in-flight departure (-while Leeward was "racing"), the author states the specific incident date/year 'wasn't able to be determined'. Plenty of available published refs. & air race historians/buffs out there f/ready contact to retrieve that timeline data for the report prior to the report release.

I am not positive, but I think that Jimmy was also responsible for removing the 'end caps' from the horizontal stabilizers AFTER he bought the plane from Sanders in August of 1983 at the same time he put the new turtledeck and canopy on. I think I have a photo somewhere of the plane sitting on the ramp at Van Nuys right after Jimmy bought it (and stripped the Jeannie markings off of it literally in front of a stunned Zeushel and crew--because they had no idea Jimmy bought it from Sanders until he showed up to take it)....it still has the Jeannie Canopy on it and no markings but a big black X on the fuselage. I'll have to look and see if the caps are on or off.

But as I commented over on WAP, there are a couple of 'gaps' or inaccuracies in the report about the history of the airframe...but none of that has any impact on the overall message of the report. Look no further than about 2/3 of the way down page 18....that is the message that should be taken away from the report. It makes me sad.

[Blue Foam]

Re: AvWeb blog ref Ghost

After a great deal of discussion with many air race maintainers who do not wish to be castigated on the web, there is some concensus on some simple rules that would have prevented this incident and are not necessarily onerous to the participants. These proposals would cover incidents and near-incidents that have occured in other classes outside of the GG incident:

1. The aircraft must be raced within stock CG limits. There is a myth in the flying community that aft CG is more efficient, and therefore faster on the race course. While efficiency can be gained while flying at aft CG against the left side of the envelope (low IAS, near optimum L/D), race aircraft run against the right side of the envelope. Even loaded, aircraft on the pylons lose far more in poor gust response at aft CG than they ever gain in efficiency. More important, a too-far-aft-CG allows pilots to over G the aircraft with no tactile sense that this is happening. High G equals loss of energy and slower lap times. We all seem to accept the concept of a "smooth" line being faster than a "rough" line. Think about it: the speed is coming from a lower average G and fewer high-G transients. Staying within stock limits actually makes pilots fly a cleaner and faster line because they tend to load the aircraft less. This is not to say that I favor a radically forward CG. I am mearly saying that we should rig no further aft than stock aft limits. It is both safer, and as the data has shown, faster.

2. The aircraft must be in trim, with no tab deflection, somewhere on the course at race speed. This is not an issue unique to GG or even other Unlimiteds such as Voodoo's trim tab departure (1997?). We have had trim issues with several aircraft in several classes. Based on past issues and the potential for aggressive departure of race aircraft from controlled flight with loss of trim tabs, race aircraft should demonstrate their ability to hold course with neutral tab positions in pitch, roll, and yaw. The reasons are self-evident.

3. The paperwork must match the aircraft. This is a sensitive subject for some teams. GG (and many other teams) did not document all of the airframe and system modifications. We can debate the airworthiness of any given mod on any aircraft in any class until the sun freezes. The fact is that some are not documented. The documentation must state who did what and when. At least then someone can ask relevant questions concerning the design, engineering, and execution of the mod. There is good design and bad, good engineering and bad, and good workmanship and bad; the point is that if the paperwork does not document that something was modified, no one will ever look. Secondarily (maybe primarily), basic maintenance and inspections that have been signed off must actually have been performed. Any class/RARA/FAA inspection on site that determines otherwise should result in the ejection of the aircraft from that year's racing.

#2 would have caught GG before the incident. 1, 2, and 3 would catch most of the "foreseable" accidents, at least on the airframe side. We still have had a few control and structural failures that would not be caught by these 3. However these 3 simple rules are not onerous and would make a positive difference.

[Leo]

Re: AvWeb blog ref Ghost

Who will have the authority/ability to enforce 1 & 2?
Not being provacative at all, just wondering about the mechanism since what is happening now has failed at least to some extent.
Great ideas, though I wonder why anyone would fly at the edge of any planes abilities without those items being addressed anyway. Guess I am just cautious by nature (I have a personal issue with equipment failing me when I could have prepared better), and obviously history shows there are those out there that are not.

[Mluvara]

Re: AvWeb blog ref Ghost

As I recall, it was your telemetry system that was onboard G.G. and as such, provided significant data that is part of this report. I think we'll all benefit (learn) from it, so again, thank you

Yes Chris, I did design and build the system. I'm glad that out of these circumstances, something good could come out of it. The interesting thing is that the parameters most looked at (GPS and G force) were installed as "nice to haves" and the system was not meant to be a crash recorder. However, it provided insight that they would not otherwise have had.

1. The aircraft must be raced within stock CG limits. There is a myth in the flying community that aft CG is more efficient, and therefore faster on the race course. While efficiency can be gained while flying at aft CG against the left side of the envelope (low IAS, near optimum L/D), race aircraft run against the right side of the envelope.

Eric, not sure if you are saying the ghost had an aft CG, but there is no conclusive evidence to point to the actual CG of the ghost at the time of the accident since one could not weigh the aircraft after the accident. All they could go off of was the supplied weight and balance documentation, which showed it was within stock limits. What actual effect the clipping had on the MAC and any flight test/engineering could not be found. Typically (in my experience), as one reduces the aspect ratio, the CG needs to move forward some.

Michael~ Maybe you could fwd this info on to the author-Clinton R. Crookshanks/NTSB, to revise his draft to include the date info & remedy the ambiguity of that slight omission. (?)

As was noted, its likely not critical to the report since they were trying to tell a story. I'm not sure if they would put in a definitive date at this point.

Michael