F-5F Accident Investigation (Continued)失事調查

去年十月我已經提出有關戰機於澎湖失事的忠告, 經與美國NTSB專家Dr. Hansrote聯繫討論後, 更証明我的論點值得大家的注意.
As early as October 2008 I pointed out the possible causes to lead Taiwanese fighters crashed in Pen-Hu, it seems I have more confidence in my perspectives through the discussion with NTSB expert Dr. Hansrote. Please pay attention to the following correspondences.

Dear Dr. Hansrote,

Today I went to air force headquarters to discuss the investigation of F-5F crashed into the ocean. Collected debris show F-5F with a very high speed dove into the water and became pieces. Because the evidence is so little, they found it is difficult to do the investigation. Therefore, I need your advice to find the possible causes.

Weather conditions were 3000'-15000' scatter and visibility 7 miles. The clouds did not affect the flight operations, according to the pilots from the other airplane.

F-5F with two pilots, the captain was Lt. Colonel ### with 3000 flight hours with F-5F and the student pilot was Lt. ### with 70 flight hour with F-5F. Flight operations were to bomb (or shoot) a target on the sea so the fighter was with a low altitude. Initially, they was 500' / 10 miles from the target. Then they tried to do a 40 degree climb to about 4000'. However, because of the clouds close-by, the pilot decided to do a bomb (shoot) operation with a small angle about 20 degree. Since the fighter climbed too high, and they had to headdown to maintain on the correct course. When they was 4000' the speed indicated 400. When they descent to 1500' the speed indicated 460. The pilot could not pull the fighter up, then dove into the ocean. The above description was based on the radar information.

The fighter had a normal maintenance record.

Flight plans indicated they were trying to practice the big angle (40 degree) bomb practice.

Because you were a F-16 combat pilot, I hope you understand the operations I said above. According to your flight experience, can you tell me the possible reasons why the pilots could not pull the plane up?




Captain Yang,
This is totally unofficial, but their is a phenomena call the the push-pull effect.
This is when you push over , pull up , and push over again. In this maneuver, upon pull up one's "G tolerance" may fall below one 1 "g". The best defense is to avoid this maneuver, and if you trapped in it "grunt breathing" may save you from a blacking out. In that the pilot involved was low time, he may not have known about this phenomena. It should be taught in combat tactics. I have a complete video of this phenomena and in my textbook "Applied Aviation Physiology", P-13, You still may have a copy?
It is obtainable in "Amazon com.". Their may be other reason for the mishap, but this one strike me a a probable cause of "G Loc" due to push pull effect.
I hope you, you wife, and baby are doing fine. Let me know how it works out and if I can be of futher assistance let me.
Dr. Ron Hansrote


Dear Dr. Hansrote,

Push-pull effect was my first response to the authority. However, the investigator said it was unlikely to be push-pull effect, because they are not so weak to cause "G loc". He said F-5F is a traditional fighter but not fly by-wire. The airplane does not react so quickly to what the pilots do. If F-16 can react with in 0.1 second, F-5F will not be so fast. Besides, very often they fly with _ and + Gs and nothing happens to them. Evidence from the debris has shown that the airplane crashed into small pieces including pilots' flight suits and airplane metal. If the pilots were G-Locl, then airplane became stall. The debris should be bigger, because the impact should not be so powerful. How can you defend their viewpoints?


Capt. Yang
A stall is an unusual occurrence in Push Pull. Usually,the result is a straight in approach, as we say in the Canadian Cold Lake incident with the F- 18. Remember we can have push pull "G" or "A" loc out even with the C-150 Cessna trainer, so it doesn't always dependent on momentum but how it was applied.
The fragmentation of the debris field indicated the plane probably we in, never recovering from the dive,it could have been "A" or "G" Loc. Without having all the information this would be a theory. I have a complete film on this subject.
Dr. Ron Hansrote