I hadn't read this post at my last reply. This description sounds
accurate for the Streak Eagle flights. I'm still not sure that the
aircraft accelerated through Mach 1 in vertical flight; it sure could
have, if it did so during an Immelman!

Jim Thomas

Guy Alcala wrote:

Ed Rasimus wrote:

snip

Now, let's put to bed this idea of accelerating through the mach
straight up. While modern jets with greater than 1-to-1 T/W ratios can
accelerate through the vertical, I sincerely doubt the mach claim. Too
much is going on with drag curves, deteriorating performance with
altitude, losses in engine efficiency, etc. I think only heavy lift
rockets accelerate through the mach in near vertical, but they
transition out of vertical fairly early in the flight trajectory and
may not be vertical either.


Oh, I don't know. While not a stock production a/c, the Streak Eagle was
certainly capable of doing so [From Jeff Ethell's book on the F-15]:

"The 3,000m record flight was piloted by Maj Roger Smith. With a
thrust-to-weight ratio at release of over 1.6 to 1 the 'Streak Eagle' lifted
off the ground after a roll of only 400ft, approximately seven airplane
lengths. Smith quickly raised the landing gear and maintained nearly level
flight while accelerating to approximately Mach 0.6. The aircraft was then
rotated by a 5g pullup to a near vertical climb attitude. The Eagle
accelerated during this climb to Mach 1 and reached the specified 3,000m
altitude in 27.57 seconds. The 6,000m, 9,000m, and 12,000m records, were
set by Maj Willard 'Mac' MacFarlane in one flight of 16 January [1975]. The
profile was similar to the 3,000m flight except that a maximum speed of Mach
0.7 was obtained before the pullup. MacFarlane and his Eagle were at sonic
speed only 23 seconds after brake release."

"The third flight on 16 January was made by Maj Dave Peterson for the
15,000m record. On this and subsequent flights pilots were wearing pressure
suits. Upon liftoff Maj Peterson accelerated about 50ft over the runway to
0.65 Mach and pulled into a 55 degree flight path angle to reach the 15,000m
target altitude (49,212 ft) in 77.05 seconds. This is approximately 10sec
quicker to that altitude than the Saturn V rocket boosted the Apollo
spacecraft on its way to the moon."

"The 20,000m profile with Maj Smith again at the controls consisted of a
giant Immelmann manoeuvre starting at Mach 0.65 on the deck and pulling 2.5g
until the airplane was over the top at 32,000ft and acceperating in the
opposite direction. While passing throuhg 20,000ft the Eagle was vertical
with a 2.5g load factor and a rate of climb faster than the speed of sound.
At Mach 1.5 Smith pulled 4g into a 55 degree climb and held it there to
66,617ft in 122.94 secs elapsed time. The margin over the 'Foxbat' record
was 28%."

"Maj Peterson then took over for the 25,000m record and flew a similar
profile. Maximum speed achieved was Mach 1.8 just prior to the second
pullup. The specified altitude of 82,021ft was achieved in 161.02 sec at a
speed of Mach 0.6. The a/c eased over the top and descended without
incident. This beat the 'Foxbat's' time by 17%."

In 1973 the MiG-25 climbed to 30,000m in 4 min 3.86sec. when Maj Smith made
the flight to break this record, he lifted off the runway at a weight of
32,000lb after 500ft of ground roll, accelerating to Mach 0.65 and then
pulling into a 2.5g Immemann similar to the two previous record profiles.
After rolling 180 deg. at the top of the climb Smith accelerated in a slight
climb to build up total energy. The 'Streak Eagle' passed through Mach 2
approximately 21 miles downrange and two minutes from takeoff. At Mach 2.2
Smith pulled up to [Sic. 'at'] 4g and attained a 55 deg. flight path
whereupon the stick was relaxed to maintain a constant climb attitutde. The
30,000m mark (98,425ft) was achieved in 207.08sec, bettering the 'Foxbat'
time by 36 sec. The a/c maintained a nearly ballistic freefall path as it
went over the top at 102,400ft."

[Later in the book, describing his own flight in a stock F-15B with Lt. Col.
Dick Stamm, CO of the 22nd TFS, 36th TFW, from Alconbury, for an ACM hop
with the 527th; 36th TFW CO Col. Perry Smith was the wingman]:

"When Dick released the brakes and lit the afterburners, I was slammed back
in my seat with a force very similar to launches I had made from an aircraft
carrier catapult. Before I could catch my breath, the F-15 had traveled
900ft and rotated. The nose came up . . . and up . . . and up! From
rotation Dick pulled the nose up into a 90*degree climb a scant few hundred
feet off the runway. And the aircraft was accelerating while going straight
up*."

"I watched the earth recede rapidly -- this must be what a moon shot was
like -- and glanced up at a cloud deck at 15,000ft. We slammed through it
in a flash; no gradual ascent through. By the time I looked back it was far
below."

"Due to airspace and speed restrictions, Dick had to pull the burners back,
but there was no question a clean, lightly fueled Eagle will go supersonic
straight up from a standing start."

*Given that the F-15 seat is reclined at an angle of 13 degrees IIRC, the
a/c probably wasn't straight up as they'd be hanging by their heads if it
was, but at some angle around 77 degrees, unless Ethell was referencing the
HUD climb ladder at the time.

Guy