Wednesday, July 30, 2014

Today in History July 30, 1966 M-21/D-21

So the Central Intelligence Agency is working with the USAF to develop a drone that can fly between 87,000 and 95,000 feet at Mach 3.5 and has a range of 3,000 nautical miles.  Other than those performance stats, the drone would eject its payload over the ocean, an aircraft would catch it, and then the airframe would eventually self-destruct.   You ask, “Why in this day and age of real time data would you eject your payload?” Good question! The answer is these aren’t specs for a modern UAV/UAS but one from 1962.  The result was the Q-12 or D-21. 
On May 1, 1960 reality had sunk in at the CIA and Pentagon when Francis “Gary” Powers U-2A was shot down over the Soviet Union by a SA-2 SAM.  The CIA needed a higher, faster aircraft. The result was the A-12.  The A-12 is actually a Lockheed designation and does not mean Attack.  It stood for Archangel.   The A-12 would eventually evolve to become the SR-71, though they are different aircraft.   While Kelly Johnson was designing the A-12 he also came up with the Q-12.  
The Q-12 was a mini A-12.  It had the titanium construction, double delta wing, and Radar Cross Section  (RCS) reduction of the A-12.  Johnson decided on a ramjet to power the Q-12. A ramjet needs air flowing through it to ignite the fuel.   The ramjet decided on was the Marquardt RJ43-MA-11, originally designed for the CIM-10 Bomarc built by Boeing. The engine was “uprated “ for higher temperatures and longer endurance.
The Q-12 had a “Q-Bay.”  The Q-Bay was a design carryover from the U-2 and A-12.   All of the inertial guidance as well as cameras and film were fitted in a module called the “HATCH.” The size of the HATCH forced miniaturization.   At the end of the mission the Hatch would be ejected from the Q-12 and deploy a parachute.  A JC-130 would recover the package using the skyhook system developed for satellite retrieval.  If the 130 missed, it could float on the water and be retrieved via ship. 
While the CIA was non-plussed, the USAF desperately wanted the project as a recon platform and as a cruise missile.   The latter mission was dropped.   In March of 1963, Lockheed was awarded the contract for full-scale development (FSD). 
The program was given the name TAGBOARD.  The Q-12 was re-designated D-21. With that, came two A-12s, 60-6940 and 60-6941.  The A-12s were stretched to add an additional systems operator, called the LCO or Launch Control Officer.  A large aerodynamic pylon was fitted between the Vertical Stabs.  The pylon was sloped to provide a nose-high attitude for the drone.  The A-12s were designated M-21s. The “M” stood for “Mother”; the “D” for “Daughter.”
The M/D-21 combination first flew on December 22, 1964.  This was the first capture flight.  The D-21 had aerodynamic covers over the shock cone and engine nozzle, similar to the Shuttle’s tail cone when flying on the SCA 747. Johnson’s original plan was to eject these fairings before launch, but wind tunnel tests showed it was dangerous to the drone, mother aircraft, or both.  After several flights they were removed.
On March 5, 1966 the first live launch occurred.   The D-21 left the back of the M-21 and after what seemed a lifetime—though it was only a few seconds—the D-21 flew dangerously close to her mother ship.   The second launch took place on April 27th.  The D-21 cleared the M-21. It reached 90,000 feet and MACH 3.3 before a hydraulic pump failure caused it to break up over the ocean. In spite of the two failures the USAF ordered more D-21s.
The third test took place on June 16th.  The mission was a qualified success: it flew its complete profile; however, it didn’t deploy its hatch. 
The final test occurred this week, July 30th 1966, and it is the reason why I decided to report on this aircraft this week. This fourth test would be different than the previous three.  The first three had the M-21 pointing downward in a .9g dive.   Flight four would be in level flight. In real world combat, you wouldn’t really have time to trim your aircraft into a nice dive.  You would want to launch and go.
Lockheed Test Pilot Bill Park and LCO Ray Torick were flying the mission.   The release occurred successfully for 2 or 3 seconds.   Unexpectedly, the D-21 could not fly through the shockwave of the M-21.  The D-21 was thrown back into the M-21.   The explosion cleanly separated the nose from the wing area.    Both Park and Torick ejected safely.  Both landed safely; however, Torick had a failure of his pressure suit and fatally drowned.

While it was the end of TAGBOARD, it wasn’t the end of the D-21.  Johnson suggested that the D-21 be launched from B-52s. Two B-52Hs became SENIOR BOWL. The B-52 had proven successful as a mother craft for the X-15.  The pylon built for the X-15 was modified and the BUFF could carry a D-21 under each wing.  Interestingly, the intention was never to launch two missions.  The right wing Drone was considered Primary, with the left as a redundant back up.   Internally, the B-52 lost the ECM and Tail Gunners stations and were replaced with identical panels with launch controls, one for left and one for right.
The D-21 was re-designated D-21B; “B” was for Booster.  Since the BUFF couldn’t go Mach 3 to start, the ramjet a 60-foot long solid rocket fuel booster and was mounted to the bottom of the D-21. 

The first flight of SENIOR BOWL  was hardly a success.  Shortly after takeoff, the D-21B dropped off the pylon due to a stripped nut.  The Booster fired upon hitting the ground causing “quite a sight” according to crews on the ground.   Picture a Roman candle.
Four operational missions were flown over mainland China. The target was the Lop Nor Nuclear test sight. Missions were flown from Guam’s Andersen Air Force Base.   On November 9, 1969 a D-21B was launched. It failed to turn around, over flew China, and self-destructed in Siberia, Russia.  
A second “TEST” flight was flown in February 1970 to fix the issues from the first operational mission.  The second Operational mission occurred in December of that year.  The D-21B made it to Lop Nor, turned around, and then had its hatch fail. It was never recovered.    The third mission in March of 1971 repeated the process and had its hatch sunk when it was ran down by the destroyer trying to recover it.   Two weeks later, the last flight of a D-21B occurred when it disappeared over China.  The wreckage was eventually found and now resides in the China Aviation Museum.
By July of 1971 the program was cancelled.   The KH satellites and the SR-71A had come on line. The D-21 was not by any stretch of the imagination successful.  38 D-21/b were built with 21 expended in launches.  The remainders were stored at Norton Air Force Base then to the Bone Yard at Davis-Monthan Air Force base where they were designated GTD-21Bs.
The one that crashed in Siberia was attempted to be reversed-engineered by the Russians unsuccessfully.
60-6940, the surviving M-21, was mated with #510 D-21 and can be seen displayed at the Museum of Flight in Seattle.  The remaining 16 were parsed out to other museums across the country. 

Works Cited
Drendel, Lou. SR-71 Blackbird in Action. Carrollton, TX: Squadron/Signal Publications, 1982. Print.
Goodall, James C. SR-71 Blackbird. Carrollton, TX: Squadron/Signal Publications, 1995. Print. 
"Lockheed D-21 Drone." Lockheed D-21 Drone. N.p., n.d. Web. 30 July 2014. 
" - 06941 - BLACKBIRD PHOTO ARCHIVE." - 06941 - BLACKBIRD PHOTO ARCHIVE. N.p., n.d. Web. 30 July 2014.

Tuesday, July 15, 2014

The Cessna 336, 337, O-2 Skymaster

First flown on February 28, 1961 the Cessna 336,  November 34373 had a fixed undercarriage. A high wing typical of Cessna aircraft with strut bracing.   A center pod fuselage holding the two engines.   The 336 originally flew with two 175 horsepower Continental GO-300-C  geared engines.  One engine was  in a Tractor configuration in the nose, the other in a pusher in the rear of the pod.  Two booms were extended from the wings to form parallel tails with a horizontal surface fitted between.
The 336 could hold a pilot and three passengers and was initially conceived as an air taxi.   The 336 officially went into production in May of 1963.  The Production 336 had a larger passenger pod capable of holding Five plus the pilot.   The engines became Continental IO-36Os which could generate 260 horsepower each.
Flying a Skymaster is different than flying other multi or single engine aircraft.   If you lose an engine in a multi-engine aircraft the aircraft will yaw into the failed engine.  This is not the case in a Skymaster.    It is important to understand engine out failures are different and sometimes hard to detect because both engines are on the same thrust line.   The Skymaster requires usually a Multi-engine rating or some countries issue a “Centerline thrust rating” for the 336/337.
The 336 and later 337 rear engine was notorious for overheating..   In Hot and High climates the rear engine can quit on Taxi.  The same can be said about Pontiac Fieros, but I digress.   Several accidents occurred when a pilot didn’t realize the rear engine had shut down and attempted a takeoff.   The single engine take off roll exceeded the runway length.   To prevent this the FAA Issued Airworthiness Directive 77-08-05   which prohibits Skymasters from single engine take offs, and  a placard in the cockpit which reads “DO NOT INITATE SINGLE ENGINE TAKEOFF’
In February 1965 Cessna introduced the 337 Super Skymaster.   While similar in appearance to the 336 it was a complete redesign.  To aid in the overheating rear engine a dorsal intake was added.  The 337 received retractable landing gear.    To improve performance the wings incidence angle was increased and its nose cowling reshaped.  The tail boom angle was also increased to enhance tail performance.   The 337 continued production until 1982 and under for a few more years under license by Reims in France.
In 1965 the USAF was looking for a replacement for its O-1 Bird Dogs and to act as a “stop gap” off the shelf aircraft until the North American OV-10s came online.   The 26th  336 was converted to a Forward Air controller  ( FAC) and given to hard two hard points for rockets or guns.   The 336 caused the creation of the 337M.  In 1967 the USAF placed an order for what would become the O-2A   The Air Force also took 32 337s directly from the Civilian line.  These would be called O-2Bs
The O-2A differed from the 337 in many ways.  The spinners were removed from both engines.   The cabin was given additional windows above the cockpit for upward visibility.  The Cabin door on the right side was also given observation windows to improve downward viability. Eventually  the Left side window also was enlarged so the pilot could see the oncoming  aircraft it was designating for.
  The wings were now equipped with four hard points.  They hard points could hold the SUU-11/A  Minigun,  or  MAU-3A Bomb racks.  The primary weapon hung, however,  was the LAU-59/A launcher which held 19 Mk40  FFAR  ( Folding Fin Aerial Rockets)   These were often  Willy Pete’s  jargon for White Phosphorous.   This was the primary way to mark a target in the FAC role.  The 19 rockets could be fired either one at a time or the whole container could be rippled.  
O-2As were substantially heavier than 337s due to all the military gear.   The Main panel now had a gun sight.  Though for most FACs a grease pencil mark on the windscreen worked just as well if not better.  There was an Armament control panel added to the main controls.  Armor was placed below the seats and the fuel tanks were given foam linings.
Behind the cockpit was a rack of radios.   UHF for talking to the other TAC aircraft.  FM to talk to the ground troops.  Lastly a VHF radio, to be able to talk to home base to coordinate air strikes.  This was a problem all the way up through the first Gulf War.    Also in this rack was the navigation suite of ; TACAN, VOR,  and ADF.
The O-2Bs, which were production 337Gs,  were originally purchased as trainers to get  pilots and ground crews familiar with the aircraft.  Eventually the O-2Bs would also go into war as PSYOP aircraft.  These aircraft would be given a huge loud speaker on the left side to broadcast propaganda.  They were also given a “Bomb bay” so they could drop leaflets.  They came to be known as BS Bombers.
 In South East Asia the USAF lost a 178 aircraft.  Eventually in the conflict they were replaced by OV-10 Broncos.
After the war the O-2 soldiered on in Active Duty and Air National Guard.   A small child’s mother used to hate Saturday Mornings when between 6-10  O-2s would fly over their house make a racket like a swarm chain saws .  Those 111th Tactical Air Support Group would eventually fly OA-37s and OA-10s and within the last week begin their new mission flying MQ-9 Reapers as the 111th Attack wing.
One of my all-time favorite squadron transitions, and in the  WTF, category  was the 105th Tactical Support Group  became the 105th Military Airlift Group . The mission went from flying O-2s  to flying C-5As !  How’s that for a conversion? 
 U.S. military service ended for the O-2A when the US ARMY retired the last two. They were used as observation aircraft at the Yuma Proving Range, and were turned over to museums in 2010, not bad for a Stop Gap aircraft from the sixties.  Adding additional support to the old adage “There is nothing more permanent than something that’s temporary.”   
Much like one of my other favorite aircraft  the DC-3  the 337 was given the Basler Turbo conversions treatment.   The Basler Turbo 37 had both Continentals removed.  The fuselage was stretched from 29 feet 9 inches to  36 Feet 10 Inches allowing for 9 passengers and a pilot.   The Pusher engine was replaced with at 550 HP Pratt & Whitney PT6 with a Three Blade Prop.  The aircraft can take off fully loaded (for Cleveland) in under 450 Feet.
O-2s served on the fire lines of California also.   California Department of Forestry and Fire Protection went to Davis-Monthan Air Force Base, the Boneyard, and picked 20 airframes from 40 they were given access to.  By 1976 the O-2 were again directing “Air Strikes” and continued to serve until the late 90s when they were replaced by OV-10s
For 10 years from 1991 to 2001 the Hermanos al Rescate used Skymaster to look out for and drop supplies to Cuban refugees fleeing to Florida by boat.   Much like another conflict in the Skymasters past, two of the Brothers to the Rescue aircraft  were shot down by  a  Cuban MiG-29 over international waters while on a search mission.  A third was targeted until a pair of F-15As crossed into that international air space.
Overall 2,993 Skymasters were built.
To this day this little boy loves to hear the sound of those swarming chain saws. 
Works Cited
"O-2 Skymaster." O-2 Skymaster. N.p., n.d. Web. 12 July 2014. <>.
"Skymaster Owners And Pilots Site (SOAP) C336, C337, O-2." Skymaster Owners And Pilots Site (SOAP) C336, C337, O-2. N.p., n.d. Web. 12 July 2014. <>.
"Skymaster." Skymaster. N.p., n.d. Web. 12 July 2014. <>.
"Spectrum SA-550." Wikipedia. Wikimedia Foundation, 07 Jan. 2014. Web. 12 July 2014. <>.